Use of the carbon dioxide laser for perianal and rectal surgery.

The skin of the perianal region is very thin and sensitive. The carbon dioxide laser is a very effective tool for removing tumors and treating conditions of this area. It offers a "no touch" method of treatment for conditions of the perianal region. There is less bleeding, less pain, less swelling with the use of the carbon dioxide laser. The carbon dioxide laser is an effective tool for excising perianal tumors, rectal tumors, performing anal sacculectomies and treating perianal fistulas.     

Comparative study of serological methods for the detection of antibodies to porcine reproductive and respiratory syndrome virus.

A comparison was made of serological diagnostic methods used for the detection of antibodies against porcine reproductive and respiratory syndrome (PRRS) virus. In the "phase I" PRRS test panel comparison, a panel of sera collected from 135 pigs of various ages, from North American herds with and without PRRS histories, were sent to 4 different laboratories and tested by an indirect immunofluorescent assay (IFA), an immunoperoxidase monolayer assay (IPMA) and an indirect enzyme-linked immunosorbent assay (iELISA). In the "phase II" PRRS test panel comparison, a panel of 382 sera collected from pigs of various ages, PRRS histories, and from various locations in North America and France, were divided into 2 panels (A & B) and sent to 3 Canadian laboratories and tested by the IFA and iELISA. In the phase I comparison, agreement between the IFA of laboratory 4 and the iELISA and IPMA of laboratory 3 was excellent (kappa values of 95% and 98%, respectively). This contrasted with the poor agreement between these laboratories and the IFA results of laboratories 1 and 2 in the phase I trial. In the phase II comparison, the results demonstrated good agreement between various tests both within and between laboratories. The overall performance of the iELISA was superior in the combination of sensitivity (96.1%) and specificity (100%) relative to the reference classification of the serum samples and repeatability (kappa value 98%). The iELISA is technically superior to IFA and IPMA, time efficient, cost effective and suitable for testing of a large number of samples over a short period of time. Thus, the iELISA may be a better alternative to IFA or IPMA for routine detection of PRRS viral antibodies in swine sera.     

Regulation of rumen lactate metabolism and the role of lactic acid in nutritional disorders of ruminants

This paper present recent results concerning both the role of lactate as an intermediate in rumen fermentation, and the rapid accumulation of lactic acid in ruminant lactic acidosis and related syndromes. Special attention is given to the factors which regulate microbial lactate formation and fermentation in the rumen.When readily fermentable carbohydrates are presented to the rumen microflora there is at first a rapid fermentation to normal end-products which include the volatile fatty acids. These cause a decrease in the pH which may fall below the critical value of 5.5. As a result changes occur in the microbial population: protozoa are killed, methanogenic bacteria and lactate fermenters are inhibited, streptococci and finally lactobacilli are selectively increased. In many anaerobic and facultative aerobic bacteria lactic acid formation is selectively increased within the cell during rapid fermentation of carbohydrate. When the rate of glycolysis is high, increased intracellular levels of fructose-1, glycolysis is high, increased intracellular levels of fructose-1, 6-diphosphate may activate the enzyme lactate dehydrogenase. The importance of the buffer capacity of rumen contents and saliva and the rate of salivation in preventing the acidic conditions within the rumen are stressed. Bicarbonate is the most important buffer component in preventing the decrease in pH.The lactate fermentation capacity of rumen contents is determined by the substrate concentration and by the diet which is fed to the animals. During adaptation to a concentrate diet or to a diet which contains lactic acid there is an increase in the number of lactilytic bacteria. Feeding lactates or lactate containing silages, although it raises the capacity of the rumen contents to ferment lactic acid, has not proved to be a satisfactory way to adapt ruminants to high-energy rations. In the case of lactate feeding this may be because a group of CO₂-requiring organisms is selectively encouraged instead ofMegasphaera elsdenii, the only important lactate fermenter which is able to grow at low pH values. This hypothesis and suggestions for further work on this problem are discussed.

