Befragung zum Status-Quo der Tierhaltung bei 287 süddeutschen Bio-Betrieben (Demeter- und Bioland)[Inquiry to the status quo of livestock husbandry in organic farms in southern germany]

Fazit: Die gegenüber früheren Untersuchungen gestiegenen Bestandsgrößen weisen darauf hin, daß sich im ökologischen Landbau ein ähnlicher Strukturwandel wie in der konventionellen Landwirtschaft vollzieht (Wachstum und Spezialisierung). Die Auswertung zeigt ferner, daß die Betriebe zunehmend bemüht sind, bereits jetzt den zukünftigen Haltungsvorschriften der EU-Verordnung zu entsprechen. Fast alle Betriebe führen Weidegang durch und trotz der relativ geringen Bestandsgröße haben die meisten Betriebe bereits Laufställe; Auslaufmöglichkeiten fallen demgegenüber allerdings noch ab

Entwicklung, Erprobung, Umsetzung und Evaluation von Strategien in den Bereichen Tiergesundheit, Haltung, Fütterung, Management in der ökologischen Ferkelerzeugung

Die ökologische Ferkelerzeugung weist hinsichtlich Tiergesundheit, Leistungsfähigkeit und Wirtschaftlichkeit große Defizite auf. Die Ursachen sind komplex und betreffen u.a. Fütterung, Haltung und Hygiene. Für diese Bereiche sollten durch Exakt- und Praxisversuche Lösungsansätze entwickelt werden. Teilprojekte umfassten folgende Themen: Der Einfluss unterschiedlicher Raufutter in der Fütterung tragender Sauen, die Wirkung einer Inulinzugabe sowie vom Extrudieren von Ackerbohnen in Sauen- und Ferkelfutter, die Bewertung alternativer Desinfektionsverfahren, ein Vergleich von Einzelhaltung versus kombinierte Einzel- und Gruppenhaltung säugender Sauen sowie die Optimierung des Ferkelliegebereichs in der Ferkelaufzucht. Zentrale Ergebnisse: - Die verschiedenen Raufuttervarianten (Kleegrassilage, Heu, Maissilage, Topinamburknollen) hatten keine negativen Effekte auf Körperkonstitution und Reproduktionsleistungen der Sauen. - Die Saugferkel der mit Inulin versorgten Sauen entwickelten sich gegenüber der Kontrollgruppe während der Säugezeit leistungsmäßig besser, während der Ferkelaufzucht gab es keine Leistungssteigerungen. Der Einsatz von getoasteten Ackerbohnen führte zu signifikant besseren Ferkelzunahmen gegenüber dem Einsatz von extrudierten Ackerbohnen. - Keines der getesteten alternativen Desinfektionsverfahren (Heißwasserdampf, elektroaktiviertes Wasser, Abflammen) ist eine Alternative zur chemischen Desinfektion bezüglich Keimreduktion, Arbeitsaufwand und Kosten. - Gruppensäugen führt bei Sauen zu erhöhter Aktivität sowie zu spezifischen Verhaltensanpassungen. Leistungseinbußen konnten weder für Sauen noch für Ferkel dokumentiert werden. „Gruppensäugen“ führt zu einem höheren Arbeitszeitbedarf und steigenden Baukosten. - Der Liegebereich für Aufzuchtferkel ist in vielen Betrieben nicht optimal und durch z. T. einfache Maßnahmen (Abdichten des Liegenestes, Wärmedämmung des Bodens, Bodenheizung, Anbringen einer weiteren Wärmequelle) für die Tiere zu verbessern

An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats

Background: Horizontal gene transfer through natural transformation of members of the microbiota of the lower gastrointestinal tract (GIT) of mammals has not yet been described. Insufficient DNA sequence similarity for homologous recombination to occur has been identified as the major barrier to interspecies transfer of chromosomal DNA in bacteria. In this study we determined if regions of high DNA similarity between the genomes of the indigenous bacteria in the GIT of rats and feed introduced DNA could lead to homologous recombination and acquisition of antibiotic resistance genes. Results: Plasmid DNA with two resistance genes (nptII and aadA) and regions of high DNA similarity to 16S rRNA and 23S rRNA genes present in a broad range of bacterial species present in the GIT, where constructed and added to standard rat feed. Six rats, with a normal microbiota, were fed DNA containing pellets daily over four days before sampling of the microbiota from the different GI compartments (stomach, small intestine, cecum and colon). In addition, two rats were included as negative controls. Antibiotic resistant colonies growing on selective media were screened for recombination with feed introduced DNA by PCR targeting unique sites in the putatively recombined regions. Conclusions: The analyses showed that extensive ingestion of DNA (100 \ub5g plasmid) per day did not lead to increased proportions of kanamycin resistant bacteria, nor did it produce detectable transformants among the aerobic microbiota examined for 6 rats (detection limit <1 transformant per 1.1 x 108 cultured bacteria). The key methodological challenges to HGT detection in animal feedings trials are identified and discussed

