Concentration, Source, and Total Health Risks of Cadmium in Multiple Media in Densely Populated Areas, China

Cadmium (Cd) is a non-essential and harmful element to humans. Cadmium contamination is a serious issue for human health, especially in densely populated agroecology areas. In this study, the investigation of an agroecology area was conducted to gain insight into the relationship between Cd in wheat and soil and then evaluate the Cd total risk for human health. The soil samples and their matching wheat samples, underground water samples, and atmospheric deposition (air) samples were collected from a wheat-growing area in an agroecology plain. The cadmium concentration in the four types of media, in order, was air > soil > wheat > water. The mean concentration of the geoaccumulation index (Igeo) showed that the total Cd in soil (Cd-T) and Cdair reached a mild and moderate pollution level. The results of the correlation and principal component analysis (PCA) showed that the majority of Cdwheat originated from Cd-2 (exchangeable), Cd-4 (humic acid-bound), and Cd-7 (residual). Furthermore, the results of the stepwise multiple linear regression (SMLR) showed that three fractions were primarily controlled by Cd-T: clay, cation exchange capacity (CeC), and total organic carbon (TOC). In addition, the total cancer risk (CR) of Cd in multiple media was, in the order wheat > water > soil > air. It is noteworthy that the Cd content in underground water and wheat by the ingestion pathway posed cancer risks to the local residents and provided a comprehensive insight into multiple media environment management. Furthermore, it provides a very significant basic study for detailed research into the mobility and transformation for factions.

Quantitative MRI of Perivascular Spaces at 3T for Early Diagnosis of Mild Cognitive Impairment

BACKGROUND AND PURPOSE

The limitations inherent in the current methods of diagnosing mild cognitive impairment have constrained the use of early therapeutic interventions to delay the progression of mild cognitive impairment to dementia. This study evaluated whether quantifying enlarged perivascular spaces observed on MR imaging can help differentiate those with mild cognitive impairment from cognitively healthy controls and, thus, have an application in the diagnosis of mild cognitive impairment.

MATERIALS AND METHODS

We automated the identification of enlarged perivascular spaces in brain MR Images using a custom quantitative program designed with Matlab. We then quantified the densities of enlarged perivascular spaces for patients with mild cognitive impairment (n = 14) and age-matched cognitively healthy controls (n = 15) and compared them to determine whether the density of enlarged perivascular spaces can serve as an imaging surrogate for mild cognitive impairment diagnosis.

RESULTS

Quantified as a percentage of volume fraction (v/v%), densities of enlarged perivascular spaces were calculated to be 2.82 ± 0.40 v/v% for controls and 4.17 ± 0.57 v/v% for the mild cognitive impairment group in the subcortical brain (P < .001), and 2.74 ± 0.57 v/v% for the controls and 3.90 ± 0.62 v/v% for the mild cognitive impairment cohort in the basal ganglia (P < .001). Maximum intensity projections exhibited a visually conspicuous difference in the distributions of enlarged perivascular spaces for a patient with mild cognitive impairment and a control patient. By means of receiver operating characteristic curve analysis, we determined the sensitivity and specificity of using enlarged perivascular spaces as a differentiating biomarker between mild cognitive impairment and controls to be 92.86% and 93.33%, respectively.

CONCLUSIONS

The density of enlarged perivascular spaces was found to be significantly higher in those with mild cognitive impairment compared with age-matched healthy control subjects. The density of enlarged perivascular spaces, therefore, may be a useful imaging biomarker for the diagnosis of mild cognitive impairment.

Meat quality traits and proteome profile of woody broiler breast (pectoralis major) meat

Woody breast meat has recently become prevalent in the broiler industry in both the United States and European Union. Recent publications have described the meat quality characteristics of woody breast meat as having hardened areas and pale ridge-like bulges at both the caudal and cranial regions of the breast. The present study investigated the meat quality (pH, color, cooking loss, and shear force) and protein quality characteristics (protein and salt-soluble protein content) in woody breast meat as compared to normal breast meat. In addition, the differences in the muscle proteome profiles of woody and normal breast meat were characterized. Results indicated that woody breast meat had a greater average pH (P < 0.0001) and cooking loss (P = 0.001) than normal breast meat, but woody breast meat did not differ in shear force (P > 0.05) in comparison to normal breast meat samples. The L*, a*, and b* values of woody breast fillets were greater than normal breast fillets (P < 0.0001 to L*; P = 0.002 to a*; P = 0.016 to b*). The woody breast meat had more fat (P < 0.0001) and moisture (P < 0.021) and less protein (P < 0.0001) and salt-soluble protein (P < 0.0001) when compared with normal breast fillets. Whole muscle proteome analysis indicated 8 proteins that were differentially expressed (P < 0.05) between normal and woody breast meat samples. The differences in muscle proteome between normal and woody breast meat indicated an increased oxidative stress in woody breast meat when compared to normal meat. In addition, the abundance of some glycolytic enzymes, which are critical to the regeneration of adenosine triphosphate (ATP) in postmortem muscles, was lower in woody breast meat than in normal breast meat. Proteomic differences provide additional information on the biochemical pathways and genetic variations that lead to woody breast meat. Further research should be conducted to elucidate the genetic and nutritional contributions to the proliferation of woody breast meat in the United States.