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Kurzfassung Neuere Erkenntnisse über die Rolle von Laktat als Träger der Pansenfermentation und die schnelle Akkumulierung von Milchsäure bei Laktatazidose von Wiederkäuern sowie verwandte syndrome werden unter besonderer Beachtung von Faktoren die die mikrobische Laktatbildung und Fermentation im Pansen regulieren, erörtert.Werden den Pansenmikroben leicht fermentierbare Kohlehydrate angeboten, so findet zunächst eine schnelle Fermentation zu normalen Endprodukten statt, zu denen flüchtige Fettsäuren gehören. Diese verursachen einen Abfall des pH-Werts, unter Umständen unter die Kritische Schwelle von 5,5. Das Ergebnis sind Aenderungen der Mikrobenpopulation: Protozoen werden abgetötet, methanogene Bakterien und Laktatfermentatoren inhibiert, Streptokokken und schliesslich Laktobazillen selektiv vermehrt. Bei vielen anaerobischen und fakultativ aerobischen Bakterien wird die Milchsäurebildung in der Zelle während der schnellen Fermentation von Kohlehydraten selektiv verstärkt. Bei hohem Glykolysesatz kann es zur Aktivierung der Enzymlaktatdehydrogenase durch erhöhte intrazelluläre Werte von Fruktose-1, 6-Diphosphat kommen. Die Bedeutung der Pufferkapazität des Panseninhalts und des Speichels sowie der Speichelflussrate zur Verhütung einer Uebersäue-rung im Pansen werden hervorgehoben. Bikarbonat ist die wichtigste Pufferkomponente zur Verhütung eines pH-Abfalls.Die Fähigkeit zur Laktatfermentation des Panseninhalts wird bestimmt durch die Substratkonzentration und durch das den Tieren verabreichte Futter, dem die Probe des Panseninhalts entnommen wird. Während der Anpassung an konzentriertes oder Milchsäure enthaltendes Futter nimmt die Zahl der laktolytischen Bakterien zu. Die Verfütterung von Laktaten oder laktat haltigem Silofutter wird zwar die Fähigkeit des Pansen inhalts zur Fermentation von Milchsäure steigern, hat sich jedoch nicht als zufrieden-stellende Art der Anpassung von Wiederkäuern an Hochenergierationen erwiesen. Das kann daran liegen, dass im Fall der Laktatfütterung an Stelle vonMegasphaera elsdenii, dem einzig wichtigen Laktatfermentator, der bei niedrigen pH-Werten wachsen kann, die Grupe der CO₂ benötigenden Organismen selektiv gefördert wird. Diese Hypothese und Anregungen für weitere Arbeiten in dieser Richtung werden erörtert.

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Resume Les auteurs procèdent à l'examen des résultats obtenus récemment sur le rôle du lactate en tant qu'agent de fermentation dans le rumen, l'accumulation rapide de l'acide lactique dans l'acidose lactique des ruminants et les syndromes connexes. Ils considèrent en particulier les facteurs de régulation de la formation de bacilles lactiques et la fermentation dans le rumen.Quand des hydrates de carbone immédiatement fermentables sont fournis aux microbes du rumen, il se produit tout d'abord une fermentation rapide qui aboutit à la formation des produits finals normaux, notamment des acides gras volatils. Ces derniers entraînent une baisse du pH, qui tombe parfois au-dessous de la valeur critique 5.5. En conséquence, des modifications interviennent dans la population microbienne: les protozoaires sont tués, les bactéries méthanogènes et les ferments lactiques sont paralysés, les streptocoques et enfin les lactobacilles voient leur nombre s'accroître pour certains d'entre eux. Chez de nombreuses bactéries anaérobies et par fois aérobies, la formation d'acide lactique s'accroit selectivement dans la cellule au cours de la fermentation rapide des hydrates de carbone. Quand le taux de glycolyse est elévé, il peut se produire une activation de la déshydrogénase de l'enzyme lactique du fait d'un accroissement des niveaux intracellulaires de fructose-1, 6-diphosphate. Les auteurs soulignent l'importance du rôle de tampon que jouent le contenu du rumen, la salive et le taux de salivation pour éviter le développement d'un milieu acide dans le rumen. Le bicarbonate est l' element tampon essentiel au maintien du pH.La capacité de fermentation lactique du contenu du rumen est fonction de sa concentration en substrats et du régime alimentaire de l'animal avant qu'on ne préléve echantillons du contenu du rumen. Pendant la période d'adaptation à une nourriture concentrée ou à une nourriture contenant de l'acide lactique, il se produit une augmentation du nombre des bacilles lactiques. L'apport dans la nourriture de lactates ou de silages contenant des lactate augmente la capacité du contenu du rumen a faire fermenter l'acide lactique mais ne s'est pas révélé pour une manière satisfaisante d'habituer les ruminants a un régime hautement énergétique. Cela peut etre dû au fait que, dans le cas d'une alimentation à base de lactates, le groupe d'organismes demandant la presence de CO₂ se trouve selectivement favorisé aux dépens desMegasphaera elsdenii, seul ferment lactique important capable de se développer avec un pH faible. Les auteurs examinent cette hypothèse ainsi que les suggestions pour la poursuite des travaux sur cette question.

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Riassunto Vengono discussi i risultati di recenti ricerche sul ruolo del lattato come intermediario nella fermentazione nel rumine e sul rapido accumulo di acido lattico nella acidosi lattica ed in altre analoghe sindromi dei ruminanti. Vengono esaminati in particolare i fattori che presiedono alla regolazione della formazione e fermentazione microbica del lattato nel rumine.Quando la flora microbica del rumine riceve carboidrati di agevole fermentazione, si verifica dapprima una fermentazