Napier grass (Pennisetum purpureum Schum) management strategies for dairy and meat production in the tropics and subtropics: yield and nutritive value.

Napier grass (Pennisetum purpureum Schumach) comprises up to 80% of the cattle diet in many tropical and subtropical regions and is used primarily by smallholder farmers. Despite the grass's high yield, resulting animal productivity from this grass is low. One of the key reasons for the low animal productivity of Napier grass is its low nutritive value under current management. Taken together, previous work has shown the current yield, crude protein (CP), and metabolisable energy (ME) of Napier grass to be 26 t dry matter (DM)/ha/year, 96 g/kg DM, and 8.7 MJ/kg DM, respectively, ranging from 2 to 86 t DM/ha/year, 9 to 257 g CP/kg DM, and 5.9 to 10.8 MJ ME/kg DM, respectively, suggesting an opportunity for significant improvement on both yield and nutritive value of this grass. The DM yield and nutritive value of this grass are inversely related, indicating a trade-off between yield and quality; however, this trade-off could be minimised by increasing sowing density and harvesting frequency. Available literature shows that this simple management strategy of increasing sowing density (50 cm × 40 cm) and harvesting frequency (11-12 harvests/year) provides 71 t DM/ha with 135 g/kg DM CP and 10.8 MJ ME/kg DM. This quality of Napier grass has the potential to increase both milk and meat production substantially in the tropics and subtropics, and the farmers will likely find this simple management acceptable due to the high yield obtained through this management. However, there is a paucity of work in this field. Therefore, management strategies to improve the nutritive value of Napier grass are required to increase milk and meat production in the tropics and subtropics and in doing so improve the food security of more than half of the global population living in these regions.

Field and in-silico analysis of harvest index variability in maize silage.

Maize silage is a key component of feed rations in dairy systems due to its high forage and grain yield, water use efficiency, and energy content. However, maize silage nutritive value can be compromised by in-season changes during crop development due to changes in plant partitioning between grain and other biomass fractions. The partitioning to grain (harvest index, HI) is affected by the interactions between genotype (G) × environment (E) × management (M). Thus, modelling tools could assist in accurately predicting changes during the in-season crop partitioning and composition and, from these, the HI of maize silage. Our objectives were to (i) identify the main drivers of grain yield and HI variability, (ii) calibrate the Agricultural Production Systems Simulator (APSIM) to estimate crop growth, development, and plant partitioning using detailed experimental field data, and (iii) explore the main sources of HI variance in a wide range of G × E × M combinations. Nitrogen (N) rates, sowing date, harvest date, plant density, irrigation rates, and genotype data were used from four field experiments to assess the main drivers of HI variability and to calibrate the maize crop module in APSIM. Then, the model was run for a complete range of G × E × M combinations across 50 years. Experimental data demonstrated that the main drivers of observed HI variability were genotype and water status. The model accurately simulated phenology [leaf number and canopy green cover; Concordance Correlation Coefficient (CCC)=0.79-0.97, and Root Mean Square Percentage Error (RMSPE)=13%] and crop growth (total aboveground biomass, grain + cob, leaf, and stover weight; CCC=0.86-0.94 and RMSPE=23-39%). In addition, for HI, CCC was high (0.78) with an RMSPE of 12%. The long-term scenario analysis exercise showed that genotype and N rate contributed to 44% and 36% of the HI variance. Our study demonstrated that APSIM is a suitable tool to estimate maize HI as one potential proxy of silage quality. The calibrated APSIM model can now be used to compare the inter-annual variability of HI for maize forage crops based on G × E × M interactions. Therefore, the model provides new knowledge to (potentially) improve maize silage nutritive value and aid genotype selection and harvest timing decision-making.

A review of bio-impedance devices.

