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Macroalgal holobiont studies involve understanding interactions between the host, its microbiota, and the environment. We analyzed the effect of bacteria-kelp interactions on phenotypic responses of two genetically distinct populations of giant kelp, Macrocystis pyrifera (north and south), exposed to different nitrogen (N) concentrations. In co-culture experiments with different N concentration treatments, we evaluated kelp growth responses and changes in three specific molecular markers associated with the N cycle, both in epiphytic bacteria (relative abundance of nrfA-gene: cytochrome c nitrite reductase) and macroalgae (expression of NR-gene: nitrate reductase; GluSyn-gene: glutamate synthase). Both kelp populations responded differently to N limitation, with M. pyrifera-south sporophytes having a lower specific growth rate (SGR) under N-limiting conditions than the northern population; M. pyrifera-north sporophytes showed no significant differences in SGR when exposed to low-N and high-N concentrations. This corresponded to a higher GluSyn-gene expression in the M. pyrifera-north sporophytes and the co-occurrence of specific nrfA bacterial taxa. These bacteria may increase ammonium availability under low-N concentrations, allowing M. pyrifera-north to optimize nutrient assimilation by increasing the expression of GluSyn. We conclude that bacteria-kelp interactions are important in enhancing kelp growth rates under low N availability, although this effect may be regulated by the genetic background of kelp populations.

BACKGROUND: Bio‐oils can be effectively used for the preparation of bio‐based materials owing to their chemical compositions. In this study, brown macroalgal‐derived bio‐oil was used for the synthesis of graphene oxide‐carbon dot composite by a simple hydrothermal process. RESULTS: A simple and facile hydrothermal process was explored for the preparation of green‐emitting graphene oxide‐carbon dot (GO‐CD) composite from brown macroalgal biomass‐derived bio‐oil as carbon source in water medium at 170 °C for 4 h. An aqueous solution of the prepared GO‐CD composite exhibited green emission under ultraviolet (UV) radiation exposure. Raman spectroscopy and transmission electron microscopy analyses confirmed the successful formation of GO‐CD composite. Physicochemical characterizations such as phase structure and optical properties of the GO‐CD were investigated by X‐ray diffraction, UV–visible and photoluminescence analyses. The effects of the GO‐CD composite on the seed germination of mung bean were studied. It was found that, compared with the control (100/0 vol% water; total length of plant ∼20 cm), the 75/25 vol% water/GO‐CD ratio treatment resulted in better plant growth (total length of plant ∼25 cm) under the studied conditions. Further increase in GO‐CD concentration above the optimum level resulted in a decrease in plant growth but did not have a significant effect on the mass, root and leaf mass development. CONCLUSION: Brown macroalgal bio‐oil‐derived graphene oxide‐carbon dot composite were explored for the seed germination of mung bean and the results showed that a low concentration enhanced the plant growth. © 2019 Society of Chemical Industry

In terrestrial plants, it is well known that genetic diversity can affect responses to abiotic and biotic stress and have important consequences on farming. However, very little is known about the interactive effects of genetic and environmental factors on seaweed crops. We conducted a field experiment on Gracilaria chilensis to determine the effect of heterozygosity and nutrient addition on two southern Chilean farms: Ancud and Chaica. In addition to growth rate and productivity, we measured photosynthetic responses, photosynthetic pigment concentration (chlorophyll a and phycobiliproteins), C:N ratio (C:N), and epiphytic load. Nutrient addition affected the growth rate, productivity, phycobilin, and C:N content, but not the epiphytic load. These results were independent of the heterozygosity of the strains used in the experiments. Interestingly, depending on the sampled sites, distinct photosynthetic responses (i.e., maximal quantum yield, Fv /Fm , and maximal electron transport rate, ETRmax ) to nutrient addition were observed. We propose that thallus selection over the past few decades may have led to ecological differentiation between G. chilensis from Chaica and Ancud. The lack of effect of heterozygosity on growth and physiological responses could be related to the species domestication history in which there is a limited range of genetic variation in farms. We suggest that the existing levels of heterozygosity among our thalli is not sufficient to detect any significant effect of genetic diversity on growth or productivity in Metri bay, our experimental site located close to the city of Puerto Montt, during summer under nitrogen limiting conditions.

Seaweeds are rich in different bioactive compounds with potential uses in drugs, cosmetics and the food industry. The objective of this study was to analyze macromolecular antioxidants or nonextractable polyphenols, in several edible seaweed species collected in Chile (Gracilaria chilensis, Callophyllis concepcionensis, Macrocystis pyrifera, Scytosyphon lomentaria, Ulva sp. and Enteromorpha compressa), including their 1st HPLC characterization. Macromolecular antioxidants are commonly ignored in studies of bioactive compounds. They are associated with insoluble dietary fiber and exhibit significant biological activity, with specific features that are different from those of both dietary fiber and extractable polyphenols. We also evaluated extractable polyphenols and dietary fiber, given their relationship with macromolecular antioxidants. Our results show that macromolecular antioxidants are a major polyphenol fraction (averaging 42% to total polyphenol content), with hydroxycinnamic acids, hydroxybenzoic acids and flavonols being the main constituents. This fraction also showed remarkable antioxidant capacity, as determined by 2 complementary assays. The dietary fiber content was over 50% of dry weight, with some samples exhibiting the target proportionality between soluble and insoluble dietary fiber for adequate nutrition. Overall, our data show that seaweed could be an important source of commonly ignored macromolecular antioxidants.

Interest in third-generation biomass such as macroalgae has increased due to their high biomass yield, absence of lignin in their tissues, lower competition for land and fresh water, no fertilization requirements, and efficient CO2 capture in coastal ecosystems. However, several challenges still exist in the development of cost-effective technologies for processing large amounts of macroalgae. Recently, genetically modified micro-organisms able to convert brown macroalgae carbohydrates into bioethanol were developed, but still no attempt to scale up production has been proposed. Based on a giant kelp (Macrocystis pyrifera) farming and bioethanol production program carried out in Chile, we were able to test and adapt this technology as a first attempt to scale up this process using a 75 L fermentation of genetically modified Escherichia coli. Laboratory fermentation tests results showed that although biomass growth and yield are not greatly affected by the alginate:mannitol ratio, ethanol yield showed a clear maximum around a 5:8 alginate:mannitol ratio. In M. pyrifera, a much greater proportion of alginate and lower mannitol abundance is found. In order to make the most of the carbohydrates available for fermentation, we developed a four-stage process model for scaling up, including acid leaching, depolymerization, saccharification, and fermentation steps. Using this process, we obtained 0.213 Kg ethanol Kg−1 dry macroalgae, equivalent to 9.6 m3 of ethanol hectare−1 year−1, reaching 64% of the maximum theoretical ethanol yield. We propose strategies to increase this yield, including synthetic biology pathway engineering approaches and process optimization targets. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Antimicrobials are heavily used in Chilean salmon aquaculture. We previously found significant differences in antimicrobial-resistant bacteria between sediments from an aquaculture and a non-aquaculture site. We now show that levels of antimicrobial resistance genes (ARG) are significantly higher in antimicrobial-selected marine bacteria than in unselected bacteria from these sites. While ARG in tetracycline- and florfenicol-selected bacteria from aquaculture and non-aquaculture sites were equally frequent, there were significantly more plasmid-mediated quinolone resistance genes per bacterium and significantly higher numbers of qnrB genes in quinolone-selected bacteria from the aquaculture site. Quinolone-resistant urinary Escherichia coli from patients in the Chilean aquacultural region were significantly enriched for qnrB (including a novel qnrB gene), qnrS, qnrA and aac(6')-1b, compared with isolates from New York City. Sequences of qnrA1, qnrB1 and qnrS1 in quinolone-resistant Chilean E. coli and Chilean marine bacteria were identical, suggesting horizontal gene transfer between antimicrobial-resistant marine bacteria and human pathogens.

Antimicrobial resistance (AR) detected by disc diffusion and antimicrobial resistance genes detected by DNA hybridization and polymerase chain reaction with amplicon sequencing were studied in 124 marine bacterial isolates from a Chilean salmon aquaculture site and 76 from a site without aquaculture 8 km distant. Resistance to one or more antimicrobials was present in 81% of the isolates regardless of site. Resistance to tetracycline was most commonly encoded by tetA and tetG; to trimethoprim, by dfrA1, dfrA5 and dfrA12; to sulfamethizole, by sul1 and sul2; to amoxicillin, by blaTEM ; and to streptomycin, by strA-strB. Integron integrase intl1 was detected in 14 sul1-positive isolates, associated with aad9 gene cassettes in two from the aquaculture site. intl2 Integrase was only detected in three dfrA1-positive isolates from the aquaculture site and was not associated with gene cassettes in any. Of nine isolates tested for conjugation, two from the aquaculture site transferred AR determinants to Escherichia coli. High levels of AR in marine sediments from aquaculture and non-aquaculture sites suggest that dispersion of the large amounts of antimicrobials used in Chilean salmon aquaculture has created selective pressure in areas of the marine environment far removed from the initial site of use of these agents.

Growth, production and biofiltration rates of seaweed, Ulva lactuca were investigated at two stocking densities (3 kg and 6 kg m−2) and two effluent flow rates (5.4 and 10.8 m3 day−1) to optimize an integrated mariculture system at Saudi Red Sea coast. effluents from fish-rearing tank, stocked with 200 kg fish (Oreochromis spilurus), fed to six seaweed tanks via sedimentation tank. Fish growth (weight gain 1.75 g fish day−1), net production (NP, 10.16 kg m−3) and survival (94.24%) were within acceptable limits. Ulva showed significantly higher (F = 62.62, d.f. 3, 35; P

The worldwide growth of aquaculture has been accompanied by a rapid increase in therapeutic and prophylactic usage of antimicrobials including those important in human therapeutics. Approximately 80% of antimicrobials used in aquaculture enter the environment with their activity intact where they select for bacteria whose resistance arises from mutations or more importantly, from mobile genetic elements containing multiple resistance determinants transmissible to other bacteria. Such selection alters biodiversity in aquatic environments and the normal flora of fish and shellfish. The commonality of the mobilome (the total of all mobile genetic elements in a genome) between aquatic and terrestrial bacteria together with the presence of residual antimicrobials, biofilms, and high concentrations of bacteriophages where the aquatic environment may also be contaminated with pathogens of human and animal origin can stimulate exchange of genetic information between aquatic and terrestrial bacteria. Several recently found genetic elements and resistance determinants for quinolones, tetracyclines, and β-lactamases are shared between aquatic bacteria, fish pathogens, and human pathogens, and appear to have originated in aquatic bacteria. Excessive use of antimicrobials in aquaculture can thus potentially negatively impact animal and human health as well as the aquatic environment and should be better assessed and regulated.