An international parentage and identification panel for the domestic cat (Felis catus)

Seventeen commercial and research laboratories participated in two comparison tests under the auspices of the International Society for Animal Genetics to develop an internationally tested, microsatellite-based parentage and identification panel for the domestic cat (Felis catus). Genetic marker selection was based on the polymorphism information content and allele ranges from seven random-bred populations (n = 261) from the USA, Europe and Brazil and eight breeds (n = 200) from the USA. Nineteen microsatellite markers were included in the comparison test and genotyped across the samples. Based on robustness and efficiency, nine autosomal microsatellite markers were ultimately selected as a single multiplex ‘core’ panel for cat identification and parentage testing. Most markers contained dinucleotide repeats. In addition to the autosomal markers, the panel included two gender-specific markers, amelogenin and zinc-finger XY, which produced genotypes for both the X and Y chromosomes. This international cat parentage and identification panel has a power of exclusion comparable to panels used in other species, ranging from 90.08% to 99.79% across breeds and 99.47% to 99.87% in random-bred cat populations

Essential Role of Cdc42 in Ras-Induced Transformation Revealed by Gene Targeting

The ras proto-oncogene is one of the most frequently mutated genes in human cancer. However, given the prevalence of activating mutations in Ras and its association with aggressive forms of cancer, attempts to therapeutically target aberrant Ras signaling have been largely disappointing. This lack of progress highlights the deficiency in our understanding of cellular pathways required for Ras-mediated tumorigenesis and suggests the importance of identifying new molecular pathways associated with Ras-driven malignancies. Cdc42 is a Ras-related small GTPase that is known to play roles in oncogenic processes such as cell growth, survival, invasion, and migration. A pan-dominant negative mutant overexpression approach to suppress Cdc42 and related pathways has previously shown a requirement for Cdc42 in Ras-induced anchorage-independent cell growth, however the lack of specificity of such approaches make it difficult to determine if effects are directly related to changes in Cdc42 activity or other Rho family members. Therefore, in order to directly and unambiguously address the role of Cdc42 in Ras-mediated transformation, tumor formation and maintenance, we have developed a model of conditional cdc42 gene in Ras-transformed cells. Loss of Cdc42 drastically alters the cell morphology and inhibits proliferation, cell cycle progression and tumorigenicity of Ras-transformed cells, while non-transformed cells or c-Myc transformed cells are largely unaffected. The loss of Cdc42 in Ras-transformed cells results in reduced Akt signaling, restoration of which could partially rescues the proliferation defects associated with Cdc42 loss. Moreover, disruption of Cdc42 function in established tumors inhibited continued tumor growth. These studies implicate Cdc42 in Ras-driven tumor growth and suggest that targeting Cdc42 is beneficial in Ras-mediated malignancies

Expression of B-RAF V600E in Type II Pneumocytes Causes Abnormalities in Alveolar Formation, Airspace Enlargement and Tumor Formation in Mice

Growth factor induced signaling cascades are key regulatory elements in tissue development, maintenance and regeneration. Perturbations of these cascades have severe consequences, leading to developmental disorders and neoplastic diseases. As a major function in signal transduction, activating mutations in RAF family kinases are the cause of human tumorigenesis, where B-RAF V600E has been identified as the prevalent mutant. In order to address the oncogenic function of B-RAF V600E, we have generated transgenic mice expressing the activated oncogene specifically in lung alveolar epithelial type II cells. Constitutive expression of B-RAF V600E caused abnormalities in alveolar epithelium formation that led to airspace enlargements. These lung lesions showed signs of tissue remodeling and were often associated with chronic inflammation and low incidence of lung tumors. The inflammatory cell infiltration did not precede the formation of the lung lesions but was rather accompanied with late tumor development. These data support a model where the continuous regenerative process initiated by oncogenic B-RAF-driven alveolar disruption provides a tumor-promoting environment associated with chronic inflammation

Live-Cell Microscopy Reveals Small Molecule Inhibitor Effects on MAPK Pathway Dynamics

