Cellular receptors for matrix proteins in normal human kidney and human mesangial cells

In the present study we evaluated the distribution of cell adhesion molecules, referred as very late antigens (VLA), in the normal human kidney and in mesangial cells in culture (MC). In addition, we assessed the functional properties of VLA proteins on MC. Normal human kidney and MC were stained by immunoperoxidase with mouse monoclonal antibodies to VLA proteins. We demonstrated that VLA-3, a protein that binds FN, laminin and collagen, is the predominant VLA protein in the human glomerulus and on MC. VLA-3 is located in the mesangium and on the glomerular visceral epithelial cell and endothelial cell surfaces in contact with the glomerular basement membrane. VLA-1 was demonstrated in the glomerular mesangium and VLA-5, an FN specific receptor, was present in the mesangium on glomerular endothelial cells and on MC. VLA-2 and VLA-4 were not present in the normal glomerulus nor on MC. In functional studies we evaluated the binding of MC to FN coated surfaces and the binding and phagocytosis of FN coated fluorescent beads by MC. We showed that MC bind to FN coated surfaces and that the binding is inhibited by anti-FN antibodies, EDTA and peptides containing the amino acid sequence Arg-Gly-Asp (RGD). In addition, anti-VLA-5 but not anti-VLA-3 antibodies inhibited significantly the binding of MC to FN, MC demonstrated binding and phagocytosis of FN coated beads and, purified FN inhibited both phenomena. By affinity chromatography and immunoprecipitation we demonstrated that MC FN binding proteins and MC VLA proteins are composed of two distinct protein chains that have Mr characteristics similar to those of normal human fibroblasts VLA proteins. In conclusion, the glomerular distribution of VLA-3 suggests that this protein is primarily involved on the adhesion of glomerular cells to basement membranes and matrix. MC FN receptors (VLA-5) mediate the binding of MC to FN and could mediate the phagocytosis of FN coated antigen or immune complexes by mesangial cells.     

Modification of the percutaneous approach to peritoneal dialysis catheter placement under peritoneoscopic visualization: clinical results in 78 patients.

The placement of percutaneous peritoneal dialysis catheters under direct peritoneoscopic visualization is a relatively new technique for establishing peritoneal dialysis access. In this study, in which a modification of the Seldinger technique was used to facilitate the placement of the peritoneoscope, the experience with 82 consecutive catheterization procedures in 78 patients is reported. In 2 (2.4%) of 82 catheterization procedures, we were unable to enter the peritoneal cavity but experienced no other complications unique to the percutaneous approach. Of the 80 successful catheterization procedures, 76 represented first-time catheter placement and constituted a population subjected to life-table analysis examining catheter survival rates, the time to first cutaneous exit site or s.c. tunnel infection, and the time to first episode of peritonitis. After a follow-up period of 50.1 patient yr, 11 catheters were lost because of catheter dysfunction. Other clinical complications included peritoneal fluid leaks at the cutaneous exit site in 11 instances (0.22/patient yr), cutaneous exit site infection in 7 instances (0.14/patient yr), s.c. tunnel infection in 2 instances (0.04/patient yr), and 34 episodes of peritonitis (0.68/patient yr). The results of this study demonstrate that the suggested modification of the percutaneous placement of peritoneal dialysis catheters, under peritoneoscopic visualization, is a viable method for establishing peritoneal access.     

105Changes in Nitric Oxide Levels After Deep Dermal injury in the Female,Red Duroc Pig (FRDP)

Introduction : Hypertrophic scar is a devastating sequel to burns and other tangential skin injuries. It follows deep dermal injuries and does not occur after superficial injuries. Nitric oxide (NO) plays many important roles in wound healing from inflammation to scar remodeling. Studies have shown that expression of nitric oxide synthase and nitric oxide production are decreased in human hypertrophic scar. However little is known about NO involvement in the early stages of hypertrophic scarring, because of the lack of an animal model. It was recently reported that the female red Duroc pig (FRDP) makes thick scar, which is similar to human hypertrophic scar. We hypothesized that NO production in wounds on the female, red Duroc pig is similar to that of human hypertrophic scar and that NO involvement in deep wounds is different from that in superficial wounds. Methods : Superficial (0.015” to 0.030”) and deep (0.045” to 0.060”) wounds were created on the backs of four FRDPs. Biopsies were collected at weeks 1.5, 4, 8 and 21 post wounding including samples of uninjured skin. Nitric oxide levels were measured with the Griess reaction assay and normalized with tissue protein level. Results : Superficial wounds healed with an invisible scar whereas the deep wounds healed with scar resembling mild hypertrophic scar. The thickness of the scars from the deep wounds was significantly greater than uninjured skin and healed superficial wounds (p < 0.01). NO levels were increased at 1.5 weeks in deep wounds compared to superficial wounds and uninjured skin (p < 0.05). At 8 weeks, NO levels in deep wounds had returned to the level of uninjured tissue and superficial wounds. By 21 weeks, NO levels had decreased significantly when compared to superficial wounds (p < 0.01). There were no differences in NO levels between uninjured skin and superficial wounds at any time point (p > 0.05). Conclusions : NO production is similar in late, deep wounds on the female, red Duroc pig to that reported in the literature for human hypertrophic scar further validating this animal model. NO production is quite different after deep wounds as compared to superficial wounds in the FRDP. Early elevation in nitric oxide production might account for excessive inflammation in deep wounds that become thick scars in the FRDP. Nitric oxide regulators and effects at early stages of scar formation should be elucidated further and the FRDP appears to be a useful model.     

TREATMENT OF PALMOPLANTER HYPERHIDROSIS BY IONTOPHORESIS

Twenty-seven patients with idiopathic palmoplanter hyperhidrosis were treated with Iontotherapy over a one year period. In twenty-four cases there was a good response but maintenance therapy was required every 3-4 weeks.KEY WORDS: Iontophoresis, Palmoplanter hyperhidrosis     

B19 parvovirus replicates in circulating cells of acutely infected patients

B19 parvovirus is the etiologic agent of fifth disease and transient aplastic crisis. In natural infections, B19 antigen and DNA have been detected in sera early in the course of aplastic crisis and only rarely in fifth disease. We have found B19 DNA in circulating cells of infected patients by DNA dot blot with a virus-specific probe: in four of four sickle cell patients with aplastic crisis, in one asymptomatic sibling, and in one normal adult with fifth disease. Only two of the sera showed B19 DNA. High-molecular weight intermediate forms were detected by Southern analysis of DNA extracted from cells, thus indicating active replication of virus in cells rather than passive adsorption to their surface membranes. Separation of cells into high- and low-density fractions resulted in a concentration of the virus DNA in the granulocytic fraction.