Seaweeds absorb inorganic nutrient wastes from mariculture and reduce their undesirable environmental effects. Mariculture in Saudi Arabia is increasing rapidly, thus, to exploit aquaculture wastes and to reduce coastal pollution risks, local seaweeds were cultured using mariculture effluents in integration on the Red Sea coast. The aim of the present study was to test integrated aquaculture of seaweed and marine fish (Oreochromis spilurus) for the first time in Saudi Arabia and to determine the seaweeds, Ulva lactuca and Gracilaria arcuata, biomass production and inorganic nutrient bioremediation capabilities. Results showed that G. arcuata grew at a significantly higher rate (2.71% wet weight day−1) than U. lactuca (1.77% wet weight day−1). The biomass yield (42.38 g wet weight m−2 day−1) and net yield (91.11 g wet weight day−1) of G. arcuata were also significantly higher than U. lactuca (27.39 g wet weight m−2 day−1 and 58.89 g wet weight day−1, respectively). Gracilaria arcuata removed 0.45 g m−2 day−1 of total ammonia nitrogen (TAN) with 80.15% removal efficiency and 1.03 g m−2 day−1 of soluble phosphate with 41.06% efficiency. Ulva lactuca removed 0.42 g m−2 day−1 of TAN with 83.06% removal efficiency and 1.07 g m−2 day−1 of soluble phosphate with 41.11% efficiency. Total tissue carbon of both species reached 25.1–26.9% and nitrogen content reached 3.0–3.2% of dry weight. The C/N ratio for both seaweeds was

The giant kelp Macrocystis pyrifera (L.) C. Agardh is widely distributed in the Northern Hemisphere and Southern Hemisphere, yet it exhibits distinct population dynamics at local to regional spatial scales. Giant kelp populations are typically perennial with the potential for year-round reproduction and recruitment. In southern Chile, however, annual giant kelp populations exist and often persist entirely on secondary substrata (e.g., shells of the slipper limpet Crepipatella fecunda [Gastropoda, Calyptraeidae]) that can cover up to 90% of the rocky bottom. In these populations, the macroscopic sporophyte phase disappears annually during winter and early spring, leaving a 3-4 month period in which a persistent microscopic phase remains to support the subsequent year's recruitment. We tested the effects of a suite of grazers on the recruitment success of this critical microscopic phase at two sites in southern Chile. Field experiments indicated that the snail Tegula atra negatively impacted M. pyrifera sporophyte recruitment, but that recruitment was highest in the presence of sessile female limpets, C. fecunda. Conversely, small male C. fecunda (biofilm grazers) did not regulate kelp recruitment. Laboratory observations showed that C. fecunda males only grazed on microscopic kelp gametophytes and small (

Zusammenfassung Es wurde das Vorkommen bakterizider Eigenschaften gegenuber S. typhimurium, E. coli, St. aureus, M. albus, M. lysodeikticus, E. insidiosa, Ps. aeruginosa und B. prodigiosum in verschiedenen Haustierseren untersucht. Folgende Ergebnisse wurden erzielt: 1 Es bestehen signifikante Unterschiede in der Haufigkeit des Auftretens bakterizider Eigenschaften zwischen jugendlichem Tier und Fotus. Das Serum fotaler Rinder ist so gut wie frei von bakteriziden Eigenschaften. 2 Starke und Titer der Serumbakterizidie verhalten sich nicht parallel, was fur eine geringe Spezifitat der Reaktionen spricht. In gleichem Sinne ist die Diskrepanz zwischen dem geringen Titer der Bakterizidine auf der einen Seite und der grosen, fur eine Absorption erforderlichen Menge homologer Keime auf der anderen Seite zu erklaren. 3 Die Thermolabilitat der Serumbakterizidie ist verschieden je nach der Art des untersuchten Keimes. Die Serumbakterizidie gegeniber gramnegativen Keimen ist offenbar starker thermolabil als die gegenuber grampositiven Keimen. 4 Fur das Zustandekommen einer Serumbakterizidie sind in erster Linie Antikorper verantwortlich. Eine Mitwirkung von Lysozym und Komplement kommt in Frage, ist jedoch nicht von entscheidender Bedeutung gegenuber der Mehrzahl bakterieller Infektionserreger. Auch ergaben sich keine Anhaltspunkte fur eine Mitwirkung der Plakine. 5 Die Hauptfraktionen der Serumbakterizidine befinden sich, je nach untersuchtem Testkeim, sowohl in der 19 S- als auch in der 7 S-Gamma-globulinfraktion des Serums. Summary Studies on the question of bactericidal sera The presence of bactericidal properties was studied in the sera of various animals against S. typhimurium, E. coli, St. aureus, M. albus, M. lysodeikticus, E. insidiosa, Ps. aeruginosa and B. prodigiosum. The following results were obtained: 1 There are significant differences in the frequency of the occurrence of bactericidal characters as between the young animal and the foetus. The serum of the bovine foetus is practically free from bactericidal properties. 2 The intensity and titre of serum bactericides do not run parallel, which suggests that the reaction is only slightly specific. The same conclusion is suggested by the discrepancy between the low titre of bactericidins on the one hand and the large quantity of homologous bacteria necessary for absorption on the other. 3 The thermal lability of the serum bactericides varies according to the species of agent studied. Bactericides against gram-negative organisms seem to be more thermolabile than those to gram-positive ones. 4 It seems that antibodies are the most likely cause of the bactericidal action of serum. Lysozyme and complement are equally concerned in the process but they do not play a significant determining part in the case of most bacterial infective agents. There was no evidence that platelets are concerned. 5 The principal fractions of the bactericidins are found in the serum globulin fraction 19 S as well as in 7 S. Resume Recherches sur la question de la bactericidie serique On examine differents animaux domestiques quant a l'existence de proprietes bactericides envers S. typhimurium, E. coli, St. aureus, M. albus, M. lysodeikticus, E. insidiosa, Ps. aeruginosa et B. prodigiosum. On obtient les resultats suivants: 1 Il existe des differences significatives dans la frequence d'apparition des proprietes bactericides entre les jeunes animaux et les foetus. Le serum des foetus bovins est pratiquement exempt de proprietes bactericides. 2 La force et le titre de la bactericidie serique ne sont pas paralleles, ce qui parle pour une faible specificite des reactions. Ceci explique egalement les divergences entre le faible titre des bactericidines d'une part et d'autre part la grande quantite de germes homologues necessaires pour une adsorption. 3 La thermolabilite de la bactericidie serique differe selon le germe examine. La bactericidie serique est vraisemblablement plus thermolabile a l'egard des germes gram-negatifs qu'a l'egard des germes gram-positifs. 4 Ce sont les anticorps qui, en tout premier lieu, sont responsables de la bactericidie serique. Il se pourrait que les lysozymes et le complement interviennent egalement dans le processus, mais ils n'ont pas une signification determinante pour la plupart des agents infectieux bacteriens. On ne trouve aucun indice d'une participation des plaquettes. 5 Les fractions principales des bactericidines se trouvent dins les fractions globuliniques seriques 19 S, de meme que 7 S, selon le germe teste. Resumen Estudios sobre el problema de la bactericidia serica Examinose la presencia de propiedades bactericidas frente a S. typhimurium, E. coli, St. aureus, M. albus, M. lysodeicticus, E. insidiosa, Ps. aeruginosa y B. prodigiosum en diversos sueros sanguineos de animales domesticos. Se lograron los resultados siguientes: 1 Existen diferencias significativas en la frecuencia de presentacion de propiedades bactericidas entre el animal juvenil y el feto. El suero de los fetos bovinos se halla tan bien como libre de propiedades bactericidas. 2 El valor y titulo de la bactericidia serica no se comportan de manera paralela, lo cual aboga por una especificidad escasa de las reacciones. En el mismo sentido debe explicarse la discrepancia entre el titulo escaso de las bactericidinas por un lado y la enorme cantidad de germenes homologos precisa para una absorcion por otro. 3 La termolabilidad de la bactericidia serica es diversa segun el tipo del germen examinado. La serobactericidia frente a los germenes gramnegativos es mas termolabil que frente a los agentes grampositivos. 4 Los anticuerpos son responsables, en primer lugar, de que se verifique una serobactericidia. Se puede registrar la cooperacion de lisozima y complemento, aunque no es de importancia decisiva frente a la mayoria de los agentes etiologicos infecciosos bacterianos. Tampoco se establecieron puntos de referencia para el concurso de la plaquina. 5 Las fracciones principales de las serobactericidinas se encuentran, segun el germen patron examinado, tanto en la fraccion gammaglobulinica 19 S como en la 7 S del suero sanguineo.

