Evaluation of the relationship and genetic overlap between Kashin-Beck disease and body mass index

OBJECTIVES

Body mass index (BMI) is one of the major factors affecting the development of osteoarthritis (OA) but there is currently no information available regarding the relationship between BMI and Kashin-Beck disease (KBD). Our aim in this study was to investigate the relationship and genetic overlap between BMI and KBD.

METHOD

A total of 2050 Han Chinese subjects participated in this study. Using a cohort of 333 grade I KBD patients, logistic regression analysis was conducted to evaluate the correlation between BMI and KBD. Another independent sample of 1717 subjects was genotyped for a genome-wide association study (GWAS) using Affymetrix Human SNP 6.0 Arrays. Single nucleotide polymorphism (SNP) effect concordance analysis (SECA) was applied to the GWAS summaries of KBD and BMI for pleiotropy analysis. Genome-wide bivariate association analysis (GWBAA) of KBD and BMI was carried out to identify the genes with pleiotropic effects on KBD and BMI. The relevance of identified genes with KBD was validated by gene expression profiling and immunohistochemistry.

RESULTS

BMI correlated positively with knee movement disorder in KBD (coefficient β = 0.068, p = 0.045). SECA identified a significant pleiotropic effect (empirical p = 0.021) between KBD and BMI. In the GWBAA, the rs1893577 of the ADAMTS1 gene achieved the most significant association signal (p = 7.38 × 10^-9). ADAMTS1 was also up-regulated in KBD vs. normal (ratio = 2.64 ± 2.80) and KBD vs. OA (ratio = 2.31 ± 2.01). The rate of ADAMTS1-positive chondrocytes in KBD was significantly higher than that in OA (p < 0.05) and healthy controls (p < 0.05).

CONCLUSIONS

Our results suggest that ADAMTS1 is a novel susceptibility gene for KBD.

Association of 3q13.32 variants with hip trochanter and intertrochanter bone mineral density identified by a genome-wide association study

We performed a GWAS of trochanter and intertrochanter bone mineral density (BMD) in the Framingham Heart Study and replicated in three independent studies. Our results identified one novel locus around the associated variations at chromosomal region 3q13.32 and replicated two loci at chromosomal regions 3p21 and 8q24. Our findings provide useful insights that enhance our understanding of bone development, osteoporosis, and fracture pathogenesis.

INTRODUCTION

Hip trochanter (TRO) and intertrochanter (INT) subregions have important clinical relevance to subtrochanteric and intertrochanteric fractures but have rarely been studied by genome-wide association studies (GWASs).

METHODS

Aiming to identify genomic loci associated with BMD variation at TRO and INT regions, we performed a GWAS utilizing the Framingham Heart Study (FHS, N = 6,912) as discovery sample and utilized the Women's Health Initiative (WHI) African-American subsample (N = 845), WHI Hispanic subsample (N = 446), and Omaha osteoporosis study (N = 971), for replication.

RESULTS

Combining the evidence from both the discovery and the replication samples, we identified one novel locus around the associated variations at chromosomal region 3q13.32 (rs1949542, discovery p = 6.16 × 10^-8, replication p = 2.86 × 10^-4 for INT-BMD; discovery p = 1.35 × 10^-7, replication p = 4.16 × 10^-4 for TRO-BMD, closest gene RP11-384F7.1). We also replicated two loci at chromosomal regions 3p21 (rs148725943, discovery p = 6.61 × 10^-7, replication p = 5.22 × 10^-4 for TRO-BMD, closest gene CTNNB1) and 8q24 (rs7839059, discovery p = 2.28 × 10^-7, replication p = 1.55 × 10^-3 for TRO-BMD, closest gene TNFRSF11B) that were reported previously. We demonstrated that the effects at both 3q13.32 and 3p21 were specific to the TRO, but not to the femoral neck and spine. In contrast, the effect at 8q24 was common to all the sites.

CONCLUSION

Our findings provide useful insights that enhance our understanding of bone development, osteoporosis, and fracture pathogenesis.

Levator resection with suspensory ligament of the superior fornix suspension for correction of pediatric congenital ptosis with poor levator function

PurposeTo evaluate the surgical outcome of levator resection with suspensory ligament of the superior fornix (SLSF) suspension in severe congenital ptosis with poor levator function (LF).Patients and methodsThe medical records of 25 patients who underwent levator resection with SLSF suspension between March 2011 and January 2013 were retrospectively reviewed. All of the patients had severe congenital ptosis (>4 mm) and poor LF (<4 mm). The follow-up time ranged from 12 to 18 months (median, 15 months). Data regarding eyelid position, cosmetic outcomes, and postoperative complications were evaluated.ResultsThe average preoperative margin reflex distance-1 (MRD1) measured -0.30±0.11 mm. The average postoperative MRD1 measured 3.1±1.25 mm at the last follow-up visit. There was a statistically significant difference between preoperative and postoperative MRD1 values (P<0.001). Excellent cosmetic results occurred in 14 patients, good cosmetic results occurred in eight patients and poor cosmetic results did not occur. Three patients (12%) underwent reoperation for residual ptosis. No serious postoperative complications occurred.ConclusionLevator resection with SLSF suspension is very effective in the treatment of severe congenital ptosis with poor LF. This surgery technique results in high functional and cosmetic successes in the long term.

Effect of casein to whey protein ratios on the protein interactions and coagulation properties of low-fat yogurt

In this study, we investigated the effect of casein (CN) to whey protein (WP) ratios (4:1, 3:1, 2:1, and 1:1) on gelation properties and microstructure of low-fat yogurt made with reconstituted skim milk with or without addition of whey protein concentrate. The rheological properties (storage modulus, G'; yield stress; and yield strain) of the obtained low-fat yogurt were greatly enhanced, the fermentation period was shortened, and the microstructure became more compact with smaller pores as the CN:WP ratio decreased. When CN:WP was 2:1 or 1:1, the obtained yogurt coagulum showed higher G' and greater yield stress, with more compact crosslinking and smaller pores. In addition, the more of skim milk powder was replaced by whey protein concentrate, the more disulfide bonds were formed and the greater the occurrence of hydrophobic interactions during heat treatment, which can improve the rheological properties and microstructure of low-fat yogurt.

The aggregation behavior and interactions of yak milk protein under thermal treatment

The aggregation behavior and interactions of yak milk protein were investigated after heat treatments. Skim yak milk was heated at temperatures in the range of 65 to 95°C for 10 min. The results showed that the whey proteins in yak milk were denatured after heat treatment, especially at temperatures higher than 85°C. Sodium dodecyl sulfate-PAGE analysis indicated that heat treatment induced milk protein denaturation accompanied with aggregation to a certain extent. When the heating temperature was 75 and 85°C, the aggregation behavior of yak milk proteins was almost completely due to the formation of disulfide bonds, whereas denatured α-lactalbumin and β-lactoglobulin interacted with κ-casein. When yak milk was heated at 85 and 95°C, other noncovalent interactions were found between proteins including hydrophobic interactions. The particle size distributions and microstructures demonstrated that the heat stability of yak milk proteins was significantly lowered by heat treatment. When yak milk was heated at 65 and 75°C, no obvious changes were found in the particle size distribution and microstructures in yak milk. When the temperature was 85 and 95°C, the particle size distribution shifted to larger size trend and aggregates were visible in the heated yak milk.

