Dental implant treatment in patients with cancer on high-dose antiresorptive medication: A prospective feasibility study with 2 years follow-up

OBJECTIVES

Dental implant treatment is considered contraindicated in patients with cancer on high-dose antiresorptive medication (HDAR). The aim of this prospective, feasibility study was to evaluate implant treatment in patients with cancer on HDAR, in terms of implant survival, implant success, and oral health-related quality of life (OHLQoL) after 2 years of loading.

MATERIALS AND METHODS

Implants were inserted in three groups of HDAR patients: (1) Previous tooth extraction, no medication-related osteonecrosis of the jaw (MRONJ), (2) Previous MRONJ, now healed, (3) Existing MRONJ, planned surgical resection. Implants were placed without adjunctive bone or soft tissue argumentation. Abutment operation was performed after ≥12 weeks. Prosthetic treatment was initiated ≥14 weeks. Survival and success rate were determined, and OHLQoL was analyzed with OHIP-49 and QLQ-H&N35 questionnaires. Patients were seen for 6 months, 1- and 2 years follow-up.

RESULTS

Twenty-two patients, 39 implants, completed the implant-based prosthetic treatment. Implant-supported crowns and overdentures were fabricated. Thirteen patients (59%) with 23 implants (59%) completed 2 years follow-up. Overall implant survival and success rate after 2 years of loading were 100% and 97.4%, respectively. OHLQoL for the patients increased in all groups after the treatment, a substantial increase was seen in group 3. Two patients developed MRONJ, but not related to the implant treatment.

CONCLUSION

Dental implant treatment, with high survival and success rate and increased post-treatment OHLQoL, is feasible in HDAR patients after 2 years of loading. Caution with general recommendations should be exercised.

Tooth extractions in patients with cancer receiving high-dose antiresorptive medication: a randomized clinical feasibility trial of drug holiday versus drug continuation

OBJECTIVE

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse reaction to high-dose antiresorptive medication (AR) in patients with cancer. A temporary discontinuation of AR (drug holiday) has been suggested to potentially reduce the risk of MRONJ after oral surgery. However, no consensus exists. The aim of the present feasibility trial was to evaluate the impact of a high-dose AR drug holiday in connection with surgical tooth extraction on the development of MRONJ and patient-reported health state.

STUDY DESIGN

Patients with cancer receiving high-dose AR were randomized to a drug holiday from 1 month before to 3 months after surgical tooth extraction or drug continuation. Follow-up was scheduled at 1, 3, and 6 months postoperatively. Patient health state was evaluated using the EQ-5D-5L questionnaire.

RESULTS

The study included 23 patients (11 men, 12 women). AR included denosumab (n = 13) and bisphosphonate (n = 10) with median AR durations of 9 and 17.5 months, respectively. Four denosumab patients from the drug holiday group developed MRONJ. Differences in EQ-5D-5L between the treatment groups were found in favor of drug continuation.

CONCLUSIONS

The results indicate that a high-dose AR drug holiday does not prevent development of MRONJ after surgical tooth extraction and that patient-reported health state declines during a drug holiday compared with drug continuation.

Effects of the lysosomal destabilizing drug siramesine on glioblastoma in vitro and in vivo

Background

Glioblastoma is the most frequent and most malignant brain tumor with the patients having a median survival of only 14.6 months. Although glioblastoma patients are treated with surgery, radiation and chemotherapy recurrence is inevitable. A stem-like population of radio- and chemoresistant brain tumor-initiating cells combined with the invasive properties of the tumors is believed to be critical for treatment resistance. In the present study, the aim was to investigate the effect of a novel therapeutic strategy using the lysosomotropic detergent siramesine on glioblastomas.

Methods

Standard glioma cell lines and patient-derived spheroids cultures with tumor-initiating stem-like cells were used to investigate effects of siramesine on proliferation and cell death. Responsible mechanisms were investigated by inhibitors of caspases and cathepsins. Effects of siramesine on migrating tumor cells were investigated by a flat surface migration assay and by implanting spheroids into organotypic rat brain slice cultures followed by confocal time-lapse imaging. Finally the effect of siramesine was investigated in an orthotopic mouse glioblastoma model. Results obtained in vitro and in vivo were confirmed by immunohistochemical staining of histological sections of spheroids, spheroids in brain slice cultures and tumors in mice brains.

Results

The results showed that siramesine killed standard glioma cell lines in vitro, and loss of acridine orange staining suggested a compromised lysosomal membrane. Co-treatment of the cell lines with inhibitors of caspases and cathepsins suggested differential involvement in cell death. Siramesine caused tumor cell death and reduced secondary spheroid formation of patient-derived spheroid cultures. In the flat surface migration model siramesine caused tumor cell death and inhibited tumor cell migration. This could not be reproduced in the organotypic three dimensional spheroid-brain slice culture model or in the mice xenograft model.

Conclusions

In conclusion the in vitro results obtained with tumor cells and spheroids suggest a potential of lysosomal destabilizing drugs in killing glioblastoma cells, but siramesine was without effect in the organotypic spheroid-brain slice culture model and the in vivo xenograft model.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3162-3) contains supplementary material, which is available to authorized users.