Zusammenfassung Die Starke der Bakterizidie des Serums monozygoter Rinderzwillinge gegenuber Salmonella typhimurium, Staphylococcus aureus und Bacterium prodigiosum variiert starker innerhalb der Paare als zwischen den Paaren. Umgekehrt ist die Varianz des Serumkonglutinintiters zwischen den Paaren wesentlich groser als innerhalb der Paare. Fur die Ausbildung des Serumkonglutiningehaltes werden deshalb genetische Ursachen vermutet, fur die Entwicklung der Serumbakterizidie scheiden sie aus. Summary Studies on monozygotic bovine twins in relation to inherited defence mechanisms in serum The concentration of bactericidins in the serum of monozygotic bovine twins against Salmonella typhimurium, Staphylococcus aureus and Bacterium prodigiosum showed greater variation within each pair than between pairs. Conversely, the variation in the serum conglutinin titre was greater between pairs than within them. These findings suggest that genetic factors determine the level of serum conglutinins but are not concerned with serum bactericidins. Resume Etudes sur des jumeaux bovins monozygotes, concernant la question d'un mecanisme de defense hereditaire dans le serum La force de la bactericidie du serum de jumeaux bovins monozygotes contre Salmonella typhimurium, Staphylococcus aureus et Bacterium prodigiosum varie davantage entre les jumeaux d'une paire qu'entre les differentes paries de jumeaux. Inversement, la variation du titre de conglutination serique est nettement plus grande entre les differentes paires de jumeaux qu'entre les jumeaux d'une paire. On suppose donc qu'il existe des causes genetiques determinant le taux de conglutinine serique, mais qu'elles n'entrent pas en ligne de compte pour le developpement de la bactericidie serique. Resumen Estudios en gemelos bovinos univitelinos sobre el problema de los mecanismos de defensa, condicionados hereditariamente, en el suero sanguineo El vigor de la bactericidia del suero sanguineo de gemelos bovinos univitelinos frente a Salmonella typhimurium, Staphylococcus aureus y Bacterium prodigiosum varia mas dentro de las parejas que entre las mismas. De forma inversa, la varianza del titulo de seroconglutininas entre las parejas es bastante mayor que dentro de los pares. Por esta razon, se sospechan causas geneticas para la formacion del contenido en seroconglutininas, desechandose para el desarrollo de la serobactericidia.

Zusammenfassung Heterologe Schweine-Antilymphozytenseren (ALS) wurden durch Immunisierung von Pferden, Schafen und Kaninchen mit Schweinemilz-Lymphknoten-Homogenaten hergestellt. Die Titer der Seren, ermittelt im Lymphagglutinationstest und im Phagozytosehemmungstest, betrugen nach Absorption mit Erythrocyten zwischen 1: 8 und 1: 256. Homologe ALS mit wirksamem Antikorpergehalt konnten auch nach Immunisierungszeiten von uber 12 Wochen nicht erzielt werden. Die in vitro getesteten Seren wurden in vivo hinsichtlich ihrer Wirkung auf das weise Blutbild des Schweines untersucht. ALS-Dosen unter 1 ml/kg Kgw. blieben ohne signifikante Leukosuppression; die Wirkung trat unabhangig von der Applikationsart ein. Die erzielte Leukopenie war abhangig vom Titer, der Dosis und der Artspezifitat der eingesetzten Seren. Eine dauerhafte Leukopenie trat erst nach Reinjektionen von 2 ml ALS/kg Kgw. in 8stundigem Abstand ein. Durch Kombination mit “Methotrexat” war keine potenzierende Wirkung moglich, es schien jedoch die Dauer der erreichten Leukopenie zu verlangern. Die getesteten ALS wirkten im Phagozytose-Hemmungstest granulozytenzerstorend, wobei Zerstorungen des Zellinnern dominierten. Gleichzeitig waren die betroffenen Zellen in ihrer Fahigkeit, Keime (Brucellen) zu phagozytieren, mehr oder weniger gestort. Der Wirkungsmechanismus des ALS scheint auf der Zellzerstorung zu beruhen. Die Moglichkeit zur Trennung von antilymphozytaren und antigranulozytaren Eigenschaften eines ALS mit Hilfe des Phagozytosehemmungstests wird erortert. Summary Preparation of anti-lymphocyte sera in pigs and its effect on the peripheral blood picture in the pig Heterologous pig anti-lymphocyte sera (ALS) were prepared by immunising horses, sheep and rabbits with homogenates of pig spleen and lymph nodes. The titre of the sera, measured by the lymph agglutination test and the phagocytosis inhibition test was between 1: 8 and 1: 256 after absorption with erythrocytes. A homologous ALS with effective antibody content could not be obtained even after more than 12 weeks' immunisation. The sera which had been tested in vitro were examined in vivo for their action on the leucocyte picture of the pig. Doses below 1 ml./kg. bodyweight produced no significant suppression of leucocytes; the effect was independent of the route of dosage. The leucopenia from larger doses depended on the titre, the dose and the species-specificity of the serum. The long-lasting leucopenia developed first after repeated injections of 2 ml. of ALS per kg. bodyweight at intervals of 8 hours. Combining the dosage with administering “Methotrexat” gave no potentiating effect but seemed to prolong the duration of the leucopenia. The ALS sera caused damage to the granulocytes in the phagocytosis inhibition test and the damage was most prominent inside the walls. At the same time the affected cells showed a reduced ability to phagocytose organisms (brucella). The mechanism of action of the ALS appears to reside in cell damage. The possibility of separating the anti-lymphocytic and anti-granulocytic properties of ALS with the help of the phagocytosis inhibition test is discussed. Resume Preparation de serums anti-lymphocytes de porcs et leur action sur la formule sanguine peripherique chez le porc On prepare des serums anti-lymphocytes de porcs heterologues (ALP), par immunisation de chevaux, de moutons et de lapins avec des homogenats de rate de porc et de ganglions lymphatiques. Les titres des serums, determines dans le test d'agglutination lymphatique et dans le test d'inhibition de la phagocytose, se situent vers 1: 8 et 1: 256 apres absorption par des erythrocytes. On ne parvient pas a produire des ALP homologues, avec une teneur en anticorps active, meme apres des periodes d'immunisation depassant 12 semaines. On examine in vivo les serums testes in vitro, afin de determiner leur action sur les globules blanc du porc. Des doses de ALP inferieures a 1 ml/kg de p. d. c. n'ont pas d'activite leucosuppressive significative; leur action ne depend pas de la maniere d'application. La leucopenie obtenue est dependante du titre, de la dose et de la specificite selon l'espece du serum employe. On n'obtient une leucopenie durable qu'apres reinjection de 2 ml de ALP/kg de p. d. c. apres un intervalle de 8 heures. Une combinaison avec du »methotrexate« ne donne pas lieu a une action potentialisante, mais semble pourtant prolonger la duree de la leucopenie obtenue. Dans le test d'inhibition des phagocytes, les ALP testes exercent une action de destruction sur les granulocytes et principalement sur l'interieur cellulaire. Simultanement, les cellules atteintes sont perturbees dans leur capacite de phagocyter des germes (brucelles). Le mecanisme d'action de l'ALP semble reposer sur la destruction cellulaire. On envisage la possibilite de differencier les proprietes antilymphocytaires et antigranulocytaires d'un ALP, a l'aide du test d'inhibition de la phagocytose. Resumen Elaboracion de sueros antilinfociticos porcinos y su accion sobre el cuadro hematico periferico en el cerdo Se obtuvieron sueros heterologos antilinfociticos porcinos (SAL) mediante la inmunizacion de caballos, ovejas y conejos con homogenados de bazo y ganglios linfaticos de cerdo. Los titulos de los sueros, determinados en la prueba de linfoaglutinacion y en la prueba de inhibicion de la fagocitosis, eran tras la absorcion con eritrocitos del orden comprendido entre 1: 8 y 1: 256. SAL homologos con contenido activo de anticuerpos no se pudieron lograr incluso despues de periodos de inmunizacion superiores a 12 semanas. Los sueros examinados in vitro se estudiaron in vivo con respecto a su accion sobre el cuadro hematico blanco del cerdo. Las dosis de SAL inferiores a 1 ml./kg. peso en pie quedaron sin leucosupresion significante; la accion se inicio de manera independiente al modo de aplicacion. La leucopenia alcanzada era independiente del titulo, de la dosis y de la especificidad de especie de los sueros empleados. Una leucopenia duradera solo se produjo tras reinyecciones de 2 ml. SAL/kg. peso vivo en intervalos de 8 horas. Mediante combinacion con »Methotrexat« no se logro ninguna accion de refuerzo, ahora bien parece prolongar la duracion de la leucopenia alcanzada. Los SAL contrastados actuaban en la prueba de inhibicion fagocitaria de modo destructor de los granulocitos, dominando la destruccion del interior celular. Al mismo tiempo, estaban alteradas las celulas afectadas en su capacidad de fagocitar germenes (brucelas). El mecanismo de accion de los SAL parece basarse en la destruccion celular. Se debate la posibilidad de separar las propiedades antilinfocitarias y antigranulocitarias de un SAL con ayuda de la prueba de inhibicion fagocitaria.

