Tumor Resistance to Fractionated Radiotherapy in Obese Mice

PURPOSE/OBJECTIVE(S)

Obesity has reached pandemic levels in the United States and will soon surpass smoking as the number one cause of preventable cancer. Clinical data demonstrate that obese cancer patients are more resistant to radiotherapy and have higher rates of recurrence. Although a growing number of cancer patients are obese, and obesity is linked to poor outcomes with radiotherapy, little is understood about how obesity impacts the efficacy of radiotherapy. Understanding if and how obesity induces radio-resistance and how to best treat obese cancer patients is a critical unmet need. In this study we test the hypothesis that tumors in obese mice have increased resistance to fractionated radiotherapy.

MATERIALS/METHODS

Control and diet induce obese (DIO) mice were generated by feeding 4-6-week-old, genetically identical, inbred C57BL/6 mice with a high-fat diet consisting of 60% kcal from fat (DIO) or a control diet consisting of 10% fat (control) until 6 months of age. Mice were then implanted with syngeneic B16F0 tumors in the hind leg. When tumors reached 5mm in diameter mice were treated with fractionated radiotherapy (12 Gy delivered in daily 4 Gy fractions X 3 days) using a 2cm electron cutout to treat the tumor + margin only.

RESULTS

DIO mice had significantly increased body weight (control 30-40 g; DIO 50-65 g), significantly increased visceral and subcutaneous fat deposits, and elevated leptin levels. Blood glucose levels and HgbA1c in DIO mice, although slighter higher than controls, were within normal limits and did not indicate insulin resistance. Mice were divided into four groups of 8 mice (control, control + RT, DIO, DIO + RT). Fractionated radiotherapy (4 Gy x 3) significantly reduced the growth of B16F0 tumors by about three-fold in control mice compared to untreated controls. Radiotherapy failed to significantly reduce tumor size in DIO mice (compared to unirradiated DIO), although the treated tumors trended towards being modestly smaller. Additionally, tumors in the DIO + RT group were significantly larger than the tumors in the control + RT group. Initial mechanistic studies suggest increased tumor proliferation and immune dysfunction in DIO mice may induce the observed radio-resistance.

CONCLUSION

Using genetically identical mice with genetically identical tumors we demonstrate, for the first time, that diet and obesity can drastically alter the anti-tumor effects of radiotherapy. Mechanistic studies and studies in other tumor models are underway. Understanding how obesity impacts radiotherapy response and developing strategies to address these issues will improve outcomes in obese patients. Thus, these studies can have a major clinical impact and represent a step towards personalized medicine by tailoring radiotherapy treatment strategies to a patient's metabolic parameters.

POS0451 DEFICIENCY OF PPM1A IN MACROPHAGE AGGRAVATES PRISTANE-INDUCED LUPUS-LIKE DISEASE

Background

Protein phosphatase Mg2+/Mn2+-dependent 1A (PPM1A) is a phosphatase which regulates various intracellular cell signaling pathways including inflammation. We previously suggested that the inflammatory signal decreased the PPM1A protein level in macrophage and this reduction had correlation with the chronic inflammatory bone disease, implying the possible role of PPM1A in inflammatory responses of macrophage.

Objectives

In this study, we aim to elucidate the potential role of PPM1A in macrophage to regulate inflammatory response during the disease progression of systemic lupus erythematosus.

Methods

We generated macrophage-specific conditional gene-knockout (PPM1Afl/fl;LysM-Cre) mice and developed a lupus-like disease with immune complex glomerulonephritis in these PPM1Afl/fl;LysM-Cre mice by intraperitoneal pristane injection. Mouse serum was collected every 4 weeks after pristane injection. Serum anti-dsDNA IgG, anti-ssDNA IgG, interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) was quantified by ELISA. After 41 weeks from pristane injection, histological changes in the kidney, spleen, and lung tissues were observed. To analyze M1/M2 polarization in vitro, LysM-Cre and PPM1Afl/fl;LysM-Cre mouse bone marrow-derived macrophages were cultured with lipopolysaccharide (LPS)/interferon-γ (IFN-γ) or interleukin-4 (IL-4) to check M1 or M2 related genes.