Reduced Field-of-View Diffusion Tensor Imaging of the Optic Nerve in Retinitis Pigmentosa at 3T

BACKGROUND AND PURPOSE

Diffusion tensor imaging may reflect pathology of the optic nerve; however, the ability of DTI to evaluate alterations of the optic nerve in retinitis pigmentosa has not yet been assessed, to our knowledge. The aim of this study was to investigate the diagnostic potential of reduced FOV-DTI in optic neuropathy of retinitis pigmentosa at 3T.

MATERIALS AND METHODS

Thirty-eight patients and thirty-five healthy controls were enrolled in this study. Measures of visual field and visual acuity of both eyes in all subjects were performed. A reduced FOV-DTI sequence was used to derive fractional anisotropy, apparent diffusion coefficient, principal eigenvalue, and orthogonal eigenvalue of the individual optic nerves. Mean fractional anisotropy, ADC, and eigenvalue maps were obtained for quantitative analysis. Further analyses were performed to determine the correlation of fractional anisotropy, ADC, principal eigenvalue, and orthogonal eigenvalue with optic nerves in patients with mean deviation of the visual field and visual acuity, respectively.

RESULTS

The optic nerves of patients with retinitis pigmentosa compared with control subjects showed significantly higher ADC, principal eigenvalue, and orthogonal eigenvalue and significantly lower fractional anisotropy (P < .01). For patients with retinitis pigmentosa, the mean deviation of the visual field of the optic nerve was significantly correlated with mean fractional anisotropy (r = 0.364, P = .001) and orthogonal eigenvalue (r = -0.254, P = .029), but it was not correlated with mean ADC (P = .154) and principal eigenvalue (P = .337). Moreover, no correlation between any DTI parameter and visual acuity in patients with retinitis pigmentosa was observed (P > .05).

CONCLUSIONS

Reduced FOV-DTI measurement of the optic nerve may serve as a biomarker of axonal and myelin damage in optic neuropathy for patients with retinitis pigmentosa.

Epigenomic elements analyses for promoters identify ESRRG as a new susceptibility gene for obesity-related traits

OBJECTIVES

With ENCODE epigenomic data and results from published genome-wide association studies (GWASs), we aimed to find regulatory signatures of obesity genes and discover novel susceptibility genes.

METHODS

Obesity genes were obtained from public GWAS databases and their promoters were annotated based on the regulatory element information. Significantly enriched or depleted epigenomic elements in the promoters of obesity genes were evaluated and all human genes were then prioritized according to the existence of the selected elements to predict new candidate genes. Top-ranked genes were subsequently applied to validate their associations with obesity-related traits in three independent in-house GWAS samples.

RESULTS

We identified RAD21 and EZH2 as over-represented, and STAT2 (signal transducer and activator of transcription 2) and IRF3 (interferon regulatory transcription factor 3) as depleted transcription factors. Histone modification of H3K9me3 and chromatin state segmentation of 'poised promoter' and 'repressed' were over-represented. All genes were prioritized and we selected the top five genes for validation at the population level. Combining results from the three GWAS samples, rs7522101 in ESRRG (estrogen-related receptor-γ) remained significantly associated with body mass index after multiple testing corrections (P=7.25 × 10(-5)). It was also associated with β-cell function (P=1.99 × 10(-3)) and fasting glucose level (P<0.05) in the meta-analyses of glucose and insulin-related traits consortium (MAGIC) data set.Cnoclusions:In summary, we identified epigenomic characteristics for obesity genes and suggested ESRRG as a novel obesity-susceptibility gene.

Integrative analysis of genome-wide association studies and gene expression profiles identified candidate genes for osteoporosis in Kashin-Beck disease patients

SUMMARY

The molecular mechanism of osteoporosis (OP) in Kashin-Beck disease (KBD) patients was unclear. Our results suggest that KBD and OP shared some common causal genes, functionally involved in skeletal growth and development and chronic inflammation. Our results provide novel clues for clarifying the molecular mechanism of OP in KBD patients.

INTRODUCTION

KBD is a chronic skeletal disorder with osteopenia and OP. The pathogenesis of OP in KBD patients remains elusive.

METHODS

A total of 1717 subjects participated in this study. KBD was diagnosed according to the clinical diagnosis criteria of China (GB16395-1996). The bone mineral density (BMD) and bone areas of the ulna and radius, hip, and lumbar (L1-L4) were measured with a Hologic 4500 W dual-energy X-ray absorptiometry scanner. Genotyping was conducted using Affymetrix SNP Array 6.0. Gene expression profiling of peripheral blood mononuclear cells of KBD and OP patients were compared using Affymetrix HG-U133 plus 2.0 arrays and Agilent Human 1A arrays, respectively. Genome-wide association studies (GWAS) were conducted by PLINK. SCEA and DAVID were applied for pleiotropy and functional enrichment analysis, respectively.

RESULTS

SCEA analysis observed significant pleiotropic effects between KBD and the ulna and radius BMD (P value = 5.99 × 10(-3)). GWAS meta-analysis identified six candidate genes with pleiotropic effects, including PDGFD, SOX5, DPYD, CTR9, SPP1, and COL4A1. GO analysis identified 16 significant GO shared by KBD and the ulna and radius BMD, involved in cell morphogenesis and apoptosis. Pathway enrichment analysis detected two common pathways for KBD and the ulna and radius BMD, including calcium signaling pathway and vascular smooth muscle contraction pathway. Gene expression analysis detected three up-regulated inflammation-related genes for KBD and OP, including IL1B, IL8, and CCL1.

CONCLUSION

This study reported several candidate genes involved in the development of OP in KBD patients.

Relationship of sarcopenia and body composition with osteoporosis

The purpose of the study is to investigate the relationship between sarcopenia and body composition and osteoporosis in cohorts of three different races with a total of 17,891 subjects. Lean mass and grip strength were positively associated with bone mineral densities (BMDs). Subjects with sarcopenia were two times more likely to have osteoporosis compared with normal subjects.

INTRODUCTION

The relationship between sarcopenia and osteoporosis is not totally clear. First, the present study assessed this relationship by using two different definitions for sarcopenia. Second, we examined the associations of body composition (including muscle mass as a major and important component) and muscle strength on regional and whole-body BMDs.

METHODS

In total, 17,891 subjects of African American, Caucasian, and Chinese ethnicities were analyzed. Sarcopenia was defined by relative appendicular skeletal muscle mass (RASM) cut points and also by the definition of the European Working Group on Sarcopenia in Older People (low RASM plus low muscle function). Multiple regression analyses were conducted to examine the association of fat mass, lean mass (including muscle mass), and grip strength with regional and whole-body BMDs. Multivariate logistic regression analysis was performed to explore the association between sarcopenia and osteopenia/osteoporosis.