Zusammenfassung Durch die Heranziehung biochemischer Systeme mit einfacher Vererbungsweise ist es gelungen, zusatzlich zur Blutgruppenuntersuchung ein weiteres Kriterium zur Klarung fraglicher Abstammungsfalle in der Rinderzucht zu gewinnen. Anhand eines Untersuchungsmaterials von 698 Abstammungsfallen, bei denen eine Serumtypenbestimmung durchgefuhrt wurde, und 359 Fallen, bei denen die Hamoglobintypenbestimmung erfolgte, wird die Effektivitat beider biochemischer Systeme fur die Klarung fraglicher Abstammungen in den suddeutschen Rinderrassen bestimmt und mit den aufgrund der Genfrequenzen in den einzelnen Rassen errechneten Erwartungswerten verglichen. Danach betragt die Ausschlushaufigkeit in unserem Untersuchungsgut fur das Serumtransferrinsystem 23% und fur das Hamoglobintypensystem etwa 9%. Beide Systeme sind geeignet, die durch die Blutgruppenuntersuchung erzielbare Ausschluschance weiterhin zu erhohen. Summary The use of inherited serum and haemoglobin characters for genealogical determinations in cattle breeding By using biochemical systems which have a simple mode of genetic transmission, it is possible to supplement blood group determinations in answering questions relating to family history in cattle. After examining 698 cases by serological typing and 359 by haemoglobin typing, the effectiveness of both biochemical criteria in answering such questions in South German breeds of cattle was determined and the gene frequency investigated. The results showed for serum transferrin system an exclusion value of 23% and for haemoglobin typing about 9%. Both systems are of value in supplementing the results of blood group determinations to exclude certain genetic relationships. Resume De la possibilite d'utiliser les caracteres hereditaires lies au serum et a l'hemoglobine pour juger de l'ascendance en elevage bovin Recourant aux systemes biochimiques d'heredite simple, il a ete possible d'obtenir au dela de la determination des groupes sanguins, un critere supplementaire permettant de clarifier certains cas douteux d'ascendance en matiere d'elevage bovin. 698 cas ont fourni le materiel pour la determination des types seriques et 359 pour celle des types hemoglobiniques; ainsi a pu etre decelee la valeur effective des deux systemes biochimiques pour clarifier des ascendances douteuses chez des races bovines d'Allemagne du sud, puis de comparer ces resultats avec les chiffres obtenus par le calcul base sur la frequence des genes. Il en est resulte, pour notre materiel de recherches, un taux d'exclusion de 23% pour le systeme de tranferrine serique et d'environ 9% pour le systeme de type hemoglobinique. Les deux systemes sont en mesure d'accroitre encore les chances que fournit deja la recherche des groupes sanguins pour exclure certaines appartenances genetiques. Resumen La posibilidad de aplicacion de las caracteristicas sericas y hemoglobinicas hereditarias en la prueba genealogica en zootecnia bovina Mediante el recurso de sistemas bioquimicos con forma de herencia simple, se ha logrado, aditivamente al examen del grupo sanguineo, un nuevo criterio en la aclaracion de casos dudosos de descendencia en la explotacion bovina. Con ayuda de un material de examen de 698 casos de descendencia en los cuales se llevo a cabo la determinacion del serotipo y de 359 casos, en los que se contrasto el tipo hemoglobinico, se examino la efectividad de ambos sistemas bioquimicos para aclarar descendencias dudosas en las razas bovinas de Alemania meridional, comparandose con los valores de expectativa calculados con arreglo a las frecuencias genicas en las distintas razas. Segun esto, la frecuencia de exclusion se cifra en nuestro material de examen para el sistema de la serotransferrina en el 23% y para el sistema de tipos hemoglobinicos en el 9% aproximadamente. Ambos sistemas son apropiados para seguir aumentando la probabilidad de exclusion lograda por medio del examen de los grupos sanguineos.

Zusammenfassung 1. Es wurde die Serumtransferrintypen- und Hamoglobintypenverteilung in deutschen Rinderrassen untersucht und die Genfrequenzen in Populationen von 8 verschiedenen einheimischen Rassen sowie beim podolischen Steppenrind Jugoslawiens bestimmt. 2. Es bestehen Unterschiede in den Genfrequenzen der Serumtransferrinund Hamoglobintypen zwischen den untersuchten Rassen. Die Signifikanz dieser Unterschiede wurde gepruft. 3. Bei allen untersuchten Populationen wurden die aufgrund des Vorhandenseins genetischer Gleichgewichtsbedingungen erwarteten Genfrequenzen den gefundenen Werten gegenubergestellt, die Signifikanz der Abweichungen berechnet und Vergleiche zu fruheren blutgruppengenetischen Untersuchungen angestellt. 4. Die Theorie des genetischen Gleichgewichts und die Anwendbarkeit polymorpher genetischer Systeme fur die Aufklarung rassengeschichtlicher Fragestellungen beim Haustier werden anhand vorliegender Ergebnisse diskutiert. Summary Studies on genetic serum transferrin and haemoglobin polymorphism of German cattle breeds 1. The distribution of serum transferrin and haemoglobin types in German cattle breeds was studied and the gene frequencies in populations of eight different indigenous breeds as well as in the podolic Yugoslavian steppe breed were determined. 2. Differences occurred in the gene frequencies between breeds, and their significance was determined. 3. In the populations studied the authors compared two values — the gene frequencies expected from the existing genetic equilibrium and the values which were actually found. The significance of the differences was determined and compared with earlier findings on the genetics of blood groups. 4. The theory of genetic equilibrium and the application of polymorphic genetic systems to explain problems of breed history in domestic animals are discussed in the light of these findings. Resume Recherches sur deux polymorphismes genetiques chez les races bovines allemandes, a savoir celui de la transferrine serique et celui de l'hemoglobine 1. La repartition des types a transferrine serique et des types hemoglo-biniques ont ete examines sur les races bovines allemandes. Leur frequence genetique a ete etablie pour des groupes d'animaux appartenant a 8 races indigenes differentes ainsi qu'aux boeufs de la steppe podolienne de Yougoslavie. 2. Les races examinees different pour ce qui concerne la frequence des genes de type transferrine d'une part et de type hemoglobinique d'autre part. On a recherche la signification de telles differences. 3. Pour tous les genres d'animaux examines, on a compare aux valeurs trouvees, la frequence des genes escomptes en fonction des conditions d'equilibre genetique; on a calcule la signification des differences trouvees et on a compare les resultats a ceux d'examens anterieurs relatifs a la genetique des groupes sanguins. 4. La theorie de l'equilibre genetique et la possibilite de recourir aux systemes genetiques polymorphes pour tirer au clair certaines questions relatives a l'historique racial chez les animaux domestiques sont discutees sur la base des resultats obtenus. Resumen Estudios sobre el polimorfismo genetico de la serotransferrina y de la hemoglobina de las razas bovinas alemanas 1. Se analizo la distribucion de los tipos de la serotransferrina y de los de la hemoglobina en las razas bovinas alemanas, determinandose las frecuencias genicas en populaciones de 8 razas autoctonas diferentes, asi como en el bovido podolico de las estepas de Yugoeslavia. 2. Existen diferencias en las frecuencias genicas de los tipos de serotransferrina y hemoglobina entre las razas estudiadas. Se ahondo en la significacion de estas diferencias. 3. En todas las populaciones estudiadas, las frecuencias genicas esperadas con arreglo a la presencia de condiciones geneticas equilibradas se enfrentaron a los valores hallados, se calculo la significacion de las desviaciones y se realizaron comparaciones con estudios anteriores de genetica de grupos sanguineos. 4. Tomando como base los resultados presentes, se discute la teoria del equilibrio genetico y la posibilidad de aplicacion de los sistemas geneticos polimorfos en la aclaracion de problemas historicos de razas en los animales domesticos.

Zusammenfassung Bei zwei Mauselinien, die auf hohes bzw. niedriges Phagozytosevermogen mittels eines Tuscheausscheidungstests gezuchtet worden waren, wurden weitere Versuche angestellt mit dem Ziel zu ermitteln, inwieweit sich die Infektionsresistenz, die Phagozytoseaktivitat der einzelnen Phagozyten, sowie das Antikorperbildungsvermogen gegenuber partikularen Antigenen im Verlauf der Selektion verandert hat. Es zeigte sich, das das relative Leber- und Milzgewicht der Mauselinien durch die Selektion beeinflust worden war, jedoch die Phagozytoseaktivitat der einzelnen Zelle sowie deren Stoffwechselaktivitat wahrend der Phagozytose unverandert geblieben waren. Aufgrund des hoheren relativen Anteils von Phagozyten zeigten die Tiere der hoch selektierten Linie eine erhohte Resistenz gegenuber einer Listeria-Infektion und besasen auch hohere Antikorpertiter im Serum nach einer Primarimmunisierung mit Schaferythrocyten; die Zahl der plaquebildenden Zellen in der Milz, bezogen auf 106 Milzzellen, zeigte keine signifikanten Unterschiede. Summary Further studies on mice genetically selected for high and low phagocytic activity Further experiments were done with two lines of mice, genetically selected for high and low granulopectic activity by means of a carbon clearance test. The following results were obtained: The relative liver/spleen weights differcd in the selected lines, the “high” selected animals having the highest relative liver/spleen weights. The in vitro phagocytic activity of individual phagocytes and their metabolic activity during phagocytosis, however, remained unaltered. Probably on account of the higher relative proportion of phagocytes the mice of the “high” line had obtained an increased resistance to a Listeria infection and showed higher antibody titres after a primary injection of sheep erythrocytes. In the number of plaque-forming cells / 106 spleen cells after injection of sheep erythrocytes no difference among lines was observed. Resume De nouveaux essais chez des souris selection nees sur la base d'un pouvoir de phagocytose eleve et bas De nouveaux essais ont ete entrepris chez deux lignees de souris elevees sur la base d'un pouvoir de phagocytose eleve et bas au moyen d'un test d'excretion dans le but de savoir jusqu'a quel point la resistance a l'infection, l'activite de la phagocytose de chaque phagocyte et la capacite de formation des anticorps vis-a-vis des antigenes particuliers s'etait modifiee au cours de la selection. Le poids du foie et de la rate des lignees de souris fut influence par la selection, alors que l'activite de la phagocytose des cellules prises individuellement ainsi que l'activite du metabolisme sont restes inchangee durant la phagocytose. Les animaux de la lignee hautement selectionnee presenterent, sur la base du taux relativement eleve des phagocytes, une resistance plus elevee a une infection a Listeria et un titre d'anticorps seriques plus haut apres une immunisation primaire avec des erythrcytes de mouton; le nombre des cellules formant des plaques dans la rate, correspondant a 106 cellules de la rate, ne presenta aucune difference significative. Resumen Nuevos ensayos en ratones seleccionados con arreglo a un poder elevado y reducido de fagocitosis En dos lineas murinas, criadas con arreglo a capacidad elevada resp. baja de fagocitosis mediante la prueba de excrecion de tinta china, se llevaron a cabo nuevos ensayos con el fin de poder apreciar en que grado se han modificado la resistencia frente a la infeccion, la actividad fagocitosica de los distintos fagocitos y la capacidad formativa de anticuerpos frente a antigenos particulares en el curso de la seleccion. Se vio que el peso relativo del higado y bazo de las lineas murinas habia sido modificado con la seleccion, mientras que no se habian alterado la actividad fagocitosica de la celula individual ni su actividad metabolica durante la fagocitosis. En vista de la proporcion mayor relativa de fagocitos mostraban los animals de la linea harto seleccionada una resistencia aumentada frente a una infeccion por Listeria, poseyendo ademas titulos mas elevados de anticuerpos en el suero sanguineo tras la inmunizacion primaria con eritrocitos ovinos; no mostraba diferencias significantes la cantidad de celulas formadoras de plaque en el bazo, referida a 106 celulas esplenicas.

