Polyamine modification in human breast tumors after short treatment with tamoxifen

The authors measured estrogen receptors, and polyamine (putrescine, spermidine and spermine) in breast tumors from patients (n = 23) who had received tamoxifen for a few days (5-10) before surgery. Women undergoing mastectomy without any preoperatory treatment were selected as the control group (n = 44). As already reported about in vitro experiments, the treatment resulted in a significant lowering of the spermidine to spermine ratio. Such a modification was larger in the ER positive tumors then in the ER negative ones and it seems to be related to the regression process of the drug-responsive tumors. On the basis of the experimental data the authors suggest the development of a in vivo tamoxifen-sensitivity test.     

Alkaline phosphatases and steroid receptors in human breast cancer

Estrogen receptors (ER), progesterone receptors (PR) and alkaline phosphatases (AP) were measured in 150 tumors from patients who underwent mastectomy for primary breast cancer. The percentage of ER positive samples was inversely related to the AP activity ranging from 88.9% in low activity samples (less than 30 U/mg prot.) down to 30.6% in the high activity ones (greater than 400 U/mg prot.). When considering only ER positive samples, the ER content was inversely related to the AP activity. This could not be demonstrated for PR. Therefore, the authors suggest the hypothesis that in human breast cancer, the AP may play a role in the dephosphorylation of the ER molecule and in the consequent modulation of its binding capability.     

Effect of lead on the reaction of O-demethylase in p-nitro anisole in the cladoceran Moina macrocopa

The presence of the Mixed-Function Oxydase (MFO) system, in Moina macrocopa was detected through the transformation of p-nitroanisole to para-nitrophenol. The presence of this enzymatic system suggested that this cladoceran participates in the biotransformation of xenobiotics in aquatic ecosystems. This capacity, in conjunction with the aquatic flea's high tolerance to environmental stress, suggested that M. macrocopa could be used in bioremediation efforts to increase ecosystem health. The effects of lead on the MFO system in M. macrocopa, were also studied. Lead acted as an inhibitor of the enzymatic complex. Therefore, induction of MFO-activity as an early warning may not work in waterbodies affected by both inducers of MFO and inhibitors like lead.     

Variation in heat shock proteins within tropical and desert species of poeciliid fishes

The 70-kilodalton heat shock protein (hsp70) family of molecular chaperones, which contains both stress-inducible and normally abundant constitutive members, is highly conserved across distantly related taxa. Analysis of this protein family in individuals from an outbred population of tropical topminnows, Poeciliopsis gracilis, showed that while constitutive hsp70 family members showed no variation in protein isoforms, inducibly synthesized hsp70 was polymorphic. Several species of Poeciliopsis adapted to desert environments exhibited lower levels of inducible hsp70 polymorphism than the tropical species, but constitutive forms were identical to those in P. gracilis, as they were in the confamilial species Gambusia affinis. These differences suggest that inducible and constitutive members of this family are under different evolutionary constraints and may indicate differences in their function within the cell. Also, northern desert species of Poeciliopsis synthesize a subset of the inducible hsp70 isoforms seen in tropical species. This distribution supports the theory that ancestral tropical fish migrated northward and colonized desert streams; the subsequent decrease in variation of inducible hsp70 may have been due to genetic drift or a consequence of adaptation to the desert environment. Higher levels of variability were found when the 30- kilodalton heat shock protein (hsp30) family was analyzed within different strains of two desert species of Poeciliopsis and also in wild-caught individuals of Gambusia affinis. In both cases the distribution of hsp30 isoform diversity was similar to that seen previously with allozyme polymorphisms.      

Comparative value of four arcelin variants in the development of dry bean lines resistant to the Mexican bean weevil

Wild Phaseolus vulgaris L. accessions containing arcelin codominant alleles 1 through 5 were reconfirmed and characterized for resistance to the Mexican bean weevil, Zabrotes subfasciatus (Boheman) (Coleoptera: Bruchidae). Accession G 02771 (arcelin 5) had the highest level of antibiosis resistance, followed by G 12952 (arcelin 4), G 12882 (arcelin 1) and G 12866 (arcelin 2). Arcelin 3 accessions conferred the lowest levels of resistance. As the presence of arcelin is inherited as a single dominant gene, a backcross breeding program has been used to transfer resistance to the Mexican bean weevil from wild beans to bean cultivars using serological techniques to detect the presence of arcelin and replicated insect feeding tests to measure resistance levels. Progeny containing arcelin 1 showed resistance equal or superior to that of the resistant check. Arcelin 2-deerived lines had intermediate levels of resistance while no resistant progenies were obtained from crosses with arcelin 3 and 4 sources. Results are discussed in relation to the deployment of arcelin alleles in bean cultivars.

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Valeurs comparées de 5 types d'arcéline dans l'obtention de lignées de Phaseolus vulgaris résistantes à Zabrotes subfasciatus

