Obvious Morphological Alterations Research Articles

The Antifungal Activities of Silver Nano-Aggregates Biosynthesized from the Aqueous Extract and the Alkaline Aqueous Fraction of Rhazya stricta against Some Fusarium Species.

Rhazya stricta is a major medicinal species used in indigenous medicinal herbal medications in South Asia, the Middle East, Iran, and Iraq to treat a variety of ailments. The current study aimed to investigate the antifungal properties of biosynthesized silver nanoparticles (AgNPs) made from R. stricta aqueous extract and its alkaline aqueous fraction. Fourier transform infrared spectroscopy (FTIR), UV-vis spectrophotometry, dynamic light scattering (DLS), and transmitted electron microscopy (TEM) were used to characterize AgNPs. The produced extracts and AgNPs were tested for their antifungal efficacy against four Fusarium spp. All of the characterization experiments proved the biosynthesis of targeted AgNPs. FTIR showed a wide distribution of hydroxyl, amino, carboxyl, and alkyl functional groups among all preparations. The DLS results showed that the produced Aq-AgNPs and the Alk-AgNPs had an average size of 95.9 nm and 54.04 nm, respectively. On the other hand, TEM results showed that the Aq-AgNPs and Alk-AgNPs had average diameters ranging from 21 to 90 nm and 7.25 to 25.32 nm. Both AgNPs absorbed UV light on average at 405 nm and 415 nm, respectively. Regarding the fungicidal activity, the highest doses of Aq-extract and Aq-AgNPs inhibited the mycelial growth of F. incarnatum (19.8%, 87.5%), F. solani (28.1%, 72.3%), F. proliferatum (37.5%, 75%), and F. verticillioides (27.1%, 62.5%), respectively (p < 0.001). Interestingly, the Alk-fraction had stronger inhibition than the biosynthesized AgNPs, which resulted in complete inhibition at the doses of 10% and 20% (p < 0.001). Furthermore, microscopic analysis demonstrated that both AgNPs caused obvious morphological alterations in the treated organisms when compared to the control. In conclusion, R. stricta's Aq-extract, alkaline fraction, and their biosynthesized AgNPs show substantial antifungal efficacy against several Fusarium spp. It is the first study to highlight the prospective biological activities of R. stricta Aq-extract and its alkaline fraction against F. incarnatum, F. proliferatum, and F. verticillioides. In addition, it is the first opportunity to deeply investigate the ultrastructural changes induced in the Fusarium species treated with R. stricta crude Aq-extract and its biosynthesized AgNPs. More studies are required to investigate their biological effect against other Fusarium or fungal species.

10-7M genistein partially alleviates 10-7M MEHP unfavorable effects in a new modified fetal rat testis culture system.

Background: Recent studies revealed that some common endocrine-disrupting chemicals (EDCs) including phthalates and phytoestrogens may exhibit low-dose effects properties. However, how low dose of these EDCs and their mixture would affect fetal rat testis development still needs further investigation. Moreover, testis organ culture system also needs further modification to provide an effective tool for ex vivo EDCs study. Methods: We firstly modified the agarose organ culture system, in which fetal rat testes were cultured for 4 days (d1 to d4) on agarose gels held by Millicell inserts. Then we used the modified agarose culture system to study the combined effects of multiple EDCs exposure. 15.5 dpc fetal rat testes were isolated and treated with vehicle, MEHP (0.1 μmol/L), GEN (0.1 μmol/L) or MEHP (0.1 μmol/L) + GEN (0.1 μmol/L). Parameters concerning testicular cell development and function were evaluated, trying to gain insight into the early molecular events after multiple EDCs exposure. Results: The development of somatic, germ cells and seminiferous tubule in 15.5 dpc fetal rat testis was better sustained in the modified agarose culture system. Based on the modified system, we found that MEHP at 0.1 μmol/L induced alterations in gonocyte markers, antioxidative enzyme activity as well as transient reduction of testosterone production, accompanied by mitochondria swelling in gonocytes and Sertoli cells. No obvious morphological and histological alterations were observed in all treated groups. However, coadministration of genistein at 0.1 μmol/L partially alleviated MEHP-induced fetal testis damage ex vivo through enhancement of antioxidative action. MEHP at low dose still showed weak endocrine disrupting properties but did not exhibit typical low-dose effects. Conclusion: Our findings indicated that the modified agarose culture system could better mimic testicular microenvironment without obvious hypoxic cell damage. Furthermore, low dose of MEHP induced mild disruption to fetal testis development, cotreatment of genistein at low dose attenuated MEHP induced fetal testis injuries in part by balancing redox state, indicating that low dose of genistein may partially protect fetal testis from phthalates induced injury.

