Intradiscal temperature monitoring using double gradient‐echo pulse sequences at 1.0T

Purpose:

To validate an unspoiled gradient‐recalled echo pulse sequence with dual echo acquisition as a means to increase temperature sensitivity while monitoring intradiscal laser ablation therapy.

Materials and Methods:

Phantom experiments as well as in vitro thermal ablation simulations were performed in an open 1.0T magnetic resonance (MR) scanner. Three methods of noninvasive MR‐thermometry based on the signal void decrease caused by T1‐relaxation time increase (T1), the temperature‐dependent proton resonance frequency (PRF) shift, and a combination of both methods with complex differences (CD) were compared. Temperature accuracy and reliability of temperature distribution were the main assessment criteria.

Results:

The optimum temperature sensitivity was found using CD in phantom experiments. During in vitro experiments the PRF showed the smallest margin of error (T1: ±1.64°C, PRF: ±1.23°C, CD: ±1.29°C) and the best qualitative evaluation of temperature.

Conclusion:

Intradiscal temperature monitoring with an unspoiled dual‐echo sequence is most accurate with PRF‐thermometry in combination with the long echo time. Magnitude images with an initial short echo time permit high image detail of the heat‐induced lesion. J. Magn. Reson. Imaging 2010;31:1499–1503. © 2010 Wiley‐Liss, Inc.     

Comparative analysis of cell death induction by Taurolidine in different malignant human cancer cell lines

Background

Taurolidine (TRD) represents an anti-infective substance with anti-neoplastic activity in many malignant cell lines. So far, the knowledge about the cell death inducing mechanisms and pathways activated by TRD is limited. The aim of this study was therefore, to perform a comparative analysis of cell death induction by TRD simultaneously in different malignant cell lines.

Materials and methods

Five different malignant cell lines (HT29/Colon, Chang Liver/Liver, HT1080/fibrosarcoma, AsPC-1/pancreas and BxPC-3/pancreas) were incubated with increasing concentrations of TRD (100 μM, 250 μM and 1000 μM) for 6 h and 24 h. Cell viability, apoptosis and necrosis were analyzed by FACS analysis (Propidiumiodide/AnnexinV staining). Additionally, cells were co-incubated with the caspase Inhibitor z-VAD, the radical scavenger N-Acetylcystein (NAC) and the Gluthation depleting agent BSO to examine the contribution of caspase activation and reactive oxygen species in TRD induced cell death.

Results

All cell lines were susceptible to TRD induced cell death without resistance toward this anti-neoplastic agent. However, the dose response effects were varying largely between different cell lines. The effect of NAC and BSO co-treatment were highly different among cell lines - suggesting a cell line specific involvement of ROS in TRD induced cell death. Furthermore, impact of z-VAD mediated inhibition of caspases was differing strongly among the cell lines.

Conclusion

This is the first study providing a simultaneous evaluation of the anti-neoplastic action of TRD across several malignant cell lines. The involvement of ROS and caspase activation was highly variable among the five cell lines, although all were susceptible to TRD induced cell death. Our results indicate, that TRD is likely to provide multifaceted cell death mechanisms leading to a cell line specific diversity.     

STAT3信号转导通路抑制剂诱导胶质瘤干细胞产生自噬的研究

背景与目的:胶质瘤干细胞(glioma stem cell,GSC)在胶质瘤发展及治疗抗拒中发挥重要作用。我们以往的研究表明,新型STAT3信号转导通路抑制剂(STAT3 inhibitor,STI)WP1193能够诱导GSC产生细胞周期阻滞及凋亡。本研究旨在探讨STI是否能在体外诱导GSC产生自噬现象。方法:从手术切除的胶质母细胞瘤中分离及培养GSC。使用STI处理GSC。利用细胞计数法检测STI对GSC增殖的影响。使用Western blot检测自噬相关蛋白LC3的表达情况。吖啶橙染色后,利用荧光显微镜及流式细胞技术检测酸性自噬小体。使用透射电镜检测GSC中自噬小体。结果:STI剂量依赖性的抑制GSC的增殖。STI处理后,GSC中出现LC3表达的切换。STI处理后,GSC中出现自噬小体,且出现自噬小体细胞的比例增加。结论:STI能够在GSC中诱导自噬现象的产生。自噬在STI治疗中的意义及调节机制需要进一步的研究。     

