Efficacy of Dexamethasone Injection at Different Sites on Postoperative Sequelae After Extracting Mandibular Impacted Third Molars: A Randomized Controlled Trial.

BACKGROUND: Dexamethasone, an efficacious anti-inflammatory agent, is widely used after tooth extraction. However, its optimal injection site is yet to be investigated. PURPOSE: We compare the efficacy of dexamethasone injection at different sites on postoperative sequelae after extracting mandibular impacted third molars (MITMs). STUDY DESIGN, SETTING, AND SAMPLE: A prospective randomized controlled trial was conducted. Healthy adults with fully MITMs scheduled for extraction were included. Exclusion criteria were 1) patients with the systemic alteration that prevented the surgical procedure; 2) pregnancy, breastfeeding, and premenstrual period; 3) hypersensitivity to the drug under test; and 4) those who did not return for postoperative follow-up at 1, 3, and 7 days. EXPOSURE VARIABLE: The subjects were randomized to 3 groups. An online randomization plan generator assigned each subject to a single treatment by randomly permuting blocks. Different sites for postoperative dexamethasone injections included the buccal side of the adjacent second molar and extraction sockets. Dexamethasone injection (4 mg) on the buccal side of the adjacent second molar (group 1), an injection on the buccal side of extraction sockets (group 2), and an injection of physiological saline (0.8 mL) on the buccal side of the adjacent second molar (control). MAIN OUTCOME VARIABLES: The outcome variables were postoperative facial swelling, limitation of the mouth opening, postoperative pain, and postoperative quality of life evaluation. The pain was assessed using a visual analog scale at 1, 3, and 7 days, postoperatively. The quality of life was recorded throughout the Posse scale at 7 days. COVARIATES: The covariates are age, sex, length of operation, and type of impacted teeth and surgery. ANALYSES: The statistical analysis was performed using analysis of variance, repeated measures analysis of variance, χ2 test, or Fisher's exact tests with P values < .05 considered statistically significant. RESULTS: Our study included 58 participants with a mean age of 19.48 ± 3.31 years; group 1 (n = 24), group 2 (n = 20), and control group (n = 14). On day 3 postoperative, the swelling and trismus were significantly less in group 1 than in the other 2 groups (P < .05), and group 1 had an overall postoperative quality of life compared to other groups (P < .05). Unaffected speech function was present in 73.7% of patients in group 1, while 50% of patients in group 2 had affected speech function 3 days after the operation (P < .05). The "unable to open mouth" of the "Eating subscale" and "felt tingling" had statistical significance (P < .05). CONCLUSION AND RELEVANCE: Dexamethasone injections on the buccal side of the adjacent second molar can be a viable option for treating facial swelling and limitation of mouth opening after total MITMs extraction.

Improved effects of the b-value for 2000 sec/mm2 DWI on an accurate qualitative and quantitative assessment of rectal cancer.

BACKGROUND AND STUDY OBJECTIVES: A higher b-value Diffusion-weighted imaging (DWI) would improve the contrast between cancerous and noncancerous tissue. Apparent diffusion coefficient (ADC)-histogram analysis is a method that can provide statistical data and quantitative information on tumor heterogeneity. This study aimed to compare two high b-values (1000 and 2000 sec/mm2) DWI in tumor detection and diagnostic performance in identifying early-stage tumor rectal cancer. PATIENTS AND METHODS: This blinded and blinded retrospective study involved 56 patients with rectal cancer and 45 patients. Two radiologists evaluated the qualitative detection parameters and quantitative parameters of the ADC evaluated histogram and compared them between two DWI sequences (b-value for 1000 sec/mm2 and 2000 sec/mm2). The characteristic curves were used to assess diagnostic administration for the ADC histogram in discriminating early-stage tumors. RESULTS: The b-value for 2000 sec/mm2 DWI significantly improved AUCs, sensitivity, specificity, and precision and decreased false-positive rate for detection compared to the b-value for 1000 sec/mm2 (p < 0.05). The mean and fifth percentile ADC value for stage I using the b-value for 1000 sec/mm2 DWI was significantly higher than stage ≥ II (p = 0.036II and 0.016 respectively), as the well as fifth, 10th, mean ADC of the fifth, 10th, and 25th ADC percentile at b-value for 2000 sec/mm2 (p = 0.031, 0.014, 0.035 and 0.025 respectively). The AUCs of the fifth percentile ADC at b-value for 2000 sec/mm2 DWI in both readers in differentiating the stage Ⅰ tumor were the highest (0.732 and 0.751). CONCLUSION: The b-value for 2000 sec/mm2 DWI could improve the accurate detection of rectal cancer. The fifth percentile ADC at b-value for 2000 sec/mm2 sec/mm2 DWI was more useful for discriminating early stage than the b-value for 1000 sec/mm2 DWI.