Individuals with cannabis use are associated with widespread morphological alterations in the subregions of the amygdala, hippocampus, and pallidum

BackgroundCannabis is the most frequently used illicit drug worldwide. Although multiple structural MRI studies of individuals with cannabis use (CB) have been undertaken, the reports of the volume alterations in the amygdala, hippocampus, and pallidum are not consistent. This study aims to detect subregion-level morphological alterations, analyze the correlation areas with cannabis usage characteristics, and gain new insights into the neuro mechanisms of CB. MethodsBy leveraging the novel surface-based subcortical morphometry method, 20 CB and 22 age- and sex-matched healthy controls (HC) were included to explore their volumetric and morphological differences in the three subcortical structures. Afterward, the correlation analysis between surface morphological eigenvalues and cannabis usage characteristics was performed. ResultsCompared with volumetric measures, the surface-based subcortical morphometry method detected more significant global morphological deformations in the left amygdala, right hippocampus, and right pallidum (overall-p < 0.05, corrected). More obvious morphological alterations (atrophy or expansion) were observed in specific subregions (vertex-based p-value<0.05, uncorrected) of the three subcortical structures. Both positive and negative subregional correlation areas were reported by the correlation analysis. ConclusionsThe current study illuminated new pathophysiologic mechanisms in the amygdala, hippocampus, and pallidum at the subregion level, which may inform the subsequent smaller-scale CB research.

Thiosulfate sulfurtransferase prevents hyperglycemic damage to the zebrafish pronephros in an experimental model for diabetes

Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), also known as Rhodanese, was initially discovered as a cyanide detoxification enzyme. However, it was recently also found to be a genetic predictor of resistance to obesity-related type 2 diabetes. Diabetes type 2 is characterized by progressive loss of adequate β-cell insulin secretion and onset of insulin resistance with increased insulin demand, which contributes to the development of hyperglycemia. Diabetic complications have been replicated in adult hyperglycemic zebrafish, including retinopathy, nephropathy, impaired wound healing, metabolic memory, and sensory axonal degeneration. Pancreatic and duodenal homeobox 1 (Pdx1) is a key component in pancreas development and mature beta cell function and survival. Pdx1 knockdown or knockout in zebrafish induces hyperglycemia and is accompanied by organ alterations similar to clinical diabetic retinopathy and diabetic nephropathy. Here we show that pdx1-knockdown zebrafish embryos and larvae survived after incubation with thiosulfate and no obvious morphological alterations were observed. Importantly, incubation with hTST and thiosulfate rescued the hyperglycemic phenotype in pdx1-knockdown zebrafish pronephros. Activation of the mitochondrial TST pathway might be a promising option for therapeutic intervention in diabetes and its organ complications.

Truncated analog Brevinin2-CE-N26V5K: Revelation the Augmentation of Antimicrobial Activity.

