Amyloidosis in pigtailed macaques (Macaca nemestrina): epidemiologic aspects

A retrospective study of amyloidosis in pigtailed macaques (Macaca nemestrina) at the Washington Regional Primate Research Center (WRPRC) was conducted. Between 1971 and 1985, 248 of 1,952 (13%) necropsies revealed amyloidosis in pigtailed macaques. The influence of demographic factors, diseases and experimental interventions on amyloidosis was examined. Univariate analyses, using two controls for each case, indicated that age, sex, birthplace and residence were related to amyloidosis. After adjusting for age, females were not at greater risk. However, monkeys born at the WRPRC were at greater risk and monkeys 0 to 5 years old residing at the breeding colony were at greater risk than monkeys at the research center. After adjustment for age, monkeys were at greater risk of developing amyloidosis if they had a history of episodes of diarrhea, respiratory disease or trauma. As the number of episodes increased, the risk increased. Monkeys with retroperitoneal fibromatosis, a manifestation of simian D retrovirus infection, were also at greater risk. Using logistic regression and controlling for age, sex, birthplace and residence, monkeys with diarrhea remained at an elevated risk for amyloidosis. Compared with a model combining diarrhea, respiratory disease, septicemia, surgery, trauma and retroperitoneal fibromatosis, a model with diarrhea alone accounted for most of the increased risk.     

Variability of entrainment of cohesive sediments in freshwater

Estimates of sediment entrainment are required for models of particle transport in lakes and estuaries but are difficult to make because of the multiplicity of factors affecting cohesiveness of surficial sediments. We present results of sediment resuspension studies performed in an annular flume calibrated with laser-Doppler velocimetry. In our experiments, using sediments collected from two sites in the R. Raisin which flows into L. Erie and from one site in the western basin of L. Erie near the mouth of the R. Raisin, we applied shear stresses at the sediment-water interface in steps from 2 to 12 dyne/cm². Percent water content at the surface of the sediments was either 77 or 74%, and trials were run with and without oxygenating the water overlying the sediments. Entrainment rates as a function of shear stress at the sediment-water interface were best described by a power-law relationship. All but 14% of the variability in the power law expression was due to shear stress and percent water content; the variability not accounted for was due to differences in particle size distributions, chemical properties, and biological activity in the sediments.     

Video microscopic analysis of ionophore induced acrosome reactions of lobster (Homarus americanus) sperm

Sperm from the American lobster (Homarus americanus) are normally nonmotile. However, during fertilization, the sperm undergo a calcium-dependent acrosome reaction that propels them forward about 18 μMm. The reaction occurs in two phases, eversion and ejection, which take place too quickly to permit analysis by direct observation. The purposes of this study were to examine the structural changes occurring in sperm during the normal acrosome reaction and to determine the rate of the reaction using video microscopy. The reaction was induced in vitro by ionophore A23187 and recorded using a video system attached to a Nikon Nomarski interference microscope. Videotapes were played back frame by frame (30 frames/sec), and images of reactions from 10 sperm were analyzed. The acrosome reaction, including the eversion of the acrosomal vesicle and ejection of the subacrosomal material and nucleus, can be divided into 4 steps: (1) expansion of the apical cap followed by expansion of the remainder of the acrosomal cylinder; expansion of the cylinder begins at its apical end and proceeds toward its base, (2) eversion of the apical half of the acrosomal vesicle and initial contraction of the apical cap, (3) eversion of the basal half of the acrosomal vesicle, continued contraction of the apical cap, and ejection of the subacrosomal material and nucleus, and (4) final contraction of the apical cap and ejection of the acrosomal filament. During steps 2, 3, and 4, the mean forward movement of sperm is 12.7, 3.9, and 1.1 μMm, respectively. Although the time required to complete the reaction ranged from 0.66 to 5.16 s, most sperm reacted in less than 3. s, and these sperm were considered to have typical rates. For sperm that reacted in less than 3 s, both step 1 and step 4 take about 0.2 s and show little variation among sperm. the time required to complete steps 2 and 3 averaged 0.63 and 0.37 s, respectively. Forward movement of the sperm during the acrosome reaction is caused by eversion of the inner and outer acrosomal material and contraction of the apical cap. The protein(s) responsible for this contraction is not yet known. © 1993 Wiley-Liss, Inc.     