Comparative studies of TIMP-1 immunohistochemistry, TIMP-1 FISH analysis and plasma TIMP-1 in glioblastoma patients

Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been associated with poor prognosis and resistance towards chemotherapy in several cancer forms. In a previous study we found an association between a low TIMP-1 tumor immunoreactivity and increased survival for glioblastoma patients, when compared to moderate and high TIMP-1 tumor immunoreactivity. The aim of the present study was to further evaluate TIMP-1 as a biomarker in gliomas by studying TIMP-1 gene copy numbers by fluorescence in situ hybridization (FISH) on 33 glioblastoma biopsies and by measuring levels of TIMP-1 in plasma obtained pre-operatively from 43 patients (31 gliomas including 21 glioblastomas) by enzyme-linked immunosorbent assay (ELISA). The results showed TIMP-1 gene copy numbers per cell ranging from 1 to 5 and the TIMP-1/CEN-X ratio ranging between 0.7 and 1.09, suggesting neither amplification nor loss of the TIMP-1 gene. The TIMP-1 protein levels measured in plasma were not significantly higher than TIMP-1 levels measured in healthy subjects. No correlation was identified between TIMP-1 tumor cell immunoreactivities and the TIMP-1 gene copy numbers or the plasma TIMP-1 levels. In conclusion, high immunohistochemical TIMP-1 protein levels in glioblastomas were not caused by TIMP-1 gene amplification and TIMP-1 in plasma was low and not directly related to tumor TIMP-1 immunoreactivity. The study suggests that TIMP-1 immunohistochemistry is the method of choice for future clinical studies evaluating TIMP-1 as a biomarker in glioblastomas.

Shift of microRNA profile upon orthotopic xenografting of glioblastoma spheroid cultures

Glioblastomas always recur despite surgery, radiotherapy and chemotherapy. A key player in the therapeutic resistance may be immature tumor cells with stem-like properties (TSCs) escaping conventional treatment. A group of promising molecular targets are microRNAs (miRs). miRs are small non-coding RNAs exerting post-transcriptional regulation of gene expression. In this study we aimed to identify over-expressed TSC-related miRs potentially amenable for therapeutic targeting. We used non-differentiated glioblastoma spheroid cultures (GSCs) containing TSCs and compared these to xenografts using a NanoString nCounter platform. This revealed 19 over-expressed miRs in the non-differentiated GSCs. Additionally, non-differentiated GSCs were compared to neural stem cells (NSCs) using a microarray platform. This revealed four significantly over-expressed miRs in the non-differentiated GSCs in comparison to the NSCs. The three most over-expressed miRs in the non-differentiated GSCs compared to xenografts were miR-126, -137 and -128. KEGG pathway analysis suggested the main biological function of these over-expressed miRs to be cell-cycle arrest and diminished proliferation. To functionally validate the profiling results suggesting association of these miRs with stem-like properties, experimental over-expression of miR-128 was performed. A consecutive limiting dilution assay confirmed a significantly elevated spheroid formation in the miR-128 over-expressing cells. This may provide potential therapeutic targets for anti-miRs to identify novel treatment options for GBM patients.

Acute hypoxia induces upregulation of microRNA-210 expression in glioblastoma spheroids

AIM

Tumor hypoxia and presence of tumor stem cells are related to therapeutic resistance and tumorigenicity in glioblastomas. The aim of the present study was therefore to identify microRNAs deregulated in acute hypoxia and to identify possible associated changes in stem cell markers.

MATERIALS & METHODS

Glioblastoma spheroid cultures were grown in either 2 or 21% oxygen. Subsequently, miRNA profiling was performed and expression of ten stem cell markers was examined.

RESULTS

MiRNA-210 was significantly upregulated in hypoxia in patient-derived spheroids. The stem cell markers displayed a complex regulatory pattern.

CONCLUSION

MiRNA-210 appears to be upregulated in hypoxia in immature glioblastoma cells. This miRNA may represent a therapeutic target although it is not clear from the results whether this miRNA may be related to specific cancer stem cell functions.

Clinical value of CD133 and nestin in patients with glioma: a population-based study

Cancer stem cell-related (CSC) markers have been suggested to have promising potentials as novel types of prognostic and predictive markers in gliomas. However no single CSC-related marker is currently used in clinical decisions. The aim of this study was to investigate the prognostic value of CD133 and nestin separately and in combination using a novel quantitative approach in a well-characterized population-based cohort of glioma patients. The expression of CD133 and nestin was measured by systematic random sampling in stained paraffin sections from 239 glioma patients diagnosed between 2005 and 2009. We found that the expression of CD133 did not correlate with WHO grade, and there was no association with overall survival (OS). The level of nestin correlated positively with WHO grade. In patients with WHO grade II tumors, a high level of nestin was associated with short progression-free survival (PFS) in multivariate analysis. High levels of co-localization were associated with poor PFS in patients with WHO grade II tumors, but not with OS. We conclude that CD133 was not an independent prognostic factor, but a high level of nestin was associated with poor PFS in patients with WHO grade II tumors. The combination of double-immunofluorescence and automated analysis seems to be a feasible and reproducible approach for investigation of the prognostic potential of biomarkers.

Expression of the lysosomal-associated membrane protein-1 (LAMP-1) in astrocytomas

Targeting of lysosomes is a novel therapeutic anti-cancer strategy for killing the otherwise apoptosis-resistant cancer cells. Such strategies are urgently needed for treatment of brain tumors, especially the glioblastoma, which is the most frequent and most malignant type. The aim of the present study was to investigate the presence of lysosomes in astrocytic brain tumors focussing also on the therapy resistant tumor stem cells. Expression of the lysosomal marker LAMP-1 (lysosomal-associated membrane protein-1) was investigated by immunohistochemistry in 112 formalin fixed paraffin embedded astrocytomas and compared with tumor grade and overall patient survival. Moreover, double immunofluorescence stainings were performed with LAMP-1 and the astrocytic marker GFAP and the putative stem cell marker CD133 on ten glioblastomas. Most tumors expressed the LAMP-1 protein in the cytoplasm of the tumor cells, while the blood vessels were positive in all tumors. The percentage of LAMP-1 positive tumor cells and staining intensities increased with tumor grade but variations in tumors of the same grade were also found. No association was found between LAMP-1 expression and patient overall survival in the individual tumor grades. LAMP-1/GFAP showed pronounced co-expression and LAMP-1/CD133 was co-expressed as well suggesting that tumor cells including the proposed tumor stem cells contain lysosomes. The results suggest that high amounts of lysosomes are present in glioblastomas and in the proposed tumor stem cells. Targeting of lysosomes may be a promising novel therapeutic strategy against this highly malignant neoplasm.

