Increased expression of amyloid precursor protein promotes proliferation and migration of AML1/ETO-positive leukemia cells and be inhibited by panobinostat

Amyloid precursor protein (APP) is a highly conserved integral membrane protein extensively expressed in various types of cells. Previously we found that overexpression of APP in patients with AML1/ETO-positive acute myeloid leukemia (AML) associated with a higher incidence of extramedullary infiltrationin and indicate a poor prognosis. In this study, we attempted to define the roles of APP in AML1/ETO-positive leukemia cells. Western blotting and qRT-PCR analysis showed that protein levels of APP are significantly higher in Kasumi-1, a t(8;21)/ AML1/ETO-positive M2-type AML cell line. Stable knockdown of APP by lentivirus-based RNA interference (RNAi) dramatically impaired colony-formation and migration ability of Kasumi-1 cells, whereas APP knockdown had very little effect on cell viability, apoptosis, cell cycle and differentiation. We further explored whether the pan-histone deacetylase inhibitor panobinostat could deplete the protein levels of APP in Kasumi-1 cells. Treatment with panobinostat caused depletion of APP in Kasumi-1 cells. These findings indicate that overexpression of APP is involved in promoting proliferation and migration of AML1/ETO-positive leukemia cells and can be inhibited by panobinostat, which provide an attractive prospect for treatment of AML1/ETO-positive AML.

First Report of Tomato mottle mosaic virus Infection of Pepper in China

Tomato mottle mosaic virus (ToMMV), a tentative member in genus Tobamovirus, was first reported from a greenhouse tomato sample collected in Mexico in 2013 (2). In August 2013, foliar mottle, shrinking, and necrosis were observed on pepper plants in several vegetable greenhouses of Lhasa, Tibet Autonomous Region, China. Seven symptomatic samples were collected and tested by dot-blot ELISA with antisera against Cucumber mosaic virus, Tobacco mosaic virus (TMV), Cucumber green mottle mosaic virus, Tomato spotted wilt virus, Turnip mosaic virus, and Broad bean wilt virus 2 (kindly provided by Dr. Xueping Zhou of Zhejiang University, China) (3). One of the bell pepper (Capsicum annuum var. grossum) samples reacted with the TMV antibody. Rod-shaped virus particles 300 nm in length were observed in this sample under electron microscopy. The results suggested that a tobamovirus closely related to TMV might be a causal agent. Total nucleic acids were then extracted from all seven samples using a CTAB method (1) and tested by RT-PCR using a pair of tobamovirus degenerate primers, TobamoF (GCWAAGGTKGTWYTBGTRGAYGG) and TobamoR (GTAATTGCTATTGDGTWCCWGC). These two primers were designed according to a conserved region of the TMV, Tomato mosaic virus, and ToMMV genomes (nt 2551-3433 of ToMMV genome [KF477193]). An amplicon of approximately 880 bp was obtained only from the TMV-positive sample. The amplicon was cloned and sequenced (GenBank Accession No. KJ605653). NCBI BLAST search showed that it shared the highest identity (99%) with ToMMV (KF477193), and shared the sequence homology of 82% to Tomato mosaic virus (AF332868) and 77% to TMV (V01408). The results indicated that the symptomatic pepper was infected with ToMMV. To investigate the distribution and incidence of ToMMV, 313 samples of symptomatic pepper, tomato, pumpkin, cucumber, radish, Chinese cabbage, broad bean, pea, and kidney bean samples were collected from 65 fields in Yunnan Province and Tibet Autonomous Region, and tested in RT-PCR with ToMMV-specific primers ToMMVF (AGAGAGATGGCGATAGGTTAAC, identical to nt 830-851 of ToMMV genome, GenBank Accession No. KF477193) and ToMMVR (CTGCAGTCATAGGATCTACTTC, complementary to nt1849-1828). The virus was detected in three tabasco peppers (C. frutescens) from Yunnan and one bell pepper plant from Tibet, suggesting that ToMMV has a restricted host range and is not common in these two regions. To our knowledge, this is the first report of natural infection of ToMMV in peppers as well as in China. References: (1) R. Li et al. J. Virol. Methods 154:48, 2008. (2) R. Li et al. Genome Announc. 1(5):e00794-13, 2013. (3) Y. Xie et al. Virol. J. 10:142, 2013.

