Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Biochemical

  • serum biochemical
  • various biochemical

  • Terms modified by Biochemical

  • biochemical abnormality
  • biochemical activity
  • biochemical alteration
  • biochemical analysis
  • biochemical application
  • biochemical approach
  • biochemical aspect
  • biochemical assessment
  • biochemical basis
  • biochemical cascade
  • biochemical change
  • biochemical characteristic
  • biochemical characterization
  • biochemical component
  • biochemical composition
  • biochemical constituent
  • biochemical content
  • biochemical control
  • biochemical criterioN
  • biochemical data
  • biochemical determination
  • biochemical difference
  • biochemical disturbance
  • biochemical effects
  • biochemical evaluation
  • biochemical event
  • biochemical evidence
  • biochemical examination
  • biochemical factor
  • biochemical failure
  • biochemical feature
  • biochemical finding
  • biochemical function
  • biochemical improvement
  • biochemical index
  • biochemical information
  • biochemical investigation
  • biochemical level
  • biochemical machinery
  • biochemical marker
  • biochemical measure
  • biochemical measurement
  • biochemical mechanism
  • biochemical methods
  • biochemical model
  • biochemical monitoring
  • biochemical network
  • biochemical observation
  • biochemical outcome
  • biochemical oxygen demand
  • biochemical parameter
  • biochemical pathway
  • biochemical phenotype
  • biochemical process
  • biochemical profile
  • biochemical progression
  • biochemical property
  • biochemical rationale
  • biochemical reaction
  • biochemical reaction network
  • biochemical recurrence
  • biochemical relapse
  • biochemical remission
  • biochemical response
  • biochemical result
  • biochemical risk factor
  • biochemical screening
  • biochemical sign
  • biochemical signal
  • biochemical studies
  • biochemical study
  • biochemical techniques
  • biochemical test
  • biochemical testing
  • biochemical value
  • biochemical variable

  • Selected Abstracts


    ABSTRACT Ground cherry (Physalis pubescens L.) is one of the most promising exotic fruits and some interesting functional products could be developed from these berries. The fresh juice was yellowish or orangey and had a light, sweet taste with acidic nature (pH 3.5). The titratable acidity was 1.43, polyphenols 76.6 mg/100 mL and vitamin C 38.8 mg/100 mL. Physalis juice was rich in carotenoids (70 g/mL). The juice had a high level in minerals such as phosphorus (578 mg/100 mL), potassium (1,196 mg/100 mL), zinc (2.4 mg/100 mL) and boron (1 mg/100 mL). The essential amino acids in the juice such as isoleucine, valine and tryptophan (42.97, 39.92 and 39.83 mg/100 mL) were higher than those recommended by Food and Agriculture Organization/World Health Organization/United Nations Union (FAO/WHO/UNU). PRACTICAL APPLICATIONS Tropical pulpy juices play an important role in nutrition as an excellent base for low-calorie and dietetic products. Physalis fruit and juice are nutritious, containing particularly high levels of niacin, carotenoids and minerals. There are very little available data in the literature regarding physicochemical and sensory properties. As part of the first steps toward developing Physalis as commercial crop, the present study aimed to evaluate the nutritional and sensorial properties of fresh juice as a new product from Physalis. [source]


    G. CHENG
    ABSTRACT Longan fruits were stored for 6 days in atmosphere of 5, 21 (air) or 60% O2 (balance N2) at 28C and 90,95% relative humidity to examine effects of low and high O2 concentration on enzymatic browning and quality attributes of the fruit. Changes in pericarp browning, pulp breakdown, disease development, total phenol content, activities of phenol metabolism-associated enzymes, relative leakage rate, ,,, -diphenyl- , -picrylhydrazy (DPPH) radical scavenging activity, and contents of total soluble solids, titratable acidity and ascorbic acid were evaluated. Storage of fruit in a 5% O2 atmosphere markedly delayed pericarp browning in association with maintenance of high total phenolic content and reduced activities of polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonia lyase. Moreover, the fruit stored in a 5% O2 atmosphere exhibited a lower relative leakage rate and higher DPPH radical scavenging activity than fruit stored in air. This presumably was beneficial in maintaining compartmentation of enzymes and substrates, and thus, reducing pericarp browning. Pulp breakdown and disease development were also reduced by exposure to a 5% oxygenatmosphere. On the contrary, exposure of longan fruit to a 60% O2 atmosphere accelerated pericarp browning, pulp breakdown and decay development. PPO and POD activities and relative leakage rate were similar for control and 60% O2 -treated fruit after 4 and 6 days of storage. Furthermore, treatment with 60% O2 significantly decreased the phenolic content and DPPH scavenging activity of fruit. In addition, exposure to 5 or 60% O2 resulted in a higher level of total soluble solids, but a lower level of ascorbic acid of longan fruit flesh. In conclusion, exposure to a 5% O2 atmosphere showed great potential to reduce pericarp browning and extend shelf life of longan fruit. PRACTICAL APPLICATIONS Pericarp browning and pulp breakdown are the major causes of deterioration in postharvest longan. Conventional controlled atmosphere with low O2 and high CO2 is effective in maintaining quality and extending shelf life of fruits and vegetables, including inhibition of tissue browning. In this study, 5%-controlled atmosphere reduced significantly pericarp browning, pulp breakdown and rot development. It could potentially be useful as a postharvest technology of longan fruit for reducing or replacing the use of chemicals such as SO2 and fungicides, but it requires further investigation. [source]