RESULTS

BMDs were positively associated with lean mass and negatively associated with fat mass, after controlling for potential confounders. Grip strength was significantly associated with higher BMDs. Each standard deviation (SD) increase in RASM resulted in a ~37 % reduction in risk of osteopenia/osteoporosis (odds ratio (OR) = 0.63; 95 % confidence interval (CI) = 0.59, 0.66). Subjects with sarcopenia defined by RASM were two times more likely to have osteopenia/osteoporosis compared with the normal subjects (OR = 2.04; 95 % CI = 1.61, 2.60). Similarly, subjects with sarcopenia (low muscle mass and low grip strength) were ~1.8 times more likely to have osteopenia/osteoporosis than normal subjects (OR = 1.87; 95 % CI = 1.09, 3.20).

CONCLUSIONS

High lean mass and muscle strength were positively associated with BMDs. Sarcopenia is associated with low BMD and osteoporosis.

A randomized controlled trial of 2 protocols for weaning cardiac surgical patients receiving adaptive support ventilation

PURPOSE

This study aims to compare the effectiveness of weaning with adaptive support ventilation (ASV) incorporating progressively reduced or constant target minute ventilation in the protocol in postoperative care after cardiac surgery.

MATERIAL AND METHODS

A randomized controlled unblinded study of 52 patients after elective coronary artery bypass surgery was carried out to determine whether a protocol incorporating a decremental target minute ventilation (DTMV) results in more rapid weaning of patients ventilated in ASV mode compared to a protocol incorporating a constant target minute ventilation.

RESULTS

Median duration of mechanical ventilation (145 vs 309 minutes; P = .001) and intubation (225 vs 423 minutes; P = .005) were significantly shorter in the DTMV group. There was no difference in adverse effects (42% vs 46%) or mortality (0% vs 0%) between the 2 groups.

CONCLUSIONS

Use of a DTMV protocol for postoperative ventilation of cardiac surgical patients in ASV mode results in a shorter duration of ventilation and intubation without evidence of increased risk of adverse effects.

Lactogenic hormones regulate mammary protein synthesis in bovine mammary epithelial cells via the mTOR and JAK–STAT signal pathways

The expression of CSN3, hormone receptor, the expression of genes regulating the mTOR, JAK–STAT signal pathways, and the relative content of к-casein as well as total casein were determined in the present study to explore the mechanism of the effect of lactogenic hormones on milk-protein synthesis in bovine mammary epithelial cells. The results showed that apoptosis of the cells was increased by inhibitor LY294002, while the expressions of genes encoding PKB, Rheb, PRAS40 and S6K1 in the mTOR signal pathway, JAK2, STAT5A in the JAK–STAT signal pathway, and genes encoding INSR, PRLR, NR3C1 and CSN3 were all downregulated, and the relative contents of κ-casein and total casein were decreased in the mammary epithelial cells compared with those in the control group. Comparatively, the inhibitory effects of AG-490 were more profound than those of LY294002, and the double block using both inhibitors had a greater effect than the single block. The CSN3 gene expression was downregulated and the content of milk casein was decreased by the inhibitors. In addition, the expression of the hormone receptor genes was downregulated. Our results suggest that lactogenic hormones, via their receptors in the membrane, regulated the JAK–STAT and m-TOR signal pathways, and affected cell proliferation and apoptosis, leading to changes in milk-protein synthesis.

Platelet factor 4 protects bone marrow mesenchymal stem cells from acute radiation injury

OBJECTIVE

The aim of this study was to find a new radiation protector, platelet factor 4 (PF4) and to identify its effect on haemopoietic microenvironment in vitro and in vivo.

METHODS

Radiation damage on bone marrow mesenchymal stem cells ex and in vitro was set up as models. Growth curve analysis, clonogenic survival assay, FACSCalibur™ (BD Immunocytometry Systems, San Jose, CA), 5-ethynyl-2'-deoxyuridine immunofluorescence staining and quantitative reverse transcription-polymerase chain reaction were employed to assess the characterization of bone marrow mesenchymal stem cells (BMSCs), proliferation, apoptosis, cell cycle and gene expression.

RESULTS

A dose- and time-dependent enhancement of cell viability and survival was observed for PF4 treatment along with 500 cGy γ-radiation in vitro. The same phenomena were noted in vivo, including enhancement of adherence and proliferation ability while inhibition of cell apoptosis, which were associated with a short-term decrease in the G0/G1 ratio owing to S phase arrest. These were accompanied with enhanced Bcl-2 expression and p53/p21 loss.

CONCLUSION

These results uncover that PF4 might be a novel therapeutic approach, which could reduce DNA damage and increase survival of BMSCs, in part, by inhibiting p53/p21 axis and facilitating DNA damage repair.

ADVANCES IN KNOWLEDGE

This study explores the feasibility of a new radioprotector and hence may be clinically important.

Reduction and the intracellular translocation of EphB2 in Tg2576 mice and the effects of β-amyloid

AIMS

EphB2 is a member of receptor tyrosine kinases (RTKs) family that is essential for the cell adhesion, neural crest migration, axon guidance and synaptogenesis in the nervous system. Recent studies show that preservation of EphB2 in a transgenic mouse model of Alzheimer's disease (AD) rescues the cognitive deficit, suggesting a crucial role of EphB2 in AD. However, the expression and distribution profiles of EphB2 in the early stage of AD have not been reported.

METHODS

Immunohistochemistry, immunoblot and immunofluorescence were used to analyse the level of EphB2 in Tg2576 mice at different ages and in cultured neurones with Aβ treatment at different times.

RESULTS

EphB2 was reduced in an age-dependent manner in the olfactory bulb and the hippocampus of Tg2576 mice. The decrease of EphB2 appeared earlier in the olfactory bulb than the hippocampus, and reduction of EphB2 appeared earlier than that of MAP2, a dendritic cytoskeleton marker. In the cortex, EphB2 displayed a significant translocation from the neuronal processes to the cell bodies with ageing. In primary hippocampal neuronal cultures, Aβ42 treatment also induced the decrement of EphB2 that was prior to the decline of MAP2.

CONCLUSIONS

Our findings provide the first evidence for an age- and region-dependent reduction and intracellular translocation of EphB2 in Tg2576 mice, and the foremost decrement of EphB2 in the olfactory bulb may represent an early sign of AD.