Results

We found that macrophages of PPM1Afl/fl;LysM-Cre mice displayed different gene expression with LPS stimulation especially in M1/M2 related genes through the RNA-seq analysis and showed a decrease in both M1 and M2 polarization induced by LPS/IFN-γ or IL-4 stimulation. Notably, we found that PPM1Afl/fl;LysM-Cre mice with pristane injection showed a significant increase of anti-ssDNA IgG compared to LysM-Cre mice. PPM1Afl/fl;LysM-Cre mice showed severe lupus-like phenotypes such as global glomerular enlargement indicated by endocapillary proliferation and glomerular cellularity in kidney and lung inflammation accompanied by fibrosis, compared to LysM-Cre mouse by pristane injection. Together, serum IL-17 and TNF-α, which are proinflammatory cytokines, were increased in PPM1Afl/fl;LysM-Cre after pristane injection. These results indicate that PPM1A depletion in macrophage deteriorates inflammation and contributes to the tissue damage in a lupus-like disease.

Conclusion

Our findings suggest that the deficiency of PPM1A in macrophages impairs M1/M2 macrophage polarization leading to an immune imbalance in lupus-like disease model, providing a potential link between the loss of function of PPM1A in macrophages and its molecular target for treatment of systemic lupus erythematosus.

References

[1]Kwon, O. C., Choi, B., Lee, E. J., Park, J. E., Lee, E. J., Kim, E. Y., Kim, S. M., Shin, M. K., Kim, T. H., Hong, S., Lee, C. K., Yoo, B., Robinson, W. H., Kim, Y. G., & Chang, E. J. (2020). Negative Regulation of Osteoclast Commitment by Intracellular Protein Phosphatase Magnesium-Dependent 1A. Arthritis & rheumatology (Hoboken, N.J.), 72(5), 750–760. https://doi.org/10.1002/art.41180

[2]Smith, S. R., Schaaf, K., Rajabalee, N., Wagner, F., Duverger, A., Kutsch, O., & Sun, J. (2018). The phosphatase PPM1A controls monocyte-to-macrophage differentiation. Scientific reports, 8(1), 902. https://doi.org/10.1038/s41598-017-18832-7

Disclosure of Interests

None declared.

Bifidobacterium longum DS0956 and Lactobacillus rhamnosus DS0508 culture-supernatant ameliorate obesity by inducing thermogenesis in obese-mice

Excessive body fat and the related dysmetabolic diseases affect both developed and developing countries. The aim of this study was to investigate the beneficial role of a bacterial culture supernatant (hereafter: BS) of Lactobacillus and Bifidobacterium and their potential mechanisms of action on white-fat browning and lipolysis. For selection of four candidates among 55 Lactic acid producing bacteria (LAB) from human infant faeces, we evaluated by Oil Red O staining and Ucp1 mRNA quantitation in 3T3-L1 preadipocytes. The expression of browning and lipolysis markers was examined along with in vitro assays. The possible mechanism was revealed by molecular and biological experiments including inhibitor and small interfering RNA (siRNA) assays. In a mouse model, physiological, histological, and biochemical parameters and expression of some thermogenesis-related genes were compared among six experimental groups fed a high-fat diet and one normal-diet control group. The results allow us to speculate that BS treatment promotes browning and lipolysis both in vitro and in vivo. Moreover, the BS may activate thermogenic programs via a mechanism involving PKA-CREB signaling in 3T3-L1 cells. According to our data, we can propose that two LAB strains, Bifidobacterium longum DS0956 and Lactobacillus rhamnosus DS0508, may be good candidates for a dietary supplement against obesity and metabolic diseases; however, further research is required for the development as dietary supplements or drugs.

Abstract P4-08-22: Impact of application of AJCC 8th edition on survival rate of the breast cancer

Background

The AJCC 8 edition has changed much in comparison with the 7 edition. In addition to TNM stage, biologic marker (ER, PR, HER2), Histologic grade and multigene assays (oncotype Dx.) should be considered for staging. and it has been applied since January 1, 2018.

patients were recategorized and analyzed in order to know if this more complex classification helps to predict the real prognosis of the patients,

Method

We review patients who were diagnosed and treated as breast cancer at Konyang Universty Hospital. we studied retrospectively 582 patients who were followed up and were able to review.