    Biochemical and histopathological effects in pearl dace (Margariscus margarita) chronically exposed to a synthetic estrogen in a whole lake experiment

    Vince P. Palace
    Abstract Potential effects of exposure to the synthetic estrogen 17,-ethynylestradiol (EE2) were examined in several species of fish from a lake experimentally treated with environmentally relevant concentrations of the contaminant. Ethynylestradiol was added to Lake 260, a small Precambrian shield lake at the Experimental Lakes Area in northwestern Ontario, Canada, from May to October of 2001, 2002, and 2003. Mean concentrations of EE2 in epilimnetic waters ranged between 4.5 and 8.1 ng/L during the three years, with overall means of 6.1 (2.8), 5.0 (1.8), and 4.8 (1.0) ng/L for the three years, respectively. Male and female pearl dace (Margariscus margarita) captured after EE2 additions began contained up to 4,000-fold higher concentrations of the egg yolk precursor vitellogenin than fish captured from the same lake before the EE2 additions or when compared to fish from reference lakes. Edema in the ovaries, inhibited development of testicular tissue, intersex, and histopathological kidney lesions were all evident in fish exposed to EE2. Some indications that EE2 exposure affected in vitro steroidogenic capacity of the ovaries and the testes existed, although results were not always consistent between years. Pearl dace abundance was similar in the lake treated with EE2 and the reference lake. A trend exists toward a reduced overall population of pearl dace from the treated and reference lakes, as do indications that young-of-the-year size classes are less abundant in the EE2-treated lake. Biochemical and histopathological impacts observed in fish exposed to EE2 in this study have not yet been linked to clear population level impacts in pearl dace. Monitoring of these populations is ongoing. [source]

    Mechanism of modulation of T cell responses by N-palmitoylated peptides

    Clara Bueno
    Abstract Small structural changes in the antigenic peptides recognized by TCR can alter the biological properties of those peptides and convert them into weak agonists, partial agonists, or antagonists of these receptors. These altered peptide ligands (APL) are usually generated by conservative amino acid substitutions at TCR contact residues. Here, we show that APL with therapeutic properties can also be generated by attachment of palmitic acid at the N terminus of the peptide without the need to modify the peptide's primary sequence. Using N-palmitoylated pigeon cytochrome-c peptide 81,104 (PALPCC81,104), we were able to induce T cell hyporesponsiveness to the wild-type peptide in vitro. More importantly, administration of the PALPCC81,104 to mice reduced the responsiveness to the native peptide when tested ex vivo. Biochemical and functional experiments indicated that the action of N-palmitoylated peptides was due to the conversion of the native peptide into a weak agonist that could then induce T cell anergy. Our results demonstrate that N-palmitoylation of antigenic peptides is a feasible strategy to generate APL, as it avoids the need to screen multiple amino acid variants of each specific antigen to identify those with therapeutic properties. [source]

    Biochemical and functional characterization of the interaction between pentraxin 3 and C1q


    Abstract Pentraxin 3 (PTX3) is a recently characterized member of the pentraxin family of acute-phase proteins produced during inflammation. Classical short pentraxins, C-reactive protein, and serum amyloid P component can bind to C1q and thereby activate the classical complement pathway. Since PTX3 can also bind C1q, the present study was designed to define the interaction between PTX3 and C1q and to examine the functional consequences of this interaction. A dose-dependent binding of both C1q and the C1 complex to PTX3 was observed. Experiments with recombinant globular head domains of human C1q A, B, and C chains indicated that C1q interacts with PTX3 via its globular head region. Binding of C1q to immobilized PTX3 induced activation of the classical complement pathway as assessed by C4 deposition. Furthermore, PTX3 enhanced C1q binding and complement activation on apoptotic cells. However, in the fluid-phase, pre-incubation of PTX3 with C1q resulted in inhibition of complement activation by blocking the interaction of C1q with immunoglobulins. These results indicate that PTX3 can both inhibit and activate the classical complement pathway by binding C1q, depending on the way it is presented. PTX3 may therefore be involved in the regulation of the innate immune response. [source]

    Biochemical and electrophysiological changes of substantia nigra pars reticulata driven by subthalamic stimulation in patients with Parkinson's disease

    Salvatore Galati
    Abstract To understand the events underlying the clinical efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN), electrophysiological recordings and microdialysis evaluations were carried out in the substantia nigra pars reticulata (SNr), one of the two basal ganglia (BG) nuclei targeted by STN output, in patients with Parkinson's disease (PD). Clinically effective STN-DBS caused a significant increase of the SNr firing rate. The poststimulus histogram (PSTH) showed an excitation peak at 1.92,3.85 ms after the STN stimulus. The spontaneous discharge of SNr neurons was driven at the frequency of the stimulation (130 Hz), as shown in the autocorrelograms (AutoCrl). The fast Fourier transform (FFT) analysis showed a peak at 130 Hz, and a less pronounced second one at 260 Hz. Accordingly, in the distribution of the interspike intervals (ISIs), the mode was earlier, and skewness more asymmetric. Biochemically, the increased excitatory driving from the STN was reflected by a clear-cut increase in cyclic guanosine 3',5'-monophosphate (cGMP) levels in the SNr. These results indicate that the beneficial effect of DBS in PD patients is paralleled with a stimulus-synchronized activation of the STN target, SNr. Our findings suggest that, during STN-DBS, a critical change towards a high-frequency oscillatory discharge occurs. [source]