Brevinin2-CE (B2CE), a natural peptide containing 37 amino acids, was first isolated from the skin secretions of the Chinese forest frog Rana chensinensis. B2CE shows good antibacterial activity. In this study, a series of B2CE analogs with differences in cationicity, α-helicity, hydrophobicity and amphipathic properties were designed through chain-length deletion and amino acid substitution. The most potent, nontoxic analog, B2CE-N26V5K, was identified by examination of its antibacterial activity, hemolytic activity, and stability under physiological conditions. The increased cationicity, hydrophobicity and more obvious hydrophilic and hydrophobic surface of B2CE-N26-N16WA18KG23K did not improve the antibacterial activity but increased the hemolytic activity of this modified peptide. The helicity might promote antibacterial activity for brevinin-2 peptides, as the 15-aa analogs with lower helicity show decreased potency against different test bacteria (approximately 2- to 72-fold) compared to B2CE-N26V5K. Additionally, the results indicated that the "Rana box" does not affect the antimicrobial activity of brevinin-2 peptides, as B2CE, B2CE-nonDS and B2CE-C31-37S have similar strong inhibitory effects on both gram-positive and gram-negative bacteria. However, the "Rana box" does affect the hemolytic activity, as the HC50 values of the 3 peptides range from 25 ~ 130 µM. Furthermore, B2CE-N26V5K caused obvious morphological alterations of the bacterial surfaces, as shown by atomic force microscopy. Additionally, B2CE-N26V5K exhibited strong membrane-disrupting activity when examined using the LIVE/DEAD Bac Light Bacterial Viability Kit. Thus, the antibacterial effect of B2CE-N26V5K on gram-negative and gram-positive bacteria may be caused by cell membrane attack. In conclusion, the excellent candidate B2CE-N26V5K was obtained and has application prospects as a novel anti-infective agent.

Pdx1 Knockout Leads to a Diabetic Nephropathy- Like Phenotype in Zebrafish and Identifies Phosphatidylethanolamine as Metabolite Promoting Early Diabetic Kidney Damage.

The pdx1-/- zebrafish mutant was recently established as a novel animal model of diabetic retinopathy. In this study, we investigate whether knockout of pdx1 also leads to diabetic kidney disease (DKD). pdx1-/- larvae exhibit several signs of early DKD, such as glomerular hypertrophy, impairments in the filtration barrier corresponding to microalbuminuria, and glomerular basement membrane (GBM) thickening. Adult pdx1-/- mutants show progressive GBM thickening in comparison with the larval state. Heterozygous pdx1 knockout also leads to glomerular hypertrophy as initial establishment of DKD similar to the pdx1-/- larvae. RNA sequencing of adult pdx1+/- kidneys uncovered regulations in multiple expected diabetic pathways related to podocyte disruption and hinting at early vascular dysregulation without obvious morphological alterations. Metabolome analysis and pharmacological intervention experiments revealed the contribution of phosphatidylethanolamine in the early establishment of kidney damage. In conclusion, this study identified the pdx1 mutant as a novel model for the study of DKD, showing signs of the early disease progression already in the larval stage and several selective features of later DKD in adult mutants.

The effects of Tbx15 and Pax1 on facial and other physical morphology in mice.

DNA variants in or close to the human TBX15 and PAX1 genes have been repeatedly associated with facial morphology in independent genome‐wide association studies, while their functional roles in determining facial morphology remain to be understood. We generated Tbx15 knockout (Tbx15 −/−) and Pax1 knockout (Pax1 −/−) mice by applying the one‐step CRISPR/Cas9 method. A total of 75 adult mice were used for subsequent phenotype analysis, including 38 Tbx15 mice (10 homozygous Tbx15 −/−, 18 heterozygous Tbx15 +/−, 10 wild‐type Tbx15 +/+ WT littermates) and 37 Pax1 mice (12 homozygous Pax1 −/−, 15 heterozygous Pax1 +/−, 10 Pax1 +/+ WT littermates). Facial and other physical morphological phenotypes were obtained from three‐dimensional (3D) images acquired with the HandySCAN BLACK scanner. Compared to WT littermates, the Tbx15 −/− mutant mice had significantly shorter faces (p = 1.08E‐8, R2 = 0.61) and their ears were in a significantly lower position (p = 3.54E‐8, R2 = 0.62) manifesting a “droopy ear” characteristic. Besides these face alternations, Tbx15 −/− mutant mice displayed significantly lower weight as well as shorter body and limb length. Pax1 −/− mutant mice showed significantly longer noses (p = 1.14E‐5, R2 = 0.46) relative to WT littermates, but otherwise displayed less obvious morphological alterations than Tbx15 −/− mutant mice did. We provide the first direct functional evidence that two well‐known and replicated human face genes, Tbx15 and Pax1, impact facial and other body morphology in mice. The general agreement between our findings in knock‐out mice with those from previous GWASs suggests that the functional evidence we established here in mice may also be relevant in humans.