Bioinformatics analysis of synovial fluid-derived mesenchymal stem cells in the temporomandibular joint stimulated with IL-1ß.

The stimulation of interleukin-1ß (IL-1ß) is the risk factor for temporomandibular joint osteoarthritis (TMJOA). We aim to investigate IL-1ß stimulation-related gene and signal pathways in synovial fluid-derived mesenchymal stem cells (SF-MSCs) inflammatory activation to predict the occurrence of TMJOA. The microarray dataset GSE150057 was downloaded from the gene expression omnibus (GEO) database, and principal component analysis (PCA) was performed on the involved genes to obtain differential genes (DEGs). Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway were performed based on the DAVID database. The protein-protein interaction (PPI) network was constructed by the STRING database to identify hub genes. Based on the correlation between differential expression levels of lncRNAs and mRNAs, the co-expression network of lncRNA-mRNA was established. A total of 200 DEGs were obtained. Among 168 differential mRNAs, 126 were up-regulated and 42 were down-regulated; among 32 differential lncRNAs, 23 were up-regulated and 9 were down-regulated. Then, GO analysis showed that DEGs were mainly involved in signal transduction, inflammation, and apoptosis processes. KEGG pathway mainly involved the TNF signaling pathway, NF-κB signaling pathway, NOD-like receptor signaling pathway, and cytokine-cytokine-receptor interaction. Ten hub genes were recognized by PPI analysis, including CXCL8, CCL2, CXCL2, NFKBIA, CSF2, IL1A, IRF1, VCAM1, NFKB1, and TNFAIP3. In conclusion, our study has indicated the role of IL-1ß stimulation in the progression of SF-MSCs inflammation and predicted DEGs and downstream pathways.

Ultraviolet Light-Based Micropattern Printing on Titanium Surfaces to Promote Early Osseointegration.

Patterned interfaces are widely used for surface modification of biomaterials because of a morphological unit similar to that of native tissue. However, engineering fast and cost-effective high-resolution micropatterns directly onto titanium surfaces remains a grand challenge. Herein, a simply designed ultraviolet (UV) light-based micropattern printing to obtain geometrical patterns on implant interfaces is fabricated by utilizing customized photomasks and titanium dioxide (TiO2 ) nanorods as a photo-responsive platform. The technique manipulates the cytoskeleton of micropatterning cells on the surface of TiO2 nanorods. The linear pattern surface shows the elongated morphology and parallel linear arrangements of human mesenchymal stem cells (hMSCs), significantly enhancing their osteogenic differentiation. In addition to the upregulated expression of key osteo-specific function genes in vitro, the accelerated osseointegration between the implant and the host bone is obtained in vivo. Further investigation indicates that the developed linear pattern surface has an outstanding effect on the cytoskeletal system, and finally activates Yes-Associated Protein (YAP)-mediated mechanotransduction pathways, initiating hMSCs osteogenic differentiation. This study not only offers a microfabrication method that can be extended to fabricate various shape- and size-controlled micropatterns on titanium surfaces, but also provides insight into the surface structure design for enhanced bone regeneration.