Bio-impedance measurement analysis primarily refers to a safe and a non-invasive technique to analyze the electrical changes in living tissues on the application of low-value alternating current. It finds applications both in the biomedical and the agricultural fields. This paper concisely reviews the origin and measurement approaches for concepts and fundamentals of bio-impedance followed by a critical review on bio-impedance portable devices with main emphasis on the embedded system approach which is in demand due to its miniature size and present lifestyle preference of monitoring health in real time. The paper also provides a comprehensive review of various bio-impedance circuits with emphasis on the measurement and calibration techniques.

Dielectrically Modulated III-V Compound Semiconductor Based Pocket Doped Tunnel FET for Label Free Biosensing Applications.

In this paper, a novel structure of double gate tunnel FET has been proposed and simulated for biosensing applications. The device uses III-V compound semiconductors and an n+ doped pocket at the source channel junction. Biomolecules of different dielectric constants (K) with different charge densities (Nbio), both negative and positive, are inserted in the nano-gap cavities (15 nm ×1.5 nm) that have been created under gates near source channel junction to capture biomolecules. From extensive 2D simulations, ION sensitivity of 4.351 ×108/1.03 ×108/1.514 ×109 , subthreshold swing sensitivity of 15.67/20.21/18.57 mV/dec, and threshold voltage sensitivity of 18/12/23 mV for neutral (K = 12)/negatively charged biomolecules ( [Formula: see text] C/cm2, K = 12)/positively charged biomolecules ( [Formula: see text] C/cm2, K = 12) respectively has been observed. Also, transconductance sensitivity of 9.74 ×107 and ION/IOFF sensitivity of 5.255 ×108 for neutral biomolecules (K = 12) has been calculated. Furthermore, the device performance with one-third filled cavities, two-third filled cavities and fully filled cavities has also been studied. The performance of the proposed biosensor has been compared with the previously published work and it has been observed that the sensitivity of the proposed biosensor is 100 times better than the best reported biosensor.

L-Shaped High Performance Schottky Barrier FET as Dielectrically Modulated Label Free Biosensor.

In this work, we demonstrate the realization of L-Shaped Schottky Barrier FET as a biosensing device with improved sensitivity. The proposed device uses dual material gate with work functions of 4.2 eV (Al) and 4.8 eV (Cu) and Hafnium Oxide (HfO2) as the gate dielectric. In order to detect the biomolecule, a nano-gap cavity is created in the vertical gate (Gate1) by etching out the oxide. The electrical characteristics of biomolecules such as dielectric constant and charge density modulate the Schottky Barrier width, which in turn, changes the drive current of the device. Various sensitivity parameters have been thoroughly investigated at [Formula: see text] and a comparative analysis with the conventional device has been performed. The results so obtained reveal that [Formula: see text] sensitivity of the proposed device is much better for both neutral as well as charged biomolecules (maximum of 21x for neutral, at K = 12; 20x for charged biomolecules at ρ = -5×10 10cm-2, at K = 12). Besides this, the [Formula: see text] sensitivity, transconductance ( [Formula: see text]) sensitivity and selectivity show similar improvements. Further, the proposed device shows better sensitivity performance at low as well as at higher temperatures as compared to the state-of-the-art biosensing devices.

Evaluation of the Anticancer Activity of Phytomolecules Conjugated Gold Nanoparticles Synthesized by Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin).

The conventional physical and chemical synthetic methods for the preparation of metal nanoparticles have disadvantages as they use expensive equipment and hazardous chemicals which limit their applications for biomedical purposes, and are not environment friendly. However, for the synthesis of biocompatible nanomaterials, plant-based techniques are eco-friendly and easy to handle. Herein a simple, single-step biosynthesis of gold nanoparticles using aqueous extracts of Nigella sativa (NSE) and Zingiber officinale (GE) as a reducing and capping agent has been demonstrated. The formation of gold nanoparticles (Au NPs) was confirmed by X-ray diffraction, UV-Vis, and EDS spectroscopies. Spectroscopic and chromatographic analysis of GE and NSE revealed the presence of bioactive phytochemical constituents, such as gingerol, thymoquinone, etc., which successfully conjugated the surface of resulting Au NPs. TEM analysis indicated the formation of smaller-sized, less-aggregated, spherical-shaped Au NPs both in the case of GE (~9 nm) and NSE (~11 nm). To study the effect of the concentration of the extracts on the quality of resulting NPs and their anticancer properties, three different samples of Au NPs were prepared from each extract by varying the concentration of extracts while keeping the amount of precursor constant. In both cases, high-quality, spherical-shaped NPs were obtained, only at a high concentration of the extract, whereas at lower concentrations, larger-sized, irregular-shaped NPs were formed. Furthermore, the as-prepared Au NPs were evaluated for the anticancer properties against two different cell lines including MDA-MB-231 (breast cancer) and HCT 116 (colorectal cancer) cell lines. GE-conjugated Au NPs obtained by using a high concentration of the extract demonstrated superior anticancer properties when compared to NSE-conjugated counterparts.

