Immunohistochemical and clinical evaluation of cathepsin expression in soft tissue sarcomas

Lysosomal proteases are known to enhance the spread of epithelial tumour cells, but little is known of the possible role of proteases in the growth of soft tissue sarcomas (STS). We investigated the expression of cathepsins D, B, S, H, L and procathepsin L in frozen sections of 34 STS from 34 patients by immunohistochemistry (IHC). Cathepsins D, B and H were relatively highly expressed in STS (77–91%). The expression rate of cathepsins S and L and of procathepsin L was lower (40–66%). Cathepsin S and L expression showed a moderate (P = 0.078 andP = 0.019) and procathepsin L a strong (P = 0.00001) correlation with the survival rate of STS patients. Cathepsin S expression is also correlated with the local recurrence rate (P < 0.01). Lysosomal proteases may play a role in STS progression, and cathepsin expression may also have, significance as a prognostic factor in STS.     

Induction of intervertebral disc-like cells from adult mesenchymal stem cells

The potential of adult mesenchymal stem cells (MSCs) to differentiate towards cartilage, bone, adipose tissue, or muscle is well established. However, the capacity of MSCs to differentiate towards intervertebral disc (IVD)-like cells is unknown. The aim of this study was to compare the molecular phenotype of human IVD cells and articular chondrocytes and to analyze whether mesenchymal stem cells can differentiate towards both cell types after transforming growth factor beta (TGF beta)-mediated induction in vitro. Bone marrow-derived MSCs were differentiated in spheroid culture towards the chondrogenic lineage in the presence of TGF beta(3) dexamethasone, and ascorbate. A customized cDNA-array comprising 45 cartilage-, bone-, and stem cell-relevant genes was used to quantify gene expression profiles. After TGF beta-mediated differentiation, MSC spheroids turned positive for collagen type II protein and expressed a large panel of genes characteristic for chondrocytes, including aggrecan, decorin, fibromodulin, and cartilage oligomeric matrix protein, although at levels closer to IVD tissue than to hyaline articular cartilage. Like IVD tissue, the spheroids were strongly positive for collagen type I and osteopontin. MSC spheroids expressed more differentiation markers at higher levels than culture-expanded IVD cells and chondrocytes, which both dedifferentiated in monolayer culture. In conclusion, mesenchymal stem cells adopted a gene expression profile that resembled native IVD tissue more closely than native joint cartilage. Thus, these cells may represent an attractive source from which to obtain IVD-like cells, whereas modification of culture conditions is required to approach the molecular phenotype of chondrocytes in hyaline cartilage.     

Paclitaxel and cyclosporine A show supra-additive antiproliferative effects on smooth muscle cells by activation of protein kinase C

We intended to establish a pharmacologic concept of synergistic antiproliferative effects on smooth muscle cells (SMC) by using paclitaxel and cyclosporine A at clinically applicable doses. Coronary SMC were incubated with paclitaxel and cyclosporine A at concentrations of 10 – 20 nmol/L and 83 – 415 nmol/L, respectively. Antiproliferative effects were assessed by cell counts, [³H]thymidine incorporation and cell cycle analysis. In addition, apoptosis was studied by cytoplasmic histone-associated DNA fragments and in vitro protein kinase C activity (PKC) was determined by immunoassay. We found paclitaxel and cyclosporine A to exert a highly supra-additive antiproliferative effect on SMC with significant reductions of cell counts (p < 0.01) and [³H]thymidine incorporation (p < 0.05). SMC were found to be arrested at the G2/M transition. This antiproliferative effect was observed in the absence of DNA fragmentation above values obtained for single compound treatment, which had virtually no impact on cell proliferation. DNA fragmentation started to increase at a drug combination comprising paclitaxel at the higher dose of 20 nmol/L. Under the treatment with both paclitaxel and cyclosporine A, PKC activity showed a 1.8-fold increase (p < 0.05) compared with untreated controls. In conclusion, PKC mediates supra-additive antiproliferative effects of paclitaxel and cyclosporine A on SMC. The data demonstrate a highly efficient pharmacologic concept for the inhibition of SMC proliferation. Further studies are needed to test this concept under in vivo conditions for the prevention of restenosis or transplant vasculopathy by systemic application of cyclosporine A – when already applied for immunosuppressive purposes – and local delivery of paclitaxel. Received: 28 August 2001, Returned for revision: 25 September 2001, Revision received: 20 November 2001, Accepted: 4 December 2001     

Melatonin protects kidney grafts from ischemia/reperfusion injury through inhibition of NF-kB and apoptosis after experimental kidney transplantation

