Variations in KCNQ1 are associated with type 2 diabetes and beta cell function in a Chinese population

AIMS/HYPOTHESIS

Recent genome-wide association studies in East Asian populations reported that single nucleotide polymorphisms (SNPs) in KCNQ1 are associated with type 2 diabetes. The aim of this study was to validate this finding in a Chinese population.

METHODS

We genotyped four SNPs, rs2074196, rs2237892, rs2237895 and rs2237897, in a group of 3,503 Shanghai Chinese individuals, comprising 1,769 type 2 diabetic patients and 1,734 normoglycaemic controls. Both the cases and the controls were extensively phenotyped for anthropometric and biochemical traits related to glucose metabolism. Arginine stimulation tests under fasting conditions were performed in a subgroup of 466 cases.

RESULTS

All four of the SNPs were associated with type 2 diabetes, with rs2237892 showing strongest evidence for association (OR 1.532, 95% CI 1.381-1.698, p = 5.0 x 10(-16)). The SNP rs2237897 was associated with both acute insulin and C-peptide response after arginine stimulation in a subgroup of cases (p = 0.0471 and p = 0.0156, respectively). The SNP rs2237895 was associated with both first- and second-phase insulin secretion in the controls (p = 0.0334 and p = 0.0002, respectively).

CONCLUSIONS/INTERPRETATION

In this study we found that KCNQ1 was associated with type 2 diabetes susceptibility in a Chinese population, possibly through its effect on beta cell function.

Severity of leukoaraiosis correlates with clinical outcome after ischemic stroke

BACKGROUND

Leukoaraiosis (LA) is closely associated with aging, a major determinant of clinical outcome after ischemic stroke. In this study we sought to identify whether LA, independent of advancing age, affects outcome after acute ischemic stroke.

METHODS

LA volume was quantified in 240 patients with ischemic stroke and MRI within 24 hours of symptom onset. We explored the relationship between LA volume at admission and clinical outcome at 6 months, as assessed by the modified Rankin Scale (mRS). An ordinal logistic regression model was developed to analyze the independent effect of LA volume on clinical outcome.

RESULTS

Bivariate analyses showed a significant correlation between LA volume and mRS at 6 months (r = 0.19, p = 0.003). Mean mRS was 1.7 +/- 1.8 among those in the lowest (< or =1.2 mL) and 2.5 +/- 1.9 in the highest (>9.9 mL) quartiles of LA volume (p = 0.01). The unfavorable prognostic effect of LA volume on clinical outcome was retained in the multivariable model (p = 0.002), which included age, gender, stroke risk factors (hypertension, diabetes mellitus, atrial fibrillation), previous history of brain infarction, admission plasma glucose level, admission NIH Stroke Scale score, IV rtPA treatment, and acute infarct volume on MRI as covariates.

CONCLUSIONS

The volume of leukoaraiosis is a predictor of clinical outcome after ischemic stroke and this relationship persists after adjustment for important prognostic factors including age, initial stroke severity, and infarct volume.

Compact high-power red-green-blue laser light source generation from a single lithium tantalate with cascaded domain modulation

1W quasi-white-light source has been generated from a single lithium tantalate with cascaded domain modulation. The quasi-white-light is combined by proper proportion of the red, green and blue laser light. The red and the blue result from a compact self-sum frequency optical parametric oscillation when pumped by a single green laser. The efficiency of quasi-white-light from the green pump reaches 27%. This compact design can be employed not only as a stable and powerful RGB light source but also an effective blue laser generator.

Postsurgical drainage and the risk of breast cancer recurrence in Chinese breast cancer patients

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Background: Clinical investigations suggest that while primary breast cancer surgical removal favorably modifiers the natural history of breast cancer. Postoperative drainage, a surgery-derived discharge after breast cancer surgery, reflecting some biological features of surgical stimulation, was assessed and explored its relationship with breast cancer recurrence in this study. Methods: A total of 1445 women undergoing surgery between Jan 1, 2000 and Dec31, 2002 in Cancer Hospital of Fudan University, Shanghai, China was retrospectively studied. Survival curves were performed with Kaplan-Meier method and the predictive value of postsurgical drainage was estimated using proportional Cox regression model. Conclusions: The larger drainage volume POD 1 is a useful marker, suggesting a greater stimulation to surgical treatment compared to the lower ones. Awareness of the relationship between early surgery-stimulated effects and harmful wound healing response might help to explore new strategies to block or deplete these harmful effects, resulting in improving patients' survival.