Human immune deficiency virus-related structural alterations in the brain are dependent on age.

Currently, it is still unknown whether human immune deficiency virus (HIV)‐related structural alterations in the brain are dependent on age. With people living with HIV at different ages, we aim to investigate age‐specific structural alterations in HIV patients. Eighty‐three male HIV patients and eighty‐three age‐matched male controls were enrolled, and high‐resolution T1 weighted images were collected and analyzed with four morphological metrics. Then, statistical analyses were respectively conducted to ascertain HIV effects, age effects, and medication effects in brain structure of HIV patients, and the relationship with neuropsychological evaluations were further explored. Finally, discriminative performances of these structural abnormalities were quantitatively testified with three machine learning models. Compared with healthy controls, HIV patients displayed lower gray matter volumes (GMV), lower gyrification index, deeper sulcus depth, and larger cortical thickness (CTH). Age‐specific differences were found in GMV and CTH: young‐aged HIV patients displayed more obvious morphological alterations than middle‐aged HIV patients when comparing corresponding age‐matched healthy controls. Furthermore, age‐specific long‐term medication effect of combination antiretroviral therapy were also presented. Additionally, several subcortical structural changes were negatively associated with language, attention and motor functions. Finally, three machine learning models demonstrated young‐aged HIV patients were easier to be recognized than middle‐aged HIV patients. Our study indicated young‐aged HIV patients were more vulnerable to HIV infection in brain structure than middle‐aged patients, and future studies should not ignore the age effect in studying the HIV‐related abnormalities.

Toxicopathological, proinflammatory and stress response evaluation of Terminalia catappa extract in male Wistar rats.

The present study was carried out to assess the oral safety, proinflammatory and stress response effect of Terminalia catappa aqueous leaf extract (TCA) in male Wistar rats. The acute and sub-acute oral toxicity of TCA was assessed using guidelines 423 and 407 of the Organisation for Economic Co-operation and Development (OECD), respectively. Signs of clinical toxicity, morbidity and mortality were observed. The biochemical, haematological, proinflammatory, stress response and histopathological indices were assessed. In the acute toxicity study, no sign of clinical toxicity, morbidity, and mortality was observed for TCA treatment, up to 5000 mg/kg bwt. However, in the sub-acute toxicity study, repeated daily TCA treatment significantly (p<0.05) altered the body weight gain, plasma alkaline phosphatase activity and albumin concentration. There were no obvious morphological and macroscopic alterations in the organs investigated. TCA appear not to elicit any proinflammatory, stress, systemic and organ toxic effect when utilised at the reported dose and time frame.

Molecular Identification of a Moricin Family Antimicrobial Peptide (Px-Mor) From Plutella xylostella With Activities Against the Opportunistic Human Pathogen Aureobasidium pullulans.