A Potential Complication After Drainage in Odontogenic Descending Necrotizing Mediastinitis: Chyle Leakage.

ABSTRACT: Descending necrotizing mediastinitis is a serious complication of odontogenic infections. Incision and drainage of the maxillofacial infection with mediastinal drainage represent the principal management. However, chyle leakage after drainage in descending necrotizing mediastinitis is rare and has not been reported. Here the authors present a case of a 74-year-old man with chyle leakage after mediastinal drainage, which is successfully treated.

The association between low birth weight and dental caries among 11-to-13-year-old school age children in Ningbo, China.

BACKGROUND: The association between low birth weight (LBW) and dental caries is currently unclear. The aim of this study was to investigate the association of LBW with dental caries in permanent teeth in children of Ningbo city. METHODS: A total of 1975 children aged 11-to-13 years in Ningbo, China were enrolled in this cross-sectional study. LBW was defined as a birthweight< 2500 g. Ten dentists assessed the status of dental caries in permanent teeth in line with the World Health Organization (WHO) criteria and guidelines. Decayed, missing or filled teeth were considered to have dental caries. Parental questionnaires were used to collect child information. Non-conditional logistic regression analysis was used to estimate odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). RESULTS: Dental caries in permanent teeth was found in 610 children (30.9%), with a mean DMFS of 2.09 (SD = 1.2). The adjusted ORs for dental caries in permanent teeth was 1.46 (95% CI 1.00, 2.13) for LBW. CONCLUSIONS: LBW was not associated with dental caries in permanent teeth in the study population.

Prediction of Clinical Pathologic Prognostic Factors for Rectal Adenocarcinoma: Volumetric Texture Analysis Based on Apparent Diffusion Coefficient Maps.

Texture analysis has been used to characterize and measure tissue heterogeneity in medical images. The purpose of this study was to investigate the potential of texture features derived from apparent diffusion coefficient (ADC) maps, to serve as imaging markers for predicting important histopathologic prognostic factors in rectal cancer. One hundred patients of rectal cancer received 3 T preoperative magnetic resonance imaging including diffusion-weighted imaging (DWI). Skewness, kurtosis, uniformity from the histogram and entropy, energy, inertia, correlation from gray-level co-occurrence matrix (GLCM) derived from whole-lesion volumes were measured. Independent sample t-test or Mann-Whitney U-test and receiver operating characteristic (ROC) curves were used for statistical analysis. Uniformity, energy and entropy were significantly different (p = 0.026, 0.001, and 0.006, respectively) between stage pT1-2 and pT3-4 tumors. Skewness, kurtosis and correlation were significantly different (p = 0.000, 0.006, and 0.041, respectively) between grade 1-2 and grade 3 tumors. Energy and entropy (p = 0.008 and 0.033, respectively) could significantly differentiate negative circumferential resection margin (CRM) from positive CRM. Furthermore, predicted probabilities derived by logistic regression analysis yielded greater area under the curve (AUC) in differentiating pT3-4 stage and grade 3 grade tumors. Texture features derived from ADC maps may useful to predict important histopathologic prognostic factors of rectal cancer.

Differential inhibition of GH family 11 endo-xylanase by rice xylanase inhibitor and verification by a modified yeast two-hybrid system.

