A phase II trial of stereotactic radiosurgery boost following surgical resection for solitary brain metastases

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Background: At present there is no standard of care for adjuvant therapy following resection of solitary brain metastases. The objective of this study was to determine the local control, survival, patterns of relapse and the incidence of brain injury following a surgery-stereotactic radiosurgery (SRS) combined therapy approach while avoiding upfront whole brain radiation therapy (WBRT). Methods: The eligibility criteria included radiologically proven solitary brain metastases, KPS≥70 and a neurologic function score of 0–2. Following the surgical resection, SRS was delivered to the surgical cavity 4–8 weeks later to a dose of 15–22 Gy in a single fraction using the BrainLAB linear accelerator system. Patients were followed with neurological examination and serial MRI images done every 3 months following the procedure. Results: 25 out of 50 patients needed for the study have been accrued since it opened in August 2004. Four patients have failed locally, with a median time to local failure of 9.5 months. The one year local control at the site of original disease was 35%. Two of the four patients who had local recurrence at the time of relapse also had evidence of leptomeningeal disease. Six additional patients developed new brain metastases, resulting in a 1 year brain relapse free survival of 38% following the combined approach. The median overall survival was 12 months. One patient (4%) developed radiation necrosis that required surgical intervention 6 months following the procedure. Six patients (24%) needed WBRT, two patients (8%) needed further SRS and one patient (4%) needed surgery as salvage following development of new brain lesions with this approach. Conclusions: The preliminary results of surgery-SRS approach appear inferior to surgery-WBRT data for solitary brain metastases in terms of local control and development of new brain metastases. However, relapses can be subsequently managed with WBRT without adversely affecting the overall survival and the morbidity.

No significant financial relationships to disclose.

Adenosine triphosphate-based chemotherapy response assay (ATP-CRA)-guided cisplatin-based two-drug chemotherapy in unresectable non-small cell lung cancer

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Background: Heterogeneity of tumor response to chemotherapy is a big obstacle in cancer treatment. The aim of this study was to investigate correlations of ATP-CRA and clinical outcome after ATP-TCA-guided cisplatin-based chemotherapy in unresectable NSCLC. Methods: From Sep. 2003 to Oct. 2005, ATP-CRA was done in tumor tissue specimen obtained from patients with suspected lung malignancy. ATP-CRA tested sensitivities of anticancer drugs used widely in advanced NSCLC such as cisplatin, carboplatin, paclitaxel, docetaxel, gemcitabin, and vinorelbine. The cell death rate was determined by measuring the intracellular ATP levels of untreated controls and drug exposed cells. A sensitive drug was defined as a drug producing 30% or more reduction of ATP compared to untreated controls. Test-guided cisplatin-based two-drug chemotherapy was given to pathologically confirmed NSCLC. Results: 31 patients were enrolled and their median follow-up duration was 13.3 months. Response rate was 48.3%. Median progression-free and overall survivals were 4.4 months and 11.2 months, respectively. Patients were dichotomized into platinum-sensitive (S) and resistant (R) groups. S-group (19) contained cases sensitive to platinum alone (6) or both drugs (13). R-group (12) contained cases sensitive to none (9) or the other drug alone (3). Clinical response rate was higher in S-group (75.0% vs 35.3% in R-group; p = 0.0635). Considering correlations of test results and clinical response, positive/negative predictive values were 64.7% / 75.0% with the predictive accuracy of 69.0%. Although without significant differences in histology, stage, and performance status, S-group had longer progression-free (5.0 vs 2.4 months in R-group; p = 0.056) and overall (21.8 vs 9.7 months in R-group; p = 0.018) survivals. Conclusions: In vitro chemosensitivity test, ATP-CRA results and clinical outcome were correlated well after test-guided cisplatin-based two-drug chemotherapy in unresectable NSCLC, presenting favorable response and survival in platinum-sensitive versus resistant group.