Homozygous loss-of-function mutation of the LEPREL1 gene causes severe non-syndromic high myopia with early-onset cataract

High myopia is a severe visual impairment which can increase the risk of retinal degeneration, subretinal hemorrhage, choroidal neovascularization, cataract and retinal detachment. We recruited an autosomal-recessive high myopia family, with affected subjects who also present early-onset cataract, retinal degeneration and other complications. Using targeted capturing and whole exome sequencing, we identified a homozygous non-sense mutation in the LEPREL1 gene which causes premature termination of the translation at the fifth amino acid (c.13C>T; p.Q5X), co-segregating with the phenotypes. LEPREL1 encodes a proline hydroxylase called prolyl 3-hydroxylase 2 (P3H2), a 2-oxoglutarate-dependent dioxygenase that hydroxylates collagens. The results show that LEPREL1 plays an important role in eye development and homozygous loss-of-function mutation of this gene can cause severely high myopia and early-onset cataract. Our study also strongly suggests that the disruption of collagen modification is one of the pathogenic mechanisms of high myopia and cataract.

A causal role for circulating miR-34b in osteosarcoma

PURPOSE

To investigate the associations between plasma miR-34b/c expression levels and osteosarcoma (OS).

SUBJECTS AND METHODS

A case-control study was conducted in 133 patients with OS and 133 controls. MiR-34b/c levels were detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assays. Genotyping of SNP rs4938723 was done using the TaqMan assay. The causal association was examined by mendelian randomization analysis.

RESULTS

Plasma miR-34b level was significantly lower in OS patients than in controls (P = 0.001). Expression levels of miR-34b in OS tissues decreased (P = 3.22 × 10(-4)) and was significantly related with its expression in plasma (r = 0.21, P = 0.004). Compared with wild-type TT genotype, the variant genotypes of rs4938723 TC/CC were significantly associated with increased OS risk (TC vs. TT: OR, 1.97 [95% CI: 1.40-2.55], P = 0.021; CC vs. TT: OR, 2.76 [95% CI: 2.00-3.53], P = 0.009; TC + CC vs. TT: OR, 2.16 [95% CI: 1.61-2.70], P = 0.006), consistent with its decreased effect on plasma miR-34b (TC vs. TT: -0.32 (-0.43, -0.21), P < 0.001; CC vs. TT: -0.70 (-0.84, -0.56), P < 0.001; TC + CC vs. TT: -0.42 (-0.53, -0.32), P < 0.001). Adjustment for miR-34b completely abolished the association between SNP rs4938723 and OS risk (P > 0.05). In addition, plasma expression levels of miR-34b were significantly decreased in the metastatic patients compared with that in the non-metastatic ones (P = 0.004).

CONCLUSION

Plasma miR-34b was causally associated with OS risk and related with its metastatic status, suggesting that plasma miR-34b might be a novel biomarker and a potential treatment target for OS.

Sonographic characteristics of placental site trophoblastic tumor

OBJECTIVE

To investigate clinical features and ultrasound findings in cases of placental site trophoblastic tumor (PSTT).

METHODS

Fourteen cases of PSTT treated at our institution between May 2004 and October 2010 were identified and the clinical features and findings on transvaginal sonography (TVS) were investigated. Pathological confirmation of PSTT was obtained in all cases.

RESULTS

The most frequent symptoms associated with PSTT were abnormal vaginal bleeding, which was present in 11 cases, and amenorrhea, which was present in five cases. The interval from antecedent pregnancy to diagnosis was 4-36 (median, 12.5) months. Blood serum was positive for beta-human chorionic gonadotropin (β-hCG) at the time of ultrasound examination, although the level was generally low, with a median of 166.2 IU/L (range, 4.5-3480.2). Sonographic presentation of PSTT was classified into one of three types according to the characteristics observed on TVS: Type I, heterogeneous solid mass in the uterine cavity (four cases), with minimal to a moderate degree of vascularization on color Doppler imaging; Type II, heterogeneous solid mass in the myometrium (six cases), with minimal to a high degree of vascularization (only one case was highly vascularized); and Type III, cystic lesions in the myometrium (four cases) with a high degree of vascularization (lacunar-type lesions).

CONCLUSIONS

Combined with clinical features, characteristics demonstrated by TVS provide evidence for the suspicion of PSTT and could contribute to clinical decision making.

Vagal-Central Nervous System Interactions Modulate the Feeding Response to Peripheral Enterostatin

Enterostatin selectively inhibits the intake of dietary fat after both peripheral and central administration. We have investigated the role of the hepatic vagus nerve in modulating the peripheral response to enterostatin in Sprague-Dawley rats adapted to a high fat (HF) diet. Intraperitoneal (ip) enterostatin reduced intake of HF diet after overnight starvation. This response was abolished by selective vagal hepatic branch transection. Immunohistochemical techniques were used to identify the location of Fos protein in brain nuclei after ip enterostatin. Fos protein was evident in the nucleus tractus solitarius (NTS), parabrachial, paraventricular and supraoptic nuclei. The pattern of expression of Fos-like immunoreactivity differed from that induced by the lipoprivic agent beta-mercaptoacetate. Transection of the hepatic vagus blocked the central Fos responses to ip enterostatin. We conclude that afferent hepatic vagal nerve activity is required for the feeding response to peripheral enterostatin.

A follow-up association study of two genetic variants for bone mineral density variation in Caucasians

SUMMARY

We tested whether two genetic variants were associated with BMD at multiple clinically relevant skeletal sites in Caucasians. We found that variant rs7776725 is consistently associated with hip, spine, wrist and whole-body BMD, which highlights the potential importance of this variant or linked variants for osteoporosis.

INTRODUCTION

A recent genome-wide association study identified two single nucleotide polymorphisms (SNPs), rs7776725 and rs1721400, that were associated with bone mineral density (BMD) variation at the radius, tibia and calcaneus in a Korean population. In this study, we aimed to test whether the association of these two genetic variants can be replicated in Caucasians and whether their association with BMD can be extended to other clinically relevant skeletal sites.

METHODS

We performed this study in two large cohorts of unrelated US Caucasians. Area BMD at the hip, spine, wrist (ultra-distal radius) and whole body were measured with Hologic dual-energy X-ray absorptiometer. SNPs were genotyped with Affymetrix human genome-wide genotyping arrays. Association analyses were performed using PLINK.

RESULTS

We detected highly significant association (combined p = 1.42 × 10(-16)) of rs7776725 with wrist BMD but only borderline association signal (combined p = 0.017) for rs1721400 with wrist BMD. In addition, we found that rs7776725 was associated with BMD at the hip, spine and whole body. At the FAM3C gene locus where rs7776725 was located, we identified several other SNPs (rs4727922, rs1803389, rs718766 and rs7793554) that were also associated with BMD.

CONCLUSIONS

This is the first follow-up association study of rs7776725 and rs1721400 with BMD. The rs7776725 showed consistent association with BMD at multiple clinically important skeletal sites, which highlighted the potential importance of rs7776725 or linked SNPs for risk of osteoporosis. Further in-depth re-sequencing studies and functional assays are necessary to elucidate the underlying mechanisms.