Antimicrobial peptides (AMPs) represent the largest group of endogenous compounds and serves as a novel alternative to traditional antibiotics for the treatment of pathogenic microorganisms. Moricin is an important α-helical AMP plays a crucial role in insect humoral defense reactions. The present study was designed to identify and characterize novel AMP moricin (Px-Mor) from diamondback moth (Plutella xylostella) and tested its activity against bacterial and fungal infection including the opportunistic human pathogen Aureobasidium pullulans. Molecular cloning of Px-Mor using rapid amplification of cDNA ends revealed a 482 bp full length cDNA with 198 bp coding region. The deduced protein sequence contained 65 amino acids, and the mature peptides contained 42 amino acid residues with a molecular mass of 4.393 kDa. Expression analysis revealed that Px-Mor was expressed throughout the life cycle of P. xylostella with the highest level detectable in the fourth instar and prepupa stage. Tissue specific distribution showed that Px-Mor was highly expressed in fat body and hemocyte. In vitro, antimicrobial assays indicated that Px-Mor exhibited a broad antimicrobial spectrum against Gram positive bacteria (GPB), Gram negative bacteria (GNB) and fungi. Moreover, scanning electron microscopy and transmission electron microscopy (TEM) revealed that Px-Mor can cause obvious morphological alterations in A. pullulans, which demonstrated its powerful effect on the mycelia growth inhibition. Taken together, these results indicate that Px-Mor plays an important role in the immune responses of P. xylostella and can be further exploited as an antimicrobial agent against various diseases including for the treatment of A. pullulans infection.

Toxicopathological evaluation of a 28-day repeated dose administration of Zea mays L. (Poaceae), Stigma maydis aqueous extract on key metabolic markers of Wistar rats

Zea mays L., Stigma maydis is a waste product of corn cultivation with good therapeutic applications against several debilitating diseases. This study evaluated the safety of its aqueous extract on key metabolic markers of Wistar rats using Organisation for Economic Co-operation and Development (OECD) guidelines. In the acute toxicity test, single oral administration of 5000 mg/kg body weight of the extract was given to the animals and observation was made for 14 days. The repeated dose toxicity study was conducted via daily oral administration of graded concentrations (50, 100, 200 and 500 mg/kg) of the extract for 28 days. Clinical toxicity signs, behavioural changes, haematological, and biochemical parameters were thereafter evaluated. The extract at 5000 mg/kg produced no treatment-induced signs of toxicity, behavioural changes or mortality in the animals. Thus, its LD50 was estimated to be above 5000 mg/kg. In the repeated dose toxicity study, treatments with the extract revealed no significant difference in haematological and clinical biochemistry parameters. However, at 500 mg/kg, the extract significantly increased the body weight, the exploratory ability as well as serum concentrations of leukocytes and platelets of the treated animals compared to the control group. Cage side observations recorded no treatment-mediated signs of toxicity and macro-histopathological examinations of all the investigated organs also revealed no obvious morphological alterations. Overall, the effects elicited by the aqueous extract of Z. mays, S. maydis suggest that it is unlikely to be toxic to the investigated tissues and may be labelled and classified as practically non-toxic within the tested doses and period of investigation.

Enhanced Bioconcentration of Bisphenol A in the Presence of Nano-TiO2 Can Lead to Adverse Reproductive Outcomes in Zebrafish.

Titanium dioxide nanoparticles (n-TiO2) and bisphenol A (BPA) are widespread environmental contaminants in the aquatic environment. We hypothesized that n-TiO2 may adsorb BPA, and thus modify its bioavailability and toxicity to aquatic organisms. In this study, the bioavailability and toxicity of BPA (0, 2, 20, 200 μg/L) was investigated in the presence of n-TiO2 (100 μg/L). The n-TiO2 sorbed BPA and the resulting nanoparticles were taken up by zebrafish, where they translocated to the liver, brain, and gonad tissues. Increased tissue burdens of both BPA and n-TiO2 were observed following coexposure, and they also caused a reduction in plasma concentrations of estradiol (E2), testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Plasma vitellogenin (VTG) concentrations were significantly increased in males and females upon exposure to BPA. Histological examination of the ovary and testes did not show obvious morphological alterations; however, inhibition of egg production was noted in the presence of n-TiO2. The results indicated that n-TiO2 acts as a carrier of BPA and enhances its bioconcentration in zebrafish, leading to endocrine disruption and impairment of reproduction.