Abstract:  Free radicals are involved in pathophysiology of ischemia/reperfusion injury (IRI). Melatonin is a potent scavenger of reactive oxygen and nitrogen species. Thus, this study was designed to elucidate its effects in a model of rat kidney transplantation. Twenty Lewis rats were randomly divided into 2 groups (n = 10 animals each). Melatonin (50 mg/kg BW) dissolved in 5 mL milk was given to one group via gavage 2 hr before left donor nephrectomy. Controls were given the same volume of milk only. Kidney grafts were then transplanted into bilaterally nephrectomized syngeneic recipients after 24 hr of cold storage in Histidine–Tryptophan–Ketoglutarate solution. Both graft function and injury were assessed after transplantation through serum levels of blood urea nitrogen (BUN), creatinine, transaminases, and lactate dehydrogenase (LDH). Biopsies were taken to evaluate tubular damage, the enzymatic activity of superoxide dismutase (SOD) and lipid hydroperoxide (LPO), and the expression of NF-kBp65, inducible nitric oxide synthase (iNOS), caspase-3 as indices of oxidative stress, necrosis, and apoptosis, respectively. Melatonin improved survival ( P  < 0.01) while decreasing BUN, creatinine, transaminases, and LDH values up to 39–71% ( P  < 0.05). Melatonin significantly reduced the histological index for tubular damage, induced tissue enzymatic activity of SOD while reducing LPO. At the same time, melatonin down-regulated the expression of NF-kBp65, iNOS, and caspase-3. In conclusion, donor preconditioning with melatonin protected kidney donor grafts from IRI-induced renal dysfunction and tubular injury most likely through its anti-oxidative, anti-apoptotic and NF-kB inhibitory capacity.     

Determination of the oxidation rate of medium-chain triglycerides in newborn infants with the 13C trioctanoin breath test

Up to the present time medium chain triglycerides (MCT) have been applied solely for the enteral nutrition of newborn infants. Results of the oxidative utilization of parenterally applicated MCT have not yet been published. We therefore investigated the MCT oxidation with the 13C trioctanoin breath test in neonates. The patients received parenterally 10 mg/kg MCT (1-13C3 trioctanoin) enriched with the stable isotope 13C and emulsified with MCT/LCT 10%. The expired 13CO2 resulting from fat oxidation was determined by a ratio-mass-spectrometer. The 13C content of exhaled air represents the rate of fatty acid oxidation. Within the test period the fatty acid oxidation showed a clear dependency on the simultaneous carbohydrate supply. The oxidation rates of MCT were about twice als high as those of long chain triglycerides (LCT). On account of their high energetic level, MCT-containing emulsions are, in principle, also suitable for the parenteral nutrition of newborn infants.     

Nonadhesive organ culture of human exocrine pancreatic cells with their stroma

INTRODUCTION: Studies using explanted tissue have shown that it is possible to keep adult human cells in organ culture with a preserved morphology for up to 1 month as spheres in a nonadhesive organ culture. AIMS: The current study was to determine whether human exocrine pancreatic cells also can be grown in this manner. METHODOLOGY: Small tissue samples from organ donors and tumor-free resection rim from patients with pancreatic carcinoma were obtained (n = 16 adults). From each patient, fragments of approximately 300 microm in diameter were cultured and investigated with light microscopy and scanning and transmission electron microscopy at the time of explantation and after 5, 10, 20, 30, and 40 days of culture. RESULTS: Incubation of cultured fragments with vital dyes revealed a viable epithelium. At the time of explantation all the tissue fragments had a rough appearance with an uneven, torn periphery. During the first week of culture the fragments became rounder, with a smooth surface covering the whole circumference. This spheroid morphology persisted for the rest of the 6-week culture period. The fragments were within 1 week covered by a highly differentiated, polarized epithelium with secretory apparatus, apical secretion granules, and microvilli, as well as specialized cell junctions, with the same appearance as acinoductal pancreatic cells of the original tissue. The core of the fragments consisted of connective tissue with vascular elements, fibroblasts, leukocytes, and a few ductal and acinar elements. Transmission electron microscopy of the spheroids revealed a continuous basal lamina underneath the epithelium. Immunostaining for cytokeratin 5, 6, 7, 8, 17, and 18 was strongly positive in the epithelium. CONCLUSION: These results show that normal exocrine pancreatic cells can be grown in vitro in a nonadhesive organ culture with their stroma.     

Acute stress reactions after submarine accidents

The aim of the present study was to explore contextual and individual factors associated with acute stress reactions in three Norwegian submarine crews exposed to different significant peacetime maneuver accidents. Approximately 2 to 3 weeks after the accidents, crew members completed the Coping Style Questionnaire, the General Health Questionnaire, the Impact of Event Scale, and the Post-Traumatic Symptom Scale. Although exposed subjects (N = 47) revealed more posttraumatic stress symptoms than nonexposed crew members on shore leave (N = 7), they showed less acute stress reactions than survivors from a surface ship accident in the Norwegian Navy. Inspection of individual cases revealed that 4% of the exposed submariners showed high loads of acute stress symptoms. Unit cohesion and habitual coping styles emerged as resilience factors, whereas previous exposure to critical incidents and personal experience of not coping in the accident situation emerged as vulnerability factors, explaining 32% of the acute stress reactions reported by submarine crew members.