The pattern of tumor progression on first-line immune checkpoint inhibitor-based systemic therapy for Chinese advanced hepatocellular carcinoma -CLEAP 004 study

Background

For decades, stratification criteria for first-line clinical studies have been highly uniform. However, there is no principle or consensus for restratification after systemic treatment progression based on immune checkpoint inhibitors (ICIs). The aim of this study was to assess the patterns of disease progression in patients with advanced hepatocellular carcinoma (HCC) who are not eligible for surgical intervention, following the use of immune checkpoint inhibitors.

Methods

This is a retrospective study that involved patients with inoperable China liver stage (CNLC) IIIa and/or IIIb. The patients were treated at eight centers across China between January 2017 and October 2022. All patients received at least two cycles of first-line treatment containing immune checkpoint inhibitors. The patterns of disease progression were assessed using RECIST criteria 1.1. Different progression modes have been identified based on the characteristics of imaging progress. The study's main outcome measures were post-progression survival (PPS) and overall survival (OS). Survival curves were plotted using the Kaplan-Meier method to compare the difference among the four groups. Subgroup analysis was conducted to compare the efficacy of different immunotherapy combinations. Variations in the efficacy of immunotherapy have also been noted across patient groups exhibiting alpha-fetoprotein (AFP) levels equal to or exceeding 400ng/mL, in contrast to those with AFP levels below 400ng/mL.

Results

The study has identified four distinct patterns of progress, namely p-IIb, p-IIIa, p-IIIb, and p-IIIc. Diverse patterns of progress demonstrate notable variations in both PPS and OS. The group p-IIb had the longest PPS of 12.7m (95% 9.3-16.1) and OS 19.6m (95% 15.6-23.5), the remaining groups exhibited p-IIIb at PPS 10.5 months (95%CI: 7.9-13.1) and OS 19.2 months (95%CI 15.1-23.3). Similarly, p-IIIc at PPS 5.7 months (95%CI: 4.2-7.2) and OS 11.0 months (95%CI 9.0-12.9), while p-IIIa at PPS 3.4 months (95%CI: 2.7-4.1) and OS 8.2 months (95%CI 6.8-9.5) were also seen. Additional stratified analysis was conducted and showed there were no differences of immunotherapy alone or in combination in OS (HR= 0.92, 95%CI: 0.59-1.43, P=0.68) and PPS (HR= 0.88, 95%CI: 0.57-1.36, P=0.54); there was no significant difference in PPS (HR=0.79, 95% CI: 0.55-1.12, P=0.15) and OS (HR=0.86, 95% CI: 0.61-1.24, P=0.39) for patients with AFP levels at or over 400ng/mL. However, it was observed that patients with AFP levels above 400ng/mL experienced a shorter median progression of PPS (8.0 months vs. 5.0 months) after undergoing immunotherapy.

Conclusion

In this investigation of advanced hepatocellular carcinoma among Chinese patients treated with immune checkpoint inhibitors, we identified four distinct progression patterns (p-IIb, p-IIIa, p-IIIb and p-IIIc) that showed significant differences in PPS and OS. These findings demonstrate the heterogeneity of disease progression and prognosis after immunotherapy failure. Further validation in large cohorts is necessary to develop prognostic models that integrate distinct progression patterns to guide subsequent treatment decisions. Additionally, post-immunotherapy progression in patients with AFP levels ≥400ng/mL indicates a shortened median PPS. These findings provide valuable insights for future personalized treatment decisions.

Change of indocyanine green clearance ability and liver function after transcatheter intraarterial therapies and its impact on outcomes of resectable hepatocellular carcinoma: a retrospective cohort study

BACKGROUND

Indocyanine green (ICG) clearance test is a classical measurement of hepatic reserve, which involves surgical safety and patient recovery of hepatocellular carcinoma (HCC). We aim to compare effects of hepatic arterial infusion chemotherapy (HAIC) and transcatheter arterial chemoembolization (TACE) on liver function and outcomes of subsequent hepatectomy.

MATERIAL AND METHODS

HCC patients receiving HAIC/TACE in SYSUCC with repeated ICG clearance tests were retrospectively enrolled. ICG eliminating rate (ICG-K), ICG retention rate at 15-minutes (ICG-R15) and ordinary laboratory tests were collected. Peri-therapeutic changes of values were compared between the groups. Propensity score matching (PSM) and inverse probability of treatment weighing (IPTW) were employed to validate findings. Post-hepatectomy liver failure (PHLF), overall survival (OS) and recurrence-free survival (RFS) were analyzed in patients with subsequent curative hepatectomy.

RESULTS

204 patients treated with HAIC (n=130) and TACE (n=74) were included. ΔICG-R15 was greater in the HAIC arm before matching (mean, 3.8% vs. 0.7%, P<0.001), after PSM (mean, 4.7% vs. 1.1%, P=0.014) and IPTW (mean, 2.0% vs. -3.6%, P<0.001). No difference was found for ΔALB, ΔALBI, ΔTBIL, ΔALT, ΔAST and ΔPT-INR. Multivariable analyses revealed elder age, cirrhosis, HAIC, greater ΔTBIL and ΔALBI were associated with deteriorating ICG-R15. Among those (105 for HAIC and 48 for TACE) receiving hepatectomy, occurrence of grade B/C PHLF (4.8% vs. 8.3%, P=0.616), OS (median, unreached vs. unreached, P=0.94) and RFS (median, 26.7 vs. 17.1 mo, P=0.096) were comparable between the two arms. In subgroup analyses, preoperative HAIC yield superior RFS (median, 26.7 vs. 16.2 mo, P=0.042) in patients with baseline ICG-R15≤10%.

CONCLUSION

Preoperative FOLFOX-HAIC caused apparent impairment of ICG clearance ability than TACE yet comparable impact on liver function and post-hepatectomy outcomes.

[Percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of spinal metastases]

OBJECTIVE

To investigate the effectiveness of percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of patients with spinal metastases.