Stage was classified according to AJCC 7th edition and AJCC 8th edition. survival rate of each stage were analyzed in both editions.

Result

Mean follow up period was 68.6 months. Total 582 patients were included. There was no change in the stage in 257 patients. In 195 patients, the stage was elevated and in 130 patients, the stage was changed down. When classified as AJCC 7th edition, the 5year-survival rate was 95.9% in stage I, 97.9% in stage II, 93.1% in stage III and 89.9% in stage IV. The survival rate of patients in stage I was lower than that of stage II. However, when the AJCC 8th edition was applied, the 5- year survival rate was 97.9% in stage I, 96.9% in stage II, 92.2% in stage III, and 89.9% in stage IV. In 8th edition, the patients in lower stage has higher survival rate.

Conclusion

The prediction of survival rate by stage was more accurate and the difference in survival rate of each stages was more clearly distinguished when The AJCC 8th edition was applied than AJCC 7th edition. AJCC 8th edition was reliable and useful for prediction of prognosis of breast cancer patient.

Citation Format: Kwon S, Yoon DS, Bae IE, Choi WJ, Choi IS, Lee SE, Moon JI, Sung NS, Park SM. Impact of application of AJCC 8th edition on survival rate of the breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-22.

Geoarchaeological Evidence of Middle-Age Tsunamis at Stromboli and Consequences for the Tsunami Hazard in the Southern Tyrrhenian Sea

Large-scale landslides at volcanic islands are one of the most dangerous geological phenomena, able to generate tsunamis whose effects can propagate far from the source. However, related deposits are scarcely preserved on-land in the geologic records, and are often difficult to be interpreted. Here we show the discovery of three unprecedented well-preserved tsunami deposits related to repeated flank collapses of the volcanic island of Stromboli (Southern Italy) occurred during the Late Middle Ages. Based on carbon datings, on stratigraphic, volcanological and archaeological evidence, we link the oldest, highest-magnitude investigated tsunami to the following rapid abandonment of the island which was inhabited at that time, contrary than previously thought. The destructive power of this event is also possibly related to a huge marine storm that devastated the ports of Naples in 1343 (200 km north of Stromboli) described by the famous writer Petrarch. The portrayed devastation can be potentially attributed to the arrival of multiple tsunami waves generated by a major landslide in Stromboli island, confirming the hypothetical hazard of these phenomena at a regional scale.

Note: Commercial SQUID magnetometer-compatible NMR probe and its application for studying a quantum magnet

We present a compact nuclear magnetic resonance (NMR) probe which is compatible with a magnet of a commercial superconducting quantum interference device magnetometer and demonstrate its application to the study of a quantum magnet. We employ trimmer chip capacitors to construct an NMR tank circuit for low temperature measurements. Using a magnetic insulator MoOPO₄ with S = 1/2 (Mo⁵⁺) as an example, we show that the T-dependence of the circuit is weak enough to allow the ligand-ion NMR study of magnetic systems. Our ³¹P NMR results are compatible with previous bulk susceptibility and neutron scattering experiments and furthermore reveal unconventional spin dynamics.

Comparative evaluation of MCP gene in worldwide strains of Megalocytivirus (Iridoviridae family) for early diagnostic marker

Members of the Iridoviridae family have been considered as aetiological agents of iridovirus diseases, causing fish mortalities and economic losses all over the world. Virus identification based on candidate gene sequencing is faster, more accurate and more reliable than other traditional phenotype methodologies. Iridoviridae viruses are covered by a protein shell (capsid) encoded by the important candidate gene, major capsid protein (MCP). In this study, we investigated the potential of the MCP gene for use in the diagnosis and identification of infections caused Megalocytivirus of the Iridoviridae family. We selected data of 66 Iridoviridae family isolates (53 strains of Megalocytivirus, eight strains of iridoviruses and five strains of Ranavirus) infecting various species of fish distributed all over the world. A total of 53 strains of Megalocytivirus were used for designing the complete primer sets for identifying the most hypervariable region of the MCP gene. Further, our in silico analysis of 102 sequences of related and unrelated viruses reconfirms that primer sets could identify strains more specifically and offers a useful and fast alternative for routine clinical laboratory testing. Our findings suggest that phenotype observation along with diagnosis using universal primer sets can help detect infection or carriers at an early stage.