Proteomic approach to characterize biochemistry of meat quality defects

Proteomics can be used to characterize quality defects including pale, soft, and exudative (PSE) meat (pork and poultry), woody broiler breast meat, reddish catfish fillets, meat toughness, and beef myoglobin oxidation. PSE broiler meat was characterized by 15 proteins that differed in abundance in comparison to normal broiler breast meat, and eight proteins were differentially expressed in woody breast meat in comparison to normal breast meat. Hemoglobin was the only protein that was differentially expressed between red and normal catfish fillets. However, inducing low oxygen and/or heat stress conditions to catfish fillets did not lead to the production of red fillets. Proteomic data provided information pertaining to the protein differences that exist in meat quality defects. However, these data need to be evaluated in conjunction with information pertaining to genetics, nutrition, environment of the live animal, muscle to meat conversion, meat quality analyses and sensory attributes to understand causality, protein biomarkers, and ultimately how to prevent quality defects.

A Diffusion Tensor Imaging Study on White Matter Abnormalities in Patients with Type 2 Diabetes Using Tract-Based Spatial Statistics

BACKGROUND AND PURPOSE

Patients with type 2 diabetes mellitus have considerably higher risk of developing cognitive impairment and dementia. WM changes in these patients have been reported. Our aim was to demonstrate that gradual and continuous WM change and the associated cognitive decline in patients with type 2 diabetes mellitus can be captured by DTI parameters, which can be used to complement neuropsychological test scores in identifying patients with type 2 diabetes mellitus with and without mild cognitive impairment.

MATERIALS AND METHODS

Forty-two patients with type 2 diabetes mellitus, divided into a group with mild cognitive impairment (n = 20) and a group with normal cognition (n = 22), were enrolled with age-, sex-, and education-matched healthy controls (n = 26). 3T DTI followed by Tract-Based Spatial Statistics analysis was used to investigate the differences in fractional anisotropy, mean diffusivity, axial diffusivity (λ1), and radial diffusivity (λ23) among the groups. A receiver operating characteristic analysis assessed the performance of DTI parameters for separating the 2 groups with type 2 diabetes mellitus.

RESULTS

The whole-brain Tract-Based Spatial Statistics analysis revealed that 7.3% and 24.9% of the WM exhibited decreased fractional anisotropy and increased mean diffusivity (P < .05), respectively, between the diabetes mellitus with mild cognitive impairment and the diabetes mellitus with normal cognition groups, while considerably larger WM regions showed fractional anisotropy (36.6%) and mean diffusivity (58.8%) changes between the diabetes mellitus with mild cognitive impairment and the healthy control groups. These changes were caused primarily by an elevated radial diffusivity observed in the patients with diabetes mellitus with mild cognitive impairment. Radial diffusivity also exhibited subtle but statistically significant changes between the diabetes mellitus with normal cognition and the healthy control groups. Analyses on individual fiber tracts showed pronounced fractional anisotropy reduction and mean diffusivity elevation in regions related to cognitive functions. The receiver operating characteristic analysis on the right cingulum (hippocampus) showed that fractional anisotropy produced a larger area under the curve (0.832) than mean diffusivity (0.753) for separating mild cognitive impairment from normal cognition among patients with type 2 diabetes mellitus. When fractional anisotropy was combined with mean diffusivity, the area under the curve was further improved to 0.857.

CONCLUSIONS

DTI parameters can show a substantial difference between patients with type 2 diabetes mellitus with and without mild cognitive impairment, suggesting their potential use as an imaging marker for detecting cognitive decline in patients with type 2 diabetes mellitus. More important, DTI parameters may capture gradual and continuous WM changes that can be associated with early stages of cognitive decline in patients with type 2 diabetes mellitus before they can be diagnosed clinically by using conventional neuropsychological tests.

