Long-term nipple shrinkage following augmentation by an autologous rib cartilage transplant in free DIEP-flaps.

Aesthetically pleasing nipple-areola reconstruction is a satisfying part of a two-stage breast reconstruction. The up to 50% [Banducci DR, Le TK, Hughes KC. Long-term follow-up of a modified Anton-Hartrampf nipple reconstruction. Ann Plast Surg 1999;43(5):467-9; discussion 469-70] postoperative shrinkage following a conventional nipple reconstruction is a well-known problem. Augmentation of the nipple with autologous banked cartilage seems to be a promising solution. From 2000-2003, 17 patients underwent a nipple-areola-complex reconstruction following secondary breast reconstruction using free perforator flaps. The rib cartilage harvested during the preparation of the internal thoracic vessels was banked subcutaneously and six months later replanted under the 'arrow flap' after contouring it in a 'mushroom' shape. One year later the shrinkage of the nipple in comparison to the intraoperative status was measured. In addition, patients were asked about their personal palpation impression and the aesthetic outcome. The average height decreased one year postoperatively about 25%. Thirteen of 17 patients judged the aesthetic outcome as very good, 16 nipples healed without cartilage protrusion and no patient felt discomfortable stiffness of the nipple. Our concept of a nipple augmentation with rib cartilage improves the projection and allows a more correct judgement of the later nipple shrinkage. We consider this technique to be an aesthetically satisfying and safe method, which could be used with any kind of breast reconstruction.

Effects of modified collagen matrices on human umbilical vein endothelial cells.

The most commonly used biomaterials fail to ensure sufficient angiogenesis for fast in vivo incorporation. This results in central necrosis and consequent infection. One way of obtaining a high angiogenic response is the application of vascular endothelial growth factor (VEGF). To obtain a sustained release of these cytokines, heparin was incorporated into collagen matrices using 1-ethyl-3(3-dimethyl-aminopropyl) carbodiimide (EDC) and N-hydroxysuccinmide (NHS). The functionality of the heparinized collagen matrices was then enhanced by immobilization of VEGF via its heparin-binding domain. This procedure changed in vitro degradation behavior and water-binding capacity. Accelerated endothelial cell proliferation was also achieved. A range of different heparin and EDC/NHS concentrations in combination with VEGF induced variation in endothelial cell growth and tubulogenic formation. Polymerized collagen scaffolds presented biointeractive systems with integrated angiogenic activity. This may become a useful tool in the clinical therapy of disorders connected with wound healing.

Update on the use of collagen/glycosaminoglycate skin substitute-six years of experiences with artificial skin in 15 German burn centers.

The clinical use of an artificial skin substitute (Integra) has been celebrated enthusiastically as an improvement in burn therapy over a period of more than 10 years. Many case-reports have shown the positive effects of the treatment with Integra as a skin substitute. In this study we examine the alterations of Integra-usage in Germany. Fifteen German burn centres have been interviewed respectively over a time period of 6 years with interviews in the years 1999, 2001, and 2003. The goal of this study is to focus on the problems associated with the use of artificial skin and to create a manual for Integra-therapy including indication, pre-, intra-, and postoperative treatment. Since the first Integra Users seminar in Germany in 1999 repeated interviews have been conducted with fifteen German burn centres. The collected results of the last 6 years were evaluated. These results show a change in the indication for the therapy with artificial skin towards extensive full thickness burned patients and as extended indication especially for posttraumatic reconstruction. This article gives our guidelines for the usage and handling of Integra and shows that Integra is an important reconstructive dermal substitute for the severely burned or posttraumatic patient if handled by a skilled surgeon in a correct way.

Cellular localization, membrane distribution, and possible function of guanylyl cyclases A and 1 in collecting ducts of rat.