    Phase Reversion-Induced Nanograined/Ultrafine-Grained Structures in Austenitic Stainless Steel and their Significance in Modulating Cellular Response: Biochemical and Morphological Study with Fibroblasts,

    R. Devesh Kumar Misra
    Materials science, engineering, and biological sciences have been combined to improve the tissue compatibility of medical devices. In this regard, nano/ultrafine structuring of austenitic stainless steel obtained using an innovative approach of "phase-reversion" has been evaluated for modulation of cellular activity. The biochemical and morphology study with fibroblasts point toward the improvement of tissue compatibility on comparison with coarse-grained structures, strengthening the foundation of nanostructured materials for bio-medical applications. [source]

    Side chain specificity of ADP-ribosylation by a sirtuin

    FEBS JOURNAL, Issue 23 2009
    Kamau Fahie
    Endogenous mono-ADP-ribosylation in eukaryotes is involved in regulating protein synthesis, signal transduction, cytoskeletal integrity, and cell proliferation, although few cellular ADP-ribosyltransferases have been identified. The sirtuins constitute a highly conserved family of protein deacetylases, and several family members have also been reported to perform protein ADP-ribosylation. We characterized the ADP-ribosylation reaction of the nuclear sirtuin homolog Trypanosoma brucei SIR2-related protein 1 (TbSIR2RP1) on both acetylated and unacetylated substrates. We demonstrated that an acetylated substrate is not required for ADP-ribosylation to occur, indicating that the reaction performed by TbSIR2RP1 is a genuine enzymatic reaction and not a side reaction of deacetylation. Biochemical and MS data showed that arginine is the major ADP-ribose acceptor for unacetylated substrates, whereas arginine does not appear to be the major ADP-ribose acceptor in reactions with acetylated histone H1.1. We performed combined ab initio quantum mechanical/molecular mechanical molecular dynamics simulations, which indicated that sirtuin ADP-ribosylation at arginine is energetically feasible, and involves a concerted mechanism with a highly dissociative transition state. In comparison with the corresponding nicotinamide cleavage in the deacetylation reaction, the simulations suggest that sirtuin ADP-ribosylation would be several orders slower but less sensitive to nicotinamide inhibition, which is consistent with experimental results. These results suggest that TbSIR2RP1 can perform ADP-ribosylation using two distinct mechanisms, depending on whether or not the substrate is acetylated. Structured digital abstract ,,MINT-7288298: TbSIR2 (uniprotkb:O96670) adp ribosylates (MI:0557) histone H1.1 (uniprotkb:Q02539) by enzymatic studies (MI:0415) ,,MINT-7288305, MINT-7288325, MINT-7288338, MINT-7288352, MINT-7288370, MINT-7288395, MINT-7288412: TbSIR2 (uniprotkb:O96670) adp ribosylates (MI:0557) histone H1.1 (uniprotkb:P02253) by enzymatic studies (MI:0415) ,,MINT-7288385: TbSIR2 (uniprotkb:O96670) deacetylates (MI:0197) histone H1.1 (uniprotkb:Q02539) by deacetylase assay (MI:0406) ,,MINT-7288424: hADPRH (uniprotkb:P54922) cleaves (MI:0194) histone H1.1 (uniprotkb:Q02539) by enzymatic studies (MI:0415) [source]

    The myeloid leukemia factor interacts with COP9 signalosome subunit 3 in Drosophila melanogaster

    FEBS JOURNAL, Issue 3 2008
    Wakana Sugano
    The human myeloid leukemia factor 1 (hMLF1) gene was first identified as an NPM,hMLF1 fusion gene produced by chromosomal translocation. In Drosophila, dMLF has been identified as a protein homologous to hMLF1 and hMLF2, which interacts with various factors involved in transcriptional regulation. However, the precise cellular function of dMLF remains unclear. To generate further insights, we first examined the behavior of dMLF protein using an antibody specific to dMLF. Immunostaining analyses showed that dMLF localizes in the nucleus in early embryos and cultured cells. Ectopic expression of dMLF in the developing eye imaginal disc using eyeless-GAL4 driver resulted in a small-eye phenotype and co-expression of cyclin E rescued the small-eye phenotype, suggesting the involvement of dMLF in cell-cycle regulation. We therefore analyzed the molecular mechanism of interactions between dMLF and a dMLF-interacting protein, dCSN3, a subunit of the COP9 signalosome, which regulates multiple signaling and cell-cycle pathways. Biochemical and genetic analyses revealed that dMLF interacts with dCSN3 in vivo and glutathione S -transferase pull-down assays revealed that the PCI domain of the dCSN3 protein is sufficient for this to occur, possibly functioning as a structural scaffold for assembly of the COP9 signalosome complex. From these data we propose the possibility that dMLF plays a negative role in assembly of the COP9 signalosome complex. [source]

    Biochemical and spectroscopic characterization of the bacterial phytochrome of Pseudomonas aeruginosa