Development of polymorphic expressed sequence tag-single sequence repeat markers in the common Chinese cuttlefish, Sepiella maindroni

The common Chinese cuttlefish (Sepiella maindroni) is one of the popular edible cephalopod consumed across Asia. To facilitate the population genetic investigation of this species, we developed fourteen polymorphic microsatellite makers from expressed sequence tags of S. maindroni. The number of alleles at each locus ranged from 6 to 10 with an average of 7.9 alleles per locus. The ranges of observed and expected heterozygosity were from 0.615 to 0.962 and 0.685 to 0.888, respectively. Four loci were found deviated significantly from Hardy-Weinberg equilibrium. The polymorphism information content ranged from 0.638 to 0.833. These polymorphic microsatellite loci will be helpful for the population genetic, genetic linkage map, and other genetic studies of S. maindroni.

Predictive role of RRM1 and BRCA1 mRNA expression on the clinical outcome of advanced non-small cell lung cancer

This study aimed to evaluate the association between RRM1 and BRCA1 expressions and the therapeutic efficacy of platinum-based chemotherapy in non-small cell lung cancer patients in terms of their response and prognosis. In total, 377 patients agreed to participate in our study, and all of them received platinum-based combination chemotherapy between January 2008 and January 2009. The relative cDNA quantitation for RRM1 and BRCA1 was conducted using a fluorescence-based, real-time detection method, using β-actin as a reference gene. The average age of the 377 patients was 64.6 years (range: 25.5-86.4 years), including 269 men and 108 women. Patients with high RRM1 expression benefited more from a platinum-containing regimen, and patients with high BRCA1 expression showed a high response rate to a platinum-containing regimen and reduced disease progression. Patients with high RRM1 expression were associated with a longer progression-free survival (PFS) and overall survival (OS) than those with low expression, and the hazard ratios (HRs) (95% confidence interval (CI)) were 0.67 (0.32-0.91) and 0.54 (0.30-0.95), respectively. Patients with high BRCA1 expression showed longer PFS and OS compared to those with low expression, and the HRs (95%CI) were 0.54 (0.30-0.95) and 0.62 (0.32-0.93), respectively. These results could be used in personalized chemotherapy decisions and to increase the response rate and prolonged survival, and could encourage exploration of the predictive value of other genes.

The adsorption behavior of U(VI) on granite

The effects of pH, counter ions and temperature on the adsorption of U(VI) on Beishan granite (BsG) were investigated in the presence and absence of fulvic acid (FA) and humic acid (HA). The adsorption edge of U(VI) on BsG suggested that U(VI) adsorption was mainly controlled by ion exchange and outer-sphere complexation at low pH, whereas inner-sphere complex was the dominant adsorption species in the pH range of 4.0-9.0. Above pH 9.0, Na2U2O7 might play an important role in the rise of U(VI) adsorption again. Counter ions such as Cl(-), SO4(2-) and PO4(3-) can provoke U(VI) adsorption on BsG to some extent, which was directly correlated to the complexing ability of U(VI)-ligand. More noticeably, the large enhancement of U(VI) adsorption in the presence of phosphate can be attributed to the ternary complex formation (BsG-PO4-UO2), precipitation ((UO2)3(PO4)2(s)) and secondary phase (Na-autunite). Both FA and HA can slightly increase U(VI) adsorption at low pH, whereas they strongly inhibited U(VI) adsorption at high pH range. Artificial synthesized granite (AsG) prepared in the laboratory is impossible to use as an analogue of natural granite because of the large difference in the adsorption and surface properties.