Human leukocyte antigen-G is frequently expressed in glioblastoma and may be induced in vitro by combined 5-aza-2'-deoxycytidine and interferon-γ treatments: results from a multicentric study

Human leukocyte antigen-G (HLA-G) is a nonclassical major histocompatibility complex (MHC) class I molecule involved in immune tolerance processes, playing an important role in the maintenance of the semi-allogeneic fetus. Although HLA-G expression is restricted in normal tissues, it is broadly expressed in malignant tumors and may favor tumor immune escape. We analyzed HLA-G protein and mRNA expression in tumor samples from patients with glioblastoma collected in France, Denmark, and Brazil. We found HLA-G protein expression in 65 of 108 samples and mRNA in 20 of 21 samples. The absence of HLA-G protein expression was associated with a better long-term survival rate. The mechanisms underlying HLA-G gene expression were investigated in glioma cell lines U251MG, D247MG, and U138MG. Induction of HLA-G transcriptional activity was dependent of 5-aza-2'-deoxycytidine treatment and enhanced by interferon-γ. HLA-G protein expression was observed in U251MG cells only. These cells exhibited a permissive chromatin state at the HLA-G gene promoter and the highest levels of induced HLA-G transcriptional activity following 5-aza-2'-deoxycytidine treatment. Several antigen-presenting machinery components were up-regulated in U251MG cells after demethylating and IFN-γ treatments, suggesting an effect on the up-regulation of HLA-G cell surface expression. Therefore, because of its role in tumor tolerance, HLA-G found to be expressed in glioblastoma samples should be taken into consideration in clinical studies on the pathology and in the design of therapeutic strategies to prevent its expression in HLA-G-negative tumors.

Abstract 4241: Glioma spheroids obtained via ultrasonic aspiration are viable and express stem cell markers: a new tissue resource for glioma research

Ultrasonic aspirators allow safe, rapid and accurate removal of brain tumors. However, the tissue fragments removed are used surprisingly little in research. The aim of this study was to investigate whether such tissue fragments could be cultured as organotypic multicellular spheroids and whether these spheroids could be used in cancer stem cell research. Biopsy-derived spheroids have earlier been shown to represent an important alternative to commercially available cell lines, but access to biopsy tissue is often limited. Tissue fragments obtained by ultrasonic aspiration from 10 glioblastomas and tumor biopsy tissue from seven of these tumors were collected and cultured in serum-containing and serum-free medium. After culturing, the fragments formed spheroids, which were prepared for histological staining. For comparison, the corresponding fixed non-cultured patient biopsies were also included in the study. Hematoxylin eosin staining showed that viable glioma spheroids were obtained from both ultrasonic and biopsy tissue using both serum-containing and serum-free medium. Independent of the type of tissue used for the spheroids, the immunohistochemical expression of GFAP decreased, whereas the expression of VWF and the Ki-67 proliferation index increased in spheroids cultured in serum-free versus serum-containing medium. Independent of the type of medium, both ultrasonic and biopsy tissue expressed significantly higher levels of the investigated stem cell markers CD133, Nestin and Bmi-1 compared to the non-cultured patient biopsies. In conclusion, we found that is was easy to obtain viable glioma spheroids from ultrasonic tissue fragments. Although differences in expression of the different markers were found, the overall expression was preserved, thereby suggesting ultrasonic tissue fragments as a new tissue resource for glioma research.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4241. doi:1538-7445.AM2012-4241

Abstract 5563: Comparative studies of TIMP-1 immunohistochemistry, TIMP-1 FISH analysis and plasma TIMP-1 in glioblastoma patients

Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been associated with poor prognosis in various cancers as well as with resistance towards chemotherapy. In a previous study we found an association between a high immunohistochemical TIMP-1 protein level and a shorter survival for glioblastoma patients. The aim of the present study was to further evaluate TIMP-1 as a prognostic marker in gliomas by performing TIMP-1 fluorescence in situ hybridization (FISH) and by measuring TIMP-1 in plasma. TIMP-1 FISH analysis was performed on 33 glioblastoma biopsies in order to elucidate if the increased levels of TIMP-1 protein could be explained by gene amplification. Moreover, blood samples were collected from 43 patients (31 gliomas including 21 glioblastomas) prior to brain tumor surgery. The plasma TIMP-1 protein level was measured by ELISA. The results showed TIMP-1 FISH scores between 0.7 and 1.1, suggesting neither amplification nor loss of the TIMP-1 gene. The TIMP-1 level measured in plasma was not significantly higher than the TIMP-1 level measured in healthy matched controls. No correlation was identified between the immunohistochemical TIMP-1 levels and the FISH scores or the plasma TIMP-1 levels. In conclusion, TIMP-1 FISH scores or plasma TIMP-1 levels are without prognostic potential in gliomas. The present study suggests that the high immunohistochemical TIMP-1 protein levels in gliomas are not caused by TIMP-1 gene amplification. Moreover, TIMP-1 in plasma is low and not directly related to the tumor TIMP-1 level found by immunohistochemistry. The study suggests that TIMP-1 immunohistochemistry is the method of choice when using TIMP-1 as a biomarker in gliomas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5563. doi:1538-7445.AM2012-5563

