Prognostic significance of serum vascular endothelial growth factor per platelet count in gastric cancer patients

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Background: Recent studies have shown that VEGF expression not in tissues but in serum sample is correlated with tumor vascularity, and high serum VEGF levels could predict poor prognosis in cancer patients. However there are limited data regarding the clinical and prognostic significance of serum VEGF levels per platelet count in advanced gastric cancer. In this study, we conducted a study to evaluate the prognostic implication of serum VEGF per platelet count in patients with advanced gastric cancer. Methods: 111 patients with histologically confirmed gastric cancer, 10 patients with early gastric cancer were included and control serum samples were acquired from 10 healthy volunteers. The levels of VEGF were measured using human VEGF quantitative enzyme-linked immunosorbent assay (ELISA). Survival curves were calculated using the Kaplan-Meier method and survival comparisons were made by the log rank test in metastatic gastric cancer. The Cox proportional hazards regression model was utilized for multivariate analyses after univariate analysis defined relevant prognostic variables. Results: A trend toward a significant positive correlation between serum VEGF and platelet counts was observed in patients of AGC (r = 0.477, P = 0.000) and there was a significant correlation between serum VEGF levels and differentiation of tumor (p = 0.014), stage (p = 0.036). The overall survival (log rank, p =0.0432) and the progression free survival (median 4.5 vs. 8.9 months; log rank, p =0.0116) were significantly shorter in patients with high VEGF per platelet count (≥1.626 pg/106). In the multivarivate analysis, performance status (P=0.025), the presence of peritoneal carcinomatosis (P=0.006), serum VEGF per platelet (P=0.005) were found to be significantly associated with poor progression free survival. Conclusions: This study demonstrated that serum VEGF per platelet count are correlated with poor overall survival and progression free survival in patients with advanced gastric cancer. Therefore measurement of serum VEGF per platelet might be useful markers for predicting disease progression and prognosis of advanced gastric cancer.

No significant financial relationships to disclose.

Clinical outcome of sequential chemotherapy in metastatic and/or recurrent gastric cancer

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Background: Little is known about data on subsequent chemotherapy (CTx) following 1st-line CTx in stage IV gastric cancer. The purpose of this study was to analyze the natural history of stage IV gastric cancer with sequential CTx Methods: A total of 532 patients (pts) with unresectable gastric adenocarcinoma were studied. They were managed with a strategy of maximal administration of CTx only if pts’ general conditions were allowed. Response evaluation was performed by RECIST every 2 cycles. Response of unmeasurable lesions was dichotomized only into stable disease or progressive disease. Results: When pts were divided into CTx group (460 of 532, 87%) and best supportive care group (BSC; 72 of 532, 13%) resulting from poor performance/pt's refusal/comorbidity (31/23/18), the former had younger age (p = 0.046), better performance (p < 0.001), and less advanced metastatic sites (p = 0.001) than the latter. Median overall survivals from diagnosis of unresectable cancer were 12.0/13.3/2.5 months for overall/CTx/BSC, respectively. 87%/47%/23% of the whole pts received 1st/2nd/3rd-line CTx, respectively. Median number of regimens delivered was 2. Maximally 5th-line CTx was given to 15 pts (3%). Response and disease control rates were 21.7%/12.5%/11.8% and 79.4%/56.3%/49.4% for 1st/2nd/3rd lines, respectively. Median progression-free and overall survivals from CTx were 5.5/3.4/2.5 months and 12.1/7.9/5.5 months for 1st/2nd/3rd lines, respectively. The most common cause of discontinuation of CTx was disease progression (68%/74%/70%) followed by pt's refusal (22%/13%/12%) for 1st/2nd/3rd lines, respectively. Prognosticators were performance status, histology, metastatic site, and CTx before 1st or 2nd line. Conclusions: When pts with unresectable gastric cancer were managed with a strategy of maximal administration of CTx, a considerable number of pts could receive 2nd or 3rd line CTx, showing modest activity. Performance status and metastatic site were consistent prognosticators even if lines changed. Our data on the natural history of stage IV gastric cancer with sequential CTx may suggest that clinical trials can be performed in a 2nd or 3rd line setting as well.

No significant financial relationships to disclose.

Comparison of long-term outcome between doublet versus triplet neoadjuvant chemotherapy in nonmetastatic osteosarcoma of extremity

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Background: Multimodal approach had improved outcomes of non-metastatic osteosarcoma. This study was to compare outcomes between doublet (AP; doxorubicin and cisplatin) and triplet (IAP; AP and ifosfamide) neoadjuvant chemotherapy for non-meteastatic osteosarcoma of extremity in a single institute. Methods: A total of 124 osteosarcoma patients were enrolled. In AP group, doublet regimen was given to 77 patients from 1991 to 1999, who received intra-arterial cisplatin(120mg/m2) at day 1 and intravenous doxorubicin (25mg/m2) for 3 days. In IAP group, triplet regimen was given to 49 patients from 2000 to 2007, who received ifosfamide additionally at a dose of 2.5g/m2/day for 3 days. After completion of 3 cycles of chemotherapy, patients underwent limb-salvage surgery. We assessed tumor response according to pathologic tumor necrosis, and treated further adjuvant chemotherapy. In AP group, responder received 3 more cycles of AP, while non-responders received 6 cycles of ifosfamide-contaning regimens. In IAP group, all patients had 3 more cycles of IAP chemotherapy. Results: The median follow-up duration was 5.2 years (0.4–16.7). The most frequent site and histology were distal femur and osteoblastic type. Overall pathologic response was more than 90% tumor necrosis in 74.8% of patients. Total necrosis of tumor was also found in 46 patients (37.4%). There was no difference between two groups in pathologic response (76.3% vs. 72.3%; p=0.62) or other clinico-pathologic parameters. Tumor recurrence was occurred in 31.5% of patients with the most common site of lung (84.6%). There was no difference between two groups in recurrence (p=0.17) or lung metastasis (p=0.53). There were no statistical differences in disease free survival (p=0.75) and overall survival (p=0.07) between two groups. In toxicity profiles, there were more hematologic toxicity in IAP group (febrile neutropenia,p<0.001; thrombocytopenia,p<0.05), while there were no statistical differences in treatment related death. Conclusions: The addition of ifosfamide to doxorubicin and cisplatin in neoadjuvant chemotherapy did not show improved outcomes in this study. Further trials are required to elucidate optimal neoadjuvant chemotherapy and effective salvage regimens.

