Involved-field radiotherapy for patients with limited small cell lung cancer: Patterns of local-regional failure and feasibility

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Background: To investigate the feasibility of the involved-field radiotherapy in patients with limited-stage small cell lung cancer (LSCLC) according to the patterns of local failure, focused on the first local-regional failure. Methods: Two clinical phase II studies for patients with LSCLC treated at our institute between 1997 and 2007 were reviewed. All patients received combined chemotherapy (CHT) with cisplatin and etoposide, and thoracic RT (TRT) was generally delivered sequentially following one to three cycles of CHT and consisted of either 56 Gy in 40 fractions for 4 weeks or 55 Gy in 22 fractions for 4–5 weeks. TRT fields encompassed primary tumor volume (post-CHT) and the involved nodal areas (pre- and post-CHT) without elective node irradiation. The local-regional failure was defined as failure within thoracic cavity and supraclavicular fossa except for pleural effusion, which was then divided into two subtypes: in-field and out-field failure according to the first occurred site in the planning target volume or not. Results: There were 89 patients completed the planed regimen and eligible for evaluating patterns of failure, 54 patients (57%) in 56 Gy cohort and 35 patients(43%) in 55 Gy cohort. The media cycles of CHT were 6 (4–8). The overall survival and local progression-free survival rates for 89 patients at 2 years were 56% and 71%, respectively, with a median survival of 25.6 months. 56 patients (63%) developed distant metastases and 21 patients (24%) developed local-regional failures: 12 in-field and 9 out-field. 8 out of 9 out-field failures occurred in the ipsilateral supraclavicular fossa, and the media duration to the end of TRT was 6 mouths (5–14). Comparing the 56 Gy and 55 Gy cohorts, the rates of any thoracic, in-field and out-field failures were no difference significantly. Conclusions: Thoracic radiotherapy using involved-field technique in patients with LSCLC resulted in a high failure rate of the supraclavicular fossa. Whether improving accuracy for the initial evaluation of clinical stage could reduce out-field failure in supraclavicular fossa need to be investigated.

No significant financial relationships to disclose.

A novel model including CXCR4 and CDK6 as potential predictive marker for docetaxel (doc) sensitivity in gastric cancer (GC)

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Background: A growing body of evidence has shed light on biomarkers for chemotherapeutic agent sensitivity in gastric cancer (GC) treatment. It has been demonstrated β-tubulin Ш (TUBB3) and microtubule associated protein tau (MAPT) might be considered as potential markers for taxanes treatment. However, an integrated predictive model for docetaxel (doc) sensitivity is still needed to customized chemotherapy in gastric cancer. Methods: Doc resistant gastric cancer cell line was established by exposure to gradually increasing doc concentration on an intermittent dosage schedule. Microarray was performed to explore different gene expression levels between parental cells and resistant cells. 11 gastrointestinal cancer cell lines were used to validate gene levels by real-time quantitative PCR as well as doc cytotoxicity. Histoculture drug response assay (HDRA) was adopted to examine doc sensitivity in 25 surgically dissected GC specimens. Discrimination analyses were used to determine which linear combinations of these genes best distinguished responder patients from nonresponder patients by adding one more genes each time. Results: After functional analysis of microarray, a panel of 11 genes were further validated, which resulting 4 genes, CXCR4 (P=0.047), CDK6 (P=0.014), USP15 (P<0.001) and CDH1 (P=0.001) that correlated to the doc sensitivity. The mRNA levels of CXCR4 and CDK6 were significantly higher in resistant GC specimens (P=0.0298, 0.022 respectively). A final response index including 5 genes (CXCR4, CDK6, USP15, TUBB3 and MAPT) showed potential predictive value for doc associated chemotherapy with an accuracy of 84% (P=0.001). Conclusions: A predictive model with five genes for doc therapy was generated and showed novel predictive role in doc sensitivity in GC.

No significant financial relationships to disclose.

