CURRENT CONCEPTS IN PERIPHERAL NERVE INJURY REPAIR.

Even though reconstructive surgery of the nerves underwent significant progress due to experimental and clinical research over the past 40 years, injuries to the peripheral nerves still remain a great challenge for microsurgery. Literature results of these procedures are often evaluated as very good but the final result is often characterized by an achievement of only a useful and not full function, which is rather rare. It is not only a simple suture; the success is also based on functional regeneration and interconnection of the nerve fibres. This is limited by correct surgical technique, the age of the patient, delay from the time of injury and the mechanism or localization of the injury. Some injuries even now remain untreatable (such as the most severe brachial plexus injuries or long traction injuries of the peroneal nerve). Apart from standard neurolysis and epi- or perineural suture with or without nerve grafts, distal nerve transfers (in case of proximal injuries) and end-to-side neurorrhaphy (mainly in trauma of sensitive nerves) have recently been frequently used. The future is however based on influence of nerve regeneration at the cellular level using substances with growth potential. The main prerequisite of successful surgery is however early indication of surgical revision in a specialized centre.

[Auto- and alloreactivity of T lymphocytes in myelodysplastic syndrome]. / Auto- a aloreaktivita T lymfocytu u myelodysplastického syndromu.

BACKGROUND: Successful therapy with ATG and cyclosporine A in some myelodysplastic syndrome (MDS) patients led us to study the existence of T cells attacking autologous hemopoietic cells. In our study, we attempted to give the direct prove of autoreactive T cells in MDS (autoreactivity analysis). Simultaneously, we analysed the capacity of MDS patients to respond to allogeneic cells from unrelated individuals (alloreactivity analysis). METHODS AND RESULTS: Autoreactive lymphocytes directed against own bone marrow mononuclear cells were analysed using the modification of cell mediated cytotoxic reaction. With one exception we did not confirm the presence of autoreactive T cells among 10 patients examined. Analysis of alloreactivity was performed by means of standard cell mediated cytotoxic reaction and mixed lymphocyte reaction. Surprisingly, the cytotoxic response to allogeneic cells was negative in 11 MDS patients from 16 analysed. When comparing refractory anaemia (RA) and refractory anaemia with ring sideroblasts (RARS) patients, the proportion of negative results was higher in RA (78 %) than in RARS (40 %). In mixed lymphocyte reaction, the response of MDS cells to allogeneic cells of unrelated individual was positive in all tested patients. The preliminary testing of TNF and IFNgamma secretion examined in supernatants of effector cells showed impaired levels of both cytokines in RA and normal levels in RARS in accordance with the findings achieved in alloreactivity analysis. CONCLUSIONS: Autoreactive T cells were not found in MDS patients using our experimental arrangement. Analysis of alloreactivity showed the defect in effector--cytotoxic--phase of cell mediated cytotoxic reaction in the majority of MDS patients. The initial phase of this reaction represented in vitro by mixed lymphocyte reaction gave normal results. The possible reasons of disturbed alloreactivity and its relevance to immunity in MDS are commented in discussion.

[Increased sP-selectin and other cardiovascular risk factors: fibrinogen, tissue plasminogen activator (t-PA Ag) and acute phase proteins after kidney transplantation]. / Zvýsení sP-selektinu a dalsích kardiovaskulárních rizikových faktoru: fibrinogenu, tkánového aktivátoru plasminogenu (t-PA Ag), jeho inhibitoru (PAI-1 Ag) a proteinu akutní fáze u nemocných po transplantaci ledviny.

BACKGROUND: Our study was designed to monitor the presence of the "coronary artery disease (CAD) risk factors" after kidney transplantation. METHODS: 26 kidneys transplant recipients with well-functioning (creatinine clearance > 0.8 mL/s) renal allografts receiving cyclosporine A (CsA) as the basic component of immunosuppressive therapy and 60 healthy age-matched controls were included into the study. As "CAD risk factors" were determined the levels of fibrinogen, acute phase proteins orosomucoid and C-reactive protein, t-PA Ag, PAI-1 Ag and soluble adhesion molecules E-selectin, P-selectin and ICAM-1 in the peripheral blood serum or plasma. RESULTS: Renal transplant recipients showed higher BMI (p < 0.001) and levels of fibrinogen (p < 0.001), t-PA Ag (p = 0.007) and PAI-1 Ag (p < 0.001), acute phase protein orosomucoid (p < 0.001) and higher level of soluble P-selectin (p = 0.038). The levels of sICAM-1 and sE-selectin did not differ statistically significantly from those in controls. CONCLUSION: Our study has demonstrated renal graft recipients with good kidney function already show significantly raised levels of "CAD risk factors" fibrinogen, acute phase reactant orosomucoid, t-PA Ag, PAI-1 Ag and sP-selectin.

Soluble TNF and IL-2 receptors in patients with breast cancer.

INTRODUCTION: Cytokines were shown both to enhance tumour growth and formation of metastases and to inhibit proliferation of tumour cells. TNF alpha may mediate apoptosis and necrosis of cancer cells, while the exact role of IL-2 remains to be elucidated. Plasma levels of TNF alpha and TNF and IL-2 soluble receptors (sTNF-R, sIL-2R) should thus be in some relation to some biological characteristics of the breast cancer. MATERIAL AND METHODS: Plasma levels of TNF alpha, sTNF-R I and II and sIL-2R were measured in 31 women with different stages of breast cancer both before the institution of therapy and after 3 months of the treatment. RESULTS: Plasma levels of both types of sTNF-Rs were higher in patients with breast cancer than in controls (sTNF-R I--2166.6 +/- 568.9 vs. 1121.3 +/- 260.6 pg/ml, p < 0.001, sTNF-R II--3792.8 +/- 958.9 vs. 1996.2 +/- 404.3 pg/ml, p < 0.001) with no significant difference between clinical stages. Plasma levels of both sTNF-R (0.871, p < 0.001) and sIL-2R tightly correlated with each other. Plasma levels of TNF alpha decreased after treatment (from 3.92 +/- 1.86 to 3.40 +/- 1.15 pg/ml, p < 0.01), but plasma levels of sTNF-Rs and sIL-2R were not influenced by the therapy. CONCLUSION: Plasma levels of soluble TNF receptors may thus serve as a non-specific marker of the untreated breast cancer. Their relation to other biologic characteristics of this tumour is not clear. It remains also to be clarified if the long-term treatment leads to the normalization of sTNF-Rs plasma levels.