    FEBS JOURNAL, Issue 8 2005
    Ronja Tasler
    Phytochromes are photochromic biliproteins found in plants as well as in some cyanotrophic, photoautotrophic and heterotrophic bacteria. In many bacteria, their function is largely unknown. Here we describe the biochemical and spectroscopic characterization of recombinant bacterial phytochrome from the opportunistic pathogen Pseudomonas aeruginosa (PaBphP). The recombinant protein displays all the characteristic features of a bonafide phytochrome. In contrast with cyanobacteria and plants, the chromophore of this bacterial phytochrome is biliverdin IX,, which is produced by the heme oxygenase BphO in P. aeruginosa. This chromophore was shown to be covalently attached via its A-ring endo-vinyl group to a cysteine residue outside the defined bilin lyase domain of plant and cyanobacterial phytochromes. Site-directed mutagenesis identified Cys12 and His247 as being important for chromophore binding and photoreversibility, respectively. PaBphP is synthesized in the dark in the red-light-absorbing Pr form and immediately converted into a far-red-light-absorbing Pfr-enriched form. It shows the characteristic red/far-red-light-induced photoreversibility of phytochromes. A chromophore analog that lacks the C15/16 double bond was used to show that this photoreversibility is due to a 15Z/15E isomerization of the biliverdin chromophore. Autophosphorylation of PaBphP was demonstrated, confirming its role as a sensor kinase of a bacterial two-component signaling system. [source]

    Biochemical and molecular characterization of a laccase from the edible straw mushroom, Volvariella volvacea

    FEBS JOURNAL, Issue 2 2004
    Shicheng Chen
    We have isolated a laccase (lac1) from culture fluid of Volvariella volvacea, grown in a defined medium containing 150 m CuSO4, by ion-exchange and gel filtration chromatography. Lac1 has a molecular mass of 58 kDa as determined by SDS/PAGE and an isoelectric point of 3.7. Degenerate primers based on the N-terminal sequence of purified lac1 and a conserved copper-binding domain were used to generate cDNA fragments encoding a portion of the lac1 protein and RACE was used to obtain full-length cDNA clones. The cDNA of lac1 contained an ORF of 1557 bp encoding 519 amino acids. The amino acid sequence from Ala25 to Asp41 corresponded to the N-terminal sequence of the purified protein. The first 24 amino acids are presumed to be a signal peptide. The expression of lac1 is regulated at the transcription level by copper and various aromatic compounds. RT-PCR analysis of gene transcription in fungal mycelia grown on rice-straw revealed that, apart from during the early stages of substrate colonization, lac1 was expressed at every stage of the mushroom developmental cycle defined in this study, although the levels of transcription varied considerably depending upon the developmental phase. Transcription of lac1 increased sharply during the latter phase of substrate colonization and reached maximum levels during the very early stages (primordium formation, pinhead stage) of fruit body morphogenesis. Gene expression then declined to ,,20,30% of peak levels throughout the subsequent stages of sporophore development. [source]

    Crystal structure of a staphylokinase variant

    FEBS JOURNAL, Issue 2 2002
    A model for reduced antigenicity
    Staphylokinase (SAK) is a 15.5-kDa protein from Staphylococcus aureus that activates plasminogen by forming a 1 : 1 complex with plasmin. Recombinant SAK has been shown in clinical trials to induce fibrin-specific clot lysis in patients with acute myocardial infarction. However, SAK elicits high titers of neutralizing antibodies. Biochemical and protein engineering studies have demonstrated the feasibility of generating SAK variants with reduced antigenicity yet intact thrombolytic potency. Here, we present X-ray crystallographic evidence that the SAK(S41G) mutant may assume a dimeric structure. This dimer model, at 2.3- resolution, could explain a major antigenic epitope (residues A72,F76 and residues K135-K136) located in the vicinity of the dimer interface as identified by phage-display. These results suggest that SAK antigenicity may be reduced by eliminating dimer formation. We propose several potential mutation sites at the dimer interface that may further reduce the antigenicity of SAK. [source]

    Molecular mechanism of ubiquitin recognition by GGA3 GAT domain

    GENES TO CELLS, Issue 7 2005
    Masato Kawasaki
    GGA (Golgi-localizing, ,-adaptin ear domain homology, ARF-binding) proteins, which constitute a family of clathrin coat adaptor proteins, have recently been shown to be involved in the ubiquitin-dependent sorting of receptors, through the interaction between the C-terminal three-helix-bundle of the GAT (GGA and Tom1) domain (C-GAT) and ubiquitin. We report here the crystal structure of human GGA3 C-GAT in complex with ubiquitin. A hydrophobic patch on C-GAT helices ,1 and ,2 forms a binding site for the hydrophobic Ile44 surface of ubiquitin. Two distinct orientations of ubiquitin Arg42 determine the shape and the charge distribution of ubiquitin Ile44 surface, leading to two different binding modes. Biochemical and NMR data strongly suggest another hydrophobic binding site on C-GAT helices ,2 and ,3, opposite to the first binding site, also binds ubiquitin although weakly. The double-sided ubiquitin binding provides the GAT domain with higher efficiency in recognizing ubiquitinated receptors for lysosomal receptor degradation. [source]

    Biochemical and mutational analyses of the cathepsin c gene (CTSC) in three North American families with Papillon Lefvre syndrome

    HUMAN MUTATION, Issue 1 2002
    Y. Zhang
    Abstract Papillon Lefvre syndrome (PLS) is an autosomal recessive disorder characterized by palmoplantar hyperkeratosis and severe periodontitis. The disease is caused by mutations in the cathepsin C gene (CTSC) that maps to chromosome 11q14. CTSC gene mutations associated with PLS have been correlated with significantly decreased enzyme activity. Mutational analysis of the CTSC gene in three North American families segregating PLS identified four mutations, including a novel mutation p.G139R. All mutations were associated with dramatically reduced CTSC protease enzyme activity. A homozygous c.96T>G transversion resulting in a p.Y32X change was present in a Mexican PLS proband, while one Caucasian PLS proband was a compound heterozygote for the p.Y32X and p.R272P (c.815G>C) mutations. The other Caucasian PLS proband was a compound heterozygote for c.415G>A transition and c.1141delC mutations that resulted in a p.G139R and a frameshift and premature termination (p.L381fsX393), respectively. The c.415G>A was not present in more than 300 controls, suggesting it is not a CTSC polymorphism. Biochemical analysis demonstrated almost no detectable CTSC activity in leukocytes of all three probands. These mutations altered restriction enzyme sites in the highly conserved CTSC gene. Sequence analysis of CTSC exon 3 confirmed the previously reported p.T153I polymorphism in 4 of the 5 ethnically diverse populations studied. 2002 Wiley-Liss, Inc. [source]

