[Intracortical dedifferentiated chondrosarcoma]

Chondrosarcoma is the second most frequent mesenchymal malignant tumour of the bone. Classification of this kind of tumour is made by clinical, radiological und pathological means. A case of an intracortical chondrosarcoma was first reported by Babinet et al. 2003 [2]. During the staging examination of a 59-year-old patient referred to our clinic because of a squamous cell carcinoma of the oropharynx, we also found a highly malignant intracortical dedifferentiated chondrosarcoma of the distal femur shaft. Due to the primary assumption of bone metastasis of the oropharynx tumour, marginal extralesional tumour resection was performed followed by composite osteosynthesis. Considerations on differential diagnosis and their implications for further therapy are discussed.

Expression profile of human beta-defensin 3 in oral squamous cell carcinoma

Although it is known that innate immunity is important for protecting the body against foreign agents such as bacteria, little is known about elements of the innate immune system that have antitumor activity. This prospective study was designed to investigate the function of human beta-defensin 3 (hBD-3), an important component of the innate immune response, in oral squamous cell carcinoma (OSCC). Paired cancerous and noncancerous specimens of 45 patients who underwent surgical treatment for OSCC were examined for hBD-3 expression on protein and mRNA. Clinical and pathological features such as age, gender, tumor and lymph node status, UICC stage, and histological grading were correlated. hBD-3 was significantly overexpressed in tumors in comparison to healthy tissue examined with real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis (p = .004). Immunohistochemical stain for hBD-3 was much more pronounced in tumors than in corresponding healthy mucosa. The results illustrate that hBD-3 is frequently overexpressed in oral squamous cell carcinomas and seems to be related to oncogenesis. Increased expression of hBD-3 in oral squamous cell carcinomas suggests its potential role in the pathogenesis of oral cancer. This might be a starting point for novel pharmacological/molecular treatment modalities.

ADAM10 regulates FasL cell surface expression and modulates FasL-induced cytotoxicity and activation-induced cell death

The apoptosis-inducing Fas ligand (FasL) is a type II transmembrane protein that is involved in the downregulation of immune reactions by activation-induced cell death (AICD) as well as in T cell-mediated cytotoxicity. Proteolytic cleavage leads to the generation of membrane-bound N-terminal fragments and a soluble FasL (sFasL) ectodomain. sFasL can be detected in the serum of patients with dysregulated inflammatory diseases and is discussed to affect Fas-FasL-mediated apoptosis. Using pharmacological approaches in 293T cells, in vitro cleavage assays as well as loss and gain of function studies in murine embryonic fibroblasts (MEFs), we demonstrate that the disintegrin and metalloprotease ADAM10 is critically involved in the shedding of FasL. In primary human T cells, FasL shedding is significantly reduced after inhibition of ADAM10. The resulting elevated FasL surface expression is associated with increased killing capacity and an increase of T cells undergoing AICD. Overall, our findings suggest that ADAM10 represents an important molecular modulator of FasL-mediated cell death.

Polybrene improves transfection efficacy of recombinant replication-deficient adenovirus in cutaneous cells and burned skin

BACKGROUND

The hostile environment found in acute and chronic wounds decreases the physiological half-life of purified synthetic or recombinant peptides dramatically. Gene therapy, on the other hand, may be a viable option since it relies on the cellular machinery of the host to locally manufacture the proteins of interest. The aim of this study was to evaluate and optimize the local administration of transient cutaneous adenoviral gene delivery in wounds.

METHODS

Primary human keratinocytes (HKC) and HaCaT cells were transfected with replication-deficient adenovirus (Ad5) containing the reporter gene for beta-galactosidase (LacZ). The vector was used alone or precoated with either (1) Lipofectamine 2000, (2) FuGENE 6, or (3) Polybrene. For in vivo testing a rat burn model was used. Animals were randomized into three groups: (1) Ad5-LacZ alone; (2) Ad5-LacZ precoated with Polybrene, or (3) carrier control (phosphate-buffered saline (PBS)). Samples were harvested from burned and unburned tissue sections after either 48 h or 7 days. Transgene expression was quantified by bioluminometric assay and localized using immunohistochemistry. A BrdU assay was performed to determine the influence of the used transfection reagents on cell proliferation.

RESULTS

Transfection efficacy was significantly improved in vitro (p < 0.001) as well as in partial thickness burned (p = 0.015) and unburned skin (p > 0.001) after precoating Ad5 with Polybrene compared to Ad5 alone. Transgene expression was 10-fold higher in burned skin (9305 pg/mg protein) compared to unburned skin (859 pg/mg protein).

CONCLUSIONS

It is feasible to improve transfection efficacy in vitro and in vivo by precoating the adenovirus with Polybrene.