Inconsistent immunohistochemical expression patterns of four different CD133 antibody clones in glioblastoma

The putative tumor stem cell marker CD133 is the marker of choice for identifying brain tumor stem cells in gliomas, but the use of different CD133 antibody clones possibly recognizing different CD133 splice variants with epitopes of different glycosylation status confuses the field. The aim was to investigate if current inconsistent CD133 observations could be a result of using different CD133 antibodies for immunohistochemical identification of CD133. Ten glioblastomas were immunohistochemically stained with four different CD133 antibody clones (AC133, W6B3C1, C24B9, and ab19898) and analyzed by quantitative stereology. Moreover, the CD133 staining pattern of each antibody clone was investigated in kidney, pancreas, and placenta tissue as well as in glioblastoma and retinoblastoma cultures and cell lines. All antibody clones revealed CD133+ niches and single cells in glioblastomas, but when using different clones, their distribution rarely corresponded. Morphology of identified single cells varied, and staining of various tissues, cultures, and cells lines was also inconsistent among the clones. In conclusion, the authors report inconsistent CD133 detection when using different primary CD133 antibody clones. Thus, direct comparison of studies using different antibody clones and conclusions based on CD133 immunohistochemistry should be performed with caution.

Abstract 4319: Effects of chemotherapeutics on organotypic corticostriatal slice cultures identified by a new panel of fluorescent and immunohistochemical markers

Effects of chemotherapeutics on glioma cell lines and spheroids are usually investigated without evaluating the effects of even very high concentrations of chemotherapeutics on normal brain tissue. To perform such investigations, the aim of the present study was to establish a panel of markers for detection of general cell death and more specific neuronal and glial degeneration induced by chemotherapeutics in organotypic rat corticostriatal slice cultures. Organotypic rat corticostriatal slice cultures were exposed to the alkylating agents temozolomide and nimustine, the tyrosine kinase inhibitor imatinib mesylate and the microtubule destabilizing agent vincristine. Densitometric measurements of uptake of the fluorescent dye propidium iodide were used for quantifying cellular degeneration. Moreover, paraffin sections were HE stained and immunohistochemically stained for the neuronal marker MAP2, the astroglial marker GFAP, and the oligodendrocyte marker p25α. The results showed that clinical drug concentrations were non-toxic. However, a time dependent increase in PI uptake was observed for supratherapeutic concentrations of the drugs, except for temozolomide, where no toxicity was observed at all. Corresponding immunostaining showed loss of MAP2 staining and increased expression of GFAP and p25α for cultures exposed to 1000 nM vincristine. Cultures exposed to supratherapeutic concentrations of nimustine and imatinib mesylate disintegrated, leaving no tissue for histology.

In conclusion, corticostriatal slice cultures and the established panel of markers represent an excellent tool for detecting toxicity by chemotherapeutics. Toxicity was not detected at clinical concentrations, but high concentrations with toxic effects were identified suggesting that some of the earlier identified anti-cancer effects in the literature are general cytotoxic effects and not specific anti-cancer effects.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4319. doi:10.1158/1538-7445.AM2011-4319

Abstract P4-08-08: Cross Reactivity of Clinically Validated Anti-HER2 Antibodies

Background: Human epidermal growth factor receptor (HER-) 2 belongs to the family of epidermal growth factor receptors (EGFRs) with homology to HER1, HER3 and HER4. HER2 is over-expressed in approximately 20% of invasive human breast cancers (Wolff, Hammond et al. 2007). Over-expression of HER2 is associated with a poor prognosis; however, the protein can be targeted by anti-HER2 therapy (trastuzumab, Herceptin®) (Slamon, Leyland-Jones et al. 2001). Trastuzumab therapy is offered only to patients whose tumors over-express HER2 protein and/or show amplification of the HER2 gene. Accordingly, the expression level of HER2 protein and/or amplification of the HER2 gene are determined routinely in all newly diagnosed breast cancers. Essential to this testing of HER2 expression at the protein level is the availability of specific antibody-based test systems.

Aim: The aim of the present study was to investigate the specificity of three clinically approved commercially available anti-HER2 antibodies towards members of the EGFR-family.

Methods: We studied the antibody used in the Herceptest™ (Dako), the PATHWAY® antibody (Ventana Medical Systems, Inc.) and the Oracle™ antibody (Leica Microsystems). Antibody specificity was investigated by manually performed immunohistochemistry (IHC) and in competitive ELISAs. For IHC, Chinese Hamster Ovary (CHO) cells were transiently transfected with the intracellular domain of respectively HER1, HER2, HER3 and HER4 and all three antibodies were applied to sections of formalin-fixed paraffin-embedded (FFPE) transfected cells. In ELISA, cross reactivity towards HER1 and HER4 was tested with peptides corresponding to the C-terminal part of HER1 and HER4.

Results: In IHC experiments, all three antibodies stained cells transfected with HER2. Binding of the antibodies to HER2 was confirmed bycompetitive ELISA. However, in IHC experiments the PATHWAY® and the Oracle™ antibodies also stained cells transfected with HER4. Competitive ELISAs confirmed binding of the PATHWAY® antibody to HER4, whereas binding of the Oracle™ antibody to HER4 could not be confirmed in a competitive ELISA. None of the antibodies cross reacted with HER1 and HER3 homologous to the HER2 binding site of the antibodies.