    Human PARM-1 is a novel mucin-like, androgen-regulated gene exhibiting proliferative effects in prostate cancer cells

    Cathrine Fladeby
    Abstract In this paper we characterize hPARM-1, the human ortholog of rat PARM-1 (prostatic androgen-repressed message-1) and demonstrate its role in prostate cancer. Immunofluorescence microscopy and ultrastructural analysis revealed the localization of hPARM-1 to Golgi, plasma membrane and the early endocytic pathway but not in lysosomes. Biochemical and deglycosylation studies showed hPARM-1 as a highly glycosylated, mucin-like type I transmembrane protein. Analysis of expression of hPARM-1 in various human tissues revealed its presence in most human tissues with especially high expression in heart, kidney and placenta. Androgen controls the expression of the gene as a marked 7-fold increase is seen in the androgen-dependent prostate cancer cell line, LNCaP on androgen stimulation. This is further supported by its decrease in expression in CWR22 xenograft upon castration. Moreover, ectopic expression of hPARM-1 in PC3 prostate cancer cells increased colony formation, suggesting a probable role in cell proliferation. These results suggest that hPARM-1 may have a role in normal biology of the prostate cell and in prostate cancer. 2007 Wiley-Liss, Inc. [source]

    Cutaneous and neurologic manifestations of biotinidase deficiency

    Paloma Cornejo Navarro
    A male newborn with no obstetric or familial antecedents, except that his parents were cousins, developed hypotonia, lethargy, and feeding problems from birth. Analysis revealed a marked metabolic acidosis and hyperammonemia. Three weeks later, he was admitted to hospital in order to receive parenteral nutrition and to undertake a study for metabolic diseases. The boy did not improve in spite of the use of parenteral nutrition and began to present with inspiratory stridor and tachypnea. One week later, he presented with an erythematous scaling eruption, which was especially intense in the lumbosacral region ( Fig. 1a,b). The scalp was only slightly affected. Figure 1. Erythematous scaling eruption, more intense in the lumbosacral region Laboratory findings were compatible with biotinidase deficiency diagnosed by demonstrating absent enzyme activity. His parents were also studied and they were found to have partial biotinidase deficiency (30% of enzyme activity). After 37 days of life, the baby was given a treatment consisting of 20 mg of biotin per day intravenously. Biochemical and neurologic alterations improved quickly. Meckel's diverticulum and a duodenal membrane were detected at the second month of life after a gastroduodenal survey, and both were operated on. The skin lesions did not improve, however, and intravenous biotin had to be increased to 40 mg/day. The eruption disappeared after 10 days. On his first birthday, he remained asymptomatic with 40 mg of oral biotin. [source]

    DROUGHT STRESS: Role of Carbohydrate Metabolism in Drought-Induced Male Sterility in Rice Anthers,

    G. N. Nguyen
    Abstract Rice plants exposed to three consecutive days of water stress (,0.5 MPa) show a reduction in male fertility and grain set, which is attributed to increased levels of reactive oxygen species (ROS) and activation of a programmed cell death. This current research was conducted to further investigate the association of sugar metabolism with microspore abortion in rice anthers. Biochemical assays showed that sucrose, glucose and fructose contents were found to be significantly increased in anthers from water stressed plants compared with the control. qRT-PCR analyses and in situ hybridization of metabolic genes (sugar transporters, invertase and phosphotransferase/kinases) demonstrated that the supply of sugars for developing microspores and the initial steps of sugar utilization e.g. glycolysis, were not repressed. However, it appears that the accumulation of sugars in stressed anthers might involve a reduction of mitochondrial activity during the tricarboxylic acid cycle, which could result in excessive production of ROS and a depletion of the ATP pool. These results also suggest that higher levels of sugars at all stages of anther development seemed to be associated with some measure of protection to the anthers against oxidative stress. Induced expression of sugar transporter genes might have maintained the high levels of sugar in the tapetum and the locules, which alleviated oxidant damage caused by excessive ROS generation. Thus, the increased level of sugars might potentially be a natural response in providing protection against oxidant damage by strengthening the antioxidant system in anthers. [source]

    Biochemical and morphometric parameters as indicators of sex and gonadal stages in maturing Persian sturgeon, Acipenser persicus

    R. Malekzadeh Viayeh
    First page of article [source]

    Antimicrobial resistance profiling and DNA Amplification Fingerprinting (DAF) of thermophilic Campylobacter spp. in human, poultry and porcine samples from the Cork region of Ireland

    B. Lucey
    Antimicrobial resistance (R) typing and DNA Amplification Fingerprinting (DAF) of a random collection of 84 Irish thermophilic Campylobacter isolates is described. The collection included human, veterinary (porcine) and poultry isolates cultured between 1996 and 1998 in the Cork region of Ireland. Biochemical and molecular methods were used to identify Campylobacter jejuni and Camp. coli. Many of these isolates were simultaneously resistant to several common antimicrobial agents. In particular, resistance to ampicillin, spectinomycin, sulphafurazole and tetracycline was common. A total of 74 DAF profiles was identified among the study collection, showing a high degree of diversity. Dendrogram analysis of the DNA patterns identified three main clusters at the 50% similarity level, which included two clusters of Camp. coli and a third containing a mixture of Camp. jejuni and Camp. coli. [source]