Genetic loci regulating cadmium content in rice grains.

It has been estimated that up to 90% of human exposure to cadmium is through food, and that cadmium within rice grains can be a major contributor to that dietary source. In this study genome wide association mapping was conducted on the Bengal and Assam Aus Panel (BAAP) of rice to identify quantitative trait loci and candidate genes for lowering grain cadmium. Field experiments were conducted over two years under two different irrigation systems: continually flooded and alternate wetting and drying (AWD). There was significant effects of water treatment, genotype, and genotype by water treatment interaction. Importantly, AWD increased grain cadmium, on average, by 49.6% and 108.8% in year 1 and 2 respectively. There was between 4.6 and 28 fold variation in cadmium concentration. A total of 58 QTLs were detected but no loci are clearly specific to one water regime despite approximately 20% of variation attributable to genotype by water regime interaction. A number of QTLs were consistent across most water treatments and years. These included QTLs on chromosome 7 (7.23-7.61, 8.93-9.04, and 29.12-29.14 Mbp), chromosome 5 (8.66-8.72 Mbp), and chromosome 9 (11.46-11.64 Mbp). Further analysis of the loci on chromosome 7 (8.93-9.04 Mbp), identified the candidate gene OsNRAMP1, where cultivars with a deletion upstream of the gene had higher concentrations of cadmium compared to the cultivars that did not have the deletion. The distribution of alleles within the BAAP suggest this QTL is easily detected in this population because it is composed of aus cultivars. Local genome cluster analysis suggest high Cd alleles are uncommon, but should be avoided in breeding. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at (10.1007/s10681-020-02752-1).

Study of Partial Oxidation of Methane by Ni/Al2O3 Catalyst: Effect of Support Oxides of Mg, Mo, Ti and Y as Promoters.

Catalysts of 10% Ni, supported on promoted alumina, were used to accomplish the partial oxidation of methane. The alumina support was doped with oxides of Mo, Mg, Ti and Y. An incipient wetness impregnation technique was used to synthesize the catalysts. The physicochemical properties of the catalysts were described by XRD, H2-TPR (temperature programmed reduction), BET, TGA, CO2-TPD (temperature-programmed desorption) and Raman. The characterization results denoted that Ni has a strong interaction with the support. The TGA investigation of spent catalysts displayed the anticoking enhancement of the promoters. The impact of the support promoters on the catalyst stability, methane conversion and H2 yield was inspected. Stability tests were done for 460 min. The H2 yields were 76 and 60% and the CH4 conversions were 67 and 92%, respectively, over Ni/Al2O3+Mg, when the reaction temperatures were 550 and 650 °C, respectively. The performance of the present work was compared to relevant findings in the literature.

Plasmid DNA nicking- a Novel Activity of Soybean Trypsin Inhibitor and Bovine Aprotinin.