Effect of nutrition on plasma lipid profile and mRNA levels of ovarian genes involved in steroid hormone synthesis in Hu sheep during luteal phase

Ovarian steroid hormones regulate follicular growth and atresia. This study aims to determine whether key ovarian sterol-regulatory genes are differentially expressed in Hu sheep under different short-term nutritional regimens. Estrus was synchronized using intravaginal progestagen sponges. The ewes were assigned randomly to 3 groups. On d 6 to 12 of their estrous cycle, the control (CON) group received a maintenance diet (1.0×M), the supplemented (SUP) group received 1.5×M, and the restricted (R) group received 0.5×M. On d 7 to 12, blood samples were taken. The sheep were slaughtered at the end of the treatment, and their organs and ovaries were collected. The plasma concentrations of urea (P<0.01), total cholesterol (P<0.01), low-density lipoprotein cholesterol (P<0.01), NEFA (P<0.01), FSH (P<0.05), and estradiol (P<0.05) increased with decreasing dietary intake, whereas plasma triglyceride (P<0.01) and triiodothyronine (T3) concentrations decreased (P<0.05). The ewes in the R group had higher spleen weight and percentage of spleen to BW and lower liver and small intestine weights and percentage of liver/stomach to BW than the SUP group ewes (P<0.05). Nutritional restriction decreased the cytochrome p450 (CYP17A1) and estrogen receptor 1 (ESR1) mRNA expression (P<0.05) and increased the cytochrome p450 aromatase (CYP19A1) mRNA expression (P<0.05) in follicles>2.5 mm. Follicle size affected the mRNA expression of very low density lipoprotein receptor (VLDLR), estrogen receptor 2 (ESR2), FSH receptor (FSHR), CYP17A1, and CYP19A1 (P<0.05). In conclusion, we suggest that a potential mechanism by which short-term negative energy balance inhibits follicular growth may involve responses to disrupted reproductive hormone concentrations and influenced the intrafollicular expression of CYP17A1, CYP19A1, and ESR1. This result may be due to increased plasma urea and lipid concentrations.

Metabolic changes of human dental pulp after rapid palatal expansion

OBJECTIVES

To investigate rapid palatal expansion (RPE)-induced metabolic changes in human dental pulp by measuring the expression and activity of aspartate aminotransferase (AST).

METHODS

mRNA and protein levels of AST in human dental pulp were measured by quantitative real-time polymerase chain reaction and Western blot, respectively. Furthermore, the activity of AST was measured by a full automatic biochemical analyzer.

RESULTS

AST mRNA and protein levels were found to be expressed in normal dental pulp. Moreover, the expression of AST was increased significantly after 14 days of RPE and then decreased at 1 month in retention. Three and 6 months after RPE, the AST expression level was gradually decreased to its baseline level. Similarly, AST activity was significantly elevated after 14 days of RPE, which was then down-regulated at 1 month in retention but was still kept at a higher level as compared with the control group. The enzymatic activity of AST was slowly decreased to its baseline level at 3 and 6 months in retention.

CONCLUSIONS

These results showed that significant reversible metabolic changes occurred in dental pulp during RPE, which revealed the high capacity of the pulp tissue for adaptation to this orthopedic method.

Elimination of ghosting artifacts from wavelength-shifting fiber neutron detectors

Misassignment of neutron position (ghosting) produces artifacts which have been observed in wavelength-shifting (WLS) fiber detectors developed for time-of-flight (TOF) neutron powder diffraction. In position-sensitive detectors (PSDs) with WLS fiber encoding, thermal and cold neutrons interact with a monolithic (6)LiF/ZnS:Ag scintillator screen, and scintillation photons are generated and transported through the crossed fibers to photomultipliers (PMTs). The neutron position is determined by photon counts in the PMTs within a preset time window. Ghosting occurs when neutrons hit the group boundaries of two neighboring PMTs for x-position multiplexing, which is modeled as resulting from a long travel length (about 3-5 mm) of a small number of scintillation photons. This model is supported by the change observed in aperture images when the threshold number for photon-pulses was adjusted for neutron event determination. When the threshold number of photon-pulses was set above 10 for each PMT, the ghost peaks in the aperture images and TOF spectra of powder diffraction were strongly suppressed or completely eliminated, and the intrinsic background levels of the WLS detectors were significantly reduced. Our result indicates that WLS fiber detector is a promising alternative for (3)He PSDs for neutron scattering.