Correction: Corrigendum: p-wave triggered superconductivity in single-layer graphene on an electron-doped oxide superconductor

Nature Communications 8: Article number: 14024 (2017); Published: 19 January 2017; Updated: 1 March 2017 The present address for U. Sassi is incorrect in this Article. This author does not have a present address. The correct full affiliation details for this author are given below: Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, UK.

p-wave triggered superconductivity in single-layer graphene on an electron-doped oxide superconductor

Electron pairing in the vast majority of superconductors follows the Bardeen-Cooper-Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional superconductivity was predicted in single-layer graphene (SLG), with the electrons pairing with a p-wave or chiral d-wave symmetry, depending on the position of the Fermi energy with respect to the Dirac point. By placing SLG on an electron-doped (non-chiral) d-wave superconductor and performing local scanning tunnelling microscopy and spectroscopy, here we show evidence for a p-wave triggered superconducting density of states in SLG. The realization of unconventional superconductivity in SLG offers an exciting new route for the development of p-wave superconductivity using two-dimensional materials with transition temperatures above 4.2 K.

Inhibition of microRNA-449a prevents IL-1β-induced cartilage destruction via SIRT1

OBJECTIVE

SIRT1 has anti-inflammatory as well as protective effects in chondrocytes. The object of this study was to investigate whether microRNA-449a regulates expression of SIRT1, which inhibits expression of catabolic genes in IL-1β-induced cartilage destruction.

MATERIALS AND METHODS

MicroRNA-449a expression was determined in OA chondrocytes and IL-1β-induced chondrocytes by real-time PCR. MicroRNA-449a binding sites on the 3'-UTR of SIRT1 mRNA and binding site conservation were examined using microRNA target prediction tools. SIRT1-overexpressing or knockdown chondrocytes were transfected with microRNA-449a or anti-microRNA-449a mimic and stimulated by IL-1β. Expression of catabolic and anabolic genes was examined by real-time PCR and western blotting. Finally, positive effects of anti-microRNA-449a on expression of these genes were confirmed by western analysis of OA chondrocytes.

RESULTS

Expression of microRNA-449a was increased in OA chondrocytes and IL-1β-induced chondrocytes. MMP-13 expression was enhanced, whereas type II collagen and SIRT1 expression were decreased in IL-1β-induced chondrocytes. SIRT1 overexpression resulted in decreased expression of catabolic genes such as MMPs and ADAMTSs in response to IL-1β, but these effects were moderated by microRNA-449a. Suppression of microRNA-449a by anti-microRNA-449a inhibited expression of catabolic genes despite IL-1β stimulation, but these effects were abolished in SIRT1 knockdown chondrocytes. Furthermore, expression of catabolic genes was decreased and expression of type II collagen as well as SIRT1 was restored by anti-microRNA-449a in OA chondrocytes as well as in IL-1β-induced chondrocytes.

CONCLUSION

Silencing of microRNA-449a had a protective effect, inhibiting catabolic gene expression and restoring anabolic gene expression, by targeting SIRT1 in IL-1β-induced cartilage destruction.

P14: DOXYCYCLINE: A RARE CAUSE OF DRUG INDUCED PANCREATITIS

Purpose of Study

Drug-induced pancreatitis (DIP) is a rare clinicopathologic entity. We report a 58-year-old female who developed DIP secondary to administration of doxycycline.