METHODS

In the study, 12 patients of spinal metastases treated with percutaneous pedicle screw fixation combined expandable tubular retractor in our hospital were retrospectively reviewed between June 2017 and October 2019. Among the 12 patients, 9 were males and 3 were females; the median age was 62.5 years [(65.1±2.9) years]. The decompression segment of 7 patients was located at the lower thoracic spine (including 1 patient with incomplete paraplegia) and the decompression segment of 5 patients was located at the lumbar spine; Tomita score was 6.0±0.6. Perioperative data of the patients were reviewed. Visual analog scale (VAS score), Karnofsky score, and Eastern Cooperative Oncology Group (ECOG) score were compared before and after surgery. The patient's survival, adjuvant treatment, and internal fixation failure were observed in the follow-up period.

RESULTS

All the 12 patients had a successful operation with percuta-neous pedicle screw fixation combined expandable tubular retractor. The average operative time, blood loss, and blood transfused of the patients were (247.0±14.6) min, (804.2±222.3) mL and (500.0±100.0) mL, respectively. The average amount of drainage was (240.8±79.3) mL. Drainage tubes were pulled out early postoperative [(3.2±0.3) d], allowing early mobilization. The patients discharged (7.8±0.8) d postoperative. All the patients were followed up for 6-30 months, and the average overall survival time was (13.6±2.4) months. During the follow-up period, 2 patients experienced screw displacement, the internal fixation was stable after conservative treatment and no revision surgery was performed. The VAS of the patients was 7.1±0.2 before surgery, which decreased to 2.3±0.1 and 2.8±0.4 at 3 and 6 months after surgery (P < 0.05). The Karnofsky score of the patients was 59.2±1.9 before surgery, which increased to 75.0±1.9 and 74.2±3.1 at 3 and 6 months after surgery (P < 0.05). The ECOG of the patients was 2.3±0.2 before surgery, which decreased to 1.7±0.1 and 1.7±0.2 at 3 and 6 months after surgery (P < 0.05).

CONCLUSION

For selected patients with spinal metastases, minimally invasive surgical treatment of spinal metastases (percutaneous pedicle screw internal fixation combined with expandable tubular retractor) can effectively relieve the clinical symptoms and improve the quality of life, with satisfactory clinical outcome.

Prognostic Values of Alpha-Fetoprotein and Des-Gamma-Carboxyprothrombin in Hepatocellular Carcinoma in China: An Analysis of 4792 Patients

Background

The importance of alpha-fetoprotein (AFP) and des-gamma-carboxyprothrombin (DCP) in hepatocellular carcinoma (HCC) has been studied extensively in Japan, where hepatitis C virus is the predominant aetiology of HCC. The clinical profiles of HCC regarding the state of AFP and DCP in a hepatitis B virus epidemic area have not been comprehensively investigated, and the value of these tumour markers in evaluating the response to treatment and the detection of recurrence has yet to be determined.

Patients and Methods

A total of 4792 patients treated in our centre were continuously analysed regarding accessible AFP and DCP data pre- and posttreatment. Baseline characteristics were summarized, and comparisons of progression-free survival (PFS) and overall survival (OS) rates were made independently. The prognostic significance of each factor was tested with the Cox proportional hazards model. Patients who had AFP and DCP data pretreatment, pre- and posttreatment, and those who were continuously monitored more than twice were analysed separately.

Results

A total of 2600 patients (53.4%) were positive for AFP and DCP; 362 (7.6%) and 1211 (25.3%) patients were AFP- or DCP-positive, respectively, and 619 patients (12.9%) were negative for both AFP and DCP. Patients in the AFP single-positive or double-negative groups had the best OS (P<0.001). Patients with less than 50% responses in AFP and DCP after treatments suffered from worse prognostic survival (P<0.001). In the multivariate analysis, elevated AFP and DCP were identified as independent prognostic factors of PFS and OS. In addition, different tumour markers were related to different clinical and pathological traits.

Conclusion

The present study comprehensively explored the clinical value of classical tumour markers for HCC using the “point-to-line” method. Positivity of pretreatment AFP and DCP or less than 50% treatment response rates exhibited more aggressive HCC, resulting in poor PFS and OS in HCC patients.

Stereotactic Body Radiotherapy vs. Radiofrequency Ablation in the Treatment of Hepatocellular Carcinoma: A Meta-Analysis

Background: Both stereotactic body radiotherapy (SBRT) and radiofrequency ablation (RFA) are effective local treatments for hepatocellular carcinoma (HCC), but whether RFA is superior to SBRT is still controversial. Therefore, we performed a meta-analysis to compare the treatment outcomes of SBRT with RFA as curable or bridge intention. Methods: We searched online databases for studies that compared treatment outcomes for SBRT and RFA. Eligibility criteria included evaluation of local control, overall survival (OS), transplant rate, and post-transplant pathological necrosis. Results: As no randomized clinical trials met the criteria, 10 retrospective studies with a total of 2,732 patients were included. Two studies were in favor of SBRT in local control, two studies preferred RFA in OS, and others reported comparable outcomes for both. SBRT demonstrated significantly higher 1- and 3-year local control than RFA [odds ratio (OR) 0.42, 95% CI 0.24-0.74, P = 0.003; and OR 0.54, 95% CI 0.37-0.80, P = 0.002, respectively]. However, SBRT reported significantly shorter 1- and 2-year OS (OR 1.52, 95% CI 1.21-1.90, P = 0.0003; and OR 1.66, 95% CI 1.38-2.01, P < 0.00001, respectively). As bridge treatment, no significant difference was shown in transplant rate and post-transplant pathological necrosis rate (OR 0.57, 95% CI 0.32-1.03, P = 0.060; and OR 0.49, 95% CI 0.13-1.82, P = 0.290, respectively). Conclusions: This study demonstrates SBRT is able to complete a better local control for HCC than RFA, though the OS is inferior to RFA because of tumor burden or liver profiles of the enrolled studies. Well-designed, randomized, multicenter trials will be required to further investigate the conclusion.