Uranium and thorium leached from uranium mill tailing of Guangdong Province, China and its implication for radiological risk

The paper focused on the leaching behaviour of uranium (U) and thorium (Th) from uranium mill tailing collected from the Uranium Mill Plant in Northern Guangdong Province, China. Distilled water (pH 6) and sulphuric acid solution (pH 4 and 3) were used as solvent for the leaching over 22 weeks. It was found that the cumulative leach fraction from the mill tailing was 0.1, 0.1 and 0.7 % for U release, and overall 0.01 % for Th release, using distilled water, sulphuric acid solution of pH 4 and pH 3 as leaching agents, respectively. The results indicate that (1) the release of U and Th in uranium mill tailing is a slow and long-term process; (2) surface dissolution is the main mechanism for the release of U and Th when sulphuric acid solution of pH 3 is employed as the leaching agent; (3) both U and Th are released by diffusion when using sulphuric acid solution of pH 4 as the leaching agent and (4) U is released by surface dissolution, while Th is released by diffusion when using distilled water as the leaching agent. The implication for radiological risk in the real environment was also discussed.

Microwave-assisted one-step patterning of aqueous colloidal silver

A new approach of utilizing microwave to pattern gradient concentric silver nanoparticle ring structures has been presented. The width and height of a single ring and the space between adjacent rings can be adjusted by changing the silver colloidal concentration and the microwave output power. By simply enhancing the ambient vapour pressure to the saturated value during microwave-assisted evaporation, sub-100 nm rings can be deposited in between adjacent micro-rings over a distance of millimetres. Combined with microwave sintering, this approach can also create conductive silver tracks in a single step, showing huge potential in fabricating micro- and nano-electronic devices in an ultra-fast and cost-effective fashion.

Retinoblastoma protein-interacting zinc-finger gene 1 (RIZ1) dysregulation in human malignant meningiomas

Retinoblastoma protein-interacting zinc-finger gene 1 (RIZ1) expression is often silenced in many types of human tumors. However, the relationship between RIZ1 expression and malignant meningiomas remains unclear. Here we have found for the first time that the expression of RIZ1 genes are associated with meningiomas progression through extensive analyses of Affymetrix GeneChip microarray data. Further validation methods for gene expression included quantitative PCR (qPCR), western blot and immunohistochemistry analysis, and these methods confirmed that RIZ1 is significantly downregulated in malignant meningioma tissues, as compared with benign meningiomas. In addition, malignant meningioma cells were stably transfected with ectogenic RIZ1 using Lentivirus-mediated transfection, and the transfections were followed by an in vitro 5-bromo-2-deoxyuridin incorporation assay, colony formation assay, cell cycle analysis, invasive analysis, apoptotic assay and western blot analysis. Our results demonstrate that the forced expression of RIZ1 in a malignant meningioma cell line inhibited cellular proliferation and arrested the cells in the G2/M phase of the cell cycle. We also confirmed that overexpression of RIZ1 may induce apoptosis of malignant meningioma cells. Furthermore, RIZ1 overexpression in malignant meningioma cells was associated with the downregulation of c-myc expression. These results from our study indicate that RIZ1 expression is significantly downregulated as the formation of meningiomas progressed, and suggest that RIZ1 may represent a promising candidate tumor suppressor gene that contributes to malignant meningiomas.

A preliminary investigation of the relationship between circulating tumor cells and cancer stem cells in patients with breast cancer

In this study, we explored the relationship between the circulating tumor cells (CTC) and the CTC-cancer stem cells (CSC) in the patients with breast cancer. The magnetic-activated cell separation (MACS) method and flow cytometry (FCM) for selection of epithelial cells from the peripheral blood mononuclear cells (PBMC) were used to analyze the enriched epithelial cells that were labeled with anti-cytokeratin(CK)-fluorescein isothiocyanate, anti-CD44-phycoerythrin (PE) and anti-CD24-PE, respectively. The CK+ cells were attributed to CTC and the CK+CD44+ CD24-/low cells were thought as to CTC-CSC in 26 breast cancer patients, respectively. Our results showed the CK+ tumor cells were detected in 19 of 26 patients, with the CK+ tumor cells varying from 0.11% to 5.42 %. The CTC-CSC were identified in 18 of the 19 patients with CTC and the percentage of CTC-CSC in CTC was 19.01%. The results yet suggested the breast cancer patients with high-rate CK+ tumor cells were at the advanced tumor node metastases (TNM) stage III, and the patients with low-rate CK+ cells were at the modest TNM stage I. The difference between the two groups was statistically significant (p<0.001). We concluded that there is a significant relationship between CTC and CTC-CSC, but not among TNM stages, in breast cancer metastasis.