Rice xylanase inhibitor (RIXI) is a XIP-type xylanase inhibitor protein that protects rice cells from pathogenic organisms. RIXI inhibits most microbial xylanases and thus decreases their practical application. The recombinant RIXI (rePRIXI) showed evident inhibitory activities against several family 11 endo-xylanases. After interaction with rePRIXI at 50 °C for 40 min, the residual activities of reBaxA50, reBaxA, TfxA_CD214, and TfxA_CD were 55.6%, 30.3%, 30.09%, and 11.20%, respectively. Intrinsic fluorescence of reBaxA50 and TfxA_CD214 was statically quenched after interaction with rePRIXI. rePRIXI decreased hydrolysis of beechwood xylan by reBaxA50 and TfxA_CD214. Molecular dynamics simulations revealed the long loop (residues 144-153) of RIXI inserts into the catalytic cleft of family 11 xylanases. Native PAGE results revealed the formation of RIXI-xylanase complex after their interaction in the test tube. Interactions were also observed between RIXI and xylanases in living yeast cells. The results of inhibitory activity assay and modified yeast two-hybrid revealed that the inhibitory activity of RIXI on family 11 xylanase improved with the interaction strength of the RIXI-xylanase complex, indicating their positive correlation. The modified yeast two-hybrid system is relatively simple and has low cost, and its use may be extended to other studies on protein-protein interactions.

Recombinant rice xylanase inhibitor (RIXI) expressed in Escherichia coli and its inhibitory activity on family GH11endo-xylanases.

The rice xylanase inhibitor gene, rixi, was cloned from rice genome. The open reading frame of rixi was 915 bp and encoded 304 amino acids with the theoretical molecular mass of 33.9 kDa. The rixi was inserted into the new-type expression vector pCold TF, and was high-level expressed in Escherichia coli BL21 (DE3). SDS-PAGE and Western blot analysis revealed that the molecular weight of the recombinant rice xylanase inhibitor, namely reERIXI, was approximately 89.8 kDa. The reERIXI exhibited significant inhibitory activities against several family GH11 xylanases. After interaction with reERIXI, the residual activity of reBaxA50 and TfxA_CD214 were 59.24% and 44.41%, respectively. The optimal temperature of reERIXI inhibitory activity to reBaxA50 and TfxA_CD214 were 60 °C and 50 °C, respectively. The thermostability assay revealed that reERIXI was stable below 60 °C. reERIXI showed high inhibitory when interacting with reBaxA50 and TfxA_CD214 for 30-60 min. The intrinsic fluorescence spectroscopy of reBaxA50 and TfxA_CD214 was quenched with increasing reERIXI concentration. Circular dichroism measurement revealed that ratio of helix of reBaxA50 and ratio of beta of TfxA_CD214 significantly decreased when interacting with reERIXI. The total concentration of hydrolytic products from beechwood xylan decreased when reERIXI was added.

Recombinant Bacillus amyloliquefaciens xylanase A expressed in Pichia pastoris and generation of xylooligosaccharides from xylans and wheat bran.

In this study, BaxA (GenBank: KM624029), which encodes the Bacillus amyloliquefaciens xylanase A (BaxA), was highly expressed in Pichia pastoris GS115 under the control of the AOX1 promoter. The recombinant xylanase, namely rePBaxA, was purified to homogeneity by using Ni-affinity resin and its molecular weight was 35.0kDa. The optimum temperature and pH of rePBaxA were 50°C and 5.0, respectively. The kinetic parameters Michaelis-Menten constant (Km) and maximum reaction rate (Vmax) of rePBaxA were 5.41mg/mL and 22.42µmol/min/mL, respectively. High-performance liquid chromatography results showed that after 6h of hydrolysis, rePBaxA released xylose-xylohexaose (X1-X6) mixture from beechwood and birchwood xylan, with xylobiose (X2) and xylotriose (X3) as the major products, respectively. The hydrolyates from oat spelt, wheat bran insoluble xylan and pretreated wheat bran by rePBaxA included X2-X6, with X6 having the highest concentration. The mode of action analysis revealed that rePBaxA was an endo-acting xylanase with transglycosylation activity. X2 might be the minimum oligomer hydrolyzed by rePBaxA. The pretreated wheat bran and wheat bran insoluble xylan could be directly hydrolyzed by rePBaxA. This study provided a basis for using agricultural waste by-products as substrates for manufacting value-added probiotics, namely, xylooligosaccharides.

Identification of two transcription factors activating the expression of OsXIP in rice defence response.