Tescalcin is an unfavorable prognosis factor that regulats cell proliferation and survival in hepatocellular carcinoma patients

Background

Hepatocellular carcinoma (HCC) is a major health problem and a primary cause of cancer‐related death worldwide. Although great advances have achieved recently by large‐scale high‐throughput analysis, the precise molecular mechanism underlying HCC progression remains to be clearly elucidated. We investigated the relationship between Tescalcin (TESC), a candidate oncogene, and clinicopathological features of HCC patients and explored the role of TECS in HCC development.

Methods

To identify new genes involved in HCC development, we analyzed The Cancer Genome Atlas liver cancer database, and TESC was selected for further investigation. HCC tissue microarray analysis for TESC and its association with clinicopathological features were performed to investigate its clinical significance. TESC was knocked down by using short‐hairpin RNAs. Cell proliferation was analyzed by WST‐1 assay and cell counting. Cell apoptosis was tested by fluorescence‐activated cell sorting. A subcutaneous xenograft tumor model in nude mice was established to determine the in vivo function of TESC. Affymetrix microarray was used to identify its molecular mechanism.

Results

TESC was significantly increased in HCC tissues compared with the adjacent normal liver tissues. High expression of TESC was detected in 61 of 172 HCC patients by tissue microarray. Large tumor (> 5 cm) and elevated total bilirubin were associated with high TESC expression (both P < 0.050). In multivariate analysis, TESC was identified as an independent prognostic factor for short overall survival of HCC patients. TESC knockdown impaired HCC cell growth in vitro and in vivo. TESC knockdown significantly increased cell apoptosis in HCC cell lines. Furthermore, Affymetrix microarray analysis revealed that TESC knockdown inhibited tumor proliferation‐related pathways while activated cell death‐related pathways.

Conclusion

TESC was identified as an independent prognostic factor for short overall survival of HCC patients, and was critical for HCC cell proliferation and survival.

Preventive effect of celecoxib in sorafenib-related hand-foot syndrome in hepatocellular carcinoma patients, a single-center, open-label, randomized, controlled clinical phase III trial

Skin toxicity, especially hand-foot syndrome (HFS), is one of the most common sorafenib-induced adverse events (AEs) in hepatocellular carcinoma (HCC) patients, leading to treatment interruption and failure. Mucocutaneous inflammation may cause HFS; therefore, we investigated whether celecoxib can alleviate HFS, improve patients' quality of life and increase survival when administered in conjunction with active therapy. Our randomized, open-label study prospectively enrolled 116 advanced HCC patients receiving sorafenib as targeted therapy from July 2015 to July 2016. All patients were randomly assigned (1:1) via a computer-generated sequence to receive sorafenib with or without celecoxib. Sorafenib-related AEs were recorded, Survival was compared between the two groups. Compared to the Sorafenib group, the SoraCele group had lower incidence rates of ≥ grade 2 and grade 3 HFS (63.8% vs 29.3%, P < 0.001; 19.0% vs 3.4%, P = 0.008, respectively), hair loss, rash and abdominal pain. Kaplan-Meier analysis revealed a lower risk of ≥ grade 2 HFS (HR, 0.384; P = 0.002) and a lower dose reduction/interruption rate (46.6% to 15.5%, P < 0.001) in the SoraCele group. Cox proportional hazards regression analysis demonstrated that celecoxib was the only independent predictive factor of developing ≥ grade 2 HFS (HR, 0.414; P = 0.004). Longer progression-free survival (PFS) was also observed in the SoraCele group (P = 0.039), although overall survival was not prolonged (P = 0.305). These results suggest that sorafenib + Celecoxib administration alleviated sorafenib-related skin toxicity. Longer PFS was achieved in clinical practice, although overall survival was not prolonged (ClinicalTrials.gov: NCT02961998).

Radiofrequency ablation versus laparoscopic hepatectomy for hepatocellular carcinoma: A real world single center study

BACKGROUND

Both radiofrequency ablation (RFA) and laparoscopic hepatectomy (LH) are minimally invasive approach for hepatocellular carcinoma (HCC) at early stage. This study aimed to compare the efficacy of RFA and LH for treating HCC with a large cohort.

METHODS

From March 2014 to July 2016, 477 patients who underwent RFA (n = 314) or LH (n = 163) for HCC tumors meeting the criteria were included. Overall survival (OS) and recurrence-free survival (RFS) were compared. Propensity score matching (PSM) was performed to balance for the factors that may affect the choice of treatment.

RESULTS

Collectively, the 1-, 2- and 3-year OS rates were significantly greater after LH than RFA, as well the corresponding RFS rates, before and after PSM by 2:1. However, the RFA group had fewer major complications (P=0.004), shorter postoperative stays (P=0.023) and lower hospital charges (P<0.001) than the LH group. In the subgroup analysis, RFA demonstrated comparable RFS in treating less than 3 cm tumor (P=0.22) located in noncentral bisection (SII, SIII, SVI, SVII) and tumor between 3 cm and 5 cm (P=0.07) located in central bisections (SIV, SV, SVIII). The female, HBV infection, and RFA are factors of worse OS, and the latter two factors also indicated higher RFS.

CONCLUSIONS

Though, LH possessed superior intrahepatic control rate than RFA in most condition of tumor smaller than 5 cm, the RFA could be an optimal approach achieved comparable outcomes in patients with centrally located HCC, with fewer major complications, shorter postoperative stays and lower hospital charges.

A nomogram predicting the recurrence of hepatocellular carcinoma in patients after laparoscopic hepatectomy

BACKGROUND

Patients with hepatocellular carcinoma (HCC) undergoing surgical resection still have a high 5-year recurrence rate (~ 60%). With the development of laparoscopic hepatectomy (LH), few studies have compared the efficacy between LH and traditional surgical approach on HCC. The objective of this study was to establish a nomogram to evaluate the risk of recurrence in HCC patients who underwent LH.

METHODS

The clinical data of 432 patients, pathologically diagnosed with HCC, underwent LH as initial treatment and had surgical margin > 1 cm were collected. The significance of their clinicopathological features to recurrence-free survival (RFS) was assessed, based on which a nomogram was constructed using a training cohort (n = 324) and was internally validated using a temporal validation cohort (n = 108).