One Alpha-hydroxycholecalciferol Improves Growth Performance, Tibia Quality, and Meat Color of Broilers Fed Calcium- and Phosphorus-Deficient Diets

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol (1α-OH D₃) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of 1α-OH D₃ (0, 5, and 10 μg/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin D₃. As a result of this study, the addition of 1α-OH D₃ increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary 1α-OH D₃ enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, 1α-OH D₃ decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the 1α-OH D₃ improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.

Electron Transport Suppression from Tip-π State Interaction on Si(100)-2 × 1 Surfaces

We investigate the electron transport between a scanning tunneling microscope tip and Si(100)-2 × 1 surfaces with four distinct configurations by performing calculations using density functional theory and the nonequilibrium Green's function method. Interestingly, we find that the conducting mechanism is altered when the tip-surface distance varies from large to small. At a distance larger than the critical value of 4.06 Å, the conductance is increased with a reduction in distance owing to the π state arising from the silicon dimers immediately under the tip; this in turn plays a key role in facilitating a large transmission probability. In contrast, when the tip is closer to the substrate, the conductance is substantially decreased because the π state is suppressed by the interaction with the tip, and its contribution in the tunneling channels is considerably reduced.

Wnt5a promotes differentiation of human dental papilla cells

AIM

To investigate the role of Wnt5a in the process of differentiation of human dental papilla cells (HDPCs).

METHODOLOGY

Recombinant adenovirus encoding full-length Wnt5a cDNA was constructed to investigate the biological role of Wnt5a on the differentiation of HDPCs. The effect of Wnt5a on HDPCs differentiation was determined by ALP activity assay, ALP staining and mineral induction assay. Mineralization-related gene expressions were assessed by RT-PCR.

RESULTS

Immunostaining revealed Wnt5a expression in the odontoblast layer and dental papilla tissue. Over-expression of Wnt5a by transfecting HDPCs with an Wnt5a-carrying construct increased ALPase activity and the formation of mineralized nodules of HDPCs. RT-PCR analysis showed that the expressions of mineralization-related genes, such as bone sialoprotein, collagen type I, osteonectin, osteopontin (OCN), dentine matrix protein-1 were up-regulated by Wnt5a.

CONCLUSIONS

Wnt5a promoted differentiation of HDPCs.

Quantitative trait loci mapping of leaf angle and leaf orientation value in maize (Zea mays L.)

A major limiting factor for high productivity of maize (Zea mays L.) in dense planting is light penetration through the canopy. Plant architecture with a narrower leaf angle (LA) and an optimum leaf orientation value (LOV) is desirable to increase light capture for photosynthesis and production per unit area. However, the genetic control of the plant architecture traits remains poorly understood in maize. In this study, QTL for LA, LOV, and related traits were mapped using a set of 229 F(2:3) families derived from the cross between compact and expanded inbred lines, evaluated in three environments. Twenty-five QTL were detected in total. Three of the QTL explained 37.4% and five of the QTL explained 53.9% of the phenotypic variance for LA and LOV, respectively. Two key genome regions controlling leaf angle and leaf orientation were identified. qLA1 and qLOV1 at nearest marker umc2226 on chromosome 1.02 accounted for 20.4 and 23.2% of the phenotypic variance, respectively; qLA5 and qLOV5 at nearest bnlg1287 on chromosome 5 accounted for 9.7 and 9.8% of the phenotypic variance, respectively. These QTL could provide useful information for marker-assisted selection in improving performance of plant architecture with regard to leaf angle and orientation.

Small ubiquitin-like modifier-4 Met55Val polymorphism is associated with glycemic control of Type 2 diabetes mellitus in Taiwan

AIM

The development of Type 2 diabetes mellitus (T2DM) has been recognized to be associated with a combination of pancreatic beta-cell dysfunction and insulin resistance. Nuclear factor-kappaB (NF-kappaB) has been recognized as one central mediator in the reaction of inflammation and proapoptotic event in beta-cells. A functional polymorphism at the codon 55 (methionine to valine; A163G) of the small ubiquitin- like modifier-4 (SUMO4) gene may result in higher NF-kappaB activity. This study investigates whether this SUMO4 Met55Val polymorphism also contributes to the development of T2DM.