Protease inhibitors, such as trypsin inhibitor, serum alpha-1 antitrypsin, or liver aprotinin, are a class of proteins that competitively bind and block the catalytic activity of proteolytic enzymes with wide ranging biological functions. A significant number of protease inhibitors have also been shown to possess antimicrobial activity, presumed to contribute in defense against pathogenic microorganisms as plants with higher levels of protease inhibitors tend to exhibit increased resistance towards pathogens. Two proposed mechanisms for the antimicrobial activity are combating microbial proteases that play roles in disease development and disruption of microbial cell wall & membrane necessary for survival. Here we show for the first time a novel activity of soybean trypsin inhibitor and bovine aprotinin that they nick supercoiled, circular plasmid DNA. A number of experiments conducted to demonstrate the observed DNA nicking activity is inherent, rather than a co-purified, contaminating nuclease. The nicking of the plasmid results in markedly reduced efficiencies in transformation of E. coli and transfection of HEK293T cells. Thus, this work reveals yet a new mechanism for the antimicrobial activity by protease inhibitors.

Evaluation of Complications from Stainless-Steel Flexible Intramedullary Nailing in Children's Femoral Shaft Fractures and Recommendations for Continued Use.

[b]Background.[/b] Flexible intramedullary nailing is currently considered the treatment of choice for femoral diaphyseal fractures in school-aged children. The purpose of our study was to critically evaluate and analyze the complications of stainless steel flexible intramedullary nailing in children's femoral shaft fractures. (mean age, 8.2 years) with a femoral shaft fracture treated with stainless steel flexible intramedullary nailing from January 1, 2009 to July 31, 2015 and evaluated for complications.[b]Results.[/b] All fractures united in a mean time of 9.2 weeks. Minor complications were noted in 19 patients, and major complications were noted in two patients. The Flynn score was excellent in 74 patients, satisfactory in 23 patients, and poor in three patients.[b]Conclusions.[/b] 1. Stainless steel flexible intramedullary nailing in children's femoral shaft fractures is associated with minimal complications. 2. These complications are not related to the alloy of the implant and are mostly due to the long nail end; these complications can be prevented easily. 3. Stainless steel flexible intramedullary nailing is also cost effective, and we recommend its use be enhanced for the treatment of femoral shaft fractures in children.

Imiquimod-induced psoriasis-like inflammation in differentiated Human keratinocytes: Its evaluation using curcumin.

Psoriasis is considered to be a systemic disease of immune dysfunction. It is still unclear what triggers the inflammatory cascade associated with psoriasis but recent evidences suggest the vital role of IL-23/IL-17A cytokine axis in etiology of psoriasis. Several studies have been conducted in psoriatic-like animal models but ethical issues and complexity surrounding it halts the screening of new anti-psoriatic drug candidates. Hence, in this study, we developed a new in-vitro model for psoriasis using imiquimod (IMQ) induced differentiated HaCaT cells which could be used for screening of new anti-psoriatic drug candidates. The differentiated HaCaT cells were treated with IMQ (100µM) to induce psoriatic like inflammation and its effect was investigated using a natural anti-psoriatic compound, curcumin. The proliferation of psoriatic-like cells was inhibited by curcumin at 25 and 50µM concentrations. The psoriatic-like cells decreased in number with increase in apoptotic and dead cells upon curcumin treatment. Curcumin inhibited the proliferation of IMQ-induced differentiated HaCaT cells (Psoriatic-like cells) by down-regulation of pro-inflammatory cytokines, interleukin-17, tumor necrosis factor-α, interferon-γ, and interleukin-6. Apart from this, curcumin significantly enhanced the skin-barrier function by up-regulation of involucrin (iNV) and filaggrin (FLG), the regulators of epidermal skin barrier. The IMQ-induced differentiated HaCaT in vitro model recapitulated some aspects of the psoriasis pathogenesis similar to murine model. Henceforth, we conclude that this model may be used for rapid screening of anti-psoriatic drug candidates and warrant further mechanistic studies.

Nuclear Localization Signal and p53 Binding Site in MAP/ERK Kinase Kinase 1 (MEKK1).