RESULTS

Hepatitis B surface antigen (hazard ratio [HR], 1.838; P = 0.044), tumor number (HR, 1.774; P = 0.003), tumor thrombus (HR, 2.356; P = 0.003), cancer cell differentiation (HR, 0.745; P = 0.080), and microvascular tumor invasion (HR, 1.673; P  =0.007) were found to be independent risk factors for RFS in the training cohort, and were used for constructing the nomogram. The C-index for RFS prediction in the training cohort using the nomogram was 0.786, which was higher than that of the 8th edition of the American Joint Committee on Cancer TNM classification (C-index, 0.698) and the Barcelona Clinic Liver Cancer staging system (C-index, 0.632). A high consistency between the nomogram prediction and actual observation was also demonstrated by a calibration curve. An improved predictive benefit in RFS and higher threshold probability of the nomogram were determined by receiver operating characteristic curve analysis, which was also confirmed in the validation cohort compared to other systems.

CONCLUSIONS

We constructed and validated a nomogram able to quantify the risk of recurrence after initial LH for HCC patients, which can be clinically implemented in assisting the planification of individual postoperative surveillance protocols.

Erratum: Observation of D^{0} Meson Nuclear Modifications in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 113, 142301 (2014)]

This corrects the article DOI: 10.1103/PhysRevLett.113.142301.

Dijet imbalance measurements in Au+Au and pp collisions at sqrt[s_{NN}]=200 GeV at STAR

We report the first dijet transverse momentum asymmetry measurements from Au+Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2  GeV/c display a significantly higher momentum imbalance in heavy-ion collisions than in the pp reference. When reexamined with correlated soft particles included, we observe that these dijets then exhibit a unique new feature-momentum balance is restored to that observed in pp for a jet resolution parameter of R=0.4, while rebalancing is not attained with a smaller value of R=0.2.

[Clinical characteristics and prognosis of cultured negative pyogenic spondylitis]

OBJECTIVE

There are limited data describing the clinical characteristics and prognosis of culture negative pyogenic spondylitis. The aim of this study was to investigate the treatment, prognosis and clinical characteristics of culture negative pyogenic spondylitis.

METHODS

A retrospective study reviewed 74 patients who were diagnosed with spondylitis in Peking University First Hospital from January 2010 to December 2015. A total of 27 patients suffered from pyogenic spondylitis. According to the pathogenic culture results, the patients were divided into two groups: culture negative group and culture positive group. The clinical characteristics and treatment outcomes between the two groups were compared.

RESULTS

The elder were more vulnerable to pyogenic spondylitis, and of the 27 patients, 12 patients were female and 15 male. All patients had no history of administration of antibiotics prior to obtaining culture samples. A causative germ was identified in 14/27 patients (51.9%) with Staphylococcus aureus being the most common pathogen. There was no significant difference between the two groups in the patient's age, gender, visual analogue score (VAS), predisposing factor, clinical symptom, sign and spinal segment (P>0.05). Erythrocyte sedimentation rate (ESR) (P=0.056) and C-reactive protein (CRP) (P=0.040) of culture negative group were lower in contrast to culture positive group. The incidence of vertebral abscess in culture negative group was higher than in culture positive group (P=0.046). After treatment, ESR dropped almost equally in both groups, and CRP dropped faster in the culture positive group (P=0.192). At last, there was no significant difference between the two groups in hospital stay, pain relief, open debridement operation rate, and recurrence rate of infection.

CONCLUSION

ESR and CRP of the culture negative patient were lower than those of the culture positive patient, and the incidence rate of paravertebral abscess was higher than that of the culture positive patient. After administration of antibiotics, there was no significant difference between the two groups in duration of antibiotics, open debridement operation rate and recurrence rate of infection. So, culture negative may not necessarily be a negative prognostic factor for pyogenic spondylitis. However, we should watch out for the drug resistant bacteria or double infection, due to the long term use of wide-spectrum antibiotic in culture negative patients.

Charge-Dependent Directed Flow in Cu+Au Collisions at sqrt[s_{NN}]=200 GeV

We present the first measurement of charge-dependent directed flow in Cu+Au collisions at sqrt[s_{NN}]=200  GeV. The results are presented as a function of the particle transverse momentum and pseudorapidity for different centralities. A finite difference between the directed flow of positive and negative charged particles is observed that qualitatively agrees with the expectations from the effects of the initial strong electric field between two colliding ions with different nuclear charges. The measured difference in directed flow is much smaller than that obtained from the parton-hadron-string-dynamics model, which suggests that most of the electric charges, i.e., quarks and antiquarks, have not yet been created during the lifetime of the strong electric field, which is of the order of, or less than, 1  fm/c.

Measurement of the Transverse Single-Spin Asymmetry in p^{↑}+p→W^{±}/Z^{0} at RHIC

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at sqrt[s]=500  GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.

Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au+Au Collisions at RHIC

We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au+Au collisions for energies ranging from sqrt[s_{NN}]=7.7 to 200 GeV. The third harmonic v_{3}^{2}{2}=⟨cos3(ϕ_{1}-ϕ_{2})⟩, where ϕ_{1}-ϕ_{2} is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη=η_{1}-η_{2}. Nonzero v_{3}^{2}{2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v_{3}^{2}{2} persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v_{3}^{2}{2} is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v_{3}^{2}{2} for central collisions shows a minimum near sqrt[s_{NN}]=20  GeV.

Centrality and Transverse Momentum Dependence of Elliptic Flow of Multistrange Hadrons and ϕ Meson in Au+Au Collisions at √[sNN]=200 GeV

We present high precision measurements of elliptic flow near midrapidity (|y|<1.0) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy √[sNN]=200  GeV. We observe that the transverse momentum dependence of ϕ and Ω v2 is similar to that of π and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between ϕ and proton v2 at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v2.