A combination of grape seed-derived procyanidins and gypenosides alleviates insulin resistance in mice and HepG2 cells

This study investigated the effects of grape seed-derived procyanidins (GSP), gypenosides (GPE), and combination procyanidins/gypenosides on insulin resistance in mice and HepG2 cells. ICR mice were randomly divided into 2 control and 4 treatment groups. The control mice were to receive either normal diet (ND) or high-fat diet (HFD), and the treatment groups were fed high-fat diet with either 80 mg/kg of GSP (GSP80), GPE (GPE80), GSP + GPE (1: 1, GSP40 + GPE40), or 500 mg/kg of metformin for a 6-wk period. All the groups of mice except the normal control were on high-fat diet along with fructose (15%) administered in drinking water throughout the period of treatment. An insulin-resistant HepG2 cell model was developed after 24 h of 5 x 10(-7) mol/L insulin incubation. The treatment of GPE80 could significantly reduce the index of insulin resistance (HOMA-IR) and increase hepatic glycogen concentration, compared with HFD group (P < 0.05). When GSP and GPE were administered simultaneously, synergic effects were observed in decreasing the HOMA-IR index and serum total cholesterol (TC) level and enhancing glucose tolerance. All treatment groups showed considerable raise of hepatic glucokinase activity (P < 0.05 compared with HFD group). GSP application increased the consumption of extracellular glucose in HepG2 cells. Our data suggest that the combination of GSP and GPE may have functional efficacy in consumers with insulin resistance.

Increased phonon scattering by nanograins and point defects in nanostructured silicon with a low concentration of germanium

The mechanism for phonon scattering by nanostructures and by point defects in nanostructured silicon (Si) and the silicon germanium (Ge) alloy and their thermoelectric properties are investigated. We found that the thermal conductivity is reduced by a factor of 10 in nanostructured Si in comparison with bulk crystalline Si. However, nanosize interfaces are not as effective as point defects in scattering phonons with wavelengths shorter than 1 nm. We further found that a 5 at. % Ge replacing Si is very efficient in scattering phonons shorter than 1 nm, resulting in a further thermal conductivity reduction by a factor of 2, thereby leading to a thermoelectric figure of merit 0.95 for Si95Ge5, similar to that of large grained Si80Ge20 alloys.

Physiological and biochemical responses of in vitro Fusarium oxysporum f.sp. niveum to benzoic acid

The allelopathic potential of an artificially applied allelochemical, benzoic acid, on in vitro Fusarium oxysporum f.sp. niveum (a soil-borne pathogen causing watermelon wilt) was evaluated. Benzoic acid strongly inhibited its growth, sporulation and conidia germination, whereas it stimulated virulence factors of this pathogen. The biomass was reduced by 83-96 % and the conidia germinating rate and conidia production rate were decreased by 100 % at a concentration of >200 mg/L. However, phytopathogenic enzyme activities and mycotoxin production were stimulated with an increase of 10.2-1250 % for enzyme activities and 610-2630 % for mycotoxin yield.

The management of mucosal fenestration: a report of two cases

AIM

To report on the management of two patients with mucosal fenestration of root apices.

SUMMARY

Two cases of mucosal fenestration of root apices were treated by a combination of nonsurgical root canal treatment and surgery. Root-end resection was performed to bring the root apices within the alveolus before root-end filling and packing of the bony defects with demineralized freeze-dried bone allograft. The areas were then covered with connective tissue grafts taken from the hard palate before repositioning the mucogingival flap. At 1 year follow-up, the mucosal fenestrations were completely healed by soft tissue graft coverage, and radiographs revealed bony healing.

KEY LEARNING POINTS

* Connective tissue grafts can be used to manage mucosal fenestration. * Periradicular surgery and connective tissue grafts can be used in combination.