Dissociation of polysome aggregates by protease k

Apparent large size-classes of zein-synthesizing polysomes from developing kernels of Zea mays L. were converted to smaller polysomes after treatment with Protease K. The reduction in polysome size was not a result of ribonuclease activity, inasmuch as the enzyme did not affect the free polysomes or the size of the mRNA from the membrane-bound polysomes. High concentrations of MgCl(2) in polysome buffer inhibited ribonuclease activity and appeared to cause protein interaction between nascent zein polypeptides. Although Protease K inhibited the polysome's capacity for protein synthesis, it was a useful reagent for determining if polysomes were aggregated by protein.     

Multifunctionality of lipoamide dehydrogenase: Role of histidine residues in reductase reaction

Rose bengal sensitizes photoinactivation of lipoamide dehydrogenase from pig heart to a constant residual reductase activity resulting from specific destruction of histidine residues. The rate of sensitized photoinactivation is pH dependent and is associated with an ionizable group with pK 6.6 ± 0.2. All steady-state kinetic parameters are markedly reduced by photooxidation. Spectroscopic studies indicate the contribution of oxidized flavin/dithiol to the half-reduced form of the photooxidized enzyme. The proton magnetic resonance spectrum of lipoamide dehydrogenase shows resolved histidine C₂ proton peak at δ9.18 ppm and a shoulder at δ9.23 ppm. The shoulder protons are eliminated by the sensitized photooxidation and shifted upfield on deprotonation. At high pH, the characteristic Faraday A term also disappears. These observations suggest that the essential histidine stabilizes the nascent thiolate via the ion pair formation to facilitate the reductase reaction catalyzed by lipoamide dehydrogenase.     

Effects of Luteolin on Human Breast Cancer Using Gene Expression Array: Inferring Novel Genes

Taraxacum officinale (dandelion) is often used in traditional Chinese medicine for the treatment of cancer; however, the downstream regulatory genes and signaling pathways mediating its effects on breast cancer remain unclear. The present study aimed to explore the effects of luteolin, the main biologically active compound of T. officinale, on gene expression profiles in MDA-MB-231 and MCF-7 breast cancer cells. The results revealed that luteolin effectively inhibited the proliferation and motility of the MDA-MB-231 and MCF-7 cells. The mRNA expression profiles were determined using gene expression array analysis and analyzed using a bioinformatics approach. A total of 41 differentially expressed genes (DEGs) were found in the luteolin-treated MDA-MB-231 and MCF-7 cells. A Gene Ontology analysis revealed that the DEGs, including AP2B1, APP, GPNMB and DLST, mainly functioned as oncogenes. The human protein atlas database also found that AP2B1, APP, GPNMB and DLST were highly expressed in breast cancer and that AP2B1 (cut-off value, 75%) was significantly associated with survival rate (p = 0.044). In addition, a Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the DEGs were involved in T-cell leukemia virus 1 infection and differentiation. On the whole, the findings of the present study provide a scientific basis that may be used to evaluate the potential benefits of luteolin in human breast cancer. Further studies are required, however, to fully elucidate the role of the related molecular pathways.     

Identification of Coffee Genes Expressed During Systemic Acquired Resistance and Incompatible Interaction with Hemileia vastatrix

Coffee genes associated with systemic acquired resistance (SAR) and incompatible reaction against coffee leaf rust inoculation were identified by suppression subtractive hybridization. Analysis of 384 clones of each of the subtracted cDNA libraries identified genes involved in oxidative burst/apoptosis/hypersensitive response, synthesis of antimicrobial proteins, synthesis and transport of antimicrobial metabolites, signal perception and transduction, metabolism of lipids, regulated protein degradation and cell maintenance and development. Induction of distinct sets of genes in the two resistance responses was observed. A wide range of genes involved in defence responses described in other plant species was also found in coffee plants. Semi-quantitative and quantitative RT-PCR analysis of seven selected genes showed differences in their expression profile within 72 h after treatment. Full-length cDNA sequences of two β-1,3-glucanases, one induced during SAR and the other in the incompatible reaction, were obtained by 5' and 3' RACE and the sequence data suggest different properties and cellular localization of the encoded proteins.     