Zusammenfassung Auch beim Haustier stellen Makrophagen, B- und T-Zellen die fur das Ingangkommen der Immunreaktion bedeutsamen Zellsysteme dar. Wahrend sich die Makrophagen schon aufgrund ihres Phagozytosevermogens von den ubrigen immunkompetenten Zellen leicht unterscheiden lassen, bereitet die Differenzierung von B- und T-Lymphozyten und deren Subpopulationen erheblich grosere Schwierigkeiten. Es empfehlen sich Rosettentechniken und der Nachweis von oberflachlichem Immunglobulin an den Zellen. Mit Hilfe der Rosettensedimentation, der Filtration durch Nylonsaulen und mittels sog. Panning-Techniken gelingt es, B- und T-Zellen praparativ zu trennen. Ferner lassen sich B- und T-Lymphozyten mittels in vitro Funktionstests differenzieren. Im Gegensatz zu kleinen Laboratoriumstieren ist die Differenzierung der immunkompetenten Zellen und ihrer Subpopulationen (Helferzellen, Suppressorzellen, cytotoxische Zellen) mit Hilfe von serologisch nachweisbaren Antigenen auf der Zelloberflache beim Haustier noch wenig enrwickelt. Erst am Beginn steht auch die Charakterisierung von Lymphozyten-Subpopulationen aufgrund der Rosettenbildung mit bestimmten Bakterien. Summary Differentiation and separation of immunocompetent cells in swine and cattle In domestic animals macrophages and B and T cells represent the cellular basis of the immune response. Macrophages can be easily identified by their phagocytic capacity. The identification of T and B cells is much more difficult. The most commonly used techniques are rosetting methods and fluorescence staining of surface immunoglobulins. By the combined use of rosette sedimentation, filtration through nylon wool columns and panning techniques, separation of B and T cells is obtained. A further possibility for characterization of B and T cells is in vitro tests of cell function. Though the differentiation of lymphocyte subpopulations (helper, suppressor and cytotoxic cells) by means of antigenic determinants on the cell surface has been very successfully used in the mouse system, comparable data on antigenic markers on the cell surface of lymphocytes from domestic animals are scarcely available so far. Also the identification of lymphocyte subpopulations by means of rosetting techniques with bacteria has just begun. Resume Separation et differenciation de cellules immunocompetentes chez le porc et le bovin Des macrophages et des cellules B et T representent egalement chez des animaux domestiques des systemes cellulaires significatifs pour la mise en marche de la reaction immunitaire. Alors que les macrophages se laissent facilement differencier des autres cellules immunocompetentes sur la base de leur capacite de phagocytose, la differenciation des lymphocytes B et T et de leurs sous-populations presente de plus grandes difficultes. On recommande des techniques de rosettes et la mise en evidence d'une immunoglobuline de surface sur les cellules. Il est possible de separer en preparation des cellules B et T a l'aide de la sedimentation des rosettes, de la filtration sur colonne de nylon et au moyen des techniques dites «panning». Les lymphocytes B et T peuvent etre en outre differencies au moyen de tests fonctionnels in vitro. Contrairement aux animaus de laboratoire, la differenciation des cellules immunocompetentes et de leurs sous-populations (cellules cytotoxiques, etc.) a l'aide d'antigenes mis en evidence serologiquement sur la surface des cellules est encore peu developpee chez l'animal domestique. La caracterisation des souspopulations de lymphocytes sur la base de la formation des rosettes avec des bacteries determinees n'en est qu'a ses debuts. Resumen La separacion y diferenciacion de celulas inmunocompetentes en el cerdo y en los vacunos Tambien en los animales domesticos constituyen los macrofagos y las celulas B y T unos sistemas celulares significativos para la puesta en marcha de la reaccion inmunitaria. Mientras que los macrofagos ya se pueden diferenciar con facilidad, en vista de su capacidad fagocitosica, del resto de las celulas inmunocompetentes, la diferenciacion de los linfocitos B y T y de sus subpoblaciones causan unas dificultades bastante mas considerables. Se recomiendan tecnicas de rosetas y la puesta en evidencia de inmunoglobulina superficial en las celulas. Con ayuda de la sedimentacion de rosetas, la filtracion a traves de columnas de nylon y por medio de las llamadas tecnicas panning se logran separar preparativamente las celulas B y T. Ademas se pueden diferenciar los linfocitos B y T mediante tests funcionales in vitro. En contraste con los animales pequenos de laboratorio aun esta poco desarrollada la diferenciacion de las celulas inmunocompetentes y de sus subpoblaciones (celulas auxiliares, celulas supresoras, celulas citotoxicas) con ayuda de antigenos identificables serologicamente en la superficie celular en los animales domesticos. Solo en la iniciacion se encuentra tambien la caracterizacion de las subpoblaciones linfocitarias con arreglo a la formacion de rosetas con determinadas bacterias.

Zusammenfassung Es wurde der Lysozymgehalt im Blut und in der Milch von Kuhen einer Holstein-Friesian Herde untersucht. Folgende Ergebnisse wurden erzielt; 1. Die Lysozymkonzentration der Milch steigt mit zunehmendem Zellgehalt in der Milch. 2. Es besteht keine Korrelation zwischen der Lysozymkonzentration im Blut und derjenigen der Milch. 3. Der Lysozymgehalt in der Milch ist abhangig vom Laktationsstadium und steigt bis etwa zur 13. Woche post partum an. Keinen signifikanten Einflus hat dagegen das Alter der Kuhe. 4. Der Lysozymgehalt des Blutes ist abhangig vom Alter und Laktationsstadium der Kuhe. Farsen besitzen niedrigere Lysozymkonzentrationen im Blut als Kuhe. 5. Der Lysozymgehalt der Milch ist korreliert mit dem pH-Wert der Milch. Es ergibt sich eine lineare Regression. 6. Eine Keimbesiedlung von Eutervierteln bewirkt ein Ansteigen des Lysozymgehaltes der Milch, wiederum in Korrelation mit dem pH Wert der Milch. In unserem Material fuhrten Euterinfektionen mit koagulasepositiven Staphylokokken zu den hochsten Lysozymwerten in der Milch. Summary Studies on the lysozyme concentration in blood and milk of healthy and udder-infected cows The lysozyme concentration and its natural as well as pathogenic variation were studied in 360 blood and 1059 milk samples from a Holstein-Friesian herd. The following results were obtained: 1. The lysozyme concentration of the milk rises with an increasing cell number in the milk. 2. There is no correlation between lysozyme concentration in the blood and in the milk. 3. The lysozyme titres in the milk vary according to the stage of lactation. No significant variation is due to the age of the animals. 4. The lysozyme titres in the blood depend on the age and stage of lactation of the animals. Heifers have lower titres in the blood than cows. 5. Lysozyme concentration and pH value in the milk are correlated. Linear regression lines could be drawn. 6. In bacteria-contaminated milk samples an increase in the lysozyme concentration of the milk is observed, again in correlation with the pH value. Udder infections with coagulase-positive staphylococci lead to the highest lysozyme titres in the milk. Resume Recherches sur le taux de lysozyme dans le sang et le lait de bovins sains et atteints de mammite On a recherche le taux de lysozyme dans le sang et le lait de vaches provenant d'un troupeau Holstein-Friesian. Les resultats suivants furent obtenus: 1. La concentration en lysozyme du lait augmente avec l'elevation du taux cellulaire dans le lait. 2. Il y a une correlation entre la concentration en lysozyme dans le sang et dans le lait. 3. Le taux de lysozyme dans le lait depend du stade de lactation et augmente jusqu'a la treizieme semaine post partum environ. L'âge des vaches n'a par contre pas eu d'influence significative. 4. Le taux de lysozyme du sang depend de l'âge et du stade de lactation des vaches. Les genisses possedent des concentrations de lysozymes sanguines plus basses que les vaches. 5. Il y a correlation entre le taux de lysozyme du lait et le pH du lait. Il en resulte une regression lineaire. 6. Une colonisation des quartiers de la mamelle par des germes provoque une augmentation du taux de lysozyme du lait et a nouveau une correlation avec les valeurs du pH du lait. Les infections de la mamelle a staphylocoques coagulase positive donnerent les valeurs les plus elevees dans le lait avec les echantillons examines dans ce travail. Resumen Estudios sobre el contenido de lisozima en sangre y leche de vacas sanas y mamiticas Se examino el contenido de lisozima en sangre y leche de vacas de una cabana Holstein-Frisona, obteniendose los resultados siguientes: 1. La concentracion de lisozima en leche aumenta con el contenido celular creciente en la misma. 2. No existe correlacion alguna entre la concentracion de lisozima en sangre y la lactea. 3. El contenido de lisozima en leche depende del estadio de lactacion y aumenta hasta la semana 13° post partum, aproximadamente. Sin embargo, la edad de las vacas no ejerce ningun influjo significante. 4. El contenido en lisozima sanguinea depende de la edad y estadio de lactacion de las vacas. Las novillas poseen concentraciones de lisozima en sangre mas bajas que las vacas. 5. El contenido de lisozima en sangre se halla correlacionado con el valor pH de la leche, resultando una regresion lineal. 6. La anidacion de germenes en los cuarterones ocasiona el aumento del contenido en lisozima lactea, correlacionando de nuevo con el valor pH de la leche. En nuestro material conducian las infecciones mamarias con estafilococos coagulasa-positivos a los valores maximos de lisozima en leche.