Methods Used

A 48 year old female with a history of hypertension presented to the hospital with complains of nausea/vomiting, right upper-quadrant gnawing abdominal pain, 8/10 in intensity with radiation to the back. She denied exacerbating factors, use of alcohol, tobacco and drug. Patient also denied diarrhea, constipation and changes in skin or stool color. On examination patient was hypertensive (155/95) with a heart rate of 102. She had epigastric/right upper quadrant tenderness on superficial palpation, hypoactive bowel sounds without any palpable organs, rebound tenderness or rigidity. Serum lipase was elevated at 2508 IU/L, negative pregnancy and insignificant urinalysis findings. Liver function tests, lipid panel, chemistry panel and hematologic panel were within normal limits. Radiologic investigations with abdominal ultrasound depicted mild proximal dilatation of the common bile duct with smooth tapering of the duct distally indicating status post-cholecystectomy. Contrast enhanced computed tomography scan revealed mild enlargement of the body of the pancreas with adjacent peripancreatic fatty infiltration consistent with acute pancreatitis. Upon further questioning patient explains recent diagnosis (7 days) of tibial orthopedic hardware infection as she was prescribed doxycycline 200 mg twice a day in anticipation of irrigation of infected site. After confirmation, and discontinuation of doxycycline, our patient recovered and has been disease-free for over a month.

Summary of Results

Drug-induced pancreatitis is uncommon etiology of acute pancreatitis, which is responsible for 0.1%–2% of all the acute pancreatitis cases. Among adverse drug reactions, pancreatitis is often-ignored because of the difficulty in implicating a drug as its cause.

Conclusions

In our vastly evolving pharmacotherapy world, DIP should be included in the differential of idiopathic pancreatitis, especially after other common causes have been ruled out.

Cellular localization of NRF2 determines the self-renewal and osteogenic differentiation potential of human MSCs via the P53-SIRT1 axis

NRF2 (nuclear factor erythroid-derived 2-like 2) plays an important role in defense against oxidative stress at the cellular level. Recently, the roles of NRF2 in embryonic and adult stem cells have been reported, but its role in maintaining self-renewal and differentiation potential remains unknown. We studied the mechanisms of NRF2 action in mesenchymal stem cells (MSCs) derived from human bone marrow. We found that the cellular localization of NRF2 changed during prolonged cell passage and osteogenic differentiation. Blocking the nuclear import of NRF2 using ochratoxin A (OTA) induced the loss of the self-renewal and osteogenic potential of early-passage (EP) MSCs. Conversely, reinforcing the nuclear import of NRF2 using tert-butylhydroquinone (t-BHQ) improved the self-renewal capacity and maintained the differentiation potential in the osteogenic lineage of EP MSCs. Real-time quantitative PCR and western blot analysis showed that NRF2 positively regulates sirtuin 1 (SIRT1) at the mRNA and protein levels via the negative regulation of p53. The self-renewal and osteogenic potential suppressed in OTA-treated or NRF2-targeting small hairpin RNA (shRNA)-infected EP MSCs were rescued by introducing small interfering RNA (siRNA) targeting p53. t-BHQ treatment in late-passage (LP) MSCs, which lost their self-renewal and osteogenic potential, reversed these effects. In LP MSCs treated with t-BHQ for ∼7 days, the phosphorylation and nuclear localization of NRF2 improved and SIRT1 protein level increased, whereas p53 protein levels decreased. Therefore, our results suggest that NRF2 plays an important role in regulating p53 and SIRT1 to maintain MSC stemness. This study is the first to establish a functional link between NRF2 and SIRT1 expression in the maintenance of MSC self-renewal and differentiation potential.

The Model for End-stage Liver Disease score is potentially a useful predictor of hyperkalemia occurrence among hospitalized angiotensin receptor blocker users

WHAT IS KNOWN AND OBJECTIVE

Angiotensin receptor blockers (ARBs) are medications commonly used for treating conditions such as hypertension. However, ARBs are frequently associated with hyperkalemia, a potentially critical adverse event, in high-risk patients. Although both the liver and the kidney are major elimination routes of ARBs, the relationship between hepatorenal function and ARB-related hyperkalemia has not yet been investigated. The purpose of this study was to evaluate the risk of hyperkalemia, in terms of various hepatorenal functions, for hospitalized patients newly initiated on ARB treatment.

METHODS

We evaluated ARB-related hyperkalemia in a cohort of 5530 hospitalized patients, who had not previously used ARBs, between 12 April 2004 and 31 May 2012. Hepatorenal function was assessed by the Model for End-stage Liver Disease (MELD) score. Hyperkalemia risk was assessed by hepatorenal function, risks were categorized into the four MELD scoring groups, and the groups were compared with one another.