BACKGROUND: Xylanase inhibitors have been confirmed to be involved in plant defence. OsXIP is a XIP-type rice xylanase inhibitor, yet its transcriptional regulation remains unknown. RESULTS: Herbivore infestation, wounding and methyl jasmonate (MeJA) treatment enhanced mRNA levels and protein levels of OsXIP. By analyzing different 5' deletion mutants of OsXIP promoter exposed to rice brown planthopper Nilaparvata lugens stress, a 562 bp region (-1451 - -889) was finally identified as the key sequence for the herbivores stress response. Using yeast one-hybrid screening, coupled with chromatin immunoprecipitation analysis, a basic helix-loop-helix protein (OsbHLH59) and an APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factor OsERF71 directly binding to the 562 bp key sequence to activate the expression of OsXIP were identified, which is further supported by transient expression assay. Moreover, transcriptional analysis revealed that mechanical wounding and treatment with MeJA resulted in an obvious increase in transcript levels of OsbHLH59 and OsERF71 in root and shoot tissues. CONCLUSIONS: Our data shows that two proteins as direct transcriptional activators of OsXIP responding to stress were identified. These results reveal a coordinated regulatory mechanism of OsXIP, which may probably be involved in defence responses via a JA-mediated signaling pathway.

Recombination of thermo-alkalistable, high xylooligosaccharides producing endo-xylanase from Thermobifida fusca and expression in Pichia pastoris.

For xylooligosaccharide (XO) production, endo-xylanase from Thermobifida fusca was modified by error-prone PCR and DNA shuffling. The G4SM1 mutant (S62T, S144C, N198D, and A217V) showed the most improved hydrolytic activity and was two copies expressed in Pichia pastoris under the control of GAP promoter. The maximum xylanase activity in culture supernatants was 165 ± 5.5 U/ml, and the secreted protein concentration reached 493 mg/l in a 2-l baffled shake flask. After 6× His-tagged protein purification, the specific activity of G4SM1 was 2036 ± 45.8 U/mg, 2.12 times greater than that of wild-type enzyme. Additionally, G4SM1 was stable over a wide pH range from 5.0 to 9.0. Meanwhile, half-life of G4SM1 thermal inactivation at 70 °C increased 8.5-fold. Three-dimensional structures suggest that two amino acid substitutions, S62T and S144C, located at catalytic domain may be responsible for the enhanced activity and thermostability of xylanase. Xylobiose was the dominant end product of xylan hydrolysis by G4SM1. Due to its attractive biochemical properties, G4SM1 has potential value in commercial XO production.

Effects of an exogenous xylanase gene expression on the growth of transgenic rice and the expression level of endogenous xylanase inhibitor gene RIXI.

BACKGROUND: Xylanases have attracted considerable interest in recent years owing to their various applications in industry and agriculture. The use of transgenic plants to produce xylanases is a less expensive alternative to biotechnological programmes. The aim of this study was to elucidate whether introducing a foreign xylanase gene ATX into rice had any adverse effect on plant growth and development. RESULTS: A recombinant xylanase gene ATX was introduced into rice variety Zhonghua 11 through Agrobacterium-mediated transformation. The T2 generation of transgenic rice was compared with the control (non-transgenic plants). Exogenous xylanase gene ATX was expressed in rice, and all examined transgenic lines exhibited xylanase activity. The transgenic lines (T2, 'X1-3' and 'X2-5') appeared to grow and develop normally. There were no differences in net photosynthetic rate between transgenic rice lines ('X1-3' and 'X2-5') and wild type (WT) rice plants at the heading/flowering stage. Xylanases are key enzymes in the degradation of plant cell walls. Cell wall composition analysis showed that that there were no changes in cell wall polysaccharides in the root apex but some alterations in leaves in transgenic rice plants. The results also showed that the expression of exogenous xylanase gene ATX in rice would increase the expression of endogenous xylanase inhibitor gene RIXI, which could play a role in plant defence. Thus the stress resistance of transgenic rice plants might be improved. CONCLUSION: Exogenous xylanase gene ATX could be successfully expressed in rice, and the exogenous protein had no apparent harmful effects on growth and development in transgenic rice plants.