Diamagnetic levitation promotes osteoclast differentiation from RAW264.7 cells.

The superconducting magnet with a high magnetic force field can levitate diamagnetic materials. In this study, a specially designed superconducting magnet with large gradient high magnetic field (LGHMF), which provides three apparent gravity levels (μg, 1 g, and 2 g), was used to study its influence on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation from preosteoclast cell line RAW264.7. The effects of LGHMF on the viability, nitric oxide (NO) production, morphology in RAW264.7 cells were detected by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, the Griess method, and the immunofluorescence staining, respectively. The changes induced by LGHMF in osteoclast formation, mRNA expression, and bone resorption were determined by tartrate-resistant acid phosphatase staining, semiquantity PCR, and bone resorption test, respectively. The results showed that: 1) LGHMF had no lethal effect on osteoclast precursors but attenuated NO release in RAW264.7 cells. 2) Diamagnetic levitation (μg) enhanced both the formation and bone resorption capacity of osteoclast. Moreover, diamagnetic levitation up-regulated mRNA expression of RANK, Cathepsin K, MMP-9, and NFATc1, while down-regulated RunX2 in comparison with controls. Furthermore, diamagnetic levitation induced obvious morphological alterations in osteoclast, including active cytoplasmic peripheral pseudopodial expansion, formation of pedosome belt, and aggregation of actin ring. 3) Magnetic field produced by LGHMF attenuated osteoclast resorption activity. Collectively, LGHMF with combined effects has multiple effects on osteoclast, which attenuated osteoclast resorption with magnetic field, whereas promoted osteoclast differentiation with diamagnetic levitation. Therefore, these findings indicate that diamagnetic levitation could be used as a novel ground-based microgravity simulator, which facilitates bone cell research of weightlessness condition.

Puerarin protects against lead-induced cytotoxicity in cultured primary rat proximal tubular cells

Puerarin, a potent free radicals scavenger, has been demonstrated to have protective efficacy in oxidative damage induced by nephrotoxins. In the present study, the attenuating effect of puerarin (PU) on lead (Pb)-induced apoptosis and oxidative stress was investigated in cultured primary rat proximal tubular (rPT) cells. Results showed that exposure to 0.5 µM Pb induced a decrease in cell viability accompanied with obvious cellular morphological alterations and caused an increase in apoptotic rate and apoptotic morphological changes. Simultaneously, depletion of mitochondrial membrane potential (ΔΨ) and intracellular glutathione (GSH); elevation of caspase-3 activity, intracellular reactive oxygen species, and malondialdehyde levels; and inhibition of GSH peroxidase (GSH-Px) activity were revealed in the cells exposed to Pb alone. However, simultaneous supplementation with PU (50 and 100 µM) protected rPT cells from Pb-induced cytotoxicity through inhibiting apoptosis, attenuating lipid peroxidation, renewing mitochondrial function, and elevating the intracellular antioxidants (nonenzymatic and enzymic) levels. In conclusion, these findings suggested that PU, as a widely distributed dietary antioxidant, contributes potentially to inhibition of Pb-induced cytotoxicity in rPT cells.