Possible involvement of brain tumour stem cells in the emergence of a fast-growing malignant meningioma after surgical resection and radiotherapy of high-grade astrocytoma: case report and preliminary laboratory investigation

The case of a 62-year old man diagnosed with radiation-induced meningioma (RIM) after treatment for astrocytoma with an unusually short latency period of 7 months is reported. The patient first presented with a 2-month history of memory decline. Magnetic resonance imaging (MRI) showed a tumour in the left parieto-temporal lobe. Gross total resection was performed and the tumour was confirmed to be an astrocytoma. The patient received cranial radiotherapy 2 weeks later, however 7 months after radiation treatment the patient presented with headache and vomiting. MRI showed massive meningeal enhancement in the left frontal lobe, which progressively enlarged. The patient's clinical condition deteriorated and a second craniotomy was performed with complete removal of the secondary tumour, which was shown to be a malignant meningioma. Immunohistochemical staining identified CD133-positive cells in both tumours. A rare fraction of brain tumour stem cells (BTSC) was isolated from the primary astrocytoma using a serum-free culture system, suggesting that BTSC may have been involved in the rapid emergence of RIM after resection and radiation of the primary astrocytoma.

The extracellular signal-regulated kinase pathway contributes to the control of behavioral excitement

The extracellular signal-regulated kinase (ERK) pathway mediates neuronal plasticity in the CNS. The mood stabilizers lithium and valproate activate the ERK pathway in prefrontal cortex and hippocampus and potentiate ERK pathway-mediated neurite growth, neuronal survival and hippocampal neurogenesis. Here, we examined the role of the ERK pathway in behavioral plasticity related to facets of bipolar disorder. Mice with ERK1 ablation acquired reduced phosphorylation of RSK1, an ERK substrate, in prefrontal cortex and striatum, but not in hippocampus or cerebellum, indicating the ablation-induced brain region-specific ERK signaling deficits. ERK1 ablation produced a behavioral excitement profile similar to that induced by psychostimulants. The profile is characterized by hyperactivity, enhanced goal-directed activity and increased pleasure-related activity with potential harmful consequence. ERK1-ablated mice were hyperactive in multiple tests and resistant to behavioral despair in the forced swim test. These mice displayed more home-cage voluntary wheel running activities, rearings in a large arena and open-arm visits in an elevated plus maze. Treatments with valproate and olanzapine, but not lithium reduced baseline activities in ERK1-ablated mice. All three treatments attenuated amphetamine-induced hyperactivity in ablated mice. These data indicate a profound involvement of ERK1 signaling in behavioral excitement and in the behavioral action of antimanic agents. The extent to which ERK pathway perturbation contributes to the susceptibility, mood switch mechanism(s) and symptom pathophysiology of bipolar disorder requires further investigation. Whether there is a shared mechanism through which mood stabilizers produce their clinical actions on mood, thought and behavioral symptoms of mania also requires further investigation.

Composite microspheres induce the sustained release and the control of the initial release of water soluble drugs

Although epidural analgesia may provide adequate pain relief and minimize systemic side effects, long-term, even permanent placement of epidural catheter for chronic or cancer-related pain management carries a potential risk of both superficial and deep infection. The development of antibiotics microspheres that could be dwelled in epidural drug-delivery devices is likely to achieve a significant advance allowing antibiotics given by the intradiscal route to control catheter-related infections. In the present study, the composite microspheres composed of double-walled microcapsules and PLGA were constructed for encapsulating water-soluble antibiotics, cefazolin. The results show that these microspheres could efficiently control the initial release of drug, which was only 3.0% at 2 h. Cefazolin encapsulated in the composite microspheres released gradually nearly in a constant rate in the first 16 days, and still maintained a relative fast rate in the next 14 days, indicating that composite microspheres could improve the incomplete release of entrapped drugs.

The role of cooperativity with Src in oncogenic transformation mediated by non-small cell lung cancer-associated EGF receptor mutants

Non-small cell lung cancer (NSCLC)-associated epidermal growth factor receptor (EGFR) mutants are constitutively active and induce ligand-independent transformation in non-malignant cell lines. We investigated the possibility that the ability of mutant EGFRs to transform cells reflects a constitutive cooperativity with Src using a system in which the overexpression of mutant, but not wild-type, EGFR induced anchorage-independent cell growth. Src was constitutively activated and showed enhanced interaction with mutant EGFRs, suggesting that constitutive EGFR-Src cooperativity may contribute to mutant EGFR-mediated oncogenesis. Indeed, the mutant EGFR-mediated cell transformation was inhibited by Src- as well as EGFR-directed inhibitors. Importantly, a tyrosine to phenylalanine mutation of the major Src phosphorylation site on EGFR, Y845, reduced the constitutive phosphorylation of NSCLC-EGFR mutants, as well as that of STAT3, Akt, Erk and Src, and reduced the mutant EGFR-Src association as well as proliferation, migration and anchorage-independent growth. Reduced anchorage-independent growth and migration were also observed when dominant-negative-Src was expressed in mutant EGFR-expressing cells. Overall, our findings show that mutant EGFR-Src interaction and cooperativity play critical roles in constitutive engagement of the downstream signaling pathways that allow NSCLC-associated EGFR mutants to mediate oncogenesis, and support the rationale to target Src-dependent signaling pathways in mutant EGFR-mediated malignancies.