Résumé La résistance à Zabrotes subfasciatus est associée à la présence d'arcéline, une nouvelle protéine des graines, découverte chez quelques populations de Phaseolus vulgaris. 5 types d'arcéline, hérités comme allèles codominants ont été décrits dans la littérature. Nous avons reprécisé les différentes populations contenant différents types d'arcéline et caractérisé leurs résistances à Z. subfasciatus. La population G 02771, correspondant à l'arcéline 5, présente la résistance la plus élevée par antibiose, suivie de G 12952 (arcéline 4), G 12882 (arcéline 1) et G 12866 (arcéline 2). Les populations contenant l'arcéline 3 présentent le moins de résistance à Z. subfasciatus.Un programme de croisements en retour associé à des tests sérologiques pour déceler la présence d'arcéline chez les descendants jeunes et des expériences répétées d'alimentation par les insectes vec BC2F₃ a été réalisé pour transférer la résistance de populations naturelles à des cultivars de haricots. Les lignées, provenant de croisements avec des populations sauvages avec de l'arcéline 1, ont été fortement résistantes à Z. subfasciatus. Les lignées contenant de l'arcéline 2 ont été considérées comme ayant une résistance intermédiaire. Les lignées avec arcélines 3 et 4 étaient sensibles. Les raisons de l'échec du transfert de la résistance élevée des parents contenant de l'arcéline 4, sont inconnues. On a constaté que la concentration de l'arcéline dans les lignées contenant cet allèle était très faible, tandis que la concentration en arcéline 1 restait remarquablement élevée. Les recherches sont poursuivies pour déterminer les raisons de l'absence de transfert de l'arcéline 4 chez les descendants contenant cet allèle. Quoi qu'il en soit, les caractéristiques agronomiques et les qualités des lignées résistantes (codées RAZ) ont été évaluées en vue d'une diffusion pour les programmes nationaux de recherche des pays de basses altitudes intertropicaux ou Zabrotes subfasciatus fait des dégâts importants.

     

Control of cell volume in the J774 macrophage by microtubule disassembly and cyclic AMP

We have explored the possibilities that cell volume is regulated by the status of microtubule assembly and cyclic AMP metabolism and may be coordinated with shape change. Treatment of J774.2 mouse macrophages with colchicine caused rapid microtubule disassembly and was associated with a striking increase (from 15-20 to more than 90 percent) in the proportion of cells with a large protuberance at one pole. This provided a simple experimental system in which shape changes occurred in virtually an entire cell population in suspension. Parallel changes in cell volume could then be quantified by isotope dilution techniques. We found that the shape change caused by colchicine was accompanied by a decrease in cell volume of approximately 20 percent. Nocodozole, but not lumicolchicine, caused identical changes in both cell shape and cell volume. The volume loss was not due to cell lysis nor to inhibition of pinocytosis. The mechanism of volume loss was also examined. Colchicine induced a small but reproducible increase in activity of the ouabain-sensitive Na(+), K(+)-dependent ATPase. However, inhibition of this enzyme/transport system by ouabain did not change cell volume nor did it block the colchicines-induced decrease in volume. One the other hand, SITS (4’acetamido, 4-isothiocyano 2,2’ disulfonic acid stilbene), an inhibitor of anion transport, inhibited the effects of colchicines, thus suggesting a role for an anion transport system in cell volume regulation. Because colchicine is known to activate adenylate cyclase in several systems and because cell shape changes are often induced by hormones that elevate cyclic AMP, we also examined the effects of cyclic AMP on cell volume. Agents that act to increase syclic AMP (cholera toxin, which activates adenylate cyclase; IBMX, and inhibitor of phosphodiesterase; and dibutyryl cyclic AMP) all caused a volume decrease comparable to that of colchicine. To define the effective metabolic pathway, we studied two mutants of J774.2, one deficient in adenylate cyclase and the other exhibiting markedly reduced activity of cyclic AMP-dependent protein kinase. Cholera toxin did not produce a volume change in either mutant. Cyclic AMP produced a decrease in the cyclase-deficient line comparable to that in wild type, but did not cause a volume change in the kinase- deficient line. This analysis established separate roles for cyclic AMP and colchicine. The volume decrease induced by cyclic AMP requires the action of a cyclic AMP-dependent protein kinase. Colchicine, on the other hand, induced a comparable volume change in both mutants and wild type, and thus does not require the kinase.     

Differential Regulation of TLR Signaling on the Induction of Antiviral Interferons in Human Intestinal Epithelial Cells Infected with Enterovirus 71

Enterovirus 71 (EV71) causes hand-foot-and-mouth disease, which can lead to fatal neurological complications in young children and infants. Few gastrointestinal symptoms are observed clinically, suggesting the presence of a unique immunity to EV71 in the gut. We reported a robust induction of interferons (IFNs) in human intestinal epithelial cells (HT-29), which was suppressed in other types such as RD and HeLa cells. The underlying mechanism for the apparent difference remains obscure. In this study we report that in EV71-infected HT-29 cells, TLR/TRIF signaling was essential to IFN induction; viral replication increased and the induction of IFN-α, -β, -ω, -κ, and -ε decreased markedly in TRIF-silenced HT-29 cells. Importantly, TRIF was degraded by viral 3C^pro in RD cells, but resisted cleavage, and IRF3 was activated and translocated into the nucleus in HT-29 cells. Taken together, our data suggest that IFNs were induced differentially in human HT-29 cells through an intact TLR/TRIF signaling, which differs from other cell types and may be implicated in viral pathogenesis in EV71 infection.     

Development of the Intestinal RNA Virus Community of Healthy Broiler Chickens

Several RNA viruses such as astrovirus, rotavirus, reovirus and parvovirus have been detected in both healthy and diseased commercial poultry flocks. The aim of this study was to characterize (a) the development of the RNA viral community in the small intestines of healthy broiler chickens from hatch through 6 weeks of age (market age) and (b) the contribution of the breeder source vs. bird age in development of the community structure. Intestinal tissue samples were harvested from breeders and their progeny, processed for viral RNA extraction and sequenced using Illumina Hiseq sequencing technology resulting in 100 bp PE reads. The results from this study indicated that the breeder source influenced the RNA viral community only at hatch but later environment i.e. bird age had the more significant effect. The most abundant RNA viral family detected at 2, 4 and 6 weeks of age was Astroviridae, which decreased in abundance with age while the abundance of Picornaviridae increased with age.