Oncogenic mutations in the mitogen activated protein kinase (MAPK) pathway are prevalent in human tumors, making this pathway a target of drug development efforts. Recently, ATP-competitive Raf inhibitors were shown to cause MAPK pathway activation via Raf kinase priming in wild-type BRaf cells and tumors, highlighting the need for a thorough understanding of signaling in the context of small molecule kinase inhibitors. Here, we present critical improvements in cell-line engineering and image analysis coupled with automated image acquisition that allow for the simultaneous identification of cellular localization of multiple MAPK pathway components (KRas, CRaf, Mek1 and Erk2). We use these assays in a systematic study of the effect of small molecule inhibitors across the MAPK cascade either as single agents or in combination. Both Raf inhibitor priming as well as the release from negative feedback induced by Mek and Erk inhibitors cause translocation of CRaf to the plasma membrane via mechanisms that are additive in pathway activation. Analysis of Erk activation and sub-cellular localization upon inhibitor treatments reveals differential inhibition and activation with the Raf inhibitors AZD628 and GDC0879 respectively. Since both single agent and combination studies of Raf and Mek inhibitors are currently in the clinic, our assays provide valuable insight into their effects on MAPK signaling in live cells

The Distinct Conformational Dynamics of K-Ras and H-Ras A59G

Ras proteins regulate signaling cascades crucial for cell proliferation and differentiation by switching between GTP- and GDP-bound conformations. Distinct Ras isoforms have unique physiological functions with individual isoforms associated with different cancers and developmental diseases. Given the small structural differences among isoforms and mutants, it is currently unclear how these functional differences and aberrant properties arise. Here we investigate whether the subtle differences among isoforms and mutants are associated with detectable dynamical differences. Extensive molecular dynamics simulations reveal that wild-type K-Ras and mutant H-Ras A59G are intrinsically more dynamic than wild-type H-Ras. The crucial switch 1 and switch 2 regions along with loop 3, helix 3, and loop 7 contribute to this enhanced flexibility. Removing the gamma-phosphate of the bound GTP from the structure of A59G led to a spontaneous GTP-to-GDP conformational transition in a 20-ns unbiased simulation. The switch 1 and 2 regions exhibit enhanced flexibility and correlated motion when compared to non-transitioning wild-type H-Ras over a similar timeframe. Correlated motions between loop 3 and helix 5 of wild-type H-Ras are absent in the mutant A59G reflecting the enhanced dynamics of the loop 3 region. Taken together with earlier findings, these results suggest the existence of a lower energetic barrier between GTP and GDP states of the mutant. Molecular dynamics simulations combined with principal component analysis of available Ras crystallographic structures can be used to discriminate ligand- and sequence-based dynamic perturbations with potential functional implications. Furthermore, the identification of specific conformations associated with distinct Ras isoforms and mutants provides useful information for efforts that attempt to selectively interfere with the aberrant functions of these species

SMAD4 - Molecular gladiator of the TGF-β signaling is trampled upon by mutational insufficiency in colorectal carcinoma of Kashmiri population: an analysis with relation to KRAS proto-oncogene

<p>Abstract</p> <p>Background</p> <p>The development and progression of colorectal cancer has been extensively studied and the genes responsible have been well characterized. However the correlation between the <it>SMAD4 </it>gene mutations with <it>KRAS </it>mutant status has not been explored by many studies so far. Here, in this study we aimed to investigate the role of <it>SMAD4 </it>gene aberrations in the pathogenesis of CRC in Kashmir valley and to correlate it with various clinicopathological variables and <it>KRAS </it>mutant genotype.</p> <p>Methods</p> <p>We examined the paired tumor and normal tissue specimens of 86 CRC patients for the occurrence of aberrations in MCR region of <it>SMAD4 </it>and exon 1 of <it>KRAS </it>by PCR-SSCP and/or PCR-Direct sequencing.</p> <p>Results</p> <p>The overall mutation rate of mutation cluster region (MCR) region of <it>SMAD4 </it>gene among 86 patients was 18.6% (16 of 86). 68.75% (11/16) of the <it>SMAD4 </it>gene mutants were found to have mutations in <it>KRAS </it>gene as well. The association between the <it>KRAS </it>mutant genotype with <it>SMAD4 </it>mutants was found to be significant (P =< 0.05). Further more, we found a significant association of tumor location, tumor grade, node status, occupational exposure to pesticides and bleeding PR/Constipation with the mutation status of the <it>SMAD4 </it>gene (P =< 0.05).</p> <p>Conclusion</p> <p>Our study suggests that <it>SMAD4 </it>gene aberrations are the common event in CRC development but play a differential role in the progression of CRC in higher tumor grade (C+D) and its association with the <it>KRAS </it>mutant status suggest that these two molecules together are responsible for the progression of the tumor to higher/advanced stage.</p