Optimum peripheral drug deposition in patients with cystic fibrosis

In order to identify the optimum particle size and breathing pattern for high peripheral deposition of inhaled drugs in patients with cystic fibrosis, regional deposition in these patients was studied systematically as a function of particle size, inhalation volume and flow rate. Regional deposition was assessed using the single-breath regional deposition technique in which the concentration profile of inhaled and exhaled non-radioactive, monodisperse test particles is analyzed. Using this technique particle deposition within the functional dead space volume and peripherally can be assessed. Regional deposition was measured in 12 patients with cystic fibrosis using 2, 3, 4, and 5.5 microm particles, inhalation volumes of 500, 1000, 1500, and 2000 cm(3), and inhalation flow rates of 100, 250, 500, and 750 cm(3)/sec. Peripheral deposition was highest when 2-3-microm particles were inhaled with air-flow rates of 250-500 cm(3)/sec. With these parameters peripheral deposition increased with increasing inhalation volume and reached values of about 60% of the total drug inhaled. It has been shown that high peripheral drug deposition can be achieved in patients with CF when inhalations are performed using an optimized combination of particle size and breathing pattern.

Electron spin resonance on a two-dimensional electron gas in a single AlAs quantum well

Direct electron spin resonance (ESR) on a high mobility two-dimensional electron gas in a single AlAs quantum well reveals an electronic g factor of 1.991 at 9.35 GHz and 1.989 at 34 GHz with a minimum linewidth of 7 G. The ESR amplitude and its temperature dependence suggest that the signal originates from the effective magnetic field caused by the spin-orbit interaction and a modulation of the electron wave vector caused by the microwave electric field. This contrasts markedly with conventional ESR that detects through the microwave magnetic field.

[Hematogenous osteomyelitis in adults]

Hematogenous osteomyelitis (HOM) in adults is a very rare event in industrialised countries. However, in tropical regions the morbidity of HOM is more important, primarily due to the impact of sickle cell disease, thalassemia, HIV-infection and tuberculosis. HOM is most commonly caused by pyogenic bacteria and mycobacteria, but infections by fungi, viruses and parasites must also be considered. In spite of modern diagnostic procedures such as nuclear and magnetic resonance imaging, the histopathologic and microbiologic examination of bone remains the gold standard for diagnosing OM. Other diagnoses should also be considered. Nonbacterial osteomyelitic lesions (plasmacellular OM, sclerosing OM, SAPHO syndrome) as well as acute leukemia, malignant bone tumors (i.e., Ewing's sarcoma, osteosarcoma) are conditions with similar presentations. Acute HOM is best managed by appropriate antibiotic therapy. In case of failure and in chronic HOM, surgical debridement is mandatory.

[Multiple enchondromatosis: Ollier's disease]

In contrast to solitary enchondroma,patients with multiple enchondromatosis of bone (Ollier's disease) get affected in childhood by bone swelling and growth retardation. In adults, the main problem is the risk of malign transformation up to 40%.Pain, increasing local tumor and thinning of the corticalis are the typical clinical and radiological signs of transformation to a low grade chondrosarcoma. There is no need for a regular radiological screening. If a malign transformation occurs,marginal or wide resection of the lesion should be performed.

Genome-wide analysis of sixteen chordomas by comparative genomic hybridization and cytogenetics of the first human chordoma cell line, U-CH1

Cytogenetic information on chordomas is rudimentary and restricted to GTG-banding analysis of 26 cases worldwide. In this study, we present the chromosomal imbalances detected in a series of 16 chordomas (10 sacrococcyeal, five sphenooccipital, and one spinal) from 13 patients using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). On average, 3.2 losses and 4.2 gains were detected per tumor. The most common DNA copy number alterations were losses on chromosomal arms 3p (50%) and 1p (44%). Losses of 3p were detected in five of seven primary chordomas. Therefore, the loss of 3p might be an early event in chordoma genesis. The most common gains involved 7q (69%), 20 (50%), 5q (38%), and 12q (38%). Additionally, we raised the first human chordoma cell line, U-CH1, from a recurrence of a sacral chordoma. U-CH1 and its parent tumor had almost the same CGH profile. According to GTG-banding and multicolor FISH, U-CH1 has the following clonal chromosomal abnormalities: der(1)t(1;22), del(4), +del(5), +del(6), +7, del(9), del(10), +der(20)t(10;20), +21. Thus, the novel permanent human chordoma cell line U-CH1 has chordoma-typical cytogenetic aberrations. Our data suggest that tumor suppressor genes or mismatch repair genes (located at 1p31 and 3p14) and oncogenes (located in 7q36) might be involved in chordoma genesis.