Zusammenfassung 202 Schweine aus 8 verschiedenen Rassen wurden mit dem Antigen DNP-Rinderserumalbumin immunisiert und das Vorkommen haptenspezifischer Antikorper im Serum der Schweine studiert. Als Nachweismethode diente der hochempfindliche Bakteriophagen-Neutralisationstest. Wahrend 49% der Schweine nach zweimaliger Injektion des Antigens keine nachweisbaren Antikorper bildeten, waren bei 38% schwache und bei 13% der Tiere relativ starke Antikorpertiter im Serum ausgebildet. Rassenspezifische Unterschiede im Reaktionsmuster traten auf. Die Haufigkeitsverteilung innerhalb der antikorperbildenden Population steht moglicherweise in Beziehung zu der Phanotypverteilung der Lymphocytenantigene. Summary Studies on the immune response to DNP hapten in different breeds of pigs The phage neutralization technique has been employed for the detection of anti-hapten antibodies in the serum of 202 pigs from 8 different breeds after immunization with DNP-bovine serum albumin. In the serum of 49% of the pigs no antibody activity was determined, 38% had weak antibody titres and 13% rather high antibody titres in the serum. Breed-specific differences in the frequency distribution of reagents and non-reagents appeared. This frequency distribution could in some instances be correlated with the phenotype distribution of the lymphocyte antigenic system of the pigs as revealed by cytotoxity tests. Resume Recherches sur la reponse immunitaire a un haptene-DNP chez plusieurs races porcines 202 Porcs de 8 races differentes ont ete immunises avec l'antigene albumineserique bovine-DNP et on a etudie l'apparition d'anticorps haptenes specifiques dans le serum des porcs. La methode de mise en evidence fut le test trrs sensible de neutralisation par bacteriophages. 49% des porcs ne presenterent aucun anticorps, 38% montrerent un titre d'anticorps serique faible et 13% un titre relativement eleve apres deux injections. Des differences entre les races sont intervenues. La frequence de repartition a l'interieur de la population formant les anticorps est probablement liee a la repartition phenotypique des antigenes lymphocytaires. Resumen Estudios sobre la respuesta inmunologica frente al hapteno DNP en varias razas porcinas Se inminizaron 202 cerdos de 8 razas diferentes con el antigeno albumina serica bovina DNP, detectandose la presencia de los anticuerpos anti-haptenos en el suero sanguineo de los cerdos. Como metodo de identificacion se recurrio a la muy sensible prueba de neutralizacion de bacteriofagos. Mientras que no formaban el 49% de los cerdos, tras inyeccion doble de antigeno, anticuerpos identificables, se habian formado en el 38% de los animales titulos debiles de anticuerpos en el suero, y relativamente elevados en el 13%. Surgieron diferencias especificas de raza en el modelo reaccional. Parece ser que la distribucion de las frecuencias dentro de la poblacion formadora de anticuerpos se halla relacionada con la distribucion fenotipica de los antigenos linfociticos.

Zusammenfassung Es wird uber Methoden der Entnahme und Konservierung von Blut zum Zwecke der Blutgruppenforschung beim Schwein berichtet. Hierbei wird die Brauchbarkeit verschiedener Stabilisatorlosungen diskutiert und uber eigene Erfahrungen mit der Tiefkuhlkonservierung von Schweineblut berichtet. Summary Blood group studies in pigs The technique of blood sampling and preservation The methods of obtaining blood samples and storing them are described, in relation to studies on blood groups in pigs. It was possible to store blood for long periods for use in immunisation and absorption studies. Up to a litre of blood was taken from the pigs and it could be stored satisfactorily at — 18° C when suitable precautions were taken. Resume Etude des groupes sanguins chez le porc La technique de recolte et de conservation du sang L'auteur indique les methodes de recolte et de conservation du sang pour les recherches sur les groupes sanguins chez le porc. Il discute a ce propos les possibilites d'utilisation de diverses solutions stabilisatrices et fait part de ses experiences personnelles concernant la conservation du sang de porc par surcongelation. Resumen Estudios sobre los grupos sanguineos del cerdo La tecnica de la toma de sangre y conservacion de la misma Se informa sobre tecnicas de la toma y conservacion de sangre para fines de investigacion de grupos sanguineos en el cerdo. Al mismo tiempo se discute la utilidad de diversas soluciones de estabilizadores y sobre experiencias propias con la conservacion a temperaturas bajas de sangre porcina.

Zusammenfassung Mit Hilfe eines modifizierten Opsonozytophagentests wurde die Phagozytoserate von neutrophilen Granulozyten im Blut von 405 Schweinen einer bayerischen Mastprufanstalt untersucht. Als Testkeim dienten R-Formen von Brucella abortus 1119. Der Prozentsatz der in vitro phagozytierenden Granulozyten variierte zwischen 67 und 100%. Auf die Variation hatte das Geschlecht der Tiere keinen Einflus, dagegen war der Phagozytoseprozentsatz signifikant geringer in den Fruhjahrsmonaten (Marz, April, Mai) als in den Sommermonaten (Juni, Juli, August). Die Berechnung von h2 (im weiteren Sinne) bei den Halbgeschwister- und Vollgeschwistergruppen ergab Hinweise dafur, das genetischen Einflussen eine gewisse Rolle beim Zustandekommen der Variation des Merkmals zufallt. Fur die tatkraftige Unterstutzung bei der Durchfuhrung der Versuche mochten die Verfasser dem Bayerischen Staatsministerium fur Ernahrung, Landwirtschaft und Forsten, insbesondere Herrn Reg. Dir. Dr. O. Richter, ihren Dank aussprechen. Summary Studies on the inheritance of phagocytosis index in pig blood With the help of a modified opsonocytophagic test, the phagocytosis index of neutrophil granulocytes was examined in the blood of 405 pigs in a progeny testing station in Bavaria. R forms of Brucella abortus 1119 were used as the test agent. The percentage of granulocytes engaged in phagocytosis in vitro varied between 67 and 100%. The variation was unaffected by sex but it was significantly lower in spring (March to May) than in summer (June to August). The calculation of h2 in groups of siblings and half siblings suggested that genetic factors might play some part in the occurrence of variations in this character. Resume Recherches sur la question de l'heredite du taux de phagocytose dans le sang des porcs A l'aide d'un test opsonocytophagique modifie, on examine les taux de phagocytose des granulocytes neutrophiles dans le sang de 405 porcs d'une station controle d'engraissement. Comme germes, on emploie les formes R de Brucella abortus 1119. Le pourcentage des granulocytes phagocytant in vitro varie entre 67 et 100%. Le sexe des animaux n'a aucune influence sur ces variations, mais par contre on trouve un pourcentage de phagocytose significativement plus faible pendant les mois printaniers (mars, avril, mai) que pendant les mois de l'ete (juin, juillet, aout). Le calcul de h2 (au sens large) pour les groupes de demi-freres ou de vrais freres semble indiquer qu'il faut attribuer un certain role a des influences genetiques dans la manifestation des variations du caractere considere. Resumen Estudios relativos al problema de la transmision hereditaria de la tasa de fagocitosis en la sangre de cerdos Con ayuda de una prueba modificada de opsonocitofagos se examino la tasa de fagocitosis de granulocitos neutrofilos en sangre de 405 cerdos de un centro de control del engorde en Baviera. Como germen de ensayo se utilizaron formas R de Brucella abortus 1119. El porcentaje de los granulocitos fagocitados in vitro variaba entre 67 y 100%. Sobre las variaciones no ejercia influjo el sexo de los animales, mientras que el porcentaje de fagocitosis era significativamente menor en los meses de primavera (Marzo, Abril, Mayo) que en los meses de verano (Junio, Julio, Agosto). El calculo de h2 (en el sentido mas amplio) en los grupos de semihermanos y hermanos integros ofrecio indicios de que a influjos geneticos le corresponde cierto papel en la constitucion de variaciones de la caracteristica.

Zusammenfassung In einem Selektionsexperiment an Mausen wurden zwei Linien mit hohem und niedrigem Phagozytosevermogen gezuchtet. Als einziges Selektionskriterium diente die Ausscheidungsrate kolloidaler Tusche aus dem Blut. Es zeigte sich, das das untersuchte Merkmal genetisch determiniert ist und einer polygenen Steuerung unterliegt. Die Hohe und Niedrige Linie divergierten im Verlauf der Selektion immer mehr. Die Schatzung der realisierten Heritabilitat ergab Werte von 0,30 in der Hohen Linie und 0,25 in der Niedrigen Linie. Es zeigte sich, das beide Linien sich auch noch in anderen Merkmalen unterschieden: z. B. Leber- und Milzgewicht, Antikorperbildungsvermogen, Resistenz gegenuber Infektionen, Vorkommen von spontanen und kunstlich induzierten Tumoren, sowie in der Vitalitat. Die erzielten Resultate sprechen dafur, das die polygene Regulation der Immunantwort der beste Garant dafur ist, das eine genetisch heterogene Population gegenuber einer Vielfalt von Infektionserregern geschutzt ist. Summary Establishment of two lines of mice, selected for high and low phagocytic activity In a two-way selection experiment with laboratory mice we succeeded in establishing lines with high and low phagocytic activity. The only criterion of selection has been the clearance rate of colloidal carbon from the blood. The character investigated was polygenic. High and low responder lines diverged progressively during the selective breeding. The estimates of realized heritabilities were 0.30 in the high line and 0.25 in the low line. The high and low lines differed significantly in further characteristics such as liver weight, spleen weight, antibody forming capacity, resistance to infections, incidence of spontaneous and benzpyren induced tumors and vitality. The results presented are in favour of the hypothesis that the polymorphic regulation of immune-responsiveness is a fundamental characteristic of the immunity system strategy ensuring the best possible multidirectional protection at the level of a genetically heterogeneous population. Resume Elevage resistant chez la souris: Etablissement de deux lignees de souris qui ont ete selectionnees sur leur capacite de phagocytose elevee et faible Deux lignees a capacite elevee et faible de phagocytose ont ete elevees dans une experience de selection sur des souris. Le taux de secretion de l'encre colloidale a partir du sang a servi d'unique critere de selection. On a montre que le caractere recherche est determine genetiquement et qu'il sen de base a un regulateur polygenique. La lignee elevee et la lignee basse ont diverge toujours plus au cours de la selection. L'evaluation de l'heritabilite realisee a donne les valeurs de 0,30 dans la lignee elevee et 0,25 dans la lignee basse. Il a ete montre que les deux lignees se differenciaient encore par d'autres caracteres: par exemple le poids du foie et de la rate, la capacite de formation d'anticorps, la resistance aux infections, l'apparition de tumeurs spontanees et induites artificiellement ainsi que dans la vitalite. Les reultats obtenus indiquent que la regulation polygenique de la reponse immunitaire est la meilleure garantie qu'une population genetiquement heterogene est protegee vis a vis d'un grand nombre d'agents infectieux. Resumen Cria a base de resistencia en el raton: Establecimiento de dos lineas murinas, las cuales fueron seleccionadas en cuanto a una facultad extrema y reducida de fagocitosis En un experimento de seleccion en ratones, se cultivaron dos lineas con facultad elevada y reducida de fagocitosis. Como criterio unico de seleccion sirvio la tasa de excrecion de tinta china coloidal a partir de la sangre. Se verifico que la caracteristica examinada esta determinada geneticamente y esta sujeta a un gobierno poligeno. Las lineas extrema y reducida divergian cada vez mas en el transcurso de la seleccion. El calculo de la heredabilidad realizada arrojo valores de 0,30 en la linea elevada y 0,25 en la reducida. Se mostro que ambas lineas aun se diferencian en otras caracteristicas: por ej. pesos del higado y bazo, capacidad de anticuerpogenesis, resistencia antiinfecciosa, aparicion de tumores espontaneos e inducidos artificialmente, asi como en la vitalidad. Los resultados obtenidos abogan a favor de que la regulacion poligena de la respuesta inmunologica es el garante mejor de que una poblacion geneticamente heterogenea se halla protegida frente a un sinnumero de agentes etiologicos infecciosos.