No significant financial relationships to disclose.

Population pharmacokinetic (PK)/pharmacodynamic (PD) modeling and simulations for exposure‐;tumor response relationships: Motesanib in a phase II thyroid cancer (TC) trial

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Background: Motesanib is a highly selective, oral inhibitor of VEGF receptors 1, 2, and 3; PDGFR; and Kit that is being investigated for its antitumor activity. In a phase 2 monotherapy study, a response rate of 14% (per RECIST) was observed in patients (pts) with differentiated thyroid cancer (DTC; NEJM 359:31–42, 2008) compared with 1% in pts with medullary TC (MTC; Endocr Soc Ann Meeting 2007, abstract OR39–3). We evaluated the relationship between motesanib PK and tumor response, investigated whether differences in PK between MTC and DTC pts contributed to the observed difference in response, and simulated tumor response with different dose regimens in pts with TC. Methods: Data from the phase 2 TC trial were used for PK/PD modeling. The study enrolled 93 DTC and 91 MTC pts who received motesanib 125 mg once daily (QD). Motesanib concentrations were fitted to a 2- compartment population PK model. Estimates of pts’ PK parameters were used to calculate concentration and steady-state area under the curve values for motesanib, which were used as the exposure measures in population PK/PD modeling (ie, longitudinal exposure-tumor response modeling of drug effect on tumor growth dynamics). Monte Carlo simulations were used to evaluate the potential effect of doses other than 125 mg QD (75 mg and 100 mg QD) on tumor response in TC pts. Results: Clearance in MTC pts was 40% faster than in DTC pts (74 vs 44 L/h). The fit was significantly improved (P<0.001) when exposure instead of dose was used in the model. The exposure-tumor response model that incorporated the difference in exposure described change in tumor size well in both MTC and DTC populations. Clinical trial simulations using the preliminary model based on week 24 data predicted that DTC pts would achieve 19.7%, 15.7%, and 11.3% reductions in tumor size at week 24 following doses of 125 mg QD, 100 mg QD, and 75 mg QD, respectively. The actual change in median tumor size at week 24 following 125-mg QD dosing in DTC pts included in the PK/PD analysis was 17.9%. Conclusions: The use of 125 mg QD motesanib in DTC pts was supported by PK/PD modeling and Monte Carlo simulations. Differences in PK may explain the difference in tumor response observed in MTC and DTC patient populations.

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PhaseI/II clinical trial of dose escalation using daily on-line cone beam CT guided radiotherapy combined with active breath control after transcatheter arterial chemoembolization for hepatocellular carcinoma

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Background: The radiation dose is the key factor to improve survival of patients with hepatocellular carcinoma (HCC). The optimal way to increase radiation dose is to reduce uncertainties of target mainly due to respiratory motion and setup error in radiotherapy. Our previous study demonstrated that lipiodol can be a reliable surrogate of direct tumor targeting in Kv- cone beam CT(CBCT) for patients with good lipiodol embolization. Relying on lipiodol,the daily on-line CBCT guidance with ABC is feasible. By reducing geometric position uncertainty, as well as liver movement, the technique of ABC combined with on-line CBCT guidance can permit CTV(clinical target volume)-PTV(planning target volume) margin reduction and dose escalation. The purpose of the study is to apply the new technique for clinical application and investigate the dose escalation, toxicities and response of liver tumors with the technique combined with chemoembolization(TACE). Methods: 20 HCC patients with Child-Pugh A liver function score were treated by daily on-line CBCT guided radiotherapy relying on lipiodol combined with ABC after TACE. After current doses of 45Gy/ 9 fractions,3 fractions/weeks were delivered,the scheduled dose escalation ranged from 5 to 20Gy. Each mean liver dose not reached 23G y, V30 ( the percentage of normal liver volume with radiation dose≥30 Gy) less than 28%. Results: The planned dose escalation was finished in all subgroups. None of these patients developed Grade 2 or greater liver toxicity except two patients developed Grade 2 gastrointestinal complications and one had grade 1 acute liver toxicity.The overall immediate tumor response rate was 76.3%. 1-year overall survival rate was 80.5%. Conclusions: The technique of daily on-line CBCT guided radiotherapy combined with ABC after TACE is a safe and effective treatment which can reduce CTV-PTV margin significantly and increase target precision greatly. With the technique combined with TACE, the total irradiation dose above 65Gy is feasible in daily fraction of 5Gy.