The role of cooperativity with Src in oncogenic transformation mediated by non-small cell lung cancer-associated EGF receptor mutants

Non-small cell lung cancer (NSCLC)-associated epidermal growth factor receptor (EGFR) mutants are constitutively active and induce ligand-independent transformation in nonmalignant cell lines. We investigated the possibility that the ability of mutant EGFRs to transform cells reflects a constitutive cooperativity with Src using a system in which the overexpression of mutant but not wild-type EGFR induced anchorage-independent cell growth. Src was constitutively activated and showed enhanced interaction with mutant EGFRs, suggesting that constitutive EGFR-Src cooperativity may contribute to mutant EGFR-mediated oncogenesis. Indeed, the mutant EGFR-mediated cell transformation was inhibited by Src- as well as EGFR-directed inhibitors. Importantly, a tyrosine to phenylalanine mutation of the major Src phosphorylation site on EGFR, Y845, reduced the constitutive phosphorylation of NSCLC EGFR mutants as well as of STAT3, Akt, Erk and Src, and reduced the mutant EGFR-Src association as well as proliferation, migration, and anchorage-independent growth. Reduced anchorage-independent growth and migration were also observed when DN-Src was expressed in mutant EGFR-expressing cells. Overall, our findings demonstrate that mutant EGFR-Src interaction and cooperativity play critical roles in constitutive engagement of the downstream signaling pathways that allow NSCLC-associated EGFR mutants to mediate oncogenesis, and support the rationale to target Src-dependent signaling pathways in mutant EGFR-mediated malignancies.

Nonlinear spectral imaging of human hypertrophic scar based on two-photon excited fluorescence and second-harmonic generation

BACKGROUND

A noninvasive method using microscopy and spectroscopy for analysing the morphology of collagen and elastin and their biochemical variations in skin tissue will enable better understanding of the pathophysiology of hypertrophic scars and facilitate improved clinical management and treatment of this disease.

OBJECTIVE

To obtain simultaneously microscopic images and spectra of collagen and elastin fibres in ex vivo skin tissues (normal skin and hypertrophic scar) using a nonlinear spectral imaging method, and to compare the morphological structure and spectral characteristics of collagen and elastin fibres in hypertrophic scar tissues with those of normal skin, to determine whether this approach has potential for in vivo assessment of the pathophysiology of human hypertrophic scars and for monitoring treatment responses as well as for tracking the process of development of hypertrophic scars in clinic.

METHODS

Ex vivo human skin specimens obtained from six patients aged from 10 to 50 years old who were undergoing skin plastic surgery were examined. Five patients had hypertrophic scar lesions and one patient had no scar lesion before we obtained his skin specimen. A total of 30 tissue section samples of 30 mum thickness were analysed by the use of a nonlinear spectral imaging system consisting of a femtosecond excitation light source, a high-throughput scanning inverted microscope, and a spectral imaging detection system. The high-contrast and high-resolution second harmonic generation (SHG) images of collagen and two-photon excited fluorescence (TPEF) images of elastin fibres in hypertrophic scar tissues and normal skin were acquired using the extracting channel tool of the system. The emission spectra were analysed using the image-guided spectral analysis method. The depth-dependent decay constant of the SHG signal and the image texture characteristics of hypertrophic scar tissue and normal skin were used to quantitatively assess the amount, distribution and orientation of their collagen and elastin components.