Antisense expression of Gossypium hirsutum UDP-glucuronate decarboxylase in Arabidopsis leads to changes in cell wall components

UDP-glucuronate decarboxylase (UDP-xylose synthase; UXS, EC 4.1.1.35) is an essential enzyme of the non-cellulosic polysaccharide biosynthetic pathway. In the present study, using transient expression of fluorescently labeled Gossypium hirsutum UXS (GhUXS3) protein in onion epidermal cells, we observed that this protein was distributed in the cytoplasm. The GhUXS3 cDNA of cotton was expressed in an antisense orientation in Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation. Homozygous plants showing down-regulation of UXS were analyzed with northern blots. Compared to the untransformed control, transgenic plant showed shorter roots, earlier blossom formation, and delayed senescence. Biochemical analysis indicated that levels of rhamnose, mannose, galactose, glucose, xylose, and cellulose were reduced in some of the down-regulated antisense plants. These results suggest that GhUXS3 regulates the conversion of non-cellulosic polysaccharides and modulates their composition in plant cell walls. We also discuss a possible cellular function for GhUXS in determining the quality of cotton fibers.

Observation of Transverse Spin-Dependent Azimuthal Correlations of Charged Pion Pairs in p^{↑}+p at sqrt[s]=200 GeV

We report the observation of transverse polarization-dependent azimuthal correlations in charged pion pair production with the STAR experiment in p^{↑}+p collisions at RHIC. These correlations directly probe quark transversity distributions. We measure signals in excess of 5 standard deviations at high transverse momenta, at high pseudorapidities η>0.5, and for pair masses around the mass of the ρ meson. This is the first direct transversity measurement in p+p collisions.

Azimuthal Anisotropy in U+U and Au+Au Collisions at RHIC

Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v_{2}{2} and v_{2}{4}, for charged hadrons from U+U collisions at sqrt[s_{NN}]=193  GeV and Au+Au collisions at sqrt[s_{NN}]=200  GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v_{2}{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. We also show that v_{2} vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s]=200 GeV

We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05.

ΛΛ Correlation function in Au+Au collisions at √[S(NN)]=200 GeV

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200  GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.

Observation of D0 meson nuclear modifications in Au+Au collisions at sqrt[s(NN)] = 200 GeV

We report the first measurement of charmed-hadron (D(0)) production via the hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N(bin), from p+p to central Au+Au collisions. The D(0) meson yields in central Au + Au collisions are strongly suppressed compared to those in p+p scaled by N(bin), for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p(T) is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

Beam energy dependence of moments of the net-charge multiplicity distributions in Au+Au collisions at RHIC

We report the first measurements of the moments--mean (M), variance (σ(2)), skewness (S), and kurtosis (κ)--of the net-charge multiplicity distributions at midrapidity in Au+Au collisions at seven energies, ranging from sqrt[sNN]=7.7 to 200 GeV, as a part of the Beam Energy Scan program at RHIC. The moments are related to the thermodynamic susceptibilities of net charge, and are sensitive to the location of the QCD critical point. We compare the products of the moments, σ(2)/M, Sσ, and κσ(2), with the expectations from Poisson and negative binomial distributions (NBDs). The Sσ values deviate from the Poisson baseline and are close to the NBD baseline, while the κσ(2) values tend to lie between the two. Within the present uncertainties, our data do not show nonmonotonic behavior as a function of collision energy. These measurements provide a valuable tool to extract the freeze-out parameters in heavy-ion collisions by comparing with theoretical models.

Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC

We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05<x<0.2.

Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

Dielectron mass spectra from Au+Au collisions at √[s(NN)]=200 GeV

We report the STAR measurements of dielectron (e(+)e(-)) production at midrapidity (|y(ee)|<1) in Au+Au collisions at √[s(NN)]=200  GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 (ρ-like), 0.76-0.80 (ω-like), and 0.98-1.05 (ϕ-like)   GeV/c(2). The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the ρ meson. The excess yield in the ρ-like region increases with the number of collision participants faster than the ω and ϕ yields. Theoretical models with broadened ρ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.

Beam-energy dependence of the directed flow of protons, antiprotons, and pions in Au+Au collisions

Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

Jet-hadron correlations in √[s(NN)]=200 GeV p+p and central Au+Au collisions

Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √[s(NN)]=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

Energy dependence of moments of net-proton multiplicity distributions at RHIC

We report the beam energy (sqrt[sNN]=7.7-200  GeV) and collision centrality dependence of the mean (M), standard deviation (σ), skewness (S), and kurtosis (κ) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y|<0.5) and within the transverse momentum range 0.4<pT<0.8  GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the quantum chromodynamic phase diagram. The products of the moments, Sσ and κσ2, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and antiproton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation and also to a hadron resonance gas model.

Iron reduction and mineralization of deep-sea iron reducing bacterium Shewanella piezotolerans WP3 at elevated hydrostatic pressures

In this study, iron reduction and concomitant biomineralization of a deep-sea iron reducing bacterium (IRB), Shewanella piezotolerans WP3, were systematically examined at different hydrostatic pressures (0.1, 5, 20, and 50 MPa). Our results indicate that bacterial iron reduction and induced biomineralization are influenced by hydrostatic pressure. Specifically, the iron reduction rate and extent consistently decreases with the increase in hydrostatic pressure. By extrapolation, the iron reduction rate should drop to zero by ~68 MPa, which suggests a possible shut-off of enzymatic iron reduction of WP3 at this pressure. Nano-sized superparamagnetic magnetite minerals are formed under all the experimental pressures; nevertheless, even as magnetite production decreases, the crystallinity and grain size of magnetite minerals increase at higher pressure. These results imply that IRB may play an important role in iron reduction, biomineralization, and biogeochemical cycling in deep-sea environments.