MATERIALS AND METHODS

The study was performed using genomic DNA samples from 574 Type 2 diabetic patients and 323 healthy controls. The SUMO4 Met55Val polymorphism was genotyped using allele-specific real-time PCR.

RESULTS

The frequency of the G allele (encoding Val55) was significantly higher in Type 2 diabetic patients and Type 2 diabetic patients with the GG genotype had higher hemoglobin A1c level. Multivariate logistic regression analysis revealed the genotype of GG and GA was an independent risk factor contributing to the development of T2DM.

CONCLUSION

This study suggests that in Taiwan the SUMO4 Met 55Val polymorphism is associated with susceptibility to T2DM and Type 2 diabetic patients with GG genotype have worse glycemic control.

Small ubiquitin-like modifier-4 Met55Val polymorphism is associated with glycemic control of Type 2 diabetes mellitus in Taiwan

AIM

The development of Type 2 diabetes mellitus (T2DM) has been recognized to be associated with a combination of pancreatic beta-cell dysfunction and insulin resistance. Nuclear factor-kappaB (NF-kappaB) has been recognized as one central mediator in the reaction of inflammation and proapoptotic event in beta-cells. A functional polymorphism at the codon 55 (methionine to valine; A163G) of the small ubiquitin- like modifier-4 (SUMO4) gene may result in higher NF-kappaB activity. This study investigates whether this SUMO4 Met55Val polymorphism also contributes to the development of T2DM.

MATERIALS AND METHODS

The study was performed using genomic DNA samples from 574 Type 2 diabetic patients and 323 healthy controls. The SUMO4 Met55Val polymorphism was genotyped using allele-specific real-time PCR.

RESULTS

The frequency of the G allele (encoding Val55) was significantly higher in Type 2 diabetic patients and Type 2 diabetic patients with the GG genotype had higher hemoglobin A1c level. Multivariate logistic regression analysis revealed the genotype of GG and GA was an independent risk factor contributing to the development of T2DM.

CONCLUSION

This study suggests that in Taiwan the SUMO4 Met 55Val polymorphism is associated with susceptibility to T2DM and Type 2 diabetic patients with GG genotype have worse glycemic control.

Spontaneous emergence of ordered phases in crumpled sheets

X-ray tomography is performed to acquire 3D images of crumpled aluminum foils. We develop an algorithm to trace out the labyrinthian paths in the three perpendicular cross sections of the data matrices. The tangent-tangent correlation function along each path is found to decay exponentially with an effective persistence length that shortens as the crumpled ball becomes more compact. In the meantime, we observed ordered domains near the crust, similar to the lamellae phase mixed by the amorphous portion in lyotropic liquid crystals. The size and density of these domains grow with further compaction, and their orientation favors either perpendicular or parallel to the radial direction. Ordering is also identified near the core with an arbitrary orientation, exemplary of the spontaneous symmetry breaking.

X-ray tomography of a crumpled plastoelastic thin sheet

Three-dimensional x-ray tomography is performed to investigate the internal structure and its evolution of a crumpled aluminum foil ball. The upper and lower bounds of the internal geometric fractal dimension are determined, which increase with the compression. Contrary to the simulation results, we find that the mass distribution changes from being inhomogeneous to uniform. Corroborated with the evidence from previous experiments, these findings support the physical picture that the elastic property precedes the plastic one at dominating the deformation and mechanical response for all crumpled structures. We show that the interior of a crumpled ball at the plastic regime can be mapped to the compact packing of a granular system.

The association of clinical findings and exposure profiles with melamine associated nephrolithiasis

BACKGROUND

Little is known about the exposure profiles of melamine in children. We evaluated the association of clinical findings, exposure patterns and biomarkers with nephrolithiasis in children with potential exposure to melamine.

METHODS

A case-control study was conducted in children aged 0-16 years with potential exposure to contaminated dairy products. Cases were defined as nephrolithiasis detected by renal ultrasonography. On the basis of different brands of contaminated dairy products consumed, subjects were classified into high exposure, low exposure and control groups with estimated melamine exposure levels of higher than 2.5 ppm, 0.05-2.5 ppm and lower than detection limits <0.05 ppm. We measured urine melamine for those with nephrolithiasis and age-matched and gender-matched controls within the subset of the study population.