Conclusions: Two out of three clinically validated anti-HER2 antibodies were shown to cross react with HER4 in FFPE cells. As determination of HER2 over-expression and/or amplification guides therapy with trastuzumab, a valid test result by the use of specific antibodies is crucial to ensure proper personalized therapy with HER2-targeted therapy. These results warrant further investigation of anti-HER2 antibodies and of the procedures for clinical determination of HER2 protein expression. References:

Slamon DJ et al. (2001) J Med 344:783 Wolff AC et al. (2007) J Clin Oncol 25:118

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-08.

Abstract 3369: Discordant immunohistochemical expression patterns of four different CD133 antibody clones in glioblastoma

The putative tumor stem cell marker CD133 is the marker of choice for identifying brain tumor stem cells in gliomas, but the use of different antibody clones recognizing different epitopes with different glycosylation status, confuses the field. In this study, we sat out to highlight if current discordant CD133 observations could be a result of using different CD133 antibodies for immunohistochemical identification of CD133. Paraffin embedded sections of glioblastoma, kidney, pancreas and placenta tissue as well as glioblastoma and retinoblastoma cell lines were stained with four different CD133 antibody clones and analyzed using light microscopy. Ten consecutive sections of glioblastomas were analyzed with each of the four CD133 clones using quantitative stereology. Results revealed presence of CD133+ niches in glioblastomas, often in close relation to blood vessels, using all four antibody clones. The distribution of identified niches did, however, rarely correspond among each antibody clone. Staining of glioblastoma single and niche cells was predominantly cytoplasmatic, which is opposed to the membranous staining observed in epithelial cells in kidney, pancreas and placenta tissues. Quantitative stereology revealed vast dissimilarities regarding fractions of CD133+ niches and single cells among the CD133 antibody clones. Generally, the fraction of CD133 positivity identified by clone W6B3C1 was significantly higher than CD133 fractions identified by clones AC133, ab19898 and C24B9. Furthermore, clone W6B3C1 was the only clone to stain tumor blood vessels. In conclusion, we report that using different CD133 antibodies for immunohistochemical identification of CD133+ cells on paraffin sections will most likely cause dissimilar results. Thus, direct comparison of CD133 studies using different primary CD133 antibodies should be performed with caution.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3369.

Abstract 4209: Organotypic multicellular glioma spheroids prepared from tissue fragments obtained by ultrasonic aspiration

Ultrasonic aspirators are commonly used to resect brain tumors because they allow safe, rapid and accurate removal of dissected tissue. However, the tissue fragments removed by ultrasonic aspirators are used surprisingly little in daily diagnostics and in clinical research. Due to the increasing need for vital human tumor tissue for these purposes, which today require multidisciplinary approaches, the aim of this study was to investigate whether tissue fragments obtained by ultrasonic aspiration could be cultured as organotypic multicellular spheroids. These spheroids have earlier been shown to represent an important alternative to commercially available cell lines having multiple mutations and phenotypic changes. Fragments obtained by ultrasonic aspiration (sonocut) from one anaplastic astrocytoma and seven glioblastomas and tumor biopsy tissue from four of these glioblastomas were included in the present study. Sonocut and tumor biopsy tissue were mechanically dissociated into small tissue fragments and cultured in a serum containing medium on agar-coated plates. If excess tissue was available the fragments were also cultured in a serum-free medium. After 12-18 days of culturing the tissue fragments had formed spheroids which were fixated and paraffin embedded. Hematoxylin eosin staining was performed in order to investigate the viability and morphology of the spheroids. Part of the material was stained immunohistochemically for the astrocytic marker GFAP and the blood vessel markers VWF, CD31 and CD34. In the present study all sonocut cultures contained viable spheroids, whereas one of the cultures obtained from tumor biopsy tissue did not. The spheroids were able to survive and proliferate under both serum and serum-free conditions. The spheroids from both sonocut and tumor biopsy tissue contained malignant traits including high cellularity, cellular pleomorphism, mitoses and necrosis. Some spheroids consisted solely of GFAP positive tumor cells, while others contained preserved blood vessels confirmed by VWF, CD31 and CD34 immunohistochemistry. In conclusion, we found that it was possible to obtain viable spheroids from sonocut-material under both serum and serum-free conditions.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4209.

Phenotypic and functional markers for 1alpha,25-dihydroxyvitamin D(3)-modified regulatory dendritic cells

The clinical use of dendritic cells (DCs) to induce antigen-specific immune tolerance has been hampered by the lack of a widely acknowledged method for generating human regulatory DCs but even more so by the non-existence of reliable markers. Thus, we set out to find reliable markers that can be measured with simple methods to identify regulatory DCs that are applicable for future clinical studies. Human DCs were generated from peripheral blood monocytes in the presence of 1alpha,25-dihydroxyvitamin D(3) (VD3), which gave rise to a phenotype that resembles immature DCs, with the exception of high CD14 and reduced CD1a on the cell surface. These VD3-treated DCs exert a long-lasting inefficient T cell stimulation and induce T cell hyporesponsiveness with regulatory potential. Importantly, such VD3-treated DCs were readily distinguishable from untreated DCs by low levels of interleukin-23 secretion and low expression of miR-155 upon exposure to maturation stimuli. Furthermore, VD3-treated DCs showed over-expression of miR-378. All these features can be used as robust markers for quality control of VD3-treated regulatory DCs in future clinical studies.

Changes of periodontal parameters following apical surgery: a prospective clinical study of three incision techniques

AIM

To evaluate periodontal changes following apical surgery, and to relate changes to the type of incision and to the type of restoration present at the gingival margin (GM).