No significant financial relationships to disclose.

Simulation of survival with first- and second-line non-small cell lung cancer (NSCLC) therapy using a public domain drug-disease modeling framework

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Background: Modeling and simulation approaches are advocated to support drug development decisions. In this study, we evaluated the ability of a drug-disease model recently developed by scientists at the FDA using data from pivotal studies in NSCLC (Wang et al. http://www.fda.gov/ohrms/dockets/ac/08/briefing/2008–4351b1–00-index.htm ) to simulate survival and tumor response for approved therapies in NSCLC. Methods: The modeling framework comprises a longitudinal tumor size model and a survival model relating change in tumor size at first visit (week 8) and patient characteristics (tumor size and ECOG performance status at baseline) to survival time. The tumor size and survival models were used to simulate change in tumor size at first visit and expected survival in the carboplatin/paclitaxel (CP) arm of the E4599 study (first-line NSCLC, N Eng J Med. 2006;355:2542–2550) and in the erlotinib arm in the BR.21 study (second-line NSCLC, N Eng J Med. 2005;353:123–132). The predictive distributions (95% prediction interval [PI]) of survival times were derived from multiple replicates (500) of 400 CP patients and 500 erlotinib patients with similar characteristics to patients in the original studies. Results: There was a high level of concordance between the results of the simulation and the observed results in the two arms, indicating that the modeling framework successfully predicted survival and tumor response. Expected median survival was 9.8 (95% PI, 8.2–11.8) months (vs 10.3 months observed) for the CP arm and 6.8 (95% PI, 5.3–8.9) months (vs 6.7 months observed) for the erlotinib arm. The median change in relative tumor size from baseline at week 8 predicted by the model was 12.1% for the CP arm and 9.5% for the erlotinib arm. Conclusions: The modeling framework can be used to perform simulations of survival of approved treatments. These results suggest that the model could be used to simulate survival for investigational treatments based on tumor shrinkage data observed in early clinical studies (e.g. phase II) to support end-of-phase II decisions and the design of phase III studies.

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Demographic features and prognostic profiles of breast cancer patients presenting with nipple discharge in Chinese population

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Background: Breast cancer patients with nipple discharge (ND) may constitute a distinct clinical entity compared to those without ND, which has not been well elucidated in previous reports. We sought to analyze the demographic features and prognostic profiles of breast cancer patients presenting with nipple discharge in Chinese population. Methods: A total of 3234 patients, categorized as ND (2.47%) and non-nipple discharge (NND; 97.53%) according to different initial signs, were retrospectively analyzed. Survival curves were performed with Kaplan-Meier method and annual recurrence hazard was estimated by hazard function. Results: ND group tended to have smaller tumors and less axillary lymph node (ALN) involvement than NND group (P < 0.05). In the univariate analysis, we found significantly different recurrence-free survivals (RFS) between subgroups (P = 0.0182), with the rate of 77.78% for ND group and 72.46% for the other at the 11th year respectively. In Cox proportional hazards regression analysis, we found that tumor size (P < 0.001), ALN status (P < 0.001) were independent prognostic factors for RFS. To further evaluate whether prognostic effect of ND status remained unabated over time, the test for lack of proportionality was performed. However, it was statistically significant (global test, P = 0.039), which hinted at a demand for the employment of Cox non-proportional hazards regression in this analysis. In time dependent Cox model, ND status (P = 0.0495) as well as ERBB2 status (P = 0.017), tumor size (P < 0.001), ALN status (P < 0.001) were independent prognostic factors when ND and ERBB2 status were taken as time-varying covariates. Annual hazard rates for recurrence remained lower on ND group until approximately 4.5 years after surgery, while the situation was just the opposite thereafter. Conclusions: Our findings suggested that demographic features and prognostic profiles were quite different between breast cancers presenting with and without ND in Chinese population, which may indirectly uncover distinct biological behaviors and potentially enlighten novel therapeutic approaches for patients with different initial signs.