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Birth and morphological evolution of step bunches under electromigration

We analyze the dynamics of electromigration-induced step bunching in the absence of desorption. We show that, even when the instability occurs at long wavelength, hinting to a smooth morphology, the surface suddenly splits into bunches escorted with wide terraces, in agreement with several observations. As the size of the bunches increases, a nonstandard regime is exhibited, namely, the bunches do not match tangentially to the facet, as would the classical Pokrosvky-Talapov shape dictate. This Letter presents a complete scenario of evolution of bunches from their birth up to their ultimate stage.

hTERT phosphorylation by PKC is essential for telomerase holoprotein integrity and enzyme activity in head neck cancer cells

Telomerase activity is suppressed in normal somatic tissues but is activated in most cancer cells. We have previously found that all six telomerase subunit proteins, including hTERT and hsp90 are needed for full enzyme activity. Telomerase activity has been reported to be upregulated by protein kinase C (PKC), but the mechanism is not clear. In this study, we examined how PKC regulates telomerase activity in head and neck cancer cells. PKC inhibitor, bisindolylmaleimide I (BIS), inhibited telomerase activity but had no effect on the expressions of telomerase core subunits. RNA interference (RNAi) and in vitro phosphorylation studies revealed that PKC isoforms α, β, δ, ε, ζ specifically involved in telomerase regulation, and the phosphorylation target was on hTERT. Treatment with the hsp-90 inhibitor novobiocin dissociated hsp90 and hTERT as revealed by immunoprecipitation and immunoblot analysis and reduced telomerase activity. Treatment with the PKC activator SC-10 restored the association of hsp90 and hTERT and reactivate telomerase, suggesting that hTERT phosphorylation by PKC is essential for telomerase holoenzyme integrity and function. Analysis on clinical normal and tumour tissues reveal that the expressions of PKC α, β, δ, ε, ζ were higher in the tumour tissues, correlated with telomerase activity. Disruption of PKC phosphorylation by BIS significantly increased chemosensitivity to cisplatin. In conclusion, PKC isoenzymes α, β, δ, ε, ζ regulate telomerase activity in head and neck cancer cells by phosphorylating hTERT. This phosphorylation is essential for telomerase holoenzyme assembly, leading to telomerase activation and oncogenesis. Manipulation of telomerase activity by PKC inhibitors is worth exploring as an adjuvant therapeutic approach.

Intraocular pressure alterations following intravitreal triamcinolone acetonide

AIMS

To determine the prevalence of intraocular pressure (IOP) alterations following intravitreal injection of triamcinolone acetonide (IVTA) and to assess possible risk factors of IOP elevation in eyes receiving single and/or repeat injections.

METHODS

Retrospective, consecutive case series. 570 consecutive eyes of 536 patients who received a single IVTA injection (4 mg/0.1 ml) and a second set of 43 eyes of 40 patients who received a second injection. Retrospective review of all IVTA cases performed by three vitreoretinal surgeons over a 42 month period beginning in 2000. The main outcome measure was change in IOP defined as absolute value of IOP elevation (5 mm Hg or higher, 10 mm Hg or higher), and percentage of baseline (30% or higher increase from baseline IOP).

RESULTS

Of the 528 eyes receiving single injections, 281 (53.2%) had an IOP elevation; 267 eyes (50.6%) experienced an elevation of IOP of at least 30%, and 245 (45.8%) and 75 (14.2%) eyes had an increase of 5 mm Hg or 10 mm Hg or more, respectively. Baseline IOP greater than 16 mm Hg is a risk factor for post-injection IOP elevation. Of the 43 eyes which received a second injection, 28 (65.1%) experienced an increase in IOP of at least 30% of baseline. Filtering surgery was required in five (0.094%) of the single and one (2.3%) of repeat injection eyes.

CONCLUSIONS

Elevated IOP after IVTA is common and patients should be monitored beyond 6 months post-injection. Patients with a baseline IOP more than 16 mm Hg or receiving a second injection should be carefully monitored for an elevated IOP.

Patterning to enhance activity of cultured neuronal networks

Embryonic rat hippocampal neurons were cultured in order to gain insights into how small networks of neurons interact. The principal observations are the electrical activities recorded with the electrode arrays, primarily action potentials both spontaneous and evoked. Several lithographic techniques were developed for controlling with micrometer precision the patterns of surface molecules in order to control neuronal attachment and growth. Cytophilic polylysine against protein repellent and hence cytophobic polyethylene glycol were used. By combining the cellular lithography with the microelectrode arrays it was possible to guide neurons preferentially to electrodes and to begin to investigate the question as to whether the geometric pattern of a neuronal network influences the patterns of its neuroelectric activity. It is clear that the techniques are adequate to ensure contact of neurons to electrodes but not to ensure the recording of signals, even when neurons lie directly on top of electrodes. The maturation of neuroelectric activity depends on the growth of glia within the culture, such that spontaneous activity appears to become robust when the number of glia is roughly the same as the number of neurons.