METHODOLOGY

Periodontal parameters [probing depth (PD), level of GM and clinical attachment, plaque and bleeding indices] were recorded at baseline and 1 year following apical surgery. The periodontal changes were calculated and assessed with respect to the incision technique (intrasulcular incision, papilla base incision and submarginal incision), as well as to the presence and type of a restoration margin in contact with the gingiva.

RESULTS

One hundred and eighty-four teeth could be evaluated. No significant differences between the three incision techniques were found regarding changes in PDs and plaque index over time. However, significant differences between the intrasulcular and submarginal incisions were found for changes in levels of GM and clinical attachment. For example, with the intrasulcular incision, there was a mean recession of 0.42 mm at buccal sites, whereas using the submarginal incision there was a gain of 0.05 mm. No statistically significant influence could be demonstrated for the presence and type of restoration margins, or the smoking habit of the patient.

CONCLUSION

The type of incision was found to affect changes significantly in periodontal parameters within an observation period of 1 year following apical surgery, whereas the restoration margin and smoking habit did not prove to have any significant effect.

Randomized clinical trial of effect of synbiotics, neomycin and mechanical bowel preparation on intestinal barrier function in patients undergoing colectomy

BACKGROUND

The aim of this study was to investigate whether it is possible to modulate gut microflora and preserve intestinal barrier function during elective colorectal surgery by using combinations of oral antibiotics, synbiotics and mechanical bowel preparation (MBP).

METHODS

Ninety-two patients were randomly assigned to one of four groups. Group 1 had MBP only, group 2 had neomycin + MBP, group 3 had synbiotics + neomycin + MBP, and group 4 had synbiotics + neomycin but no MBP. Changes in gut microflora were assessed by culturing nasogastric aspirates and polymerase chain reaction-denaturing gradient gel electrophoresis of faecal samples. Intestinal barrier function was determined by microbiological confirmation of bacterial translocation and measurement of intestinal permeability. The inflammatory response was monitored by measurement of serum C-reactive protein and interleukin 6, and septic morbidity was recorded prospectively.

RESULTS

Four patients were excluded owing to protocol violation, leaving 24 patients in group 1, 22 in group 2, 20 in group 3 and 22 in group 4 for analysis. There was a significant decrease in Enterobacteriaceae in group 3 compared with the other groups. Group 3 had a significantly lower incidence of translocation after bowel mobilization (P < 0.001). There was no significant difference between the groups in intestinal permeability, inflammatory response or septic morbidity.

CONCLUSION

The combination of MBP, neomycin and synbiotics reduces the prevalence of faecal Enterobacteriaceae and bacterial translocation; however, this was not associated with a reduction in inflammatory response or septic morbidity in this study. Larger trials are needed before a change in practice can be recommended.

Dentine-bonded resin composite (Retroplast) for root-end filling: a prospective clinical and radiographic study with a mean follow-up period of 8 years

AIM

To evaluate treatment outcome after using a resin composite (Retroplast, RP) in combination with a dentine-bonding agent (GLUMA) as root-end filling material after 1 year as well as after more than 5 years (final examination). Also, the influence of various pre-, intra- and postoperative factors on the treatment outcome was studied.

METHODOLOGY

All patients (87) undergoing root-end resection consecutively treated by root-end filling with RP on an incisor, canine, pre-molar, or first molar (87 teeth, 118 roots) were initially enrolled in the study. RP was applied on the entire resected surface that was prepared to a slightly concave shape and after conditioning with EDTA and GLUMA. The treatment outcome involving subjective, clinical and radiographic parameters was evaluated after 1 year and at the final examination. A total of 27 patients (36 roots) were excluded from the study because of unavailability of follow-up (19) and extraction of the operated tooth for reasons other than failed surgery (8). Consequently, 60 patients (82 roots) were included in the final material. The mean follow-up period at the final examination was 8 years (range: 6.5-9 years).

RESULTS

The radiographic evaluation at the final examination revealed that 77%, 5%, 7% and 11% of the treated roots were characterized by complete, incomplete, uncertain and unsatisfactory healing, respectively. A total of 95% of the roots classified as completely healed at the 1-year control were also completely healed at the final examination. Two roots (5%) showing complete healing at the 1-year control revealed unsatisfactory healing at the final examination because of displaced or lost RP-filling. Moreover, 60% of the roots with uncertain healing at the 1-year control demonstrated complete or incomplete healing at the final examination. The classification according to subjective, clinical and radiographic parameters revealed that 78% of the teeth were characterized by a successful treatment outcome at the final examination. Evaluation of the influence of various pre-, intra- and postoperative factors on the treatment outcome revealed that the radiographic classification at the final examination was exclusively influenced by the radiographic classification at the 1-year control (P < 0.001).

CONCLUSIONS

The present long-term study indicates that RP can be used for root-end filling with a successful treatment outcome.

Haemostatic agents used in periradicular surgery: an experimental study of their efficacy and tissue reactions

AIM

To evaluate the haemostatic efficacy and the histologic tissue responses after the application of different haemostatic agents used in periradicular surgery.

METHODOLOGY

The study was conducted in the calvarium of six rabbits. Standardized bone defects (diameter 4 mm) were trephined, and different haemostatic agents were applied and compared with control defects: bone wax (left for 10 min), Stasis (ferric sulphate, left for 5 s), Expasyl (aluminium chloride, left for 2 min and left permanently in situ), and a combination of Expasyl (2 min) and Stasis (5 s). The sites were photographed before the application and after the removal of the haemostatic agents. Three independent examiners judged the initial and final bleeding (on the photographs) using a bleeding score for each site and treatment. The results were compared using Wilcoxon's signed rank test. For the histologic analysis, three animals were killed after 3 weeks and three animals after 12 weeks. Transverse, nondecalcified sections were stained with combined basic fuchsin and toluidine blue for descriptive histology.