Ethnic differentiation of copy number variation on chromosome 16p12.3 for association with obesity phenotypes in European and Chinese populations

OBJECTIVE

Genomic copy number variations (CNVs) have been strongly implicated as important genetic factors for obesity. A recent genome-wide association study identified a novel variant, rs12444979, which is in high linkage disequilibrium with CNV 16p12.3, for association with obesity in Europeans. The aim of this study was to directly examine the relationship between the CNV 16p12.3 and obesity phenotypes, including body mass index (BMI) and body fat mass.

SUBJECTS

Subjects were a multi-ethnic sample, including 2286 unrelated subjects from a European population and 1627 unrelated Han subjects from a Chinese population. Body fat mass was measured using dual energy X-ray absorptiometry.

RESULTS

Using Affymetrix Genome-Wide Human SNP Array 6.0, we directly detected CNV 16p12.3, with the deletion frequency of 27.26 and 0.8% in the European and Chinese populations, respectively. We confirmed the significant association between this CNV and obesity (BMI: P=1.38 × 10(-2); body fat mass: P=2.13 × 10(-3)) in the European population. Less copy numbers were associated with lower BMI and body fat mass, and the effect size was estimated to be 0.62 (BMI) and 1.41 (body fat mass), respectively. However, for the Chinese population, we did not observe significant association signal, and the frequencies of this deletion CNV are quite different between the European and Chinese populations (P<0.001).

CONCLUSION

Our findings first suggest that CNV 16p12.3 might be ethnic specific and cause ethnic phenotypic diversity, which may provide some new clues into the understanding of the genetic architecture of obesity.

Genetic variants in the SOX6 gene are associated with bone mineral density in both Caucasian and Chinese populations

SUMMARY

Given the biological function of SOX6 and recent genome-wide association finding, we performed a fine-mapping association analyses to investigate the relationship between SOX6 and BMD both in Caucasian and Chinese populations. We identified many single-nucleotide polymorphisms (SNPs) within or near the SOX6 gene to be significantly associated with hip bone mineral density (BMD).

INTRODUCTION

SOX6 gene is an essential transcription factor in chondrogenesis and cartilage formation. Recent genome-wide association studies (GWAS) detected a SNP (rs7117858) located at the downstream of SOX6 significantly associated with hip BMD.

METHODS

Given the biological function of SOX6 and the GWAS finding, we considered SOX6 as a new candidate for BMD and osteoporosis. Therefore, in this study, we performed a fine-mapping association analyses to investigate the relationship between SNPs within and near the SOX6 gene and BMD at both hip and spine. A total of 301 SNPs were tested in two independent US Caucasian populations (2,286 and 1,000 unrelated subjects, respectively) and a Chinese population (1,627 unrelated Han subjects).

RESULTS

We confirmed that the previously reported rs7117858-A was associated with reduced hip BMD, with combined P value of 2.45 × 10(-4). Besides this SNP, we identified another 19 SNPs within or near the SOX6 gene to be significantly associated with hip BMD after false discovery rate adjustment. The most significant SNP was rs1347677 located at the intron 3 (P = 3.15 × 10(-7)). Seven additional SNPs in high linkage disequilibrium with rs1347677 were also significantly associated with hip BMD. SNPs in SOX6 showed significant skeletal site specificity since no SNP was detected to be associated with spine BMD.

CONCLUSION

Our study identified many SNPs in the SOX6 gene associated with hip BMD even across different ethnicities, which further highlighted the importance of the SOX6 gene influencing BMD variation and provided more information to the understanding of the genetic architecture of osteoporosis.

Systems cancer medicine: towards realization of predictive, preventive, personalized and participatory (P4) medicine

A grand challenge impeding optimal treatment outcomes for patients with cancer arises from the complex nature of the disease: the cellular heterogeneity, the myriad of dysfunctional molecular and genetic networks as results of genetic (somatic) and environmental perturbations. Systems biology, with its holistic approach to understanding fundamental principles in biology, and the empowering technologies in genomics, proteomics, single-cell analysis, microfluidics and computational strategies, enables a comprehensive approach to medicine, which strives to unveil the pathogenic mechanisms of diseases, identify disease biomarkers and begin thinking about new strategies for drug target discovery. The integration of multidimensional high-throughput 'omics' measurements from tumour tissues and corresponding blood specimens, together with new systems strategies for diagnostics, enables the identification of cancer biomarkers that will enable presymptomatic diagnosis, stratification of disease, assessment of disease progression, evaluation of patient response to therapy and the identification of reoccurrences. Whilst some aspects of systems medicine are being adopted in clinical oncology practice through companion molecular diagnostics for personalized therapy, the mounting influx of global quantitative data from both wellness and diseases is shaping up a transformational paradigm in medicine we termed 'predictive', 'preventive', 'personalized', and 'participatory' (P4) medicine, which requires new strategies, both scientific and organizational, to enable bringing this revolution in medicine to patients and to the healthcare system. P4 medicine will have a profound impact on society - transforming the healthcare system, turning around the ever escalating costs of healthcare, digitizing the practice of medicine and creating enormous economic opportunities for those organizations and nations that embrace this revolution.

Are bone mineral density loci associated with hip osteoporotic fractures? A validation study on previously reported genome-wide association loci in a Chinese population

Osteoporosis is a heritable disease characterized mainly by low bone mineral density (BMD) and/or osteoporotic fractures (OF). Most genome-wide association studies on osteoporosis have focused on BMD, whereas little effort has been expended to identify genetic variants directly linked to OF. To determine whether BMD-loci are also associated with OF risk, we performed a validation study to examine 23 BMD-loci reported by recent genome-wide association studies for association with hip OF risk. Our sample consisted of 700 elderly Chinese Han subjects, 350 with hip OF and 350 healthy matched controls. We identified four BMD-loci that were significantly associated with hip OF in this Chinese population, including 7q21 (FLJ42280, P = 1.17 × 10(-4) for rs4729260; P = 0.008 for rs7781370), 6p21 (MHC, P = 0.004 for rs3130340), 13q14 (TNFSF11, P = 0.012 for rs9533090; P = 0.018 for rs9594759; P = 0.020 for rs9594738; P = 0.044 for rs9594751), and 18q21 (TNFRSF11A, P = 0.015 for rs884205). The SNP rs4729260 at 7q21 remained significantly associated, even after conservative Bonferroni's correction. Our results further highlight the importance of these loci in the pathogenesis of osteoporosis, and demonstrate that it is feasible and useful to use OF as the direct phenotype to conduct genetic studies, to enhance our understanding of the genetic architecture of osteoporosis.