Previously, we showed that Mekk1 translocates to the nucleus, interacts with tumor suppressor protein p53, and co-represses PKD1 transcription via an atypical p53 binding site on the minimal PKD1 promoter (JBC 285:38,818-38,831, 2010). In this study, we report the mechanisms of Mekk1 nuclear transport and p53 binding. Using GFP-linked constitutively active-Mekk1 (CA-Mekk1) and a deletion strategy, we identified a nuclear localization signal (HRDVK) located at amino acid (aa) residues 1,349-1,353 in the C-terminal Mekk1 catalytic domain. Deletion of this sequence in CA-Mekk1 and full-length Mekk1 significantly reduced their nuclear translocation in both HEK293T and COS-1 cells. Using co-immunoprecipitation, we identified an adjacent sequence (GANLID, aa 1,354-1,360) in Mekk1 responsible for p53 binding. Deletion of this sequence markedly reduced the interaction of Mekk1 with p53. Mekk1 does not appear to affect phosphorylation of Ser15, located in the Mdm2 interaction site, or other Ser residues in p53. However, Mekk1 mediates p53 protein stability in the presence of Mdm2 and reduces p53 ubiquitination, suggesting an interference with Mdm2-mediated degradation of p53 by the ubiquitin-proteasome pathway.

Microwave irradiation: synthesis and characterization of α-ketoamide and bis (α-ketoamide) derivatives via the ring opening of N-acetylisatin.

BACKGROUND: The carbonyl group at position 2 of N-acetylisatin behaves as an amide which is more susceptible to nucleophilic attack via ring-opening in the presence of nucleophiles. Because of this behavior, in the present work we describe the microwave synthesis of a series of α-ketoamide and bis-(α-ketoamide) derivatives via the facile ring-opening of N-acylisatin with different amines and diamines. The microwave irradiation afforded the product in less reaction time, higher yield and purity. Reaction of N-acylisatin with methanol under microwave irradiation afforded the α-phenylglyoxyl methyl ester derivatives with excellent yields and purities. Aminolysis of the ester derivatives with piperidine and morpholine afforded the same α-ketoamide derivatives obtained from direct aminolysis of N-acylisatin. The structures of the synthesized compounds were confirmed by FT-IR, NMR, X-ray and elemental analysis. RESULTS: Reaction of N-acetylisatin and N-propoionylsatin with different amines and diamines afforded a series of α-ketoamide and bis-(α-ketoamide) derivatives respectively via the ring opening of N-acylisatins. The reaction was performed under conventional condition as well as microwave irradiation. The microwave irradiation afforded the product in less reaction time, higher yield and purity. Reaction of N-acylisatin with methanol under microwave irradiation afforded the α-phenylglyoxyl methyl ester derivatives in excellent yields and purities as observed from their spectral data. A plausible mechanism involves nucleophilic attack by methanol at C2 carbonyl carbon of N-acetylisatin and subsequent ring opening to generate the α-ketoester. Aminolysis of α-ketoester with amine afforded the same α-ketoamide which is obtained by direct aminolysis of N-acylisatin. The IR, NMR spectra, microanalyses, and single crystal X-ray diffraction confirmed the structures of the synthesized compounds. CONCLUSIONS: In conclusion, we have demonstrated that microwave irradiation could be employed efficiently for the synthesis of biologically important α-ketoamide and bis-(α-ketoamide) derivatives. The microwave irradiation has more advantageous over the classical method with regard to reaction time, solvent quantity, and product yield. Reaction of N-acylisatin with methanol under microwave irradiation afforded the α-phenylglyoxyl methyl ester derivatives with excellent yields and purities. Aminolysis of the methyl ester derivatives with amine under microwave irradiation afford the same α-ketoamide derivatives as obtained from direct aminolysis of N-acylisatins.

Regulation of HFE expression by poly(ADP-ribose) polymerase-1 (PARP1) through an inverted repeat DNA sequence in the distal promoter.