Measurement of J/ψ azimuthal anisotropy in Au+Au collisions at sqrt[s(NN)]=200 GeV

The measurement of J/ψ azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at sqrt[s(NN)]=200 GeV. The measured J/ψ elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/ψ particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

Observation of an energy-dependent difference in elliptic flow between particles and antiparticles in relativistic heavy ion collisions

Elliptic flow (v(2)) values for identified particles at midrapidity in Au + Au collisions, measured by the STAR experiment in the beam energy scan at RHIC at sqrt[s(NN)] = 7.7-62.4 GeV, are presented. A beam-energy-dependent difference of the values of v(2) between particles and corresponding antiparticles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and antiparticles are not consistent with the universal number-of-constituent-quark scaling of v(2) that was observed at sqrt[s(NN)] = 200 GeV.

Cloning of a phosphatidylinositol 4-kinase gene based on fiber strength transcriptome QTL mapping in the cotton species Gossypium barbadense

Sea Island cotton (Gossypium barbadense) is highly valued for its superior fiber qualities, especially fiber strength. Based on a transcript-derived fragment originated from transcriptome QTL mapping, a fiber strength related candidate gene of phosphatidylinositol 4-kinase cDNA, designated as GbPI4K, was first cloned, and its expression was characterized in the secondary cell wall thickening stage of G. barbadense fibers. The ORF of GbPI4K was found to be 1926 bp in length and encoded a predicted protein of 641 amino acid residues. The putative protein contained a clear PI3/4K kinase catalytic domain and fell into the plant type II PI4K cluster in phylogenetic analysis. In this study, the expression of cotton PI4K protein was also induced in Escherichia coli BL21 (DE3) as a fused protein. Semi-quantitative RT-PCR analysis showed that the gene expressed in the root, hypocotyl and leaf of the cotton plants. Real-time RT-PCR indicated that this gene in Sea Island cotton fibers expressed 10 days longer than that in Upland cotton fibers, and the main expression difference of PI4K between Sea Island cotton and Upland cotton in fibers was located in the secondary cell wall thickening stage of the fiber. Further analysis indicated that PI4K is a crucial factor in the ability of Rac proteins to regulate phospholipid signaling pathways.

Directed flow of identified particles in Au+Au collisions at √[SNN]=200 GeV at RHIC

STAR's measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p[over ¯] in Au+Au collisions at √[sNN]=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p[over ¯]). In 5%-30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.

White light generation in Eu- and Mn-codoped Ca(7)Mg(2)P(6)O(24) phosphor for white light-emitting diodes

Polycrystalline Ca(7)Mg(2)P(6)O(24):Eu(2+),Mn(2+) phosphors were prepared by a solid-state reaction under a weak reductive atmosphere. The phosphors have been characterized by X-ray diffraction and fluorescence measurements. The results show that the obtained phosphors are of single-phase rhombohedral Ca(7)Mg(2)P(6)O(24). Upon excitation of 355nm ultraviolet (UV) light, two intense broad bands have clearly been observed due to the allowed 5d-4f transition of Eu(2+) and the forbidden (4)T(1)-(6)A(1) transition of Mn(2+), respectively. A white light has been obtained from Ca(7)Mg(2)P(6)O(24):0.035Eu(2+),0.5Mn(2+) phosphor with CIE chromaticity coordinates of (x=0.32, y=0.29) and color temperature of 6175K. These results suggest that Ca(7)Mg(2)P(6)O(24):Eu(2+),Mn(2+) phosphors could be a promising candidate for UV-converting white light-emitting diodes (LEDs).

Early evidence of the genus Homo in East Asia

The timing and route of the earliest dispersal from Africa to Eastern Asia are contentious topics in the study of early human evolution because Asian hominin fossil sites with precise age constraints are very limited. Here we report new high-resolution magnetostratigraphic results that place stringent age controls on excavated hominin incisors and stone tools from the Yuanmou Basin, southwest China. The hominin-bearing layer resides in a reverse polarity magnetozone just above the upper boundary of the Olduvai subchron, yielding an estimated age of 1.7Ma. The finding represents the age of the earliest documented presence of Homo, with affinities to Homo erectus, in mainland East Asia. This age estimate is roughly the same as for H. erectus in island Southeast Asia and immediately prior to the oldest archaeological evidence in northeast Asia. Mammalian fauna and pollen obtained directly from the hominin site indicate that the Yuanmou hominins lived in a varied habitat of open vegetation with patches of bushland and forest on an alluvial fan close to a lake or swamp. The age and location are consistent with a rapid southern migration route of initial hominin populations into Eastern Asia.

Enhancement of phosphor efficiency via composition modification

The luminescence efficiency of Mn4+-doped CaAl12O19 (Mn:CAO) is significantly improved by composition modification. The leading mechanism that quenches the Mn4+ photoluminescence is the formation of Mn4+ pairs in the lattice of CaAl12O19 (CAO) with interstitial O2- for charge compensation. Mixing Mg2+ ions into the CAO lattice may form Mn4+-Mg2+ pairs and reduce the number of Mn4+ pairs, thus enhancing the Mn4+ luminescence efficiency by more than three times. It is shown that the presence of Mg2+ leads to formation of additional phases that also affect the optical properties of Mn4+.

Cooperative Energy Transfer and Frequency Upconversion in Yb3+–Tb3+ and Nd3+–Yb3+–Tb3+ Codoped GdAl3(BO3)4 Phosphors

Polycrystalline GdAl(3)(BO(3))(4) phosphors co-doped with Yb(3+)/Tb(3+) and/or Nd(3+)/Yb(3+)/Tb(3+) have been synthesized by combustion method. Upon excitation with a 980 nm laser diode, an intense green upconversion luminescence has been observed in GdAl(3)(BO(3))(4):Yb,Tb phosphor. The quadratic dependence of the luminescence on the pump-laser power indicating a cooperative energy transfer process. Meanwhile, it is noticed that upon excitation with 808 nm laser diode, intense luminescence has clearly been detected in GdAl(3)(BO(3))(4):Nd,Yb,Tb phosphor. The luminescence intensity exhibits also a quadratic dependence on incident pump-laser power. However, no green-emission has been observed in GdAl(3)(BO(3))(4) phosphors co-doped with Yb(3+)/Tb(3+) or Nd(3+)/Tb(3+) respectively upon excited at 808 nm laser diode. A proposed upconversion mechanism involving energy transfer from Nd(3+) to Yb(3+), and then a cooperative energy transfer process from two excited Yb(3+) to Tb(3+) has been presented.