RESULTS

The most efficient haemorrhage control was provided by Expasyl in combination with Stasis and by Expasyl alone, whereas bone wax had the weakest bleeding reduction effect. The histologic analysis after 3 weeks demonstrated an inflammatory and foreign body tissue response towards all haemostatic agents. At 12 weeks, this tissue response was less pronounced but still present in sites treated with bone wax or Expasyl. In general, the inflammatory tissue reactions were limited to the bone defects, and never extended into the surrounding tissues.

CONCLUSIONS

Expasyl alone or in combination with Stasis appeared to be the most efficient of tested agents to control the bleeding within the bony defects created in a rabbit calvarium model.

A prospective, randomized, comparative clinical study of resin composite and glass ionomer cement for retrograde root filling

OBJECTIVE

To compare the clinical and radiographic treatment outcome of retrograde root filling with either dentin-bonded resin composite (Retroplast, RP) or glass ionomer cement (Chelon-Silver, CS).

STUDY DESIGN

A prospective, randomized clinical study of 134 consecutive patients with indication of retrograde root filling of an incisor, canine, premolar, or first molar. Either RP or CS was chosen at random as retrograde filling material. Either material was applied onto the entire resection surface after prepared slightly concave. This preparation technique makes a sealing of the entire resection surface possible and prevents marginal contraction gaps during polymerization. A total of 122 patients were available for 1-year follow-up.

RESULTS

After 1 year the proportion of successful cases was significantly higher in the RP group (73%) than in the CS group (31%) (p<0.001). Doubtful healing with a need for a longer observation period was seen in 17% of the RP cases and 19% of the CS cases. The proportion of failures in the RP group (10%) was significantly lower than that in the CS group (50%) (p<0.001). Most of the unsuccessful CS cases failed due to loosening of the retrograde filling.

CONCLUSIONS

Dentin-bonded RP applied onto the entire, slightly concave resection surface is a predictable apical sealant characterized by a high success rate. In contrast, retrograde root filling with CS results in an unacceptably high failure rate due to insufficient bonding strength to the concave resection surface.

Inhibitory effects of 1alpha,25-dihydroxyvitamin D(3) on the G(1)-S phase-controlling machinery

The nuclear hormone 1alpha,25-dihydroxyvitamin D(3) induces cell cycle arrest, differentiation, or apoptosis depending on target cell type and state. Although the antiproliferative effect of 1alpha,25-dihydroxyvitamin D(3) has been known for years, the molecular basis of the cell cycle blockade by 1alpha,25-dihydroxyvitamin D(3) remains largely unknown. Here we have investigated the mechanisms underlying the G(1) arrest induced upon 1alpha,25-dihydroxyvitamin D(3) treatment of the human breast cancer cell line MCF-7. Twenty-four-hour exposure of exponentially growing MCF-7 cells to 1alpha,25-dihydroxyvitamin D(3) impeded proliferation by preventing S phase entry, an effect that correlated with appearance of the growth-suppressing, hypophosphorylated form of the retinoblastoma protein (pRb), and modulation of cyclin-dependent kinase (cdk) activities of cdk-4, -6, and -2. Time course immunochemical and biochemical analyses of the cellular and molecular effects of 1alpha,25-dihydroxyvitamin D(3) treatment for up to 6 d revealed a dynamic chain of events, preventing activation of cyclin D1/cdk4, and loss of cyclin D3, which collectively lead to repression of the E2F transcription factors and thus negatively affected cyclin A protein expression. While the observed 10-fold inhibition of cyclin D1/cdk 4-associated kinase activity appeared independent of cdk inhibitors, the activity of cdk 2 decreased about 20-fold, reflecting joint effects of the lower abundance of its cyclin partners and a significant increase of the cdk inhibitor p21(CIP1/WAF1), which blocked the remaining cyclin A(E)/cdk 2 complexes. Together with a rapid down-modulation of the c-Myc oncoprotein in response to 1alpha,25-dihydroxyvitamin D(3), these results demonstrate that 1alpha,25-dihydroxyvitamin D(3) inhibits cell proliferation by targeting several key regulators governing the G(1)/S transition.

An air pollution model for use in epidemiological studies: evaluation with measured levels of nitrogen dioxide and benzene

The aim of the study was to evaluate the predictions derived from the Danish Operational Street Pollution Model (OSPM) when the input data are obtained by simple methods that could be used in large-scale epidemiological studies. The model calculations were thus compared with passive sampler measurements of nitrogen dioxide and benzene at 103 street locations in Copenhagen, Denmark, and at 101 locations in rural areas. Data on traffic and street configuration were collected by means of a simple registration scheme in which forms were filled out by local municipal authorities. Meteorological data were derived from routine measurements at Copenhagen airport, and data on background air pollution were based on a simple empirical model. Differences in air pollution levels between rural areas and Copenhagen and differences in nitrogen dioxide concentrations at various locations in Copenhagen were well reproduced by the OSPM. The correlation coefficients (r) between the measured and the predicted half-year average concentrations of nitrogen dioxide in Copenhagen were between 0.75 and 0.80 for various degrees of precision of the input data for the model. The results indicate that the OSPM used with the presented methods for generation of input data might be useful in assessing long-term exposure to air pollutants in epidemiological studies.