Requirement of CCL17 for CCR7- and CXCR4-dependent migration of cutaneous dendritic cells

Chemokines are known to regulate the steady-state and inflammatory migration of cutaneous dendritic cells (DCs). The β-chemokine CCL17, a ligand of CCR4, is inducibly expressed in a subset of DCs and is strongly up-regulated in atopic diseases. Using an atopic dermatitis model, we show that CCL17-deficient mice develop acanthosis as WT mice, whereas dermal inflammation, T helper 2-type cytokine production, and the allergen-specific humoral immune response are significantly decreased. Notably, CCL17-deficient mice retained Langerhans cells (LCs) in the lesional skin after chronic allergen exposure, whereas most LCs emigrated from the epidermis of allergen-treated WT controls into draining lymph nodes (LNs). Moreover, CCL17-deficient LCs showed impaired emigration from the skin after exposure to a contact sensitizer. In contrast, the absence of CCR4 had no effect on cutaneous DC migration and development of atopic dermatitis symptoms. As an explanation for the major migratory defect of CCL17-deficient DCs in vivo, we demonstrate impaired mobility of CCL17-deficient DCs to CCL19/21 in 3D in vitro migration assays and a blockade of intracellular calcium release in response to CCR7 ligands. In addition, responsiveness of CCL17-deficient DCs to CXCL12 was impaired as well. We demonstrate that the inducible chemokine CCL17 sensitizes DCs for CCR7- and CXCR4-dependent migration to LN-associated homeostatic chemokines under inflammatory conditions and thus plays an important role in cutaneous DC migration.     

Protein C, protein S, and thrombomodulin in amniotic fluid. A preliminary study

OBJECTIVES: The main components of protein C anticoagulant system are protein C (PC), protein S (PS) and thrombomodulin (TM); the system plays a protective role in pregnancy, mainly because it prevents the utero-placental circulation from local thrombosis. It is unknown whether the protein C anticoagulant pathway exists in amniotic fluid. The aim of the present study is to find out whether these three components are present in amniotic fluid. STUDY DESIGN: The study group consisted of 50 parturients with an uneventful pregnancy and birth and 25 non-pregnant controls. Amniotic fluid and blood were sampled at the end of the 1st stage of labor. PC, PS and TM were measured by immunoenzymatic method. RESULTS: All the samples of amniotic fluid contained measurable amounts of antigens of PC, PS and TM, although their concentrations were significantly lower than in the mother's blood: (i) The concentration of PC in amniotic fluid was 6.24+/-3.50% and PS 2.40+/-1.64%, while in the mothers' plasma it was 138.26+/-12.38% and 93.15+/-13.24%, respectively (P<0.0001). (ii) TM concentration in amniotic fluid constituted 63.92% of the concentration in the mother's blood (2.71+/-1.21 ng/mL vs. 4.24+/-0.88 ng/mL, P<0.001). CONCLUSION: Protein C, protein S and thrombomodulin are physiological constituents of the amniotic fluid. As their concentrations are low, it is reasonable to assume that they cannot counterbalance the procoagulant activity of amniotic fluid.     

Kynurenic acid, an endogenous constituent of rheumatoid arthritis synovial fluid, inhibits proliferation of synoviocytes in vitro

Kynurenic acid is an antagonist of ionotropic glutamate receptors. It has been found that glutamate antagonists inhibit proliferation of different human tumor cells. Since the hyperplasia of synovial fibroblasts is one of the most striking features of inflammatory arthritis, the main goals of this study were detection and quantification of kynurenic acid in synovial fluid obtained from patients with rheumatoid arthritis, and determination of its effect on proliferation of synoviocytes in vitro. Presence of kynurenic acid was determined by HPLC in all 58 samples of synovial fluid. The mean concentration was 15.89 pmol/ml. Kynurenic acid inhibited synoviocyte proliferation with the IC₅₀ value of 5.9 mM. In subthreshold concentration of 0.3 mM it enhanced antiproliferative action of celecoxib and nimesulide. In conclusion, the presence of kynurenic acid in synovial fluid was documented in patients with rheumatoid arthritis. Its potential role as an endogenous substance, controlling synoviocyte proliferation can be suggested.     

