Human skin preserved long-term in anhydric pulverized sodium chloride retains cell molecular structure and resumes function after transplantation.

BACKGROUND: Human skin is needed to cover large areas of the body lost through burns, trauma, and extensive maxillofacial surgery. Contemporary methods of skin storage are limited by the period of preservation to a few days. Our previous findings showed that fixation and storage of human skin in anhydric sodium chloride at room temperature for weeks or months preserves its morphological and molecular structure. In this study, we examined whether skin grafts preserved in sodium chloride may be successfully transplanted. METHODS: Skin was harvested from lower limbs of patients during elective surgery, placed in containers with anhydric salt powder, and kept at 22 degrees C for 3 to 12 weeks. Desalination and rehydration took place before transplantation. Desalinated fragments were transplanted onto the dorsum of scid mice. RESULTS: All grafts were accepted by recipients. Three weeks after transplantation, keratinocytes synthesized keratins 10, 16, and 17 and expressed antigens specific for stem (p63) and transient (CD29) cells. Moreover, they proliferated vigorously, their basal layer cells incorporated bromdeoxyuridine and expressed proliferative cell nuclear antigen. Isolated from transplants and cultured in vitro, they remained viable and produced enzymes. Dermis retained its structure and expressed fibroblast-specific antigen. All graft cells remained human leukocyte antigen I. CONCLUSION: Human skin preserved in anhydric sodium chloride at room temperature for months can be successfully transplanted to scid mice. We propose the concept of "spore-like" keratinocyte stem cells to explain the long-term ex vivo survival of keratinocytes. The mechanism of survival of fibroblasts remains to be determined.

Sodium chloride fixation of tissues under field conditions in tropical countries.

Fixation of skin and lymph node fragments in anhydric sodium chloride at room temperature for periods of weeks or months was found to preserve morphological structures and immunoreactivity. Fragments of a size of 6-8x6x6 mm were dried and placed in anhydric sodium chloride powder in sealed containers. Prior to further processing, the specimens were desalinated and rehydrated, then snap-frozen, sectioned, fixed in acetone and stained with monoclonal antibodies. The intensity of staining of molecular structures did not differ from that of primarily snap-frozen specimens. The method allows fixation of tissues under field conditions in tropical countries and at places lacking freezing facilities.

Human skin preserved in anhydric sodium chloride for months can be successfully transplanted.

Human skin can be preserved in pulverized sodium chloride dehydrated at 240C for 2 hours at room temperature for periods of weeks or months and successfully transplanted to scid mouse, retaining its normal morphological structure. Fragment of skin of a size of 10 x 10 x 6 mm were harvested during elective vascular and orthopaedic surgery of lower limbs, dried of blood and placed in anhydric sodium chloride powder in tight sealed containers. Prior to transplantation to scid mice, the specimens were desalinated and rehydrated. Specimes preserved for 1 to 6 months and harvested 3-4 weeks after transplantation revealed intensive incorporation of bromdeoxyuridine (BrdU) into basal keratinocytes. They expressed p63 and CD29 (stem cells, and transient cells antigens), PCNA (proliferating cell nuclear antigen) and cytokeratin 16 specific for proliferating keratinocytes. Dermal fibroblasts and few large HLA II cells showed a normal structure. Bacterial flora of skin did not change after grafting. We conclude that human skin can survive in a dehydrated state in sodium chloride for months and after transplantation the epidermal basal layer cells give rise to keratinocyte progenies. Skin fibroblasts and some resident immune cells can also survive.

Hepatocyte growth factor levels in liver and blood, and post-operative liver cell proliferation in patients with benign and malignant liver tumors after partial hepatectomy.

BACKGROUND: The purpose of our study was to investigate hepatocyte proliferation and the expression of hepatocyte growth factor (HGF) in liver tissue and blood from patients with benign and malignant liver tumors after partial hepatectomy. MATERIAL/METHODS: We studied 25 consecutive patients undergoing partial hepatectomy for metastatic colorectal adenocarcinoma (15 cases) and benign liver tumors (10 cases). Immunohistochemical examination for the presence of PCNA and HGF, c-MET/HGF-receptor expression was performed on formalin-fixed samples from: a) sections of resected fragments of liver tissue remote from the tumor; b) tumor tissue; c) remnant liver, 30 min after hepatectomy; d) fine needle aspiration liver biopsy, 7 days after liver resection. Circulating HGF and the level of AFP and GGT as biomarkers for liver cell regeneration were measured in the patients' blood at the same time. RESULTS: The proliferation rate of liver cells was higher in patients with malignant than benign liver tumors. This correlated with increased HGF in blood, but not with the expression of HGF and c-MET/HGF-R in liver tissue. The expression of HGF was detected in specimens from colorectal liver metastases. CONCLUSIONS: The mutual interactions between tumor and other cells may influence the proliferation of hepatocytes throughout the regenerative process in patients with colorectal carcinoma metastases after partial hepatectomy.