Hereditary hemochromatosis (HH) is a common autosomal recessive disorder of iron overload among Caucasians of northern European descent. Over 85% of all cases with HH are due to mutations in the hemochromatosis protein (HFE) involved in iron metabolism. Although the importance in iron homeostasis is well recognized, the mechanism of sensing and regulating iron absorption by HFE, especially in the absence of iron response element in its gene, is not fully understood. In this report, we have identified an inverted repeat sequence (ATGGTcttACCTA) within 1700bp (-1675/+35) of the HFE promoter capable to form cruciform structure that binds PARP1 and strongly represses HFE promoter. Knockdown of PARP1 increases HFE mRNA and protein. Similarly, hemin or FeCl3 treatments resulted in increase in HFE expression by reducing nuclear PARP1 pool via its apoptosis induced cleavage, leading to upregulation of the iron regulatory hormone hepcidin mRNA. Thus, PARP1 binding to the inverted repeat sequence on the HFE promoter may serve as a novel iron sensing mechanism as increased iron level can trigger PARP1 cleavage and relief of HFE transcriptional repression.

Synthesis, physicochemical properties, and in vitro antibacterial screening of palladium(II) complexes derived from thiosemicarbazone.

A new series of PdII complexes derived from thiosemicarbazone has been synthesized. The synthesized PdII complexes have been characterized on the basis of elemental analyses, FT-IR, ¹H- and ¹³C-NMR, UV/VIS, and thermal studies. A square-planar geometry has been assigned around PdII ions on the basis of results obtained from UV/VIS studies. The thiosemicarbazone ligand and its PdII complexes have been screened against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria in vitro as growth-inhibiting agents, and the results revealed significant antibacterial activities.

CMV promoter is repressed by p53 and activated by JNK pathway.

Viral promoters are widely utilized in commercial and customized vectors to drive expression of genes of interest including reporter, effector and transfection control, because of their high transcription efficiency in a variety of primary and transformed cell lines. However, we observed altered rate of transcription for these promoters under conditions such as presence of an effector protein. These variations in viral promoter driven expressions can potentially lead to incorrect conclusion, especially in comparative and quantitative experiments. We found significantly reduced viral promoter activity in cells overexpressing tumor suppressor protein p53, whereas markedly induced transcription in cells overexpressing MAP/ERK kinase kinase 1 (Mekk 1). Using deletion constructs generated from the CMV promoter, we found the transcription reduction by p53 is possibly mediated through the TATA motif present in proximal CMV promoter. The activation of the CMV promoter by Mekk 1, on the other hand, is attributed to the proximal CRE binding site in the promoter. These findings may be of interest to investigators who use CMV (or other viral) promoter driven vectors for either comparative or quantitative gene expression, or effect on promoter activity.

Cytotoxicity analysis of active components in bitter melon (Momordica charantia) seed extracts using human embryonic kidney and colon tumor cells.

Bitter melon (Momordica charantia) seed extracts (BMSE) have been used as traditional medicine for treating various ailments, although in many cases, the active component(s) are unidentified. In this study, bitter melon seeds were extracted in water, ethanol, or ethanol: water (1:1). The aqueous seed extracts (BMSE-W) exhibited marked cytotoxicity towards human embryonic kidney 293T (HEK293T) and human colon tumor 116 (HCT1116) cells. The activity in BMSE-W was unaffected by heat and proteinases treatments, and eluted in the total volume of size-exclusion HPLC, suggesting the small, organic nature of the active component(s). Gas chromatographic-mass spectrometic (GC-MS) analysis of the HPLC fractions identified methoxy-phenyl oxime (MPO) as a major active component. Acetophenone oxime, a commercially available structural homolog of MPO, demonstrated cytotoxicity comparable with that of the BMSE-W. The oxime functional group was found to be critical for activity. Increased poly-(ADP-ribose)-polymerase and beta-actin cleavage, and chromatin condensation observed in treated cells suggested apoptosis as a plausible cause for the cytotoxicity. This study, for the first time, identified a cytotoxic oxime in BMSE-W.

Identification of bound nitro musk-protein adducts in fish liver by gas chromatography-mass spectrometry: biotransformation, dose-response and toxicokinetics of nitro musk metabolites protein adducts in trout liver as biomarkers of exposure.