Genetic variation and clonal diversity of Bromus ircutensis Kom. in the Otingdag sandy land detected by ISSR markers

Genetic variation and clonal diversity of nine populations of Bromus ircutensis Kom. from the Otingdag sandy land were investigated using Inter Simple Sequence Repeat (ISSR) markers. A total of 102 bands were amplified by using II ISSR primers chosen for the study. Among those 99% were polymorphic indicating high level of genetic variation at the species level with a mean genetic diversity (H) of 0.292 and Shannon information index (1) of 0.450. Percentage of polymorphic loci (PPL) of nine populations was 76.48% on average, which provides more evidence of considerable genetic variation at the population level. AMOVA analysis revealed that total genetic variation was higher within populations (87.06%) than between populations (12.94%), which is mainly the result of the extensive gene flow (Nm = 1.682) among B. ircutensis populations. UPGMA cluster analysis divided the nine populations into two groups. There was significant or moderate negative correlations between genetic diversity parameters (PPL, H, 1) and longitude or latitude. Mantel test also showed a significant correlation between geographical distance and genetic distance (r = 0.681, p = 0.002). Our findings indicated that distribution of B. ircutensis populations was influenced by geographical and ecological factors. Clonal diversity was also high with 108 individuals identified by 11 ISSR primers being all of different genets. Our results provide a molecular basis for sustainable management and conservation ofB. ircutensis in the study area.

Phenylbutyric acid prevents rats from electroconvulsion-induced memory deficit with alterations of memory-related proteins and tau hyperphosphorylation

Electroconvulsive therapy has been commonly applied in the treatment of refractory depression, but its cognitive side effects are noticed and restrict its application. The molecular mechanisms underlying the side effects remain elusive, and there is no efficient prevention. By employing a recognized electroconvulsive shock (ECS) rat model, we found in the present study that ECS induced spatial memory deficits with simultaneous decreases in synaptic proteins of N-methyl-D-aspartate receptor 2A/B (NR2A/B) and postsynaptic density 95 (PSD95), the immediate early gene c-Fos and cAMP response element binding (CREB) proteins, all of which are memory-related proteins. ECS also caused tau hyperphosphorylation at multiple Alzheimer-related phosphorylation sites with activation of glycogen synthase kinase-3beta (GSK-3beta), Akt and phospho-PKR-like endoreticulum (PERK), and inhibition of protein phosphatase-2A (PP)-2A. Intraperitoneal injection of phenylbutyric acid (PBA), an aromatic short chain fatty acid with the functions of molecule chaperon, prevented rats from the ECS-induced memory deficits, alterations of the memory-associated proteins, and tau hyperphosphorylation. Our data suggest that PBA may be potentially used for attenuating the side effects caused by electroconvulsive therapy.

Regulation of expression of cd133, a colon cancer stem cell marker and other stemness genes/pathways, by celecoxib: Clues from clinical observations

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Background: CD133 identifies intestinal stem cells and colon CSC, the putative culprit of cancer initiation, progression and resistance. Elevated CD133 levels at protein & mRNA levels predict poor outcomes in patients (pts) with colon cancer. Given that celecoxib reduces colon polyp and only maintenance capecitabine plus celecoxib lead to paradoxically high complete remission (CR) in colon cancer pts who had no resection or positive margin resection of metastases (ASCO 2007), we hypothesized that celecoxib could modulate CD133 and other stemness genes/signaling pathways. Methods: we studied the effects of celecoxib versus 5-FU on CD133, Wnt and other stemness genes/pathways using flow cytometry, immunoflurorescence, real time RT-PCR, western blot, TOP-Flash for Wnt, limiting dilution assay, and Affymetrix in colon cancer cell lines and primary colon cancer spheres. Results: Celecoxib or 5FU inhibited the growth of COX-2+ HT29 or COX-2- DLD1 that express CD133 at 80% and 30% respectively. Only celecoxib down-regulated CD133 expression at the mRNA, and protein levels in a dose and time dependent manner. This effect could not be rescued with PGE2 and may be due to Wnt inhibition. Microarray showed 4 folds down-regulation of CD133 and other stemness genes e.g. CD24, ABC transporters, and LGR4/5, findings of colon cancer sphere under differentiation. Celecoxib affected several key stem cells signaling pathway, restored RB and promote cell cycle progression (P < 0.05). In contrast, 5FU affected G2M transition but had no effects on stemness genes/pathways (p < 0.05). Celecoxib resulted in 6–10 folds reduction in colony size and number with 5.6–36 folds down-regulation of CD133 mRNA in primary colon cancer spheres. Pts with confirmed radiographic CR who had received >6 months of maintenance capecitabine and celecoxib reached 5-year survival > 90% comparable to pts who achieved pathological CR (12/19). Conclusions: Targeting colon CSC with capecitabine and celecoxib may lead to durable CR and survival and deserves further investigation.

No significant financial relationships to disclose.

Iris recognition based on key image feature extraction

In iris recognition, feature extraction can be influenced by factors such as illumination and contrast, and thus the features extracted may be unreliable, which can cause a high rate of false results in iris pattern recognition. In order to obtain stable features, an algorithm was proposed in this paper to extract key features of a pattern from multiple images. The proposed algorithm built an iris feature template by extracting key features and performed iris identity enrolment. Simulation results showed that the selected key features have high recognition accuracy on the CASIA Iris Set, where both contrast and illumination variance exist.

Retrieving leaf area index for coniferous forest in Xingguo County, China with Landsat ETM+ images

Spatial distributions of the leaf area index (LAI) needed for carbon cycle modeling in Xingguo County, China were estimated based on correlations between the field-measurements and vegetation indices (VIs). After making geometric and atmospheric corrections to two Landsat ETM+ images, one in January 2000 and the other in May 2003, three VIs (SR, NDVI, and RSR) were derived, and their separate correlations with ground LAI measurements were established. The correlation with RSR was the highest among the three VIs. The retrieved LAI values for January 2000 were lower than those for May 2003 because of a small seasonal variation in the coniferous forests (predominantly masson pine) and the decrease in the understorey vegetation during winter.

Spatial scaling between leaf area index maps of different resolutions

We developed algorithms for spatial scaling of leaf area index (LAI) using sub-pixel information. The study area is located near Liping County, Guizhou Province, in China. Methods for LAI spatial scaling were investigated on LAI images with 960 m resolution derived in two ways. LAI from distributed calculation (LAID) was derived using Landsat ETM+ data (30 m), and LAI from lumped calculation (LAIL) was obtained from the coarse (960 m) resolution data derived through resampling the ETM+ data. We found that lumped calculations can be considerably biased compared to the distributed (ETM+) case, suggesting that global and regional LAI maps can be biased if surface heterogeneity within the mapping resolution is ignored. Based on these results, we developed algorithms for removing the biases in lumped LAI maps using sub-pixel land cover-type information, and applied these to correct one coarse resolution LAI product which greatly improved its accuracy.

Enhancing forest carbon sequestration in China: toward an integration of scientific and socio-economic perspectives

This article serves as an introduction to this special issue, "China's Forest Carbon Sequestration", representing major results of a project sponsored by the Canadian International Development Agency and the Chinese Academy of Sciences. China occupies a pivotal position globally as a principle emitter of carbon dioxide, as host to some of the world's largest reforestation efforts, and as a key player in international negotiations aimed at reducing global greenhouse gas emission. The goals of this project are to develop remote sensing approaches for quantifying forest carbon balance in China in a transparent manner, and information and tools to support land-use decisions for enhanced carbon sequestration (CS) that are science based and economically and socially viable. The project consists of three components: (i) remote sensing and carbon modeling, (ii) forest and soil assessment, and (iii) integrated assessment of the socio-economic implications of CS via forest management. Articles included in this special issue are highlights of the results of each of these components.