Sudden stoppage of rotor in a thermally driven rotary motor made from double-walled carbon nanotubes

In a thermally driven rotary motor made from double-walled carbon nanotubes, the rotor (inner tube) can be actuated to rotate within the stator (outer tube) when the environmental temperature is high enough. A sudden stoppage of the rotor can occur when the inner tube has been actuated to rotate at a stable high speed. To find the mechanisms of such sudden stoppages, eight motor models with the same rotor but different stators are built and simulated in the canonical NVT ensembles. Numerical results demonstrate that the sudden stoppage of the rotor occurs when the difference between radii is near 0.34 nm at a high environmental temperature. A smaller difference between radii does not imply easier activation of the sudden rotor stoppage. During rotation, the positions and electron density distribution of atoms at the ends of the motor show that a sp(1) bonded atom on the rotor is attracted by the sp(1) atom with the biggest deviation of radial position on the stator, after which they become two sp(2) atoms. The strong bond interaction between the two atoms leads to the loss of rotational speed of the rotor within 1 ps. Hence, the sudden stoppage is attributed to two factors: the deviation of radial position of atoms at the stator's ends and the drastic thermal vibration of atoms on the rotor in rotation. For a stable motor, sudden stoppage could be avoided by reducing deviation of the radial position of atoms at the stator's ends. A nanobrake can be, thus, achieved by adjusting a sp1 atom at the ends of stator to stop the rotation of rotor quickly.

Induction of apoptosis by capsaicin in hepatocellular cancer cell line SMMC-7721 is mediated through ROS generation and activation of JNK and p38 MAPK pathways

Capsaicin, one of the major pungent ingredients found in red peppers, has been shown to have anti-carcinogenic effect on various cancer cells through multiple mechanisms. In this study, we investigated the apoptotic effect of capsaicin on human hepatocellular cancer cell line SMMC-7721, as well as the possible mechanisms involved. Treatment of SMMC-7721 cells with capsaicin resulted in a dose-dependent inhibition of cell-viability and induction of apoptosis which was associated with the generation of ROS and persistent disruption of mitochondrial membrane potential. These effects were significantly blocked when cells were pretreated with a general antioxidant N-acetyl cysteine (NAC). We also found that capsaicin induced JNK and p38 MAPK phosphorylation. JNK and p38 MAPK inhibitor effectively blocked capsaicin-induced SMMC-7721 cell apoptosis. In addition, NAC completely blocked phosphorylation of JNK and p38 MAPK induced by capsaicin. Our results indicate that capsaicin induced in SMMC-7721 cell apoptosis through generation of intracellular ROS and activation of JNK and p38 MAPK pathways.

Gradientless temperature-driven rotating motor from a double-walled carbon nanotube

Rotation of the inner tube in a double-walled carbon nanotube (DWCNT) system with a fixed outer tube is investigated and found to be inducible by a relatively high uniform temperature (say, 300 K). We also found the mechanism of a gradientless temperature-driven rotating motor lies in the inner tube losing its geometric symmetry in a high-temperature field. This mechanism can be taken as a guide for designing a motor from such a bi-tube system. Using a computational molecular dynamics (CMD) approach and the adaptive intermolecular reactive empirical bond order (AIREBO) potential, the dynamic behavior of a bi-tube system subjected to uniformly distributed temperature is studied. In particular, the effects of environmental temperature, boundary conditions of the outer tube, and intertube gap on the dynamic behavior of the bi-tube system are investigated. Numerical examples show that a bi-tube system with the inner tube having 0.335 nm of interlayer gap produces the highest rotational speed.

TNF-α acutely upregulates amylin expression in murine pancreatic beta cells

AIMS/HYPOTHESIS

Amylin, a secretory protein mainly produced by pancreatic beta cells, is elevated in the circulation of patients with diseases related to acute and chronic inflammation, including acute pancreatitis, pancreas graft rejection, obesity and insulin resistance. TNF-α is involved in these disorders. We investigated the effect of TNF-α on amylin levels and the underlying mechanisms, using murine pancreatic beta cell line MIN6 and pancreatic islets.

METHODS

Amylin, proinsulin and prohormone convertase 1/3, 2 (Pc1/3, Pc2 [also known as Pcsk1/3 and Pcsk2, respectively]) mRNA levels, and amylin promoter and nuclear factor κB (NF-κB) activation were examined by real-time PCR and luciferase reporter assay, respectively. Amylin protein level and mitogen-activated protein kinase phosphorylation were detected by western blot. Activator protein 1 (AP1) activation was examined by electrophoretic mobility shift assay (EMSA).