    Biochemical and ultrastructural alterations in the rat ventral prostate due to repetitive alcohol drinking

    M. I. Daz Gmez
    Abstract Previous studies showed that cytosolic and microsomal fractions from rat ventral prostate are able to biotransform ethanol to acetaldehyde and 1-hydroxyethyl radicals via xanthine oxidase and a non P450 dependent pathway respectively. Sprague Dawley male rats were fed with a Lieber and De Carli diet containing ethanol for 28 days and compared against adequately pair-fed controls. Prostate microsomal fractions were found to exhibit CYP2E1-mediated hydroxylase activity significantly lower than in the liver and it was induced by repetitive ethanol drinking. Ethanol drinking led to an increased susceptibility of prostatic lipids to oxidation, as detected by t-butylhydroperoxide-promoted chemiluminiscence emission and increased levels of lipid hydroperoxides (xylenol orange method). Ultrastructural alterations in the epithelial cells were observed. They consisted of marked condensation of chromatin around the perinuclear membrane, moderate dilatation of the endoplasmic reticulum and an increased number of epithelial cells undergoing apoptosis. The prostatic alcohol dehydrogenase activity of the stock rats was 4.84 times lower than that in the liver and aldehyde dehydrogenase activity in their microsomal, cytosolic and mitochondrial fractions was either not detectable or significantly less intense than in the liver. A single dose of ethanol led to significant acetaldehyde accumulation in the prostate. The results suggest that acetaldehyde accumulation in prostate tissue might result from both acetaldehyde produced in situ but also because of its low aldehyde dehydrogenase activity and its poor ability to metabolize acetaldehyde arriving via the blood. Acetaldehyde, 1-hydroxyethyl radical and the oxidative stress produced may lead to epithelial cell injury. Copyright 2007 John Wiley & Sons, Ltd. [source]

    Effect of oral administration of arabic gum on cisplatin-induced nephrotoxicity in rats

    Abdulhakeem A. Al-Majed
    Abstract It has been recently postulated from our laboratory that Arabic gum (AG) offers a protective effect in the kidney of rats against nephrotoxicity induced by gentamicin via inhibiting lipid peroxidation. It has also recently shown a powerful antioxidant effect through scavenging superoxide anions. In this study we utilized a rat model of cisplatin (CP)-induced nephrotoxicity to determine its peak time following (1, 2, 5, and 7 days) of a single CP (7.5 mg/kg, i.p.) injection. Also, a possible protective effect of cotreatment with AG (7.5 g/kg/day p.o.) on CP-induced nephrotoxicity was investigated. Biochemical as well as histological assessments were carried out. CP-induced nephrotoxicity was manifested by significant elevations of the functional parameters blood urea, serum creatinine, and kidney/body weight ratio. Maximum toxic effects of CP were observed 5 days after its injection, while it started after day 1 in the biochemical parameters, such as glutathione depletion in the kidney tissue with concomitant increases in lipid peroxides and platinum content. Additionally, severe necrosis and desquamation of tubular epithelial cells in renal cortex as well as interstitial nephritis were observed after 5 days in CP-treated animals. Five days after AG cotreatment with CP did not protect the kidney from the damaging effects of CP. However, it significantly reduced CP-induced lipid peroxidation. These findings suggest that lipid peroxidation is not the main cause of CP-induced nephrotoxicity but it is rather more dependent on other factors such as platinum disposition in renal interstitial tubules. 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:146,153, 2003; Published online in Wiley InterScience ( DOI 10.1002/jbt.10072 [source]

    Systemic Regulation of Distraction Osteogenesis: A Cascade of Biochemical Factors,,

    S. Weiss M.D.
    Abstract This study investigates the systemic biochemical regulation of fracture healing in distraction osteogenesis compared with rigid osteotomy in a prospective in vivo study in humans. To further clarify the influence of mechanical strain on the regulation of bone formation, bone growth factors (insulin-like growth factor [IGF] I, IGF binding protein [IGFBP] 3, transforming growth factor [TGF] ,1, and basic FGF [bFGF]), bone matrix degrading enzymes (matrix-metalloproteinases [MMPs] 1, 2, and 3), human growth hormone (hGH), and bone formation markers (ALP, bone-specific ALP [BAP], and osteocalcin [OC]) have been analyzed in serum samples from 10 patients in each group pre- and postoperatively. In the distraction group, a significant postoperative increase in MMP-1, bFGF, ALP, and BAP could be observed during the lengthening and the consolidation period when compared with the baseline levels. Osteotomy fracture healing without the traction stimulus failed to induce a corresponding increase in these factors. In addition, comparison of both groups revealed a significantly higher increase in TGF-,1, IGF-I, IGFBP-3, and hGH in the lengthening group during the distraction period, indicating key regulatory functions in mechanotransduction. The time courses of changes in MMP-1, bone growth factors (TGF-,1 and bFGF), and hGH, respectively, correlated significantly during the lengthening phase, indicating common regulatory pathways for these factors in distraction osteogenesis. Significant correlation between the osteoblastic marker BAP, TGF-,1, and bFGF suggests strain-activated osteoblastic cells as a major source of systemically increased bone growth factors during callus distraction. The systemic increase in bFGF and MMP-1 might reflect an increased local stimulation of angiogenesis during distraction osteogenesis. [source]