Decontamination assessment of Bacillus anthracis, Bacillus subtilis, and Geobacillus stearothermophilus spores on indoor surfaces using a hydrogen peroxide gas generator

AIMS

To evaluate the decontamination of Bacillus anthracis, Bacillus subtilis, and Geobacillus stearothermophilus spores on indoor surface materials using hydrogen peroxide gas.

METHODS AND RESULTS

Bacillus anthracis, B. subtilis, and G. stearothermophilus spores were dried on seven types of indoor surfaces and exposed to > or =1000 ppm hydrogen peroxide gas for 20 min. Hydrogen peroxide exposure significantly decreased viable B. anthracis, B. subtilis, and G. stearothermophilus spores on all test materials except G. stearothermophilus on industrial carpet. Significant differences were observed when comparing the reduction in viable spores of B. anthracis with both surrogates. The effectiveness of gaseous hydrogen peroxide on the growth of biological indicators and spore strips was evaluated in parallel as a qualitative assessment of decontamination. At 1 and 7 days postexposure, decontaminated biological indicators and spore strips exhibited no growth, while the nondecontaminated samples displayed growth.

CONCLUSIONS

Significant differences in decontamination efficacy of hydrogen peroxide gas on porous and nonporous surfaces were observed when comparing the mean log reduction in B. anthracis spores with B. subtilis and G. stearothermophilus spores.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results provide comparative information for the decontamination of B. anthracis spores with surrogates on indoor surfaces using hydrogen peroxide gas.

NF-kappaB activation in human dental pulp stem cells by TNF and LPS

Post-natal human dental pulp stem cells (DPSCs) represent a unique precursor population in the dental pulp, which has multipotential and can regenerate a dentin/pulp-like structure. Because the dental pulp is frequently infected by oral bacteria due to dental decay, in this study, we examined whether lipopolysaccharide (LPS) and tumor necrosis factor (TNF) activated the immunologic transcription factor nuclear factor kappa B (NF-kappaB) in DPSCs. We found that both TNF and LPS activated the I-kappa B kinase complex (IKK) in DPSCs to induce the phosphorylation and degradation of IkappaBalpha, resulting in the nuclear translocation of NF-kappaB. Consistently, both TNF and LPS rapidly induced the expression of the NF-kappaB-dependent gene interleukin-8 (IL-8). However, unlike in monocytes, we found that LPS could not induce the phosphorylation of the NF-kappaB active subunit p65 in DPSCs. In summary, our studies suggest that DPSCs may be involved in immune responses during pulpal infection through activating NF-kappaB.

Estimation of haemopoietic progenitor cells in peripheral blood by the Advia 120 and BD vantage flow cytometer: a direct comparison for the prediction of adequate collections

Peripheral blood stem cells are increasingly used to ensure rapid haematological engraftment after myeloablative chemotherapy. After mobilization, progenitor cells in the blood can be enumerated to predict an adequate collection by leukapheresis. The Advia 120 automated counter has an immature cell channel measuring a parameter known as large undifferentiated cells (LUC's), which were quantified to assess their value in refining the timing of apheresis. Data were available from 102 apheresis sessions. Positive correlation was found for peripheral blood CD34+ cells and apheresis counts (r = 0.82, P < 0.0005) but not for total WCC (r = -0.15, P = 0.13) or LUC count (r = 0.12, P = 0.23). Our results indicate that the LUC population in peripheral blood has no relevance to the subsequent CD34 content of the apheresis product and CD34 cell enumeration by flow cytometry is advocated.

Development of swimming in the medicinal leech, the gradual acquisition of a behavior

Observing the development of behavior provides an assay for the developmental state of an embryo's nervous system. We have previously described the development of behaviors that were largely confined to one or a few segments. We now extend the work to a kinematic analysis of the development of swimming, a behavior that requires coordination of the entire body. When leech embryos first begin to swim they make little forward progress, but within several days they swim as effectively as adults. This increase in efficacy depends on changes in body shape and on improved intersegmental coordination of the swim central pattern generator. These kinematic details suggest how the swim central pattern generating circuit is assembled during embryogenesis.