Effect of prenatal administration of venlafaxine on postnatal development of rat offspring

About 3% of pregnant women are treated with antidepressant drugs during gestation. After delivery the number of treated women increases to 5 to 7%. Most prescribed antidepressants in pregnancy are selective serotonin re-uptake inhibitors and/or serotonin and noradrenaline re-uptake inhibitors, such as fluoxetine, paroxetine, sertraline, citalopram and venlafaxine (VENF). Despite the fact that VENF has been assigned to pregnancy category C by the FDA, experimental studies with this drug are rare. The aim of this pilot study was to investigate the effect of prenatal administration of VENF on early postnatal development of rat offspring and selected biochemical variables at weaning of pups. Pregnant female Wistar rats were treated with VENF from day 15 to 20 of gestation at the doses of 7.5, 37.5 and 70 mg/kg. Females were allowed to spontaneously deliver their pups. After delivery the pups were inspected for viability, gross malformation and they were weighed on day 0, 4 and 21 post partum. On day 21 post partum, the pups were killed, brains were removed from the skulls and blood samples were collected for biochemical assay (proteins, glucose-GOD, glucose-HEX, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and total antioxidant status). The study showed that prenatal VENF administration resulted in a mild maternal intoxication manifested by decreased body weight gain of pregnant females. There was no effect of the drug tested on the body and brain weights of offspring. No obvious morphological alterations were observed in the delivered pups. Similarly, there were no changes in the selected biochemical variables determined.

Effects of pH Values of Hydrogen Peroxide Bleaching Agents on Enamel Surface Properties

This study investigated the influence of pH values of bleaching agents on the properties of the enamel surface. Sixty freshly extracted premolars were embedded in epoxy resin and mesiodistally sectioned through the buccal aspect into two parts. The sectioned slabs were distributed among six groups (n=10) and treated using different solutions. Group HCl was treated with HCl solution (pH=3.0) and served as a positive control. Group DW, stored in distilled water (pH=7.0), served as a negative control. Four treatment groups were treated using 30% hydrogen peroxide solutions with different pH values: group HP3 (pH=3.0), group HP5 (pH=5.0), group HP7 (pH=7.0), and group HP8 (pH=8.0). The buccal slabs were subjected to spectrophotometric evaluations. Scanning electron microscopy investigation and Micro-Raman spectroscopy were used to evaluate enamel surface morphological and chemical composition alterations. pH value has a significant influence on the color changes after bleaching (p<0.001). Tukey's multiple comparisons revealed that the order of color changes was HP8, HP7>HP5, HP3>HCl>DW. No obvious morphological alterations were detected on the enamel surface in groups DW, HP7, and HP8. The enamel surface of groups HCl and HP3 showed significant alterations with an erosion appearance. No obvious chemical composition changes were detected with respect to Micro-Raman analysis. Within the limitations of this study, it was concluded that no obvious morphological or chemical composition alterations of enamel surface were detected in the neutral or alkaline bleaching solutions. Bleaching solutions with lower pH values could result in more significant erosion of enamel, which represented a slight whitening effect.

RBOHF2 of Barley Is Required for Normal Development of Penetration Resistance to the Parasitic Fungus Blumeria graminis f. sp. hordei

Plant respiratory burst oxidase homologs are prominent sources of reactive oxygen species (ROS) in signal transduction and in interaction with microbes. However, the function of respiratory burst oxidase homologue (RBOH) genes in interaction with microbes might differ for certain plant and pathogen species. We produced transgenic barley knock down (KD) for the HvRBOHF2 isoform of NADPH oxidases. Young HvRBOHF2 KD shoots did not show obvious morphological alterations from the wild type but adult HvRBOHF2 KD plants developed fewer tillers, were less fertile, and showed spontaneous cell death in leaf mesophyll. Additionally, HvRBOHF2 KD plants were unable to contain wound-induced cell death. Before developmental failure became obvious, young HvRBOHF2 KD seedlings were much more susceptible to penetration by the biotrophic powdery mildew fungus Blumeria graminis f. sp. hordei. Strikingly, the B. graminis f. sp. hordei-induced cell-wall-associated oxidative burst was not substantially attenuated in HvRBOHF2 KD plants but enhanced susceptibility apparently influenced the subcellular site of hydrogen peroxide accumulation. Taken together, misexpression of HvRBOHF2 caused failure of barley to normally develop penetration resistance to B. graminis f. sp. hordei and to control leaf cell death.