    Effects of a New Selective Estrogen Receptor Modulator (MDL 103,323) on Cancellous and Cortical Bone in Ovariectomized Ewes: A Biochemical, Histomorphometric, and Densitometric Study

    Pascale Chavassieux
    Abstract The aims of this study performed in ewes were: (1) to confirm in this animal model the effects on bone of ovariectomy (OVX) alone or associated with Lentaron (L), a potent peripheral aromatase inhibitor, used to amplify the effects of OVX and (2) to evaluate the effects of a new selective estrogen receptor modulator (SERM; MDL 103,323) on bone remodeling. Thirty-nine old ewes were divided into five groups: sham (n = 7); OVX (n = 8); OVX + L (n = 8); OVX + L + MDL; 0.1 mg/kg per day (n = 8); and OVX + L + MDL 1 mg/kg per day (n = 8). The animals were treated for 6 months. Biochemical markers of bone turnover (urinary excretion of type 1 collagen C-telopeptide [CTX], serum osteocalcin [OC], and bone alkaline phosphatase [BAP]) were measured each month. Bone biopsy specimens were taken at the beginning and after death at the end of the experiment. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) on the lumbar spine and femur. OVX induced a significant increase in biochemical markers. This effect was the highest after 3 months for CTX (+156% vs. sham) and after 4 months for OC and BAP (+74% and +53% vs. sham, respectively). L tended to amplify the effect of OVX on OC and BAP. OVX induced significant increases in the porosity, eroded, and osteoid surfaces in cortical bone but no effect was observed in cancellous bone. MDL treatment reduced the bone turnover as assessed by bone markers, which returned to sham levels as well as histomorphometry both in cortical and in cancellous bone. Cancellous osteoid thickness decreased by 27% (p < 0.05), mineralizing perimeter by 81% (p < 0.05), and activation frequency by 84% (p < 0.02) versus OVX + L. Femoral and spinal BMD were increased by MDL and tended to return to the sham values. The effects of OVX on bone turnover were different on cortical and cancellous bone. These effects on cortical bone were reflected by changes in biochemical markers. MDL markedly reduces bone turnover and increases BMD suggesting that this new agent may prevent postmenopausal bone loss. [source]

    Biochemical, histological and behavioural aspects of visual function during early development of rainbow trout

    P. S. M. Carvalho
    Retinal structure and concentration of retinoids involved in phototransduction changed during early development of rainbow trout Oncorhynchus mykiss, correlating with improvements in visual function. A test chamber was used to evaluate the presence of optokinetic or optomotor responses and to assess the functionality of the integrated cellular, physiological and biochemical components of the visual system. The results indicated that in rainbow trout optomotor responses start at 10 days post-hatch, and demonstrated for the first time that increases in acuity, sensitivity to low light as well as in motion detection abilities occur from this stage until exogenous feeding starts. The structure of retinal cells such as cone ellipsoids increased in length as photopic visual acuity improved, and rod densities increased concurrently with improvements in scotopic thresholds (22 log10 units). An increase in the concentrations of the chromophore all-trans-retinal correlated with improvements of all behavioural measures of visual function during the same developmental phase. [source]

    Phenotypic, serological and genetic characterization of Flavobacterium psychrophilum strains isolated from salmonids in Chile

    S Valdebenito
    Abstract Characterization of 20 Flavobacterium psychrophilum strains isolated from farmed Atlantic salmon and rainbow trout in Chile was done using phenotypic, antigenic and genetic techniques. Experimental infections were also performed to assess the virulence of two representative isolates and of the type strain. Biochemical and physiological analyses showed that Chilean F. psychrophilum strains, regardless of the host species, constitute a phenotypically very homogeneous group matching with previous descriptions of this pathogen. However, serological assays indicated the existence of antigenic heterogeneity with four patterns of serological reactions. The first group contained most (14 of 20) of the F. psychrophilum isolates showing cross-reaction with the antisera obtained against Atlantic salmon and rainbow trout isolates. Group 2 corresponded to four other rainbow trout isolates (1658, 1731, 1762 and 29009) that did not agglutinate with anti-1150 serum. Two minor serological groups were identified for the remaining isolates (Groups 3 and 4). Marked homogeneity was also revealed by genetic studies including 16S rRNA alleles, random amplified polymorphic DNA and REP-PCR showing that a major genetic group of F. psychrophilum may be dominant in disease outbreaks in farms. Restriction fragment length polymorphism of PCR analysis showed that gyrase genotypes B-S or B-R were found in Chilean isolates from rainbow trout and Atlantic salmon, whereas genotype A was not found. Virulence assays using Atlantic salmon indicated no relationship between the degree of pathogenicity and the host origin of the F. psychrophilum strains. [source]

    Phenotypic, serological and genetic characterization of Pseudomonas anguilliseptica strains isolated from cod, Gadus morhua L., in northern Europe