Zusammenfassung Die Lymphoidzell-Subpopulationen aus dem stromenden Blut und aus der Milz von Rindern und Schweinen wurden aufgrund ihrer Protein A-Rezeptoren, ihres Rosettenbildungsvermogens und ihres Verhaltens gegenuber Mitogenen charakterisiert. Schweinelymphoidzellen bildeten Spontanrosetten mit Schaferythrocyten, Rinderlymphoidzellen reagierten in ahnlicher Weise nur mit Neuraminidase-vorbehandelten Schaferythrocyten. 15% der Blutlymphocyten und Milzzellen des Rindes und 25–30% der entsprechenden Zellen des Schweines bildeten Spontanrosetten. Nach Vorbehandlung der Lymphoidzellen und der Schaferythrocyten mit Neuraminidase stieg der Anteil E-rosettenbildender Zellen weiter auf 30% beim Rind und uber 45% beim Schwein. Etwa 20% der untersuchten Lymphoidzellen des Rindes und der Milzzellen des Schweines bildeten EAC-Rosetten. Der entsprechende Anteil im Schweineblut betrug nur 10%. Der gefundene Prozentsatz FITC-Protein A positiver Zellen korrelierte gut mit der Anzahl EAC-rosettenbildender Zellen mit Ausnahme bei den Rinderblutlymphocyten. Rinder- und Schweinelymphoidzellen lassen sich durch die Mitogene PHA, PWM, Con A und durch bakterielles Lipopolysaccharid stimulieren. Zur Gewinnung stark angereicherter B- und T-Zellpopulationen von Rind und Schwein eignen sich die Methoden der Rosettensedimentation und Filtration durch Nylonfasersaulen. Das Verhalten dieser angereicherten Zellpopulationen gegenuber Mitogenen verleitet zu dem Schlus, das T-Zellen fur eine Stimulation durch PHA, Con A und PWM erforderlich sind, wahrend die LPS induzierte Stimulation B-zellabhangig ist. Summary Comparative studies on lymphocyte sub-populations of cattle and pigs The lymphoid cell sub-populations in the circulating blood and in the spleen of cattle and pigs were characterized on the basis of their protein A-receptors, ability to form rosettes and their reaction to mitogens. Pig lymphoid cells formed rosettes spontaneously with sheep red cells. Cattle lymphoid cells react similarly only with sheep red cells pretreated with neuraminidase. 15% of the blood lymphocytes and spleen cells of cattle and 25–30% of the corresponding cells of pigs produce spontaneous rosettes. After pretreatment of the lymphoid cells and sheep erythrocytes with neuraminidase the number of E-rosette forming cells rises further to 30% in cattle and more than 45% in pigs. Some 20% of the lymphoid cells of cattle and of the spleen cells of pigs examined produce EAC-rosettes. The corresponding figure for pig blood was only 10%. The percentage of FITC-protein A positive cells found correlated well with the number of EAC-rosette forming cells, with the exception of cattle blood lymphocytes. Cattle and pig lymphoid cells can be stimulated by the mitogens PHA, PWM, and Con A and by bacterial lipopolysaccharide. To obtain much enriched B- and T-cell populations from cattle and pigs the methods of rosette sedimentation and filtration through nylon fibre columns are well suited. The behaviour of such cell-enriched populations towards mitogens leads to the conclusion that T-cells lead to stimulation by PHA, Con A and PWM, whereas stimulation induced by LPS depends on B-cells. Resume Recherches comparees sur des sous-populations de lymphocytes chez le bovin et le porc Des sous-populations de cellules lymphoides provenant du sang et de la rate de bovins et de porcs ont ete caracterisees sur la base de leurs recepteurs proteine A, de leur capacite a former des rosettes et de leur comportement vis-a-vis de mitogenes. Les cellules lymphoides de porc ont forme spontanement des rosettes avec des erythrocytes de moutons alors que les cellules lymphoides de bovin n'ont reagi de la meme facon avec des erythrocytes de mouton qu'en presence de neuraminidase. 15% des lymphocytes du sang et des cellules de la rate du bovin et 25–30% des měmes cellules du porc ont forme spontanement des rosettes. Le nombre de cellules formant des rosettes E est monte a 30% chez le bovin et au-dessus de 45% chez le porc apres un traitement preliminaire des cellules lymphoides et des erythrocytes du mouton a la neuraminidase. 20% des cellules lymphoides examinees du bovin et des cellules de la rate du porc ont forme des rosettes EAC. Le nombre correspondant dans le sang du porc fut de seulement 10%. Le pourcentage trouve de cellules positives a proteine A-FITC a bien correspondu au nombre de cellules formant des rosettes EAC a l'exception des lymphocytes du sang de bovin. Les cellules lymphoides du bovin et du porc ont ete stimulees par les mitogenes PHA, PWM, Con A et par du lipopolysaccharide bacterien. Les methodes de sedimentation des rosettes et de filtration sur colonnes en fibre de nylon ont convenu a l'obtention de population en cellules B et T enrichies pour le bovin et le porc. Le comportement des ces populations cellulaires enrichies vis-a-vis de mitogenes a permis de conclure ques les cellules T se prětent a une stimulation par PHA, Con A et PWM alors que LPS convient pour une stimulation induite des cellules B. Resumen Estudios comparados con subpoblaciones linfocitarias de vacas y cerdos Se caracterizan las subpoblaciones de celulas linfoides de sangre circulante y esplenicas de vacunos y cerdos en atencion a sus receptores proteicos A, su capacidad rosetogena y su porte frente a mitogenos. Las celulas linfoides porcinas formaban rosetas espontaneas con eritrocitos ovinos, mientras que las celulas linfoides reaccionaban solo de forma similar si los eritrocitos de oveja estaban pretratados con neuraminidasa. 15% de los linfocitos sanguineos y celulas esplenicas de vacunos y 25–30% de las celulas correspondientes de cerdos formaban rosetas espontaneas. Tras pretratamiento de las celulas linfoides y eritrocitos ovinos con neuraminidasa siguio aumentando la fraccion E de las celulas rosetogenas hasta un 30% en vacunos y mas alla del 45% en cerdos. El 20% aprox. de las celulas linfoides examinadas de vaca y de las celulas esplenicas de cerdo formaban rosetas EAC. La fraccion correspondiente en la sangre de cerdo no importaba mas que el 10%. El porcentaje hallado de celulas FITC-proteina A positivas correlacionaba harto bien con la cantidad de celulas rosetogenas EAC, con excepcion de los linfocitos sanguineos vacunos. Las celulas linfoides de vacas y cerdos pueden estimularse mediante los mitogenos PHA, PWM, Con A y un lipopolisacarido bacteriano. Para obtener poblaciones celulares B y T enriquecidas fuertemente de vacunos y cerdos, resultan apropiados los metodos de sedimentacion de rosetas y filtracion a traves de columnas de fibras de nylon. El comportamiento de estas poblaciones celulares enriquecidas frente a los mitogenos seduce a sacar en conclusion que las celulas T son precisas para la estimulacion por PHA, Con A y PWM, mientras que la estimulacion inducida por los LPS depende de las celulas B.

SUMMARY Callophyllis variegata is a red alga that has been exported to Japan as an edible seaweed over the past few years. Available data strongly suggest that after a few years of exploitation of the C. variegata stands in southern Chile, a decline of its abundance seems to be occurring. However, there is not sufficient knowledge available to sustain harvesting strategies or to develop cultivation techniques. This study describes the C. variegata landings in the south of Chile and also provides some basic data on the biology of this species. Experiments related to the cultivation of early developmental stages, frond cultivation under controlled conditions and the regeneration capacity of the holdfast of this red alga are also presented. Spore production occurs mainly in autumn and winter and survival of carpospores decreased as the temperature increased from 8 to 12°C. Survival of tetraspores increased significantly, from 50 to 60% to over 80%, when temperature was raised from 8 to 12°C. Carpospore survival was also significantly affected by the photon flux density. This effect was mainly at 8°C, whereas at 33 mmol m -2 s -1 the survival of the spores is always low. The cultivation of apical portions of C. variegata under laboratory conditions showed that lower temperatures (8°C) significantly increased growth. Salinity and photon flux density did not have an effect on specific growth rate. Laboratory experiments demonstrated that holdfasts can regenerate fronds and that these fronds can be excised and cultivated, and are far more tolerant to environmental factors than the apical portions.