Critical Role for Hypothalamic mTOR Activity in Energy Balance

The mammalian target of rapamycin (mTOR) promotes anabolic cellular processes in response to growth factors and metabolic cues. The TSC1 and TSC2 tumor suppressors are major upstream inhibitory regulators of mTOR signaling. Mice with Rip2/Cre-mediated deletion of Tsc1 (Rip-Tsc1cKO mice) developed hyperphagia and obesity, suggesting that hypothalamic disruption (for which Rip2/Cre is well known) of Tsc1 may dysregulate feeding circuits via mTOR activation. Indeed, Rip-Tsc1cKO mice displayed increased mTOR signaling and enlarged neuron cell size in a number of hypothalamic populations, including Pomc neurons. Furthermore, Tsc1 deletion with Pomc/Cre (Pomc-Tsc1cKO mice) resulted in dysregulation of Pomc neurons and hyperphagic obesity. Treatment with the mTOR inhibitor, rapamycin, ameliorated the hyperphagia, obesity, and the altered Pomc neuronal morphology in developing or adult Pomc-Tsc1cKO mice, and cessation of treatment reinstated these phenotypes. Thus, ongoing mTOR activation in Pomc neurons blocks the catabolic function of these neurons to promote nutrient intake and increased adiposity.

Endogenous Truncated TrkB.T1 Receptor Regulates Neuronal Complexity and TrkB Kinase Receptor FunctionIn Vivo

Pathological or in vitro overexpression of the truncated TrkB (TrkB.T1) receptor inhibits signaling through the full-length TrkB (TrkB.FL) tyrosine kinase receptor. However, to date, the role of endogenous TrkB.T1 is still unknown. By studying mice lacking the truncated TrkB.T1 isoform but retaining normal spatiotemporal expression of TrkB.FL, we have analyzed TrkB.T1-specific physiological functions and its effect on endogenous TrkB kinase signaling in vivo. We found that TrkB.T1-deficient mice develop normally but show increased anxiety in association with morphological abnormalities in the length and complexity of neurites of neurons in the basolateral amygdala. However, no behavioral abnormalities were detected in hippocampal-dependent memory tasks, which correlated with lack of any obvious hippocampal morphological deficits or alterations in basal synaptic transmission and long-term potentiation. In vivo reduction of TrkB signaling by removal of one BDNF allele could be partially rescued by TrkB.T1 deletion, which was revealed by an amelioration of the enhanced aggression and weight gain associated with BDNF haploinsufficiency. Our results suggest that, at the physiological level, TrkB.T1 receptors are important regulators of TrkB.FL signaling in vivo. Moreover, TrkB.T1 selectively affects dendrite complexity of certain neuronal populations.

The induction of Metallothionein by Cadmium in sea anemone (Aiptasia pulchella)

The induction of Metallothionein by Cadmium in sea anemone (Aiptasia pulchella) Metallothioneins(MT) are cysteine rich, heat stable and low molecular weight proteins. They have been widely used as biomarkers to reflect the existence of heavy metal pollution. MT also has the potential being used in well-designed environmental monitoring programmes. Sea anemones(Aiptasia pulchella) should reflect the real condition of its surroundings due to its sedentary. In lab, they are normally reproduced by pedal laceration as asexual reproduction. After exposure to different concentrations of cadmium(0, 0.5, 1.0 and 2.0mg/L) for 24, 48 and 96 hours, obvious morphological alterations in Aiptasia pulchella were recorded. Their tentacles turned dark and their body shrinked. By using atomic absorption to measure the Cd concentration, those Cd-exposed sea anemones showed a time-dependent and a dose-dependent cadmium accumulation. From the results of immunoblotting, the amount of metallothioneins in those cd-exposed A. pulchella significantly increased followed by a time-course. The molecular weight of the induced MT is between 11 and 17.