Comparative Investigation on Nanocrystal Structure and Luminescence Properties of Gadolinium Molybdates Codoped with Er3+/Yb3+

This paper reports on the comparative investigation of nanocrystal structure and luminescence properties of Er(3+)/Yb(3+)-codoped gadolinium molybdate nanocrystals Gd(2)(MoO(4))(3) and Gd(2)MoO(6) synthesized by the Pechini method with citric acid and ethylene glycol. Their crystallization, structure transformation, and morphologies have been investigated by X-ray diffraction, thermogravimetric/differential scanning calorimetry, and transmission electron microscopy. It is noticed that Er(3+)/Yb(3+)-codoped monoclinic Gd(2)(MoO(4))(3) nanocrystals have shown an intense upconversion through a sintering of the organic complex precursor at 600 degrees C. Furthermore, it transforms to orthorhombic Gd(2)(MoO(4))(3) when the precursor is sintered at 900 degrees C. In counterpart of monoclinic Gd(2)MoO(6), however, the monoclinic structure remains unchanged when the precursor is sintered at a temperature ranging from 600 degrees C to 900 degrees C. Intense visible emissions of Er(3+) attributed to the transitions of (2)H(11/2), (4)S(3/2)-(4)I(15/2) at 520 and 550 nm, and (4)F(9/2)-(4)I(15/2) at 650 nm have been observed upon an excitation with a UV source and a 980 nm laser diode, and the involved mechanisms have been explained. It is quite interesting to observe obvious differences both in the excitation and the upconversion emission spectra of Er(3+)/Yb(3+)-codoped Gd(2)(MoO(4))(3) respectively with monoclinic and orthorhombic structure. The quadratic dependence of fluorescence on excitation laser power has confirmed that two-photons contribute to upconversion of the green-red emissions.

Decreased levels of apolipoprotein A-I in plasma of schizophrenic patients

This study aims to identify the effects of antipsychotics on plasma proteins, and on the proteins associated with schizophrenia. We applied proteomics technology to screen protein aberrations in Sprague-Dawley rats treated with antipsychotics and schizophrenic patients undergoing medication. ApoA-I was found significantly increased in the chlorpromazine-treated rats and decreased in the patients with treatment-resistant schizophrenia, which suggest that decreased levels of apoA-I might be associated with the pathology of schizophrenia and that chlorpromazine increases apoA-I levels as part of its therapeutic action.

Interleukin-10 −1082 promoter polymorphism is associated with schizophrenia in a Han Chinese sib-pair study

The interleukin-10 (IL-10) gene has been identified as a susceptibility gene for schizophrenia in Caucasians. A previous case-control study conducted by our group revealed a weak association between polymorphism, -592C/A, of the IL-10 gene promoter and schizophrenia. Our present study was aimed at confirming the association of the IL-10 promoter with schizophrenia using 197 Han Chinese sib-pair families. A family-based association test (FBAT) and haplotype analysis was undertaken using the FBAT v1.5.5. The global TDT was significant for a different polymorphism, -1082G/A (chi2=13.16, P=0.000285) and that the allele -1082G was preferentially transmitted to schizophrenia-affected children. Furthermore, haplotype TDT analysis showed that haplotype "GCC" was significantly associated with the disease (chi2=8.1, P=0.00443). Our results also indicate that the IL-10 gene may play a significant role in the etiology of schizophrenia among Han Chinese.

NPY-induced feeding: pharmacological characterization using selective opioid antagonists and antisense probes in rats

The ability of neuropeptide Y to potently stimulate food intake is dependent in part upon the functioning of mu and kappa opioid receptors. The combined use of selective opioid antagonists directed against mu, delta or kappa receptors and antisense probes directed against specific exons of the MOR-1, DOR-1, KOR-1 and KOR-3/ORL-1 opioid receptor genes has been successful in characterizing the precise receptor subpopulations mediating feeding elicited by opioid peptides and agonists as well as homeostatic challenges. The present study examined the dose-dependent (5-80 nmol) cerebroventricular actions of general and selective mu, delta, and kappa1 opioid receptor antagonists together with antisense probes directed against each of the four exons of the MOR-1 opioid receptor gene and each of the three exons of the DOR-1, KOR-1, and KOR-3/ORL-1 opioid receptor genes upon feeding elicited by cerebroventricular NPY (0.47 nmol, 2 ug). NPY-induced feeding was dose-dependently decreased and sometimes eliminated following pretreatment with general, mu, delta, and kappa1 opioid receptor antagonists. Moreover, NPY-induced feeding was significantly and markedly reduced by antisense probes directed against exons 1, 2, and 3 of the MOR-1 gene, exons 1 and 2 of the DOR-1 gene, exons 1, 2, and 3 of the KOR-1 gene, and exon 3 of the KOR-3/ORL-1 gene. Thus, whereas the opioid peptides, beta-endorphin and dynorphin A(1-17) elicit feeding responses that are respectively more dependent upon mu and kappa opioid receptors and their genes, the opioid mediation of NPY-induced feeding appears to involve all three major opioid receptor subtypes in a manner similar to that observed for feeding responses following glucoprivation or lipoprivation.

Insulin-degrading enzyme and Alzheimer disease: a genetic association study in the Han Chinese

BACKGROUND

The gene for insulin-degrading enzyme (IDE) represents a strong positional and biologic candidate for late-onset Alzheimer disease (LOAD) susceptibility. IDE is located on chromosome 10q23.3 close to a region of linkage for LOAD. In addition, many studies have identified a possible role of IDE in the degradation of amyloid beta-protein and the intracellular amyloid precursor protein (APP) domain released by gamma-secretase processing.

OBJECTIVE

To examine the association of IDE with AD in the Han Chinese.