Slime Production by Staphylococcus aureus and Staphylococcus epidermidis Strains Isolated from Patients with Diabetic Foot Ulcers

Slime production is a very important factor related to biofilm formation. The objective of the present study was to determine the frequency of slime production by Staphylococcus aureus and Staphylococcus epidermidis strains recovered from 50 patients with diabetic foot ulcers. Slime production was determined using the Congo red agar (CRA) method and compared with immunocytochemistry for the production of polysaccharide intercellular adhesin (PIA). Out of 55 S. aureus strains, 69% produced slime as shown by the CRA method. Of them, 84.2% also produced PIA. Of 17 CRA-negative strains, 70.6% produced PIA. Out of 20 S. epidermidis strains, 75% were CRA positive and 93.3% produced PIA. All CRA-negative S. epidermidis produced PIA. In conclusion, PIA production is a very common trait of S. aureus and S. epidermidis isolates obtained from diabetic foot ulcer patients.     

Morphoproteomic and pharmacoproteomic rationale for mTOR effectors as therapeutic targets in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) has a relatively high mortality rate and poor prognosis. Recently, we showed that overexpression of phosphorylated (p) nuclear factor-kappaB (NF-kappaB) in squamous cell carcinoma of the tonsil (SCCT) and high grade dysplasia is associated with a poor prognosis. Because the mammalian target of the rapamycin (mTOR) pathway contributes to the activation of NF-kappaB through immunophilin/mTOR signaling, we investigated: (a) the immunohistochemical expression and state of activation and potential clinical significance of components of the mTOR signal transduction pathway in SCCT patients (morphoproteomics); and (b) the inhibitory effects of rapamycin on the growth and state of activation of mTOR in 2 HNSCC cell lines (pharmacoproteomics). Archival biopsy materials from 39 patients with SCCT were studied by immunohistochemistry for the expression of p-mTOR (Ser 2448), and p-p70S6K (Thr 389), and/or cyclin D1. Results for SCCT were compared with adjacent non-neoplastic epithelium, when present, and with normal tonsillar epithelium from approximately age-matched controls; clinical outcomes were also assessed. SCCT showed mTOR (Ser 2448) expression in 93% (30/32 cases) with 2+ or 3+ plasmalemmal and/or cytoplasmic intensity in 84% vs 42% in surface epithelium from normal tonsils (p <0.001). The mean combined expression score (signal intensity x percentage of positive cells) for p-p70S6K was significantly greater in the SCCT group vs adjacent non-neoplastic squamous epithelium and normal tonsillar epithelium of the control group (p <0.05). A relationship existed between higher p-p70S6K expression levels in the non-neoplastic squamous epithelium adjacent to the SCCT and increased risk of death from disease (hazard ratio = 7.9; 95% confidence interval (CI) = 2.1 to 29.9; p = 0.002). There was also a relationship between nuclear expression of cyclin D1 in SCCT and shortened recurrence-free survival (p = 0.015). Two human HNSCC cell lines, SCC-15 and FaDu, were incubated with and without rapamycin to assess its impact on growth and on the expression of p-mTOR. Rapamycin in a dose-dependent fashion inhibited growth more in SCC-15, which correlated with a greater reduction in constitutively activated p-mTOR (Ser 2448) as shown by Western blotting. In conclusion, these morphoproteomic and pharmacoproteomic data collectively provide a rationale for selecting mTOR effectors as therapeutic targets in HNSCC.     

Deep brain stimulation and motor cortex and spinal cord stimulation in the treatment of movement disorders and pain syndromes -- the theoretical baseline and practical guidelines

The authors present the current views on the use of electrical stimulation in selected movement disorders (Parkinson's disease, dystonia) and pain syndromes (central and neuropathic pain) refractory to pharmacological therapy. Stimulation should be applied in cases with an established diagnosis (especially Parkinson's disease and dystonia) and with a lack of efficacy despite the best available medical therapy. Therefore it should be the last treatment option, except of generalized dystonia, where it seems to be nowadays the treatment of choice. Suggested selection criteria are based on experience of different centers and on current medical literature. They are published to make the procedure more rational and more available in Poland.