Enhancing catalytic activity of a hybrid xylanase through single substitution of Leu to Pro near the active site.

A modified error-prone PCR and high-throughout screening system based on 96-well plate were employed to improve catalytic activity of a hybrid xylanase (ATx). The mutant (FSI-A124) with enhanced activity was further heterologously expressed in Pichia pastoris under the control of GAP promoter. The recombinant xylanase driven by the Saccharomyces cerevisiae α-mating factor was secreted into culture medium. After growth in YPD medium for 96 h, xylanase activity in the culture supernatant reached 66.1 U ml(-1), which was 2.92 times as that of its parent. 6 × His-tagged purification increased the specific activity to 1557.61 U mg(-1). The optimum temperature and pH of recombinant xylanase were 55°C and 6.0, respectively. A single amino acid substitution (L49P) was observed within sequence of the mutant. Insight of the three dimensional structure revealed that proline possibly produced weaker hydrogen bond, van der Waals force and hydrophobic interaction with other residues nearby than leucine, especially for V174, contributing to the flexibility of catalytic residue E177. In this study, FSI-A124 exhibited higher xylanase activity but poorer thermostability than its parent, indicating that activity and stability might be negatively correlated.

[Recent research progress of biogenesis and functions of miRNA*].

MicroRNA*s are about 22nt noncoding RNAs, which are processed from precursors with a characteristic hairpin secondary structure in the biogenesis of microRNAs. Recently, miRNA* strands were shown to mediate post-transcriptional regulatory networks, rather than serve merely as non-functional by-product in general view. Unlike miRNAs bound to AGO1, miRNA* strands are bound to AGO2 to form RISC duplex to mediate RNAi, which is similar to siRNA. This paper mainly reviewed the recent research progresses on miRNA*, such as the biosynthesis, biological characteristics, and functions.

Identification and proteomic analysis of a novel gossypol-degrading fungal strain.

BACKGROUND: Cottonseed meal, an important source of feed raw materials, has limited use in the feed industry because of the presence of the highly toxic gossypol. The aim of the current work was to isolate the gossypol-degrading fungus from a soil microcosm and investigate the proteins involved in gossypol degradation. RESULTS: A fungal strain, AN-1, that uses gossypol as its sole carbon source was isolated and identified as Aspergillus niger. A large number of intracellular proteins were detected using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but no significant difference was observed between the glucose-containing and gossypol-containing mycelium extracts. Two-dimensional gel electrophoresis results showed that the protein spots were concentrated in the 25.0-66.2 kDa range and distributed in different pI gradients. PDQuest software showed that 51 protein spots in the gels were differentially expressed. Of these, 20 differential protein spots, including six special spots expressed in gossypol, were analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. CONCLUSION: The fungus AN-1 biodegraded gossypol and the proteomic analysis results indicate that some proteins were involved in the gossypol biodegradation during fungus survival, using gossypol as its sole carbon source.

Effects of zinc supplementation and deficiency on bone metabolism and related gene expression in rat.

One hundred male rats were randomly divided into four groups (n = 25) and fed a Zn-adequate diet (ZA, 46.39 mg/kg), Zn-deficient diet (ZD, 3.20 mg/kg), Zn-overdose diet (ZO, 234.39 mg/kg), or were pair-fed a Zn-adequate diet (PF) for 5 weeks, respectively. The body weight, femur weight, and activity of alkaline phosphatase (ALP) were reduced in the ZD group but were increased in the ZO group. Zn concentrations in both liver and femur were elevated in the ZO group, whereas femur Zn was decreased in the ZD group. The concentrations of calcium and phosphorus were lower in the ZD than those in other groups. Serum calcium concentration was decreased in the ZD. The relative expression level of ALP was decreased in both ZD and PF, and no significant differences were observed between ZO and ZA. Insulin-like growth factor-I (IGF-I) mRNA level was reduced in the ZD but unchanged in the ZO and PF group. Zn deficiency also decreased ALP mRNA level as compared with that of PF group. Carbonic anhydrase II mRNA level was not affected by Zn. Nevertheless, dietary Zn influenced the growth, bone metabolism, and expression of IGF-I and ALP in male growing rats.