    S Balboa
    Abstract The biochemical, serological and genetic characteristics of six strains of Pseudomonas anguilliseptica isolated from cod, Gadus morhua, in Scotland were compared to well characterized isolates of this same bacterial species but of different origin. Biochemical and physiological analyses showed that this group of isolates was highly homogeneous, their characteristics matching previous descriptions of the pathogen. Similar results were obtained for the six cod isolates in the serological assays, all of them belonging to the serotype O1. Marked homogeneity was observed also in the genetic study, analysed by means of RAPD, ERIC-PCR and REP-PCR procedures, showing that they were similar to isolates from gilthead seabream, Sparus aurata, black spot seabream, Pagellus bogaraveo, and turbot, Psetta maxima. Virulence assays demonstrated that the cod isolates were highly pathogenic for turbot and sole, Solea senegalensis, with LD50 between 7.6 104 and 5 107 bacterial cells per fish. [source]

    Sanitation Procedure Affects Biochemical and Nutritional Changes of Shredded Carrots

    Sal Ruiz-Cruz
    ABSTRACT:, Fresh-cut vegetables are considered convenient but with less nutritional quality compared to raw natural produce. Carrots are highly appreciated because of their carotene and antioxidant nutrients, but processing requires an appropriate sanitation procedure that ensures microbiological safety to consumers. The effect of the sanitation processing on the nutritional composition of shredded carrots was studied. Treatments tested were tap water, 200 ppm sodium hypochlorite (Cl), 40 ppm peroxyacetic acid (PA), and 100, 250, and 500 ppm acidified sodium chlorite (ASC). Measured parameters were oxygen radical absorbing capacity (ORAC), total phenolics and carotenoids, sugars, and phenylalanine ammonia lyase (PAL) and peroxidase (POD) activity. Shredded carrots sanitized with ASC retained higher levels of sugars, carotene, and antioxidant capacity. ASC also delayed the PAL and POD activity. These results show the importance of evaluating nutritional parameters during processing stages, since minimal processing does not necessarily imply loss of nutritional value. Furthermore, the availability of fresh-cut produce may increase the intake of nutrients, with a positive effect on health. [source]

    Biochemical and Conformation Changes of Actomyosin from Threadfin Bream Stored in Ice

    J. Yongswawatdigul
    ABSTRACT: Biochemical and conformational changes of actomyosin stored in ice were investigated. The K-value of threadfin bream increased from 9% to 40% after storage for 12 d. Ca2+ -, EDTA-, Mg2+ -, and Mg2+ -Ca2+ -ATPase activities of actomyosin decreased, whereas Mg2+ -EGTA ATPase activities increased. Total SH content of actomyosin increased after 3 d and decreased thereafter. Surface hydrophobicity gradually increased within 6 d. Protein loss during washing increased with storage time. A significant reduction (50%) of breaking force of thrice-washed mince was observed in fish stored in ice for 6 d. There was no evidence of proteolysis of muscle proteins stored up to 9 d as shown with SDS-PAGE. [source]

    Effect of losartan on early liver fibrosis development in a rat model of nonalcoholic steatohepatitis

    Patricio Ibaez
    Abstract Background and Aim:, Nonalcoholic steatohepatitis (NASH) is a metabolic disorder of the liver that may evolve into fibrosis or cirrhosis. Recent studies have shown reduction of experimental liver fibrosis with the use of angiotensin-converting-enzyme inhibitors or angiotensin-receptor antagonists. The aim of this study was to determine whether losartan can influence the early phase of fibrogenesis in an animal model of NASH. Methods:, To induce NASH, a choline-deficient diet (CDD) was given to Sprague-Dawley rats for 12 weeks. These animals were then compared with a control group receiving choline-supplemented diet (CSD) and a group fed a CDD plus losartan (10 mg/kg/day). Biochemical (serum levels of alanine aminotransferase and aspartate aminotransferase) and histological evaluation of fatty liver was performed by conventional techniques. Hydroxyproline content in liver tissue was assayed by spectrophotometry. In addition, mRNA levels of procollagen I and transforming growth factor (TGF)-, were assessed by semiquantitative RT-PCR and stellate cell activation by ,-actin immunofluorescence stain. Results:, After 12 weeks CDD induced a marked elevation of serum aminotranferases, a severe fatty liver infiltration with mild histological inflammation and fibrosis. These findings correlated with a significant increase in mRNA levels of both procollagen I and TGF-, and significant increased liver hydroxyproline content. No differences were seen between rats receiving CDD alone and rats receiving CDD plus losartan with regard to the biochemical, morphological or molecular alterations induced by the CDD. Conclusion:, Losartan does not seem to influence liver injury and fibrogenic events in the CDD model of NASH. [source]

    Biochemical and white blood cell profiles of baboon neonates consuming formulas with moderate and high dietary long-chain polyunsaturated fatty acids

    A.T. Hsieh
    Abstract Background, Clinical chemistry and complete blood count (CBC) values were determined in 14 term baboons (Papio species) consuming formula with moderate or high levels of dietary long-chain polyunsaturated fatty acids (LCPUFA) from 2,12 weeks of age. Method, Neonates were randomized to three groups: C: Control, no LCPUFA; L: 0.33% docosahexaenoic acid (DHA)/0.67% arachidonic acid (ARA) (w/w); L3:1.00% DHA/0.67% ARA (w/w). Blood chemistries were assessed at 6 and 12 weeks and CBC parameters were measured at 2, 4, 8, 10, 12 weeks of age. Results, Dietary LCPUFA had significant effects on serum triglyceride (C > L,L3) and calcium (L > C,L3). No other significant effects of diet were detected; pooled values are presented for all other parameters. Conclusion, These data provide longitudinal biochemical and white cell/platelet/immunological data on LCPUFA-fed baboons over the first 12 weeks of life. Data ranges are similar to reference data in cases for which values exist and hematological changes reflect trends observed during human neonatal development. [source]