A new objective evaluation method for PU cleansing using a rapid bacteria counting system.

OBJECTIVE: To assess a new rapid bacterial counting device for evaluating wound cleansing effectiveness based on dielectrophoretic impedance measurement. METHOD: Three patients with pressure ulcers with undermining were recruited, and pressure ulcer severity assessed using the DESIGN-R tool. The number of bacteria was measured using this new apparatus both before and after wound cleansing, performed by wound, ostomy, and continence nurses using apH-balanced cleanser for periwound skin and with normal saline for the wound bed and undermining area. RESULTS: The results showed that wound cleansing effectively reduced bacterial counts on the periwound skin, wound bed and undermined site, with a median number of bacteria of 3.6×106 CFU/ml before cleansing, which decreased to 1.1×106 CFU/ml after cleansing. CONCLUSION: This pilot study result suggests the usefulness of this new device for assessing the effectiveness of wound cleansing on reduction of bacterial number. Standardisation of wound cleansing technique may be achieved by hands-on education using this apparatus at bedside.

Chondrocyte-derived ezrin-like domain containing protein (CDEP), a rho guanine nucleotide exchange factor, is inducible in chondrocytes by parathyroid hormone and cyclic AMP and has transforming activity in NIH3T3 cells.

OBJECTIVE: The purpose of this study is to investigate stage- and hormone-dependent expression of chondrocyte-derived ezrin-like domain containing protein (CDEP), a putative guanine nucleotide exchange factor (GEF) for Rho in chondrocytes, and demonstrate the guanine nucleotide exchange activity of this protein in vitro, as well as the transforming activity in NIH3T3 cells. METHODS: The expression of CDEP mRNA in growth plate chondrocytes in vivo and in vitro was examined by RT-PCR Southern analysis. The guanine nucleotide exchange activity was determined using a recombinant CDEP peptide containing the DH and PH domains in Sf9 cell lysates. The transforming activity was examined using NIH3T3 cells transiently transfected with a truncated CDEP cDNA. RESULTS: CDEP mRNA was expressed at the highest level in the hypertrophic (terminal) stage of chondrocytes in vivoand in vitro. Parathyroid hormone (PTH) elicited a biphasic increase of CDEP mRNA in chondrocytes. The CDEP mRNA level increased within 1 h, then decreased nearly to the control level at 3 h. Thereafter the mRNA level started to increase at 6 h, reaching a plateau at 24 h. Dibutyryl cyclic AMP had a similar effect on CDEP expression in chondrocytes. The dissociation of [3H]GDP from RhoA was stimulated dose-dependently by Sf9 cell lysates containing the CDEP peptide. Furthermore, transfection of a truncated CDEP cDNA induced focus formation in NIH3T3 cultures. CONCLUSIONS: CDEP is a novel GEF for Rho family GTPases with the transforming activity. CDEP may play a role in mediating or modulating the action of cAMP-elevating hormones on maturing chondrocytes.

Temperature dependence of chromatic dispersion in various types of optical fiber.

The temperature dependence of chromatic dispersion is examined for various types of fiber. Its coefficient is found to depend strongly on the dispersion slope. Dispersion-flattened fiber has a significantly low coefficient of -0.0005(ps/nm/km)/ degrees C , compared with -0.0038(ps/nm/km)/ degrees C for large-core nonzero dispersion-shifted fiber. Transmission lines with low dispersion slopes consisting of pure silica core fiber and dispersion-compensating fiber also exhibit low coefficients of less than -0.001(ps/nm/km)/ degrees C because of their compensating effects.

Surgical management of congenital permanent dislocation of the patella in nail patella syndrome by Stanisavljevic procedure.

We report a patient with nail patella syndrome associated with congenital permanent dislocation of the patella successfully operated on using a modified Stanisavljevic method. The patient, a 26-year-old woman, complained of inability to completely extend her right knee joint. She had occasionally experienced the "giving way" phenomenon since childhood, but she had not received any treatment since birth. Physical examination showed that all fingernails were deformed, with longitudinal striations, while the lunules were of an abnormal triangular shape or were missing. Both patellae were palpably hypoplastic, with the right patella dislocated laterally, and the knee had an extension lag of 90 degrees. Thigh and leg muscle were slightly underdeveloped, but quadriceps muscle contraction was good. Several radiographs were taken and they showed bilateral iliac horns and hypoplasia of the bilateral humero-radial joints and of both patellae, and complete dislocation of the right patella. We employed the Stanisavljevic procedure for the reduction of the patella, with Z-lengthening of the rectus femoris and medial translocation of the tibial tuberosity. Four years after the operation, a 30-degree extension lag still exists in the right knee, but the treatment resulted in stable alignment of the quadriceps mechanism, and notably improved gait appearance.

Molecular characterization of the novel basic helix-loop-helix protein DEC1 expressed in differentiated human embryo chondrocytes.