Hydrolytic properties of a hybrid xylanase and its parents.

The hydrolytic properties of a hybrid xylanase (ATx) and its parents (reAnxA and reTfxA) were studied using xylans and xylooligosaccharides as substrates. Analysis of reaction mixtures by high-performance liquid chromatograph revealed that xylotriose (X3) was the main product released from birchwood xylan and wheat bran insoluble xylan by ATx and reAnxA, respectively. Xylobiose (X2) was the main product separately released from birchwood xylan and wheat bran insoluble xylan by reTfxA. Xylotetraose (X4), xylopentaose (X5), and xylohexaose (X6) could be hydrolyzed by ATx, which showed no activity on X2 and X3. Therefore, X4 might be the minimum oligomer hydrolyzed by ATx. X2-X6 could be hydrolyzed by reAnxA and reTfxA, respectively. All of ATx, reAnxA, and reTfxA showed transglycosylation activity.

Effects of zinc on hepatic antioxidant systems and the mRNA expression levels assayed by cDNA microarrays in rats.

BACKGROUND: This study evaluated effects of zinc on the hepatic lipid peroxidation, antioxidant components and mRNA expression levels in rats. METHODS: Three diets with different Zn levels including Zn adequacy (ZA; 34.50 mg/kg, control), Zn deficiency (ZD; 3.30 mg/kg), and Zn overdose (ZO; 345.45 mg/kg) were fed to rats for 6 weeks. The mRNA expression levels were analyzed by cDNA microarrays. RESULTS: The body weight of rats fed the ZD diet was less (p < 0.01) than that of rats fed the ZA diet. Zn overdose elevated body weight, but the increase was not detected (p > 0.05) at week 6. Although copper and iron status in serum were declined (p < 0.01), those in liver were not affected (p > 0.05) by the high intake of zinc. The glutathione peroxidase (GPx) and glutathione (GSH) remained unchanged (p > 0.05) by zinc treatment. Rats fed the ZD diet showed reductions(p < 0.01) in the Cu-Zn superoxide dismutase (Cu-Zn SOD) and catalase (CAT) activity, and increases (p < 0.01) in the malondialdehyde and hydrogen peroxide (H(2)O(2)) contents. Rats fed the ZO diet particularly had higher Cu-Zn SOD (p < 0.01) activity. The mRNA expression levels of SOD were upregulated in the ZO group, and CAT was downregulated in the ZD group, while no changes in GPx mRNA levels were found after zinc treatment. CONCLUSION: The study suggested that zinc deficiency largely decreased body weight; zinc overdose, however, moderately stimulated growth in the early growing phase of rats. High dietary zinc did not compete with liver copper and iron status. Although Zn deficiency impaired antioxidant functions, zinc overdose hardly enhanced the antioxidant systems of animals.

Insights on zinc regulation of food intake and macronutrient selection.

Zinc (Zn) is an essential trace element required for human beings and animals. This divalent cation is involved in many physiological functions, including immune and antioxidant function, growth, and reproduction. Deficiency of Zn produces several pathological disorders and abnormalities in its metabolism, such as anorexia, weight loss, poor efficiency, and growth retardation. Although it has been known for more than 50 yr that Zn deficiency regularly and consistently causes anorexia in many animal species, the mechanism that causes this phenomenon still remains an enigma. The present review describes recent research investigating the relationship between Zn deficiency and the regulation of food intake, as well as macronutrient selection.