Some species of macroalgae continue to live for extended periods of time after detachment and may even maintain reproductive structures, yet very little is known about this process. Here, we describe the presence of sporophylls (with sporogenous tissues) on floating kelp rafts of Macrocystis spp. along the coast of Chile. Surveys were conducted at nine sites (18‐501 S) during austral summer 2002, and floating kelp rafts were seen and collected at seven of these nine sites (between 22 and 501 S). Fifteen (26.8%) of the 56 samples had sporophylls, indicating maintenance of sporophylls after detachment. Some of the kelp sporophytes with reproductive blades showed signs of having been afloat for long periods (indicated by the large size of attached stalked barnacles). Additionally, experiments showed that floating kelps released viable zoospores. To understand the reproductive dynamics of floating kelps, we compared these results with information from attached populations of Macrocystis spp. at nearby coastal sites. In general, attached kelp had higher proportions of sporophylls than floating rafts, suggesting that detachment may negatively affect reproductive status. Nevertheless, floating kelps remained functionally reproductive, suggesting that zoospores may be dispersed via floating rafts. Published reports on other macroalgae indicate that some species (Lessoniaceae, Fucaceae, and Sargassaceae) are fertile and probably release zoospores or zygotes while floating or drifting in ocean currents. Because dispersal distances achieved by spores of most macroalgae are relatively short, release of spores from floating algae may be an alternative mechanism of long-distance dispersal.

Endothelial cells, covering the inner surface of vessels and the heart, are permanently exposed to fluid flow, which affects the endothelial structure and the function. The response of endothelial cells to fluid shear stress is frequently investigated in cone-plate systems. For this type of device, we performed an analytical and numerical analysis of the steady, laminar, three-dimensional flow of a Newtonian fluid at low Reynolds numbers. Unsteady oscillating and pulsating flow was studied numerically by taking the geometry of a corresponding experimental setup into account. Our investigation provides detailed information with regard to shear-stress distribution at the plate as well as secondary flow. We show that: (i) there is a region on the plate where shear stress is almost constant and an analytical approach can be applied with high accuracy; (ii) detailed information about the flow in a real cone-plate device can only be obtained by numerical simulations; (iii) the pulsating flow is quasi-stationary; and (iv) there is a time lag on the order of 10(-3) s between cone rotation and shear stress generated on the plate.

The rapid development of intensive fed aquaculture (e.g. finfish and shrimp) throughout the world is associated with concerns about the environmental impacts of such often monospecific practices, especially where activities are highly geographically concentrated or located in suboptimal sites whose assimilative capacity is poorly understood and, consequently, prone to being exceeded. One of the main environmental issues is the direct discharge of significant nutrient loads into coastal waters from open-water systems and with the effluents from land-based systems. In its search for best management practices, the aquaculture industry should develop innovative and responsible practices that optimize its efficiency and create diversification, while ensuring the remediation of the consequences of its activities to maintain the health of coastal waters. To avoid pronounced shifts in coastal processes, conversion, not dilution, is a common-sense solution, used for centuries in Asian countries. By integrating fed aquaculture (finfish, shrimp) with inorganic and organic extractive aquaculture (seaweed and shellfish), the wastes of one resource user become a resource (fertilizer or food) for the others. Such a balanced ecosystem approach provides nutrient bioremediation capability, mutual benefits to the cocultured organisms, economic diversification by producing other value-added marine crops, and increased profitability per cultivation unit for the aquaculture industry. Moreover, as guidelines and regulations on aquaculture effluents are forthcoming in several countries, using appropriately selected seaweeds as renewable biological nutrient scrubbers represents a cost-effective means for reaching compliance by reducing the internalization of the total environmental costs. By adopting integrated polytrophic practices, the aquaculture industry should find increasing environmental, economic, and social acceptability and become a full and sustainable partner within the development of integrated coastal management frameworks.

Zusammenfassung Die Messung der Oxidation von Glukose-1-14C stellt ein geeignetes Verfahren dar, um die Phagozytoseaktivitat von Blutleukocyten beim Haustier zu messen. Summary The measurement of phagocytic activity in the blood of domestic animal The measurement of oxidation of glucose-1-14C to 14CO2 during phago-cytosis is a reliable testing method for the phagocytic activity in the whole blood or in isolated polymorphonuclear leucocytes from domestic animals.

This study addresses the issues of infection prevalence and disease expression in two wild populations of the red algal host Mazzaella laminarioides and their variability associated with locality, season, and spatial location of the host in the intertidal zone. Our results demonstrated that Endophyton ramosum is the most frequent infective pathogen affecting M. laminarioides in Matanzas and Pucatrihue. This situation prevailed through the year and across the high-to-low intertidal gradient. Although there was a general trend for lower levels of infection in late winter and early spring, only in a few, cases was well-defined seasonality detected. Furthermore, clear seasonal patterns, as displayed by deformative disease in the high intertidal zone of Pucatrihue, were attenuated in the middle and lower intertidal zones. Differences in levels of infection in M. laminarioides between the high intertidal zones of Matanzas and Pucatrihue diminished toward the low intertidal zone. Thus, effects of seasonality and locality on infection prevalence may be influenced, at least in part, by the position of the hosts an the intertidal zone. Spatial distribution of the diseased individuals also varied along the beach. This pattern was consistent between the two sites and seemed related to wave exposure and the specific pathogen. Comparisons of the size distribution of noninfected fronds with their infected counterparts showed that infections by Endophyton ramosum and Pleurocapsa sp. more frequently affected medium-and large-sized fronds. This pattern was consistent temporally and similar in the two localities. Finally, a clear association between maturity and prevalence of infection was detected. This association resulted in most fronds of the noninfected segment of the host population being immature, whereas most mature fronds were infected. In conclusion, infectious diseases affecting the red alga Mazzaella laminarioides are a persistent phenomenon in wild populations of the host, although only a small segment of the infected populations displays the full expression of the disease. In spite of the suggested role of factors such as season, latitude, and spatial location of the host on disease prevalence and expression, additional studies are needed to understand fully the dynamics of infectious diseases in wild populations of algal hosts.

Evidence about the potential of mobile marine invertebrates to act as algal spore dispersal agents is presently circumstantial. Using a field correlational and experimental protocol, our study tested the hypothesis that amphipods can increase the spore recruitment of the red alga Iridaea laminarioides Bory. Iridaea laminarioides spore recruitment onto glass slides was measured at a site with high amphipod abundance and a site with low density of amphipods. To evaluate the effect of an Ulva canopy on recruitment, replicated glass slides with and without a surrounding Ulva canopy were installed at both sites. The number of I. laminarioides spores recruited on the glass slides was four to eight times higher at the high amphipod abundance site than at the low density site. However, the presence of an Ulva canopy covering the glass slides did not significantly increase the recruitment of I. laminarioides. Because the abundance of I. laminarioides, the proportion of cystocarpic plants, and the percentage of open cystocarps only differed slightly between the low and high abundance amphipod sites, we suggest that the variation in recruitment between the sites is due to the differences in amphipod abundance (and their movements) and not to differences in spore production. Moreover, the presence of I. laminarioides cystocarps showing amphipod grazing scars was significantly higher at the high amphipod density site than at the low density site.

Mid and late successional benthic algae have poor dispersal capacities. Mobile herbivores may increase dispersal of some algae because spores can survive digestion by grazers and stick to external body appendages. We show that carpospores are the only type of reproductive unit of the rhodophyte Iridaea laminarioides Bory that survive passage through the digestive tract of the amphipod Hyale sp. The spores also stick to the amphipods' legs and are thus carried by the amphipods in the field. Amphipods significantly increased (P < 0.01) the number of spores settling on artificial substrata in places where barriers prevented the normal ingress of algal propagules. The presence of artificial substrata that act as a refuge for the grazers also caused an increase (P < 0.01) in the number of settled spores. Amphipods also significantly increased (P < 0.01) the number of spores under an Ulva sp. canopy in laboratory experiments.

Zusammenfassung Es wird eine Modifikation der Antikorper-Plaque-Technik beschrieben, mit der es gelang, einzelne antikorperbildende Zellen in der Milz und den Lymphknoten beim Schwein nachzuweisen. Summary Using a modified antibody plaque technique specific detection of individual antibody-forming cells in spleens and lymphnodes of pigs was possible. The plaques only became visible when both rabbit and guinea pig serum were used as complement source.

Endothelial cells, covering the inner surface of human vessels and the heart are permanently exposed to fluid shear stres s which strongly affects endothelial structure and function . Due to their location at the interface between blood-flow an d the vascular wall endothelial cells play an essential role in he modynamics. We present a complex computational model based on the Navier-Stokes equations, Donell’s shell equations, an d additional constitutive systems of equations for the desc ription of the flow around and inside of endothelial cells. 1 Motivation and Introduction The term atherosclerosis is used to describe several diseases affecting the cardiova scular system, in particular the arteries and vessels. Atherosclerosis develops over a period of many years and invades both the superficial and the deep layers of the v essel walls. Precursor of an atherosclerotic lesion is a damage of the endothelial monolayer. These endothelial cells (EC) covering the inner surface of the vessel wall and the heart are permanently exposed to fluid shear stress. Due to their location at th e interface between blood flow and the vascular wall, endothel ial cells play a vital role in hemodynamic situations. It is k nown that the blood flow affecting EC influences significantly morp hology, neogenesis and regression of vessels. In regions of pre-atherosclerotic lesions EC are affected b y blood-flow induced instantaneous fluid shear stress which a lters in direction and intensity. From a mechanical point of view this heterogeneous shear-stress contributes to endothelia l lesions and advances the atherosclerotic processes. Since EC have an individual topological structure - prominent nucleus, varying surface shape - the shear stress is different in different su b-cellular regions. This knowledge leads to our main hypothesis concerning fluid shear-stress induced atherosclerosis

In Chile, the demand of edible seaweeds has increased during recent years and Callophyllis variegata is one of the most demanded species. This study summarizes information on phenology, aspects, in vitro culture and vegetative propagation methods for Callophyllis. Results indicate that spore production occurs mainly during winter, and recruitment of new plants appear in nature in the spring. Culture studies indicate that spores presented higher germination and growth rates at 8° C and 10 to 12 μmol m−2 s−1. Furthermore, these results indicate that this species presents a high potential for regeneration from its holdfast. The manipulation of temperature, light and culture medium enhances the regeneration process and growth of Callophyllis in the laboratory.