Ubiquitous occurrences of synthetic nitro musks are evident in the literature. The in vivo analysis of musk xylene (MX) and musk ketone (MK)-protein adducts in trout liver has been performed by gas chromatography-mass spectrometry using selected ion monitoring (GC-SIM-MS). Biotransformation, dose-response and toxicokinetics studies of 2-amino-MX (2-AMX), 2-amino-MK (2-AMK) and 4-amino-MX (4-AMX) metabolites, covalently bound to cysteine amino acids in proteins in fish liver, formed by enzymatic nitro-reduction of MX and MK, have been described. Trouts were exposed to single exposures of 0.010, 0.030, 0.10, and 0.30 mg/g MX and/or MK. Forty-two fish liver samples were collected from exposed- and control-fish subsequent to exposure intervals of 1 day, 3 days, and 7 days and were composited as per exposure schedules and times. Alkaline hydrolysis released bound metabolites from exposed liver composites that were extracted into n-hexane and then concentrated and analyzed by GC-SIM-MS. The presence of the metabolites in liver extracts was confirmed based on agreement of similar mass spectral properties and retention times with standards. In the dose-response study, the maximum adduct formation was 492.0 ng/g for 2-AMX, 505.5 ng/g for 2-AMK and 12588.5 ng/g for 4-AMX in liver at 0.03 mg/g MX and MK fish in 1 day after exposure. For toxicokinetics investigation, the highest amount of the target metabolites was found to be the same concentration as observed in the dose-response study for 1 day after exposure with 0.03 mg/g MX and MK fish and the half-lives of the metabolites were estimated to be 2-9 days based on assumption of first-order kinetics. Average recoveries exceeded 95% with a relative standard deviation (RSD) around 9%, and the limit of detection (LOD) ranged from 0.91 to 3.8 ng/g based on a signal to noise ratio of 10 (S/N=10) could be achieved for the metabolites. No metabolites were detected in the controls and exposed non-hydrolyzed liver extracts. This is the first report on dose-response and toxicokinetics of nitro musk-cysteine-protein adducts in fish liver.

MAP/ERK kinase kinase 1 (MEKK1) mediates transcriptional repression by interacting with polycystic kidney disease-1 (PKD1) promoter-bound p53 tumor suppressor protein.

Mitogen-activated protein kinase (MAPK) cascades regulate a wide variety of cellular processes that ultimately depend on changes in gene expression. We have found a novel mechanism whereby one of the key MAP3 kinases, Mekk1, regulates transcriptional activity through an interaction with p53. The tumor suppressor protein p53 down-regulates a number of genes, including the gene most frequently mutated in autosomal dominant polycystic kidney disease (PKD1). We have discovered that Mekk1 translocates to the nucleus and acts as a co-repressor with p53 to down-regulate PKD1 transcriptional activity. This repression does not require Mekk1 kinase activity, excluding the need for an Mekk1 phosphorylation cascade. However, this PKD1 repression can also be induced by the stress-pathway stimuli, including TNFα, suggesting that Mekk1 activation induces both JNK-dependent and JNK-independent pathways that target the PKD1 gene. An Mekk1-p53 interaction at the PKD1 promoter suggests a new mechanism by which abnormally elevated stress-pathway stimuli might directly down-regulate the PKD1 gene, possibly causing haploinsufficiency and cyst formation.

Transfer buffer containing methanol can be reused multiple times in protein electrotransfer.

We investigated the feasibility of repeated use of transfer buffer containing methanol in electrotransfer of proteins from sodium dodecyl sulfate-polyacrylamide gels to polyvinylidene difluoride (PVDF) membrane using a prestained protein marker of broad molecular sizes. Transfer of the antitumor protein p53 in HEK293T cell extracts, using fresh and used transfer buffer, followed by detection with anti-p53 antibody was also performed to test detectability in immunoblot. Results from these experiments indicate that the transfer buffer can be reused at least five times and maintain a similar extent of protein transfer to PVDF membrane. Repeated use of the transfer buffer containing methanol will significantly reduce the volume of hazardous waste generated and its disposal cost as well as its adverse effect on environment.