Differential expression during development of ADP-ribosylation factors, 20-kDa guanine nucleotide-binding protein activators of cholera toxin

Cholera toxin exerts its effects on cells in large part through the ADP-ribosylation of guanine nucleotide-binding proteins. Toxin-catalyzed ADP-ribosylation is enhanced by approximately 20-kDa guanine nucleotide-binding proteins termed ADP-ribosylation factors (ARFs), which are allosteric activators of the toxin catalytic unit. Rabbit antiserum against a purified bovine brain ARF (sARF II) reacted on immunoblots with two approximately 20-kDa ARF-like proteins (sARF I and II) in tissue extracts from bovine, rat, frog, and chicken. Levels of ARF were higher in brain than in non-neural tissues. In rat brain, on the second postnatal day, amounts of sARF I and II were similar. By the 10th postnatal day and thereafter, sARF II predominated. Relative levels of ARF determined by immunoreactivity were in agreement with levels assessed in functional assays of cholera toxin-catalyzed ADP-ribosylation. Based on nucleotide and deduced amino acid sequences of human and bovine cDNAs, there appear to be at least six different ARF-like genes. Northern blots of rat brain poly(A)+ RNA were hybridized with cDNA and oligonucleotide probes specific for each of the human and bovine ARF genes. From the second to the 27th postnatal day, ARF 3 mRNA increased, whereas mRNAs for ARFs 2 and 4 decreased; and those for ARFs 1, 5, and 6 were apparently unchanged. Partial amino acid sequence of sARF II is consistent with it being either the ARF 1 or 3 gene product. The developmental changes in rat brain ARF parallel neuronal maturation and synapse formation.     

Production of somatic embryos and shoots from sugarbeet callus: Effects of abscisic acid, other growth regulators, nitrogen source, sucrose concentration and genotype

Summary Two sugarbeet (Beta vulgaris L.) genotypes, REL-1 and REL-2, were used to measure the level of somatic embryo and shoot production from hormone-autonomous callus plated under varied nutrient medium combinations of abscisic acid with the growth regulators 6-benzyladenine, 1-naphthaleneacetic acid, or 2,4-dichlorophenoxyacetic acid, with eight sole nitrogen sources, or with different sucrose concentrations. Clone REL-2 produced embryos up to 35-fold more frequently than clone REL-1. Inclusion of abscisic acid at some concentrations consistently improved embryo production in all experiments and was observed to stimulate shoot production. At some concentrations, 1-naphthaleneacetic acid as well as urea and glutamine stimulated greater embryo production over the control, but only for REL-1, for which there was greater room for improvement. Three and five percent sucrose were superior to 1, 7, and 9%. Higher initial 6-benzyladenine concentration [in the range 0, 0.1−1.0 mg/L (0.44−4.44 μM)] was associated with lower embryo production but greater shoot regeneration for both clones. REL-2 was significantly better than REL-1 in shoot regeneration. The range of embryo production was more than 35-fold between genotypes, whereas the range of physiological effects was no greater than 10-fold. REL-2 has been released to sugarbeet researchers because of its superior embryogenic and shoot regeneration abilities for application in biotechnology.     

Evodiamine inhibits in vitro angiogenesis: Implication for antitumorgenicity

Evodiamine, the major bioactive compound isolated from Chinese herbal drug named Wu-Chu-Yu, has been reported to exhibit anti-tumor growth and metastasis. However, the effect of evodiamine on angiogenesis remains to be investigated. We used the fresh medium containing evodiamine or human lung adenocarcinoma cell (CL1 cells) derived conditioned media free of evodiamine to test their capability to induce in vitro angiogenesis, i.e., human umbilical vein endothelial cells (HUVECs) tube formation and invasion. We demonstrated that evodiamine could directly inhibit in vitro HUVECs tube formation and invasion. Locally administered evodiamine also inhibited the in vivo angiogenesis in the chick embryo chorioallantoic membrane (CAM) assay. The gene expression of vascular endothelial growth factor (VEGF) and the p44/p42 mitogen-activated protein kinase (MAPK, ERK) that correlated with endothelial cells angiogenesis were inhibited by evodiamine. We found that the evodiamine-treated CL1 cells derived conditioned medium showed decreased VEGF release and reduced ability of inducing in vitro tube formation. After the collection of conditioned media, the VEGF expression of remaining CL1 cells were determined by Western analyses and revealed that evodiamine decreased VEGF expression. Moreover, administration of recombinant human VEGF(165) (rhVEGF(165)) induced tube formation and ERK phosphorylation by HUVECs, and partially attenuated inhibitory effect of evodiamine. From these results, we suggested that evodiamine is a potent inhibitor of angiogenesis. The mechanism might involve at least the inhibition of VEGF expression, probably through repression of ERK phosphorylation.