[Traumatic tricuspid valve insufficiency]

We report a case of tricuspid insufficiency in connection with blunt chest trauma. The patient was involved in a car accident. The central venous catheter showed a right ventricular pressure curve, suggestive of a tricuspid valve insufficiency. A transoesophageal echocardiographic examination supported this by revealing a papillary muscle rupture. This kind of injury has been seen more frequently during the last 35 years, partly because of better diagnostic procedures and a better understanding of the pathology. The decelerating force in the right ventricular chamber produces a regurgitation thereby initiating rupture of the papillary muscle and/or the chordae tendinae. In a literature study twelve out of thirteen patients were involved in car accidents. Some of them had a dominant V-wave in the venous pulse curve, but no clinical observation is directly diagnostic. Therefore, cardiac lesions should be kept in mind whenever there is a history of blunt chest trauma. The best diagnostic approach is echocardiography.

[Acute water intoxication caused by intranasal desmopression--Minirin]

Desmopressin is used for the treatment of nocturnal enuresis. Side effects reported with intranasal desmopressin are transient headache, nausea, abdominal cramps and water intoxication with hyponatremia and grand mal seizure. We report a case of water intoxication with low serum sodium and grand mal seizure in a healthy child treated for enuresis with desmopressin. The child experienced abdominal cramps and nausea prior to the convulsions. A computerised tomography scan of the brain gave the suspicion of increased intracranial pressure ICP. The child recovered fully. We therefore recommend that parents and child are fully informed about the administration and the risk of desmopressin. If a child on desmopressin treatment experiences abdominal cramps, nausea or headache the drug should be discontinued and a physician contacted for control of serum sodium. Temporary withdrawal of desmopressin should also be considered in cases of acute illness influencing water balance.

A comparison of the immunogenicity of the native and denatured forms of a protein

The effect of heat denaturation on the physicochemical and immunological properties of a model protein, ovalbumin, and its formaldehyde/lysine-treated form was investigated. Polyacrylamide gel electrophoresis and gel filtration showed that heat denaturation converted ovalbumin to high Mr polymers, whereas formaldehyde/lysine-treated ovalbumin remained monomeric with only a small proportion forming oligomers. NMR analysis demonstrated that non-denatured structures could easily be differentiated from the denatured structures. Intraperitoneal immunization of rabbits and mice showed that both native and denatured forms of ovalbumin induced an immune response, but denatured forms of ovalbumin were found to be less immunogenic and to have a lower epitope density than native ovalbumin. Analysis of the antisera in crossed immunoelectrophoresis showed that they were specific for either native or denatured forms of ovalbumin. These findings were further investigated by ELISA and immunoaffinity chromatography, and the high specificity and low cross-reactivity was confirmed. We conclude that the immunogenic epitopes on denatured ovalbumin are different from those on ovalbumin, and that these epitopes reflect a continuum of denatured conformations.

Tissue reaction and material characteristics of four bone substitutes

The aim of the present study was to qualitatively and quantitatively compare the tissue reactions around four different bone substitutes used in orthopedic and craniofacial surgery. Cylinders of two bovine bone substitutes (Endobon and Bio-Oss) and two coral-derived bone substitutes (Pro Osteon 500 and Interpore 500 HA/CC) were implanted into 5-mm bur holes in rabbit tibiae. There was no difference in the amount of newly formed bone around the four biomaterials. Interpore 500 HA/CC resorbed completely, whereas the other three biomaterials did not undergo any detectable biodegradation. Bio-Oss was osseointegrated to a higher degree than the other biomaterials. Material characteristics obtained by diffuse reflectance infrared Fourier transform spectrometry analysis and energy-dispersive spectrometry did not explain the differences in biologic behavior.

[Traumatic hip dislocation with "spontaneous" reposition and re-luxation]

A case of traumatic hip dislocation with spontaneous reduction of the hip joint is presented. The patient was involved in a car accident, and characterized as multitraumatized. On admission to the Emergency Department there were no clinical signs of traumatic hip-dislocation, but because of the severity of the trauma an X-ray of the pelvis was performed and a fracture of the acetabulum diagnosed. The patient was taken to the operating theatre for surgery of several fractures of both upper and lower extremities. This was followed by control X-rays including both anterior-posterior and lateral views of the right hip. This demonstrated that the right hip was now dislocated. The dislocation was reduced. CT showed a larger fracture of the acetabulum, and this was treated with osteosynthesis. Patients with an unstable hip due to trauma, should as a general rule have the hip X-rayed in two planes. It is further suggested that in cases of severely traumatized patients X-ray of the pelvis should be routinely performed.

Intrauterine fertilization capsules--a clinical trial

Treatment of 26 women with tubal infertility was attempted using intrauterine capsules loaded with oocytes and spermatozoa. The stimulation protocol was as used for in vitro fertilization and embryo transfer and consisted of short-term use of Buserelin, human menopausal gonadotropin, and human chorionic gonadotropin. Oocytes were collected by ultrasonically guided transvaginal aspiration, and spermatozoa were prepared by swim-up technique. The gametes were placed in agar capsules 4 hr after oocyte collection, and the capsules were introduced to the uterine fundus using an insertion tube and piston from an intrauterine device. Six complete capsules and parts of two other capsules were expelled. None of the women became pregnant, compared with a pregnancy rate of 21% per aspiration following in vitro fertilization and embryo transfer during the same period.

Absence of monoacylglycerol pathway for triacylglycerol synthesis in goat mammary gland

Both subcellular fractions of lactating goat mammary gland and dispersed lactating goat mammary-gland cells were able to incorporate [U-3H]2-O-hexadecylglycerol into monoalkyl-monoacylglycerol. However, the incorporation of [U-3H]2-O-hexadecylglycerol into monoalkyl-monoacylglycerol by dispersed cells was not accompanied by incorporation of fatty acid synthesized de novo or added radiolabelled fatty acid. The result therefore shows that an active monoacylglycerol pathway does not exist in goat mammary gland.