No significant financial relationships to disclose.

A modeling framework to simulate motesanib efficacy in thyroid cancer

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Background: Motesanib is a highly selective, oral inhibitor of VEGF receptors 1, 2, and 3; PDGFR, and Kit with antiangiogenic and direct antitumor activity. A modeling framework that simulates clinical endpoints, including objective response rate (ORR; per RECIST) and progression-free survival (PFS), was developed to support clinical development of motesanib. This study evaluated the framework using results from a trial of motesanib in thyroid cancer (TC). Methods: Models for tumor growth inhibition (J Clin Oncol 24[18S]:abstract 6025, 2006) with drug effect driven by area under the curve (AUC) (as predicted by a population pharmacokinetic model), overall survival, and probability and duration of dose reductions were developed based on data from 93 differentiated TC (DTC) and 91 medullary TC patients who received motesanib monotherapy (125 mg once daily [QD]) in a phase 2 study (Horm Res 68[suppl 3]:28–9, 2007; NEJM 359:31–42, 2008). The full simulation framework was assessed in predicting dose intensity (starting dose of 125 mg QD), tumor size over time, ORR, and PFS. Dose-response simulations were performed in DTC patients. Results: Survival times followed a Weibull distribution with ECOG performance status, baseline tumor size, and change in tumor size from baseline at week 7 as predictors. The probability of dose reductions was dependent on time and AUC. Time to event Weibull models predicted the duration of dose reductions and dose interruptions. The models correctly predicted median daily exposure intensities up to week 24. The predicted ORR in DTC patients was 15.0% (95% prediction interval [PI], 7.5%-23.7%) compared with the observed ORR of 14.0%. Predicted median PFS was 40 weeks (95% PI, 32–49 wk) compared with the observed median PFS of 40 weeks. Dose- response simulations confirmed the appropriateness of 125-mg QD dosing in DTC: the modeling framework predicted no clinically relevant improvement in PFS would be obtained by dose intensification. Conclusions: This modeling framework (dose reduction/tumor growth inhibition/survival) will be an important tool to simulate clinical response and support clinical development decisions. Further evaluation of the model using additional datasets will be required.

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Zinc supplementation partially prevents renal pathological changes in diabetic rats

We have demonstrated that Zn supplementation mediated up-regulation of cardiac metallothionein (MT) as a potent antioxidant prevented the development of diabetic cardiomyopathy. The present study was undertaken to test whether induction of renal MT synthesis by Zn supplementation protects the kidney from diabetes-induced damage. Streptozotocin-induced diabetic rats were treated with and without Zn supplementation at 5 mg/kg in drinking water for 3 months. Diabetic renal damage was detected by examining renal pathological alterations and 24-h urinary protein levels. Three-month Zn supplementation immediately after the onset of diabetes, partially but significantly, prevented the kidney from diabetes-induced increases in 24-h urinary proteins and pathological alterations. Diabetes-induced renal oxidative damage, inflammation and up-regulated expression of profibrosis mediator connective tissue growth factor (CTGF) were also markedly attenuated by Zn supplementation, along with significant increases in Zn levels concomitant with MT expression in renal tubular cells. Direct exposure of renal tubular (HK11) cells to high levels of glucose (HG) induced CTGF up-regulation predominantly through ERK (extracellular signal-regulated kinase)1/2-dependent, and partially through p38 mitogen-activated protein kinase (MAPK)-dependent pathways. Pretreatment of HK11 cells with Zn or cadmium induced MT expression and also significantly suppressed HG-induced CTGF expression. These results provide the first evidence for Zn supplementation to attenuate diabetes-induced renal pathological changes, likely through prevention of hyperglycemia-induced CTGF expression by Zn-induced MT in renal tubular cells.