Fetoscopy under gas amniodistension: pressure-dependent influence of helium vs nitrous oxide on fetal goats

PURPOSE

Recently, gas amniodistension has been advocated for fetoscopic surgery to employ ergonomics similar to laparoscopy. However, neither the optimal type of gas nor its physiological influence on the fetus have been clearly outlined yet. This study investigates the impact of helium (HE) vs nitrous oxide (N2O) on fetal goats during fetoscopy.

METHODS

We insufflated either HE or N2O in 12 pregnant goats (15 fetuses; HE = 7, N2O = 8), then increased the pressures from 0, 4, 7, to 10 mm Hg in 30-minute intervals and recorded the fetal and maternal vital parameters. Finally, whole-body computed tomography to asses for intracorporeal gas was performed.

RESULTS

All fetuses survived. Mean fetal vital signs showed no significant differences between HE or N2O at specific pressure levels. In detail, HE/N2O at 0 vs 10 mm Hg caused a fetal temperature decrease (32.9 degrees C/33.2 degrees C vs 32 degrees C/32.5 degrees C), heart rate increase in the N2O group (100/102 vs 102/121 beats per minute), and no significant change in arterial pressure (45.8/48.3 vs 53.7/46.7 mm Hg). The PO2 was adequate (3.7/3.3 vs 3.7/2.9 kPa), whereas the pH remained unchanged (7.4/7.3 vs 7.3/7.3). However, fetal pCO2 was elevated in the N2O group before insufflation (5.5/7.2 vs 6.8/8.0 kPa) owing to maternal hypoventilation (maternal PCO2: 4.9/5.8 vs 5.0/5.4 kPa), correction of which was slower in the fetus than in the maternal animal. Computed tomography ruled out intracorporeal gas accumulation.

CONCLUSION

Neither HE nor N2O impose significant physiological harm for the fetus. Heating of the gas and maternal anesthesia seem essential. Considering the potential teratogenicity of N2O, however, HE could be the favorable environment for fetoscopic procedures under gas amniodistension.

Endogenous overproduction of β-amyloid induces tau hyperphosphorylation and decreases the solubility of tau in N2a cells

Although neurofibrillary tangles and senile plaques have been identified as the hallmark pathological changes in the brain of Alzheimer's disease (AD), the relationship between them is still not fully understood. In the present study, we have studied the effect of endogenously overproduced amyloid beta (A beta) on tau by using wild type amyloid precursor protein (APP) transfected (N2a/APP695), or Swedish mutant APP plus Delta 9 deleted presenilin-1 co-transfected (N2a/APPswe.Delta 9) and APP vector transfected (N2a/vector) cell lines. We measured the secreted and intracellular A beta, including A beta(1-40) and A beta(1-42), by Sandwich ELISA assay. It was shown that the levels of A beta were increased time-dependently in N2a/APP695 and N2a/APPswe.Delta 9 but not in N2a/vector upon butyric acid (BA) treatment. Compared with N2a/vector cells, tau in N2a/APP695 and N2a/APPswe.Delta 9 cells was not extracted by RIPA buffer, and the SDS-extracted tau protein was hyperphosphorylated at Tau-1 and PHF-1 epitopes upon BA treatment. Obvious accumulation of the hyperphosphorylated tau in N2a/APP695 and N2a/APPswe.Delta 9 cells was observed at 48 h after BA treatment. The total level of the extracted tau was reduced in N2a/APP695 and N2a/APPswe.Delta 9 lines compared with N2a/vector cells by Western blot, and this reduction of total tau was also detected by immunofluorescence staining. No obvious alteration of tau mRNA was observed in both N2a/APP695 and N2a/APPswe.Delta 9 cells compared with N2a/vector. This study provides direct evidence demonstrating that endogenously overproduced A beta not only induces tau hyperphosphorylation but also decreases the level and solubility of tau in N2a cell lines.

Association between Polymorphisms of Vitamin D Receptor Gene ApaI, BsmI and TaqI and Muscular Strength in Young Chinese Women

The association between the polymorphisms of vitamin D receptor gene ApaI, BsmI and TaqI and isokinetic muscular strength was examined in 109 healthy, young Chinese women.

METHODS

Genomic DNA was extracted from mouthwash samples and vitamin D receptor genotypes were determined with the established methods. The peak torque of the dominant limb in concentric and eccentric knee extensors and flexors and elbow extensors and flexors was measured using Cybex-Norm-770 isokinetic dynamometer at slow and fast velocities. The distribution frequency of vitamin D receptor gene alleles was analyzed by chi-square test. The difference in muscular strength between VDR genotype groups was analyzed using one-way ANOVA. The ApaI, BsmI and TaqI alleles and genotype frequencies appeared to be in a Hardy-Weinberg equilibrium. Subjects with the vitamin D receptor ApaI null (A allele) mutation (AA) exhibited significantly lower knee and elbow concentric or eccentric peak torque than those with aa homozygous or Aa heterozygous. The BB & Bb group showed significantly higher peak torque in concentric knee flexors than bb group. No association was found between vitamin D receptor gene TaqI and muscular strength. The data indicated that vitamin D receptor gene ApaI and BsmI polymorphisms rather than TaqI polymorphism might be associated with muscular strength.

Activation of glycogen synthase kinase-3 induces Alzheimer-like tau hyperphosphorylation in rat hippocampus slices in culture

Formation of neurofibrillary tangle from hyperphosphorylated tau is one of the hallmark lesions seen in Alzheimer's disease (AD) brain, and neuronal deregulation of glycogen synthase kinase-3 (GSK-3) activity plays key role in tau hyperphosphorylation. In the present study, the role of GSK-3 on tau phosphorylation in hippocampus slice culture was examined by incubating the slice with wortmannin (WT), an inhibitor of phosphatidylinositol 3-kinase (PI3K) and GF-109203X (GFX), an inhibitor of protein kinase C (PKC). It was found that treatment of the slices with GFX or WT separately induced tau hyperphosphorylation both at Ser396/Ser404 (PHF-1) and Ser199/Ser202 (Tau-1) sites. The phosphorylation rate of tau at PHF-1 and Tau-1 epitopes was further increased when GFX and WT were used in combination, and at this condition, AD-like tau accumulation was observed. GSK-3 activity was significantly increased with a concurrently decreased level of inactivated form of GSK-3. Lithium chloride (LiCl), a GSK-3 inhibitor, prevented tau from WT- and GFX-induced hyperphosphorylation. It suggests that GSK-3 is regulated through PI3K and PKC pathway, and activation of GSK-3 not only induces hyperphosphorylation of tau but also leads to accumulation of tau in cultured rat brain slice.