RESULTS AND DISCUSSION

The MELD score was significantly different between the hyperkalemic and non-hyperkalemic groups (independent t-test, P < 0.001). The MELD score 10-14, 15-19 and ≥ 20 groups showed higher risks of hyperkalemia than the lowest MELD score group {log-rank test, P < 0.001; multiple Cox proportional hazard model, hazard ratios 1.478 (P = 0.003), 2.285 (P < 0.001) and 3.024 (P < 0.001), respectively}.

WHAT IS NEW AND CONCLUSION

The MELD score showed a stronger predictive performance for hyperkalemia than either serum creatinine or estimated glomerular filtration rate alone. Furthermore, the MELD score showed good predictive performance for ARB-related hyperkalemia among hospitalized patients. The clinical implications and reasons for these findings merit future investigation.

The vitamin B12 analog cobinamide is an effective hydrogen sulfide antidote in a lethal rabbit model

BACKGROUND AND PURPOSE

Hydrogen sulfide (H2S) is a highly toxic gas for which no effective antidotes exist. It acts, at least in part, by binding to cytochrome c oxidase, causing cellular asphyxiation and anoxia. We investigated the effects of three different ligand forms of cobinamide, a vitamin B12 analog, to reverse sulfide (NaHS) toxicity.

METHODS

New Zealand white rabbits received a continuous intravenous (IV) infusion of NaHS (3 mg/min) until expiration or a maximum 270 mg dose. Animals received six different treatments, administered at the time when they developed signs of severe toxicity: Group 1-saline (placebo group, N = 9); Group 2--IV hydroxocobalamin (N = 7); Group 3--IV aquohydroxocobinamide (N = 6); Group 4--IV sulfitocobinamide (N = 6); Group 5--intramuscular (IM) sulfitocobinamide (N = 6); and Group 6-IM dinitrocobinamide (N = 8). Blood was sampled intermittently, and systemic blood pressure and deoxygenated and oxygenated hemoglobin were measured continuously in peripheral muscle and over the brain region; the latter were measured by diffuse optical spectroscopy (DOS) and continuous wave near infrared spectroscopy (CWNIRS).

RESULTS

Compared with the saline controls, all cobinamide derivatives significantly increased survival time and the amount of NaHS that was tolerated. Aquohydroxocobinamide was most effective (261.5 ± 2.4 mg NaHS tolerated vs. 93.8 ± 6.2 mg in controls, p < 0.0001). Dinitrocobinamide was more effective than sulfitocobinamide. Hydroxocobalamin was not significantly more effective than the saline control.

CONCLUSIONS

Cobinamide is an effective agent for inhibiting lethal sulfide exposure in this rabbit model. Further studies are needed to determine the optimal dose and form of cobinamide and route of administration.

Onset time of hyperkalaemia after angiotensin receptor blocker initiation: when should we start serum potassium monitoring?

WHAT IS KNOWN AND OBJECTIVE

Angiotensin receptor blockers (ARBs) frequently induce hyperkalaemia in high-risk patients. Early detection of hyperkalaemia can reduce the subsequent harmful effects. This study was performed to examine the onset time of hyperkalaemia after ARB therapy.

METHODS

We carried out a retrospective analysis to determine the onset time of hyperkalaemia (serum potassium >5·5 mm) among hospitalized patients newly starting ARB therapy between 2004 and 2012, in a tertiary teaching hospital. Predefined possible risk factors and concomitant medications were evaluated.

RESULTS AND DISCUSSION

During the 97-month study period, a total of 4267 hospitalized patients started ARBs as new drugs and 225 patients showed hyperkalaemia. A significantly increased risk of hyperkalaemia was detected among patients with a high baseline potassium [odds ratio (OR) 6·0] and those who took non-potassium-sparing diuretics (OR 2·2) or potassium supplements (OR 1·6). A high glomerular filtration rate (GFR) was associated with a lower risk of hyperkalaemia (OR 0·992). Fifty-two percentage of hyperkalaemic events occurred within the first week after initiation of ARB therapy. The highest frequency of hyperkalaemia occurred on the first day after initiation of ARBs. Hyperkalaemia occurred earlier in patients with a high baseline serum potassium level, reduced GFR, diabetes and in those without heart failure.