BACKGROUND: Natriuretic peptides regulate Na+ and H(2)O transport in the cortical collecting duct (CCD). We have shown that natriuretic peptides have no effect on ion conductances or water transport of principal cells (PC) even though a cGMP-regulated K+ channel is located in the basolateral membrane of these cells. METHODS: RT-PCR was used to screen for different guanylyl cyclases (GC) in CCD and to look for the expression of GC-1 and GC-A mRNA in CCD of male and female Wistar and Sprague-Dawley rats. Polyclonal antibodies were raised against the detected GC. BCECF was used to investigate the effects of ANP on intracellular pH in intercalated cells (IC). RESULTS: GC-A and GC-1 were detected. GC-A was immunolocalized in the luminal membrane of IC while GC-1 was mainly found in the luminal membrane of PC. GC-1 is expressed in Sprague-Dawley and Wistar rats except for male Sprague-Dawley rats, while GC-A is expressed in all strains. ANP (160 nM, n=11), urodilatin (140 nM, n=6), which had no effect in PC, significantly decreased pH(i) by 0.02+/-0.01 and 0.03 +/- 0.01 Units in IC, respectively. ANP as well as urodilatin and 8-Br-cGMP decreased the pH(i) recovery after acidification by 30 +/- 6% (n=12), 37 +/- 7% (n=8), and 19 +/- 3% (n=8), respectively. CONCLUSION: GC-A is located in the luminal membrane of IC of rat CCD and ANP acts through this receptor when regulating pH(i) via an inhibition of the Na+/H+-exchanger. PC do not possess GC-A. GC-1 seems to be the only GC in these cells of most rat strains tested and therefore, it could be responsible for the regulation of K+ channels in the basolateral membrane via cGMP-dependent protein kinase.

Factors affecting motion characteristics of frozen-thawed stallion spermatozoa.

Five experiments were conducted to evaluate damage incurred in each processing step for cryopreservation of stallion spermatozoa. In Experiment 1, semen was centrifuged for 9 centrifugation times and the percentage of spermatozoa recovered after each treatment was calculated and spermatozoal motion characteristics analysed. Recovery of spermatozoa was > or = 80% when spermatozoa were centrifuged for > or = 10 min. Experiment 2 evaluated spermatozoa cryopreserved at 5 different concentrations in each of 2 extenders (skim milk-egg yolk-glycerol, SM-EYG; and lactose-EDTA, LAC). In SM-EYG, TMOT and PMOT were higher at spermatozoal concentrations of 20, 200 and 400 x 10(6)/ml (51%/41%, 52%/44%, 50%/43%, respectively) than for samples frozen at > or = 800 x 10(6) spermatozoa/ml (41%/35%, 32%/27%; P < 0.05). Spermatozoa frozen in LAC at a concentration of 20 x 10(6)/ml resulted in the highest TMOT and PMOT (43% and 30%, respectively, P < 0.05). The effect of freezing rate on motion characteristics of spermatozoa was evaluated in Experiment 3. The VCL of spermatozoa frozen in SM-EYG was the only parameter affected by freezing rate (P < 0.05). Experiment 4 evaluated motion characteristics after cryopreservation of spermatozoa in different sized straws (0.5 or 2.5 ml) in each of 2 extenders (SM-EYG and LAC). In SM-EYG, PMOT (38%) and VCL (109 microns/s) were highest when spermatozoa were frozen in 0.5 ml straws (P < 0.05). In Experiment 5, spermatozoa thawed immediately after cryopreservation or thawed after storage in liquid nitrogen for 24-48 h were evaluated. There was no effect of length of storage in liquid nitrogen on spermatozoal motion characteristics (P < 0.05). Experiment 6 evaluated the effects of cooling time to 5 degrees C (0, 2.5 and 5 h) on motion characteristics of spermatozoa cryopreserved in 2 extenders (SM-EYG and LAC). TMOT and PMOT were effected by cooling time, and there was a cooling-time-by-extender interaction (P < 0.05). In SM-EYG, TMOT and PMOT were higher if spermatozoa were cooled to 5 degrees C prior to initiation of freezing than if freezing was initiated at 20 degrees C (P < 0.05). A suggested protocol for cryopreservation of stallion spermatozoa would include: 1) centrifugation at 400 g for 14 to 16 min; 2) extension at 23 degrees C with SM-EYG to 400 x 10(6) spermatozoa/ml; 3) cool to 5 degrees C for 2.5 h; 4) package in 0.5 ml straws at 5 degrees C; 5) freeze in liquid nitrogen vapour at -160 degrees C; and 6) thaw for 30 s in 37 degrees C water.

Nucleotide sequence of the rabbit gamma-preprotachykinin I cDNA.

We succeeded in amplifying tachykinin I specific cDNAs from cerebral tissue of guinea pig, rabbit, rat, hamster, trout and tupaia in the expected size range of 820-980 bp. The amplified 859 bp rabbit gamma-preprotachykinin I cDNA was sequenced and consisted of the whole 345 bp gamma-PPT I coding sequence including the substance P and neurokinin A coding regions and a 505 bp large 3'-nontranslated region. Both, molecular weight and sequence comparison emphasizes the very high phylogenetic age of the preprotachykinin I gene.