RESULTS

TNF-α acutely induced amylin expression at the transcriptional level and increased proamylin and the intermediate form of amylin in MIN6 cells and islets. However, it had no effect on proinsulin, Pc1/3 and Pc2 expression. Studies with (1) MIN6 cells treated with inhibitors of MEK1/2, c-Jun-N-terminal kinase (JNK) or protein kinase Cζ (PKC(ζ)), (2) MIN6 cells expressing a c-Jun-dominant negative construct and (3) islets from Fos knockout mice demonstrated that TNF-α induced amylin expression through the PKC(ζ)-extracellular signal-regulated kinase (ERK)/JNK pathways. EMSA showed that (PKC(ζ)), JNK and ERK1/2 were involved in TNF-α-induced AP1 activation, suggesting that TNF-α induces murine amylin expression through the (PKC(ζ)) - ERK1/2 - AP and PKC(ζ) - JNK - AP1 pathways. Further studies showed that TNF-α also induced murine amylin expression through the phosphatidylinositol 3 kinase-NF-κB signalling pathway and enhanced human amylin promoter activation through NF-κB and AP1.

CONCLUSIONS/INTERPRETATION

TNF-α acutely induces amylin gene expression in beta cells through multiple signalling pathways, possibly contributing to amylin elevation in acute inflammation-related pancreatic disorders.

Lentivirus-mediated expression of MxA in chicken spermatogonial stem cells

The aim of this study was to construct a lentivirus vector that carries the human myxovirus-resistant A (MxA) anti-virus gene for efficiently infecting rooster spermatogonial stem cells (SSCs). A lentiviral vector carrying the enhanced green fluorescent protein (EGFP) and MxA fusion gene (EGFP-MxA) was constructed using TOPO technology in this study. Enhanced green fluorescent protein-MxA was inserted in the right orientation as determined by restriction enzyme digest. No gene recombination in the vector occurred. After infecting 293FT cells, EGFP-MxA fusion protein was expressed as granular green fluorescence characteristic of EGFP-MxA expression, suggesting that the TOPO expression vector was properly constructed and the fusion protein expressed correctly. The EGFP-MxA recombinant lentivirus was packaged by cotransfecting 293FT cells with EGFP-MxA and the packaging plasmids. We also purified SSCs from testicle tissues from 25-day-old roosters for infection with the EGFP-MxA recombinant virus. After infecting rooster SSCs with the recombinant virus for 72 h, EGFP-MxA expression was detected by EGFP expression. Enhanced green fluorescent protein-MxA expression in SSCs was further confirmed at the transcription level by RT-PCR and at the protein level by immunocytochemistry. Staining with Hoechst 33342 showed that infected SSCs differed from the sertoli cells. Similar to stem cells, SSCs were positive for alkaline phosphoric acid enzyme and for stage-specific embryonic antigen-1 stem cell factor. The results demonstrated that the recombinant virus made in our study can infect rooster SSCs efficiently to express the anti-virus protein MxA, establishing the basis of transferring MxA into SSCs to obtain virus-resistant, genetically-modified roosters.

Molecular Biomarkers of Columnar Cell Lesions Identified by Proteomic Approaches

The widespread increase in the use of screening mammography has led to a significant rise in the detection and diagnosis of benign breast disease (BBD), which encompasses a wide variety of non-cancerous changes including columnar cell lesions (CCL). Epidemiologic studies provide evidence for a relationship between BBD and subsequent risk of developing breast cancer. Observational studies have reported CCL are found adjacent to areas of tubular carcinoma and ductal and lobular carcinomas in situ and recently published molecular data state that genetic abnormalities frequently found in low grade ductal carcinoma in situ are also found in CCL. All these data support the hypothesis that CCL are the earliest morphologically distinguishable precursor lesions to low grade ductal carcinoma in situ and invasive carcinoma. However, BBD is heterogeneous and there is limited understanding of the biological importance associated with the spectrum of lesions. The lack of accurate molecular-based risk categories, therefore, hinders the ability of assigning prognostic significance to benign biopsy findings. The purpose of our study was to identify putative molecular markers of cancer progression from epithelial cells of BBD lesions. Regions of ductal hyperplasia (DH) and normal breast epithelium were isolated from mastectomy specimens using laser capture microdissection and extracted proteins were analyzed through proteomic approaches. Of the 1,500 total protein spots resolved by 2-dimensional electrophoresis, 98 were differentially expressed between DH and normal breast epithelial proteomes. Twenty-two proteins or related isoforms were identified using mass spectrometry. Two proteins of particular interest, NAD(P)H: quinone oxidoreductase 1 (NQO1) and galectin-3, were further investigated by immunohistochemistry (IHC) on cases diagnosed with BBD lesions. NQO1 was expressed sporadically in overtly normal epithelial cells lining breast ducts, but was overexpressed in BBD and tumor tissues. Notably, we found that a subpopulation of DH tissues with CCL stained positively for NQO1 and negatively for galectin-3. This finding has significance because CCL can only be diagnosed morphologically and the presence of CCL in biopsy specimens may indicate a precancerous lesion. However, sectioning artifacts associated with core biopsies can hinder morphological diagnosis of CCL, thus a means to additionally identify these lesions using IHC has tremendous value. Together, immunohistochemical staining of NQO1 and galectin-3 may prove to be clinically relevant in the identification of CCL in biopsy samples.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2142.