Injection of okadaic acid into the meynert nucleus basalis of rat brain induces decreased acetylcholine level and spatial memory deficit

Abnormal hyperphosphorylation of tau and cholinergic deficit occur in the early stage of Alzheimer's disease (AD) and relate to the dementia symptom. Hyperphosphorylation of tau, neurofilament (NF) and other proteins in AD brain appears to be caused by a down-regulation of protein phosphatase 2A (PP2A), but the mechanism leading to cholinergic deficit is still unknown. In this study, we selectively inhibited PP2A by injection of okadaic acid (OA) into the Meynert nucleus basalis of rats. We found that injection of OA induced hyperphosphorylation of tau and NF and decreased acetylcholine (ACh) level in the nucleus basalis of Meynert. These alterations were accompanied by spatial memory deficit in OA-injected rats. We also demonstrated that the OA-induced ACh reduction may be due to a failure of intraneuronal transport of choline acetyltransferase (ChAT) from cell body to the neuronal terminals rather than an alteration of activity of ChAT or acetylcholinesterase. This study suggests that a down-regulation of PP2A may underlie both abnormal hyperphosphorylation of cytoskeletal proteins leading to neurofibrillary degeneration and cholinergic deficiency in AD.

Differential inhibition of human cancer cell proliferation by citrus limonoids

Limonoids have been shown to inhibit the growth of estrogen receptor-negative and -positive human breast cancer cells in culture. The primary objective of this study was to test the antiproliferative activity of limonoids (obacunone 17 beta-D-glucopyranoside, nomilinic acid 17 beta-D-glucopyranoside, limonin, nomilin, and a limonoid glucoside mixture), found in high concentrations in mandarin (Citrus reticulata Blanco), against a series of human cancer cell lines. The human cancer cell lines included leukemia (HL-60), ovary (SKOV-3), cervix (HeLa), stomach (NCI-SNU-1), liver (Hep G2), and breast (MCF-7). The growth-inhibitory effects of the four limonoids and the limonoid glucoside mixture against MCF-7 cells were significant, and the antiproliferative activity of the different citrus limonoids was also dose and time dependent. No significant effects were observed on growth of the other cancer cell lines treated with the four individual limonoids at 100 micrograms/ml. At 100 micrograms/ml, the limonoid glucoside mixture demonstrated a partial inhibitory effect on SKOV-3 cancer cells. With use of flow cytometry, it was found that all the limonoid samples could induce apoptosis in MCF-7 cells at relatively high concentrations (100 micrograms/ml). Considering the high concentration needed to induce apoptosis, it is unlikely that this is the primary mechanism of action for the cytotoxic effects seen with limonoids in this study. Further work is needed in this area to establish the mechanism of action of citrus limonoids on human breast cancer cells.

[Cloning of a new cDNA: responded to all-trans retinoic acid in HL-60 cell differentiation]

In this paper a new type of cDNA fragment named as W-1 gene was first cloned and sequenced from ATRA induced HL-60 cells by using differential display PCR (DD-PCR) and DNA sequencing techniques. These differentially expressing products of the gene responding to ATRA were further confirmed by Northern blotting analysis. The results showed that the expressing level of this gene induced by ATRA (10(-6) mol.L-1) for 16 hrs was much higher than that in the control HL-60 cells, but its expression in HL-60 was reduced to an unestimable level after induction of ATRA (10(-6) mol.L-1) for 24 hrs. It suggests that ATRA may increase the expression of W-1 gene during the early stage of HL-60 cell differentiation. The exact mechanism of action is being studied further.

Synthesis of 9-alkylidene-9H-fluorenes by a novel, palladium-catalyzed cascade reaction of aryl halides and 1-aryl-1-alkynes

In the presence of a palladium catalyst and NaOAc, aryl iodides react with 1-aryl-1-alkynes to afford 9-alkylidene-9H-fluorenes in good yields. The products from this reaction are highly dependent on the base employed. This process appears to involve (1) oxidative addition of the aryl iodide to Pd(0), (2) alkyne insertion, (3) rearrangement of the resulting vinylic palladium intermediate to an arylpalladium species, and (4) aryl-aryl coupling with simultaneous regeneration of the Pd(0) catalyst. Consistent with this mechanism is the fact that 9-alkylidene-9H-fluorenes can also be prepared by the Pd-catalyzed rearrangement of 1,1-diaryl-2-iodo-1-alkenes.

Function of basonuclin in increasing transcription of the ribosomal RNA genes during mouse oogenesis

Active protein synthesis during early oogenesis requires accelerated transcription of ribosomal RNA genes (rDNAs). In response to this demand, rDNAs are amplified more than 1000-fold early in Xenopus oogenesis. Here, we report evidence that rDNA is not amplified in mouse oocytes, but these cells may instead employ the zinc-finger protein basonuclin, a putative rDNA transcription factor, to enhance rRNA synthesis. This conclusion is based on observations that basonuclin is localized in the nucleolus in the mouse oocyte early in its growth phase, when rRNA transcription is highly active; and that the binding sites of basonuclin zinc fingers on the human and mouse rDNA promoters are homologous. In a co-transfection assay, basonuclin can elevate transcription from an rDNA promoter, and its zinc-finger domain can inhibit RNA polymerase I transcription, as detected by a run-on assay, in growing mouse oocytes.

The C/EBP bZIP domain can mediate lipopolysaccharide induction of the proinflammatory cytokines interleukin-6 and monocyte chemoattractant protein-1

C/EBPalpha, beta, and delta are all expressed by bone marrow-derived macrophages. Ectopic expression of any of these transcription factors is sufficient to confer lipopolysaccharide (LPS)-inducible expression of interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) to a B lymphoblast cell line, which normally lacks C/EBP factors and does not display LPS induction of proinflammatory cytokines. Thus, the activities of C/EBPalpha, beta, and delta are redundant in regard to expression of IL-6 and MCP-1. Surprisingly, the bZIP region of C/EBPbeta, which lacks any previously described activation domains, can also confer LPS-inducible expression of IL-6 and MCP-1 in stable transfectants. Transient transfections reveal that the bZIP regions of C/EBPbeta, C/EBPdelta, and, to a lesser extent, C/EBPalpha can activate the IL-6 promoter and augment its induction by LPS. Furthermore, the transdominant inhibitor, LIP, can activate expression from the IL-6 promoter. The ability of the C/EBPbeta bZIP region to activate the IL-6 promoter in transient transfections is completely dependent upon an intact NF-kappaB-binding site, supporting a model where the bZIP protein primarily functions to augment the activity of NF-kappaB. Replacement of the leucine zipper of C/EBPbeta with that of GCN4 yields a chimeric protein that can dimerize and specifically bind to a C/EBP consensus sequence, but shows a markedly reduced ability to activate IL-6 and MCP-1 expression. These results implicate the leucine zipper domain in some function other than dimerization with known C/EBP family members, and suggest that C/EBP redundancy in regulating cytokine expression may result from their highly related bZIP regions.