No significant financial relationships to disclose.

Strong mass renormalization at a local momentum space in multiorbital Ca1.8Sr0.2RuO4

We have studied the mass renormalization in Ca2-xSrxRuO4 (x=0.2) using high-resolution angle-resolved photoemission spectroscopy. We observed precise band dispersions near the Fermi level (E_{F}) and the corresponding Fermi surfaces. A characteristic flat band with approximately 4 meV dispersion accompanying sharp quasiparticle (QP) peaks shows up in a limited momentum region around (pi, 0). The QP peak rapidly evolves below the crossover temperature T;{*} approximately 20 K, which agrees well with the mass enhancement behavior indicated by thermal, magnetic, and transport properties. We discuss the origin of the mass renormalization in relation to the local flat band at (pi, 0) possibly derived from the gamma (d_{xy}) band.

An ultrahigh-vacuum apparatus for resonant diffraction experiments using soft x rays (hnu=300-2000 eV)

We have developed an ultrahigh-vacuum instrument for resonant diffraction experiments using polarized soft x rays in the energy range of hnu=300-2000 eV at beamline BL17SU of SPring-8. The diffractometer consists of modified differentially pumped rotary feedthroughs for theta-2theta stages, a sample manipulator with motor-controlled x-y-z-, tilt (chi)-, and azimuth (phi)-axes, and a liquid helium flow-type cryostat for temperature dependent measurements between 30 and 300 K. Test results indicate that the diffractometer exhibits high reproducibility (better than 0.001 degrees ) for a Bragg reflection of alpha-quartz 100 at a photon energy of hnu=1950 eV. Typical off- and on-resonance Bragg reflections in the energy range of 530-1950 eV could be measured using the apparatus. The results show that x-ray diffraction experiments with energy-, azimuth-, and incident photon polarization-dependence can be reliably measured using soft x rays in the energy range of approximately 300-2000 eV. The facility can be used for resonant diffraction experiments across the L-edge of transition metals, M-edge of lanthanides, and up to the Si K-edge of materials.

Anomalous duality of 4f electrons in filled skutterudite CeOs4Sb12

We study the electronic structure of the filled skutterudite CeOs4Sb12 using photoemission spectroscopy (PES). Soft x-ray excited Ce 3d-4f resonant PES confirms the existence of Ce 4f states at the Fermi level (EF). Temperature dependent high-resolution laser-PES spectra reveal a pseudogap formation around EF, which can be explained in terms of the hybridization gap. Simultaneously, a sharp feature is formed just above EF with decreasing temperature. The heavy-fermion-like specific heat is attributed to the occupation of this feature. The results identify the origin of the anomalous coexistence of heavy-fermion and pseudogap behavior in terms of a symmetry dependent hybridization.

Recoil effect of photoelectrons in the Fermi edge of simple metals

High energy resolution photoelectron spectroscopy of conduction electrons in the vicinity of the Fermi edge in Al and Au at excitation energies of 880 and 7940 eV was carried out using synchrotron radiation. For the excitation energy of 7940 eV, the observed Fermi energy of Al shows a remarkable shift to higher binding energy as compared with that of Au, with accompanying broadening. This is due to the recoil effect of the emitted photoelectrons. The observed spectra are well reproduced by a simple model of Bloch electrons based on the isotropic Debye model.

Programmatic implementation of rapid DST for Mycobacterium tuberculosis in Peru

BACKGROUND

Performance characteristics of novel rapid drug susceptibility tests (DST) for Mycobacterium tuberculosis may change when moving from research to implementation in actual public health practice. We describe the performance characteristics of a direct, rapid DST when implemented in Lima, Peru.

METHODS

A district laboratory validated conventional proportions and nitrate reductase methods. We collected data on samples submitted for DST from January 2005 to June 2007 and calculated frequency of testing and results, and median time to test results.

RESULTS

A total of 4102 DSTs were performed by conventional DST and 895 by nitrate reductase. Results were obtained from 72.8% of samples by conventional DST and from 70.2% of those processed by Griess; respectively 26.4% and 31.5% were multidrug-resistant tuberculosis. The median time from sample collection to test result was 31 days for Griess vs. 99 days for conventional DST.

CONCLUSIONS

Preliminary experience with the Griess method demonstrates favorable performance under program conditions.

Revisiting the valence-band and core-level photoemission spectra of NiO

We have reexamined the valence-band (VB) and core-level electronic structure of NiO by means of hard and soft x-ray photoemission spectroscopies. The spectral weight of the lowest energy state was found to be enhanced in the bulk sensitive Ni 2p core-level spectrum. A configuration-interaction model including a bound state screening has shown agreement with the core-level spectrum and off- and on-resonance VB spectra. These results identify the lowest energy states in the core-level and VB spectra as the Zhang-Rice (ZR) doublet bound states, consistent with the spin-fermion model and recent ab initio calculations within dynamical mean-field theory. The results indicate that the ZR character first ionization (the lowest hole-addition) states are responsible for transport properties in NiO and doped NiO.