CD1a expression defines an interleukin-12 producing population of human dendritic cells

Human and murine dendritic cell (DC) subsets are often defined by phenotypic features that predict their functional characteristics. In humans and mice, DC have been shown to have the ability to polarize naive CD4 T cells to a T helper type 1 (Th1) or Th2 phenotype. However, human myeloid DC generated from monocytes (monocyte-derived DC) have often been regarded as a homogeneous population, both phenotypically and functionally. Monocytes give rise to subpopulations of DC in vitro that can be separated on the basis of their expression of CD1a, a well-described DC subset marker. Importantly, we show that the CD1a(+) DC subset produces significant quantities of interleukin-12p70 (IL-12p70) upon stimulation and, similar to the murine CD8 alpha(+) DC subset, can polarize naive CD4(+) T cells to a Th1 phenotype. In contrast, CD1a(-) DC, similar to murine CD8 alpha(-) DC, do not produce significant amounts of IL-12p70 upon stimulation or polarize T cells to a Th1 phenotype. Like monocyte-derived DC, CD1a(+) and CD1a(-) DC subsets obtained from CD34(+) haematopoietic progenitors under distinct culture conditions were found to have these same features, suggesting that CD1a expression is a marker for myeloid DC that are a major source of IL-12 and Th1 CD4(+) T cell polarization in man.

Combustion smoke exposure induces up-regulated expression of vascular endothelial growth factor, aquaporin 4, nitric oxide synthases and vascular permeability in the retina of adult rats

Retinal cells respond to various experimental stimuli including hypoxia, yet it remains to be investigated whether they react to smoke inhalation. We show here that retinal cells in rats, notably the ganglion cells, Müller cells, astrocytes and blood vessels responded vigorously to a smoke challenge. The major changes included up-regulated expression of vascular endothelial growth factor (VEGF), aquaporin 4 (AQP4) and nitric oxide synthase (NOS). VEGF expression was localized in the ganglion cells, Müller cells, astrocytes and associated blood vessels. AQP4 was markedly enhanced in both astrocytes and Müller cells. Increase in vascular permeability after smoke exposure was evidenced by extravasation of serum derived rhodamine isothiocyanate which was internalized by Müller cells and ganglion cells. The tracer leakage was attenuated by aminoguanidine and N(G)-nitro-L-arginine methyl ester (L-NAME) treatment which suppressed retinal tissue NOS and nitric oxide (NO) levels concomitantly. It is suggested that VEGF, AQP4 and NO are involved in increased vascular permeability following acute smoke exposure in which hypoxia was ultimately implicated as shown by blood gases analysis. NOS inhibitors effectively reduced the vascular leakage and hence may ameliorate possible retinal edema in smoke inhalation.

Rapid method for simultaneous determination of flavonoid, saponins and polyacetylenes in folium ginseng and radix ginseng by pressurized liquid extraction and high-performance liquid chromatography coupled with diode array detection and mass spectrometry

A rapid pressurized liquid extraction (PLE) and high-performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MS) method for the simultaneous determination of one flavonoid (panasenoside), nine saponins (ginsenoside Rg1, Re, Rf, Rg2, Rb1, Rc, Rb2, Rb3 and Rd) and two polyacetylenes (panaxydol and panaxynol) in folium ginseng and radix ginseng was developed. A Prevail C(18) rocket column (33 mm x 7 mm, 3.0 microm) and gradient elution were used during the analysis. Flavonoid was quantified at 355 nm, and saponins and polyacetylenes were determined at 203 nm. The chromatographic peaks of 12 investigated compounds in samples were unambiguously identified by compared their UV spectra and/or MS data with the related reference compounds. All calibration curves showed good linearity (r>0.999) within the test ranges. The intra- and inter-day variations for 12 analytes were less than 1.17% and 2.17%, respectively. The developed method was successfully applied to determine the investigated compounds in 10 samples of radix ginseng and folium ginseng, respectively. The result showed that PLE combined with rocket column HPLC analysis could provide a rapid method for analysis of compounds in traditional Chinese medicines (TCMs), which is helpful to comprehensive evaluation of quality of radix ginseng and folium ginseng.