RESULTS

Our experiments and data analyses demonstrated apparent differences between hypertrophic scar tissue and normal skin in terms of their morphological structure and the spectral characteristics of collagen and elastin fibres. These differences can potentially be used to distinguish hypertrophic scar tissues from normal skin and to evaluate treatment responses.

CONCLUSIONS

All the measurements were performed in backscattering geometry and demonstrated that nonlinear spectral imaging has the ability to differentiate hypertrophic scar tissue from normal skin based on noninvasive SHG imaging, and TPEF imaging revealed the microstructure and spectral features of collagen and elastin fibres. With the advances in spectral imaging apparatus miniaturization, we have good reason to believe that this approach can become a valuable tool for the in vivo pathophysiology study of human skin hypertrophic scars and for assessing the treatment responses of this disfiguring disease in clinic. It can also be used to track the development of hypertrophic scars and to study wound healing processes in a noninvasive fashion without biopsy, fixation, sectioning and the use of exogenous dyes or stains.

Long-term potentiation of the responses to parallel fiber stimulation in mouse cerebellar cortex in vivo

Long-term potentiation (LTP) of parallel fiber-Purkinje cell (PF-PC) synapses in the cerebellum has been suggested to underlie aspects of motor learning. Previous in vitro studies have primarily used low frequency PF stimulation conditioning paradigms to generate either presynaptic PF-PC LTP (4-8 Hz) or postsynaptic PF-PC LTP (1 Hz). Little is known about the conditions that evoke PF-PC LTP in vivo. High frequency stimulation in vivo increases PC responsiveness to peripheral stimuli; however, neither the site of action nor the signaling pathways involved have been examined. Using flavoprotein autofluorescence optical imaging in the FVB mouse in vivo, this report describes that a conditioning stimulation consisting of a high frequency burst of PF stimulation (100 Hz, 15 pulse trains every 3 s for 5 min) evokes a long-term increase in the response to PF stimulation. Following the conditioning stimulation, the response to PF stimulation increases over 20 min to approximately 130% above baseline and this potentiation persists for at least 2 h. Field potential recordings of the responses to PF stimulation show that the postsynaptic component is potentiated but the presynaptic, parallel fiber volley is not. Paired-pulse facilitation does not change after the conditioning stimulation, suggesting the potentiation occurs postsynaptically. Blocking non-NMDA (N-methyl-d-aspartic acid) ionotropic glutamate receptors with DNQX (6,7-dinitroquinoxaline-2,3-dione disodium salt, 50 muM, bath application) during the conditioning stimulation has no effect on the long-term increase in fluorescence. However, blocking subtype I metabotropic glutamate receptors (mGLuR(1)) with LY367385 (200 muM) during the conditioning stimulation abolishes the long-term increase in fluorescence. Blocking GABAergic neurotransmission is not required to evoke this long-term potentiation. Blocking GABA(A) receptors reduces but does not eliminate the long-term potentiation. Therefore, this study demonstrates that high frequency PF stimulation generates long-term potentiation of PF-PC synapses in vivo. This novel form of LTP is generated primarily postsynaptically and is mediated by mGluR(1) receptors.

Burden of syphilis infections in Shenzhen, China: a preliminary estimation

Information on the prevalence and incidence of sexually transmitted infections is important for developing prevention and control strategies and allocating human and financial resources. However, there are no available estimates of such information for many areas in China. In this study, we used the existing data to make a preliminary estimation of syphilis infections in Shenzhen city, in south-eastern China. Data on prevalence rates of syphilis infections among different populations were obtained from the local HIV/sexually transmitted disease second-generation surveillance programme, and the sizes of different populations were estimated based on the most recently available figures. It was estimated that 83,760 (range 77,490–90,020) people are currently infected with syphilis, giving a prevalence of 0.71–0.82% (0.76% on average) in Shenzhen. Around 18% of these syphilis infections occur among men who have sex with men and another 15.8% and 8.7% occur among female sex workers and their clients, respectively. These estimates suggest that a combination of unprotected paid sex and sex between men may be sustaining the epidemic of syphilis in the study area. The preliminary estimates will assist the government in planning and improving its comprehensive intervention programmes for the future control and prevention of syphilis.