The differentiation of human embryo chondrocytes was markedly induced by the addition of Bt2cAMP to the culture medium. Using this culture system, a novel human cDNA for a basic helix-loop-helix (bHLH) protein (named DEC1) expressed primarily in the chondrocytes in response to Bt2cAMP was cloned by the subtractive hybridization method. DEC1 protein consists of 412 amino acids and exhibits structural similarities to the mammalian HES family, Drosophila hairy, and Enhancer of split m7 in the bHLH region. Northern blot analysis showed that DEC1 mRNA was expressed in various tissues including the cartilage, lung, spleen, and intestine, but not in the brain. These findings suggest that the bHLH factor DEC is involved in the control of cell differentiation in several tissues including cartilage.

Analysis of 3H-proline-labeled protein by rapid filtration in multiwell plates for the study of collagen metabolism.

Quantitative and qualitative analysis of cell cultures labeled with 3H-proline for monitoring collagen synthesis is time-consuming and occasionally generates large quantities of radioactive waste. This present work describes the application of a microwell filtration system for the analysis of collagen metabolism in chondrocytes. It is based on trichloroacetic acid (TCA) precipitation of 3H-proline-labeled proteins onto polyvinylidene difluoride membranes fitted in a 96-well plate and subsequent analysis of precipitated proteins by liquid scintillation counting, amino acid analysis and sodium dodecyl sulfate (SDS) gel electrophoresis. This method allows for the initial processing of 96 samples within 2 h, has high sensitivity and accuracy (linearity > or = 200 cpm/sample) for quantitative measurements and a capacity of up to 10 micrograms collagen/microwell. The ratio of the radioactive protein collected by this filtration assay compared to that collected by molecular sieve chromatography on Sephadex G-25 was linear over a broad range, indicating full compatibility of data and a high reproducibility for both assay systems. The quality of protein separation by SDS-polyacrylamide gel electrophoresis (PAGE) from samples obtained by the filtration assay and by dialysis was virtually identical. These features make the assay particularly suited for pulse-chase experiments and for monitoring protein degradation.

Molecular cloning and characterization of CDEP, a novel human protein containing the ezrin-like domain of the band 4.1 superfamily and the Dbl homology domain of Rho guanine nucleotide exchange factors.

A cDNA for a novel human protein named CDEP was cloned using the subtractive hybridization method between dedifferentiated cartilage cells and overtly differentiated cartilage cells. CDEP cDNA contained an open reading frame encoding 1,045 amino acids in a total length of 3.4 kb. The deduced amino acid sequence revealed that a single polypeptide contained the ezrin-like domain, which is found in cytoskeleton-associated proteins of the band 4.1 superfamily, and the Dbl homology (DH) and pleckstrin homology (PH) domains, which are conserved in the Rho GEF (guanine nucleotide exchange factor) family. Northern blot analysis demonstrated that CDEP mRNA was expressed not only in the differentiated chondrocytes but also in various fetal and adult tissues. Since members of the band 4.1 superfamily and the Rho GEF family are crucial for microfilament organization, the novel protein CDEP may be involved in the adhesion, proliferation, and differentiation of some cell types including chondrocytes via changes in the cytoskeleton.

[Do calcium and zinc ions influence matrix molecule synthesis of chondrocytes?]. / Haben Kalzium- und Zinkionen einen Einfluss auf die Matrixmolekülsynthese von Chondrozyten?

The experiments described here tested the effect of various calcium (Ca) and Zinc (Zn) concentrations on cell proliferation and matrix molecule synthesis of fetal and adult bovine chondrocytes in monolayer cultures. Levels of Ca < 0.2 mM in a culture medium or the addition of Zn (0.1-50 microM) selectively promoted the production of collagen but did not affect significantly synthesis of proteoglycans. No change in proliferation of fetal and adult chondrocytes could be observed. In contrast 10 mM Ca promoted the hypertrophic differentiation of chondrocytes (e.g. expression of collagen type X). The results are related to calcium channel configurations in chondrocytes in the discussion.

Collagen and proteoglycan production by bovine fetal and adult chondrocytes under low levels of calcium and zinc ions.

The experiments described herein tested the effects of CaCl2 and ZnCl2, added at various concentrations in the culture medium, upon the synthesis of collagen and proteoglycan by adult and fetal (articular, epiphyseal and hypertrophic) bovine chondrocytes maintained in high density multilayer cultures. CaCl2 concentrations below 0.5 mM or the addition of 1-50 microM ZnCl2 to the medium selectively promoted the production of collagen by all four populations of chondrocytes but had no effect on fibroblasts. Further, these changes had no statistically significant effect on the incorporation of 35S-sulfate into macromolecules or on the synthesis of gelatinase A, measured by gelatin zymography. The addition of CaCl2 and ZnCl2 at these concentrations did not result in a change in the relative proportion of non-crosslinked 3H-collagen molecules (synthesized in the presence of beta-aminopropionitrile) partitioning in the cell layer and medium compartments, and did not appreciably alter the pattern of collagens synthesized by any of the cell populations. The hypertrophic cells synthesized high levels of collagen type X in the presence as well as absence of exogenously added cations. However, CaCl2 at 10 mM caused a marked upregulation of collagen type X synthesis by a preparation of chondrocytes derived from the entire growth plate, consistent with the view that calcium at that concentration stimulated the differentiation of some of the cells into hypertrophic chondrocytes.