Mild hypoxic-ischemic injury in the neonatal rat brain: longitudinal evaluation of white matter using diffusion tensor MR imaging

BACKGROUND AND PURPOSE

Selective white matter (WM) damage is a known sequela of mild hypoxic-ischemic (HI) injury in the neonatal rat model. The aim of this study was to evaluate longitudinally mild HI-induced WM damage (represented by the external capsule [EC]) by diffusion tensor MR imaging (DTI) and to correlate the findings with histology.

MATERIALS AND METHODS

Seven-day-old Sprague-Dawley rats (n = 19) underwent unilateral ligation of the left common carotid artery followed by hypoxia for 50 minutes to create mild HI injury. DTI was performed longitudinally at 5 time points from day 1 to day 90 postinjury (n = 19, 16, 13, 11, 9, respectively), and fractional anisotropy (FA), trace, radial diffusivity (lambda( perpendicular)), and axial diffusivity (lambda(//)) of the injury and control contralateral ECs were quantified. Rats were randomly sacrificed (n = 15, in total), and the corresponding ECs were stained with hematoxylin-eosin, Luxol fast blue (LFB), and neurofilament (NF) to evaluate morphologic changes, amount of myelin, and axonal count at every time point. A paired t test was applied to evaluate statistical differences between both ECs, and the Pearson correlation test was used to evaluate the relationships between DTI indices and histologic evaluations. In addition, longitudinal changes in DTI indices and histologic evaluations were analyzed by a linear mixed model and an analysis of variance test, respectively.

RESULTS

We demonstrated significantly decreased FA, increased lambda( perpendicular), and similar lambda(//) in the injury compared with the control EC, which was persistent through all time points. Histologic evaluation by LFB and NF staining showed reduced myelin stain intensity in the injury EC and similar axonal counts in both ECs. Longitudinally, there was an increase in FA, a decrease in lambda( perpendicular) and trace, and stability in lambda(//) in both ECs. Also, there was progressive reduction in the differences in FA, trace, and lambda( perpendicular) between the injury and control EC, especially between day 1 and day 7 postinjury and in tandem with changes in myelin stain. FA was significantly correlated with myelin stain (r = 0.681, P < .01) and axonal count (r = 0.673, P < .01), whereas lambda( perpendicular) was significantly correlated with myelin stain only (r = -0.528, P < .01), and lambda(//), with axonal count only (r = 0.372, P = .043).

CONCLUSIONS

Diffusion indices can reflect dysmyelination in mild HI injury, continual myelination of both injury and control ECs with growth, and the partial recovery of myelin postinjury. We propose that diffusion indices may be used as biomarkers to monitor noninvasively the longitudinal changes of mild HI-induced WM damage.

SINGLE UV EXCITATION OF HOECHST 33342 AND PROPIDIUM IODIDE FOR VIABILITY ASSESSMENT OF RHESUS MONKEY SPERMATOZOA USING FLOW CYTOMETRY

Many fluorescent probes excited by visible light have been used to assess sperm quality by flow cytometry. Developing a viability evaluation method using UV excited stains would be useful for multiparameter analysis of sperm function. This investigation was conducted to determine the efficacy of Hoechst 33342 (H342) and propidium iodide (PI) dual staining for evaluating rhesus monkey sperm viability through use of flow cytometry and excited by a single UV laser. The results showed that the live cells stained only with H342 strongly correlated with expected sperm viability, and flow cytometric analyses were highly correlated with fluorescence microscopic observation. Using H342/PI/SYBR-14 triple staining method, it was found that the live/dead sperm distributions were completely concordant in both H342/PI and SYBR-14/PI assays. In addition, this dual staining was extended with fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA) to simultaneously analyze viability and acrosome integrity of sperm cryopreserved using two different extenders, TTE and TEST, and indicated that TTE offered better preservation of plasma and acrosome integrity than TEST. Therefore, the H342/PI dual staining provides an accurate technique for evaluating viability of rhesus monkey sperm and should be valuable for multiparameter flow cytometric analysis of sperm function.