RESULTS

The duration of consumption of contaminated products was longer in children with nephrolithiasis in the high exposure group than in controls (median (IQR) 12.0 (3.3-24.0) vs 6.0 (4.0-7.0) months; p = 0.048). High melamine exposure levels were significantly associated with nephrolithiasis (OR 61.04 (95% CI 12.73 to 292.84)). The risk was found to increase with estimate melamine exposure levels (p for trend <0.001). Two among 10 affected subjects with nephrolithiasis showed elevated urine melamine levels. In comparison, levels of all 20 controls were lower than the detection limit.

CONCLUSIONS

The risk of melamine-associated nephrolithiasis was related to duration of consumption of contaminated products and estimated melamine exposure levels. Though urine melamine was not a sensitive test, it might serve as an exposure biomarker in melamine-associated nephrolithiasis.

Genetic analysis of photoperiod sensitivity in a tropical by temperate maize recombinant inbred population using molecular markers

Photoperiod sensitivity is an important consideration in maize cultivation. Flowering time is affected by photoperiod and sensitivity to it limits the potential for successful exchange of germplasm across different latitudes. For resolving the genetic basis of photoperiod sensitivity in maize, a set of 207 recombinant inbred lines derived from a temperate and tropical inbred line cross was evaluated for 2 years in a long-day and short-day environment. Genetic linkage maps were constructed using 237 SSR markers with a total length 1,974.3 cM, and an average space between two makers of 8.33 cM. Twenty-nine QTL were detected for the five measured photoperiod sensitivity traits using composite interval mapping and multiple interval mapping. QTL for flowering time, plant height and leaf number, under long-day conditions, were found clustered on chromosome 10, while QTL for short-day conditions resided on chromosome 3. The QTL in the bin 10.04 region of chromosome 10 were detected associated with photoperiod sensitivity and related traits during long days. These results indicated that this region might contain an important photoperiod sensitivity element.

Higher prevalence of gastrointestinal symptoms among patients with rheumatic disorders

INTRODUCTION

Chronic disorders, such as rheumatic disorders, are associated with increased gastrointestinal (GI) complaints. Medications may be a contributory factor. This study assessed the prevalence of GI symptoms among patients followed-up in a rheumatology clinic.

METHODS

Enquiries about GI, psychological and psychosomatic symptoms (headache, insomnia, anxiety, backache and depression) were made from patients. Non-related visitors served as the control group. The underlying disorders were rheumatoid arthritis (RA, 37 percent), systemic lupus erythromatosus (SLE, 23 percent) and others (40 percent).

RESULTS

The symptom prevalence of the following complaints were: reduced appetite (10.2 percent), nausea (20.2 percent), vomiting (10.7 percent), dysphagia (7.3 percent), odynophagia (5.1 percent), early satiety (27.5 percent), heartburn (15.2 percent), dyspepsia (44.6 percent), abdominal bloating (20.8 percent) and irregular bowel habit (6.7 percent). There were no differences between the various rheumatic disorders (RA/SLE and RA/others) except for more heartburn in SLE compared to others (p-value is less than 0.05). There was no significant difference between nonsteroidal anti-inflammatory drug (NSAID) users and non-users. Patients on medications with GI (disease modifying/steroid/NSAIDs) adverse effects, experienced a higher rate of early satiety (odds-ratio [OR] 3.5, 95 percent confidence interval [CI] 1.4-8.9) and dyspepsia (OR 2.1, 95 percent CI 1.2-4.3). Compared to the control group, patients had more GI symptoms (all p-values are less than 0.05) except for irregular bowel habits. Patients also experienced more anxiety (OR 2.1, 95 percent CI 1.1-2.4) and backache (OR 2.6, 95 percent CI 1.6-4.2), and had significantly higher symptom clustering (more than two symptoms) compared to the controls (p-value is less than 0.001).

CONCLUSION

GI symptoms are common among patients with rheumatic disorders. Medications alone do not account for the high prevalence, suggesting that the underlying conditions predispose to GI symptoms.