WHAT IS NEW AND CONCLUSION

Hyperkalaemia occurs most frequently at the beginning of ARB therapy in hospitalized patients. Monitoring of serum potassium and estimated GFR after initiation of ARBs should be started within a few days or not later than 1 week, especially in patients with risk factors.

Difference of regeneration potential between healthy and diseased liver

BACKGROUND

We sought to evaluate total and segmental liver regeneration by comparing preoperative computed tomographic (CT) volumetry and CT volumetry on postoperative day (POD) 7 after a right hepatectomy, in patients with various status and surgical indications.

METHOD

We included 36 patients who underwent right lobectomy for living donor liver transplantation (healthy group), and 29 for hepatocellular carcinoma treatment (disease group). All of the disease group patients were Child-Turcotte-Pugh (CTP) class A. The regeneration of lateral, medial segment and total remnant liver volumes were assessed on POD 7 using a CT-based program. Total volumes and segmental volumes were measured for total liver, future liver remnant (FLR), and liver remnant. We calculated total and segmental early regeneration indexes, defined as [(VLR-VFLR)/VFLR]×100, where VLR is volume of the liver remnant and VFLR is volume of the FLR.

RESULT

The VLR at POD 7 showed a 72.9% increase in volume among the healthy versus 55% in the disease group, (P=.012) In the disease group, segmental volume and regeneration indexes were also significantly lower than among the healthy group: 59.0% versus 46.9% in the medial and 86.8% versus 57.7% in the lateral segment (P=.023 and P<.001) respectively.

CONCLUSION

The volume regeneration potential in diseased livers is significantly lower than that of a normal, healthy liver. So, we must consider a patient's liver status and volume profile before an extensive liver.

Construction of an open-access QT database for detecting the proarrhythmia potential of marketed drugs: ECG-ViEW

Information about the QT interval from surface electrocardiograms (ECGs) is essential for surveillance of the proarrhythmia potential of marketed drugs. However, ECG records obtained in daily practice cannot be easily used for this purpose without labor-intensive manual effort. This study was aimed at constructing an open-access QT database, the Electrocardiogram Vigilance with Electronic Data Warehouse (ECG-ViEW). This longitudinal observational database contains 710,369 measurements of QT and associated clinical data from 371,401 patients. The de-identified database is freely available at http://www.ecgview.org.

Importance of Sox2 in maintenance of cell proliferation and multipotency of mesenchymal stem cells in low-density culture

OBJECTIVES

This study has aimed to repopulate 'primitive' cells from late-passage mesenchymal stem cells (MSCs) of poor multipotentiality and low cell proliferation rate, by simply altering plating density.

MATERIALS AND METHODS

Effects of low density culture compared t high density culture on late-passage bone marrow (BM)-derived MSCs and pluripotency markers of multipotentiality were investigated. Cell proliferation, gene expression, RNA interference and differentiation potential were assayed.

RESULTS AND CONCLUSIONS

We repopulated 'primitive' cells by replating late-passage MSCs at low density (17 cells/cm(2) ) regardless of donor age. Repopulated MSCs from low-density culture were smaller cells with spindle shaped morphology compared to MSCs from high-density culture. The latter had enhanced colony-forming ability, proliferation rate, and adipogenic and chondrogenic potential. Strong expression of osteogenic-related genes (Cbfa1, Dlx5, alkaline phosphatase and type Ι collagen) in late-passage MSCs was reduced by replating at low density, whereas expression of three pluripotency markers (Sox2, Nanog and Oct-4), Osterix and Msx2 reverted to levels of early-passage MSCs. Knockdown of Sox2 and Msx2 but not Nanog, using RNA interference, showed significant decrease in colony-forming ability. Specifically, knockdown of Sox2 significantly inhibited multipotentiality and cell proliferation. Our data suggest that plating density should be considered to be a critical factor for enrichment of 'primitive' cells from heterogeneous BM and that replicative senescence and multipotentiality of MSCs during in vitro expansion may be predominantly regulated through Sox2.