METHODS

Four IDE polymorphisms (three in 5'-untranslated region and one in intron 21) were analyzed, using a population of 210 patients with LOAD and 200 control subjects well matched for age, sex, and ethnic background.

RESULTS

Among the four polymorphisms studied, only the C allele of single-nucleotide polymorphism (SNP) IDE2 showed association with AD (p = 0.005). Stratification of the data by APOE epsilon4 status indicated that the association between IDE2 and AD was confined to APOE epsilon4 carriers only. No association was found between all variants studied and AD within APOE epsilon4-negative subjects. The global haplotype frequencies showed significant differences between AD patients and control subjects. Furthermore, overrepresentation of GCTG haplotype in the AD group was found. It may be a risk haplotype for AD.

CONCLUSIONS

These results suggest a possible synergic interaction between IDE and APOE epsilon4 in the risk to develop late-onset sporadic AD. IDE might modify the effect of the APOE epsilon4 risk factor in the Han Chinese population.

Functional characterization of a cloned pig intestinal peptide transporter (pPepT1)

Absorption of dietary protein can be mediated through the uptake of AA as free AA or small peptides. A H(+)-coupled, peptide transport protein, PepT1, is responsible for the absorption of small peptides arising from digestion of dietary proteins in the small intestine. The magnitude of peptide absorption and the nutritional significance of PepT1 are unknown for many food-producing animals; thus, the objective of this study was to clone and determine the functional characteristics of the pig PepT1 (pPepT1). Two cDNA-encoding pPepT1 were isolated, which contain alternative polyadenylation sites. The predicted pPepT1 is a 708-AA protein, which shows 82.8, 85.7, and 64.7% AA identity to human, sheep, and chicken PepT1, respectively. On northern blots, two pPepT1 mRNA of approximately 2.9 and 3.5 kb were detected in the duodenum, jejunum, and ileum of the small intestine and are presumed to result from alternative polyadenylation. Uptake of [(3)H]-Gly-Sar was measured in Chinese hamster ovary cells transiently transfected with a pPepT1 expression vector to study the functional expression of pPepT1. Peptide transport was H(+)-dependent, with an optimal pH of 6.0 to 6.5. The ability of pPepT1 to transport various peptides was assayed by calculating the concentration of unlabeled peptide that inhibited 50% of [(3)H]-Gly-Sar uptake (IC(50)) in transfected cells. Eleven dipeptides and two tripeptides had IC(50) values that ranged from 0.004 to 0.53 mM. Three peptides, Lys-Lys, Arg-Lys, and Lys-Trp-Lys, had IC(50) values greater than 1. 38 mM and seem to be poor substrates for pPepT1. For all three tetrapeptides examined, uptake of Gly-Sar was too small to measure, even at a concentration of 10 mM tetrapeptide; therefore, IC(50) values could not be calculated. These results demonstrate that pPepT1 can transport a variety of dipeptides and tripeptides but not tetrapeptides.

Developmental regulation of a turkey intestinal peptide transporter (PepT1)

A cDNA encoding a turkey intestinal peptide transporter, tPepT1, was isolated from a turkey small intestinal cDNA library. The tPepT1 cDNA encodes a 714-amino acid protein with 12 predicted transmembrane domains. The amino acid sequence of tPepT1 is 94.3% identical to chicken PepT1 and approximately 60% identical to PepT1 from rat, sheep, rabbit, and human. Using a 2-electrode voltage-clamp technique in Xenopus oocytes expressing tPepT1, Gly-Sar transport was pH dependent but was independent of Na+ and K+. For the dipeptides Gly-Sar and Met-Met, the evoked inward currents indicated that the transporter was saturable and had high affinity (0.69 +/- 0.14 mM and 0.23 +/- 0.04 mM, respectively) for these substrates. However, transport of the tetrapeptide, Met-Gly-Met-Met, exhibited apparent substrate inhibition at high substrate concentrations. To study developmental regulation of PepT1 mRNA in turkey embryos, embryos (6 males and 6 females) were sampled daily from 5 d before hatch to the day of hatch (d 0). The abundance of PepT1 mRNA in the small intestine was quantified densitometrically from Northern blots after hybridization with full-length tPepT1 cDNA as probe. A 3.2-fold increase in PepT1 mRNA was observed in intestinal tissue from 5 d before hatch to d 0. This increase in PepT1 mRNA abundance indicates that the PepT1 gene is developmentally regulated and that there may be an important role for PepT1 in the neonatal poult.

New evidence on the earliest human presence at high northern latitudes in northeast Asia

The timing of early human dispersal to Asia is a central issue in the study of human evolution. Excavations in predominantly lacustrine sediments at Majuangou, Nihewan basin, north China, uncovered four layers of indisputable hominin stone tools. Here we report magnetostratigraphic results that constrain the age of the four artefact layers to an interval of nearly 340,000 yr between the Olduvai subchron and the Cobb Mountain event. The lowest layer, about 1.66 million years old (Myr), provides the oldest record of stone-tool processing of animal tissues in east Asia. The highest layer, at about 1.32 Myr, correlates with the stone tool layer at Xiaochangliang, previously considered the oldest archaeological site in this region. The findings at Majuangou indicate that the oldest known human presence in northeast Asia at 40 degrees N is only slightly younger than that in western Asia. This result implies that a long yet rapid migration from Africa, possibly initiated during a phase of warm climate, enabled early human populations to inhabit northern latitudes of east Asia over a prolonged period.

IGF-1 Antisense Strategies for Cancer Treatment

The technical approaches to gene therapy for cancer utilize ex vivo and in vivo gene-transfer methodology. This chapter focuses on applicability and use of an ex vivo approach using an IGF-1 antisense RNA strategy of treatment. Insulin-like growth factor 1 (IGF-1) and IGF-2 have pivotal roles in cell proliferation and development (for review, see 1-6). The preponderance of peptide synthesis and activity occur during fetal development, and protein synthesis is downregulated in most mature tissues except for adult liver. Further modulating the activities of these proteins are the levels of their respective cell-surface receptors and ligand-receptor interactions (3,5,6).