Phase II study of everolimus in patients with advanced gastric cancer refractory to chemotherapy including fluoropyrimidine and platinum

93

Background: To evaluate feasibility with activity and toxicities of everolimus, a novel inhibitor of mammalian target of rapamycin (mTOR), in patients with advanced gastric cancer (AGC) who failed chemotherapy including both fluoropyrimidine and platinum (FP).

Methods: Fifty-four patients were enrolled between Jul 2008 and Feb 2010. Everolimus, 10 mg daily, was given until disease progression or unacceptable toxicity. Primary objective was to determine 4-month progression-free survival (PFS) and secondary objectives were to investigate response rate, toxicity and overall survival OS rate. Pre- (n = 28) and on-treatment (n = 19) tumor biopsies were evaluated for phosphorylated (p) mTOR, pS6 kinase1, pS6 and eukaryotic initiation factor 4E binding protein 1 expression.

Results: A total of 180 cycles of everolimus were administered with a median of 2 (range, 1-20) cycles in each patient. Two patients (3.7%) achieved confirmed partial response and 19 patients (35.2%) showed stable disease, resulting in a disease control rate of 38.9%. At a median follow-up duration of 8.7 months in surviving patients (range, 3.0–19.4 months), a 4-month PFS rate was 18.4% with a median PFS of 1.7 months (95% CI, 1.5-2.2 months) and a median OS time was 8.3 months (95% CI, 4.5-12.1 months). Peritoneal metastasis (Hazard ratio [HR], 3.97; 95% CI, 1.54-10.23; p = 0.010) and low expression level of pS6Ser240/4 at baseline (HR, 7.64; 95% CI, 2.591-22.51; p = 0.001) were significantly associated with shorter PFS time. Treatment was in general well tolerated. Toxicities of grade 3/4 included anemia (9.4%), thrombocytopenia (9.4%), hepatic dysfunction (11.3%) and pulmonary toxicities (one interstitial pneumonitis and a diffuse alveolar hemorrhage [DAH] case). The DAH and cardiopulmonary dysfunction in another case resulted in treatment-related mortalities.

Conclusions: Everolimus monotherapy showed modest activity against AGC refractory to FP. pS6Ser240/4 might be a potential biomarker for the clinical activity of everolimus. The toxicity profile was generally mild. However, careful monitoring for treatment-related pulmonary complication seems to be required.

[Table: see text]

Dominance specific visual extinction associated with callosal disconnection

Callosal disconnection signs are closely related to asymmetric hemispheric specialization of cognitive functions. Although extinction is more commonly associated with the right parietotemporal lesion, it may occur following lesions of the corpus callosum. After an infarction involving the left splenium, a 58-year-old right-handed man had no disconnection symptoms that had been reported earlier, but showed visual extinction with left or right visual hemifield dominant stimuli. Our results suggest that dominance specific visual extinction might be another disconnection sign associated with splenial lesion.

Presenilin enhancer-2 (PSENEN), a component of the gamma-secretase complex, is involved in adipocyte differentiation

This study was conducted to identify genes expressed during adipocyte differentiation of bovine intramuscular fibroblast-like cells using differential display reverse-transcriptase polymerase chain reaction. The presenilin enhancer-2 (PSENEN) gene was found to be down-regulated during adipocyte differentiation of bovine intramuscular fibroblast-like cells. The ectopic expression of bovine PSENEN in 3T3-L1 reduced adipogenesis and the inhibition of endogenous PSENEN by siRNA induced adipogenesis on d 4 of adipocyte differentiation of 3T3-L1 cells. Interestingly, the expression of gamma-secretase complex gene-related Notch signaling was decreased at d 2 and d 4 during adipocyte differentiation. In addition, expression of the Notch-signaling genes (Notch-1, Hes-1, Pref-1, adipsin) was regulated during adipocyte differentiation by regulation of PSENEN expression. These results suggest that PSENEN plays an important role in adipocyte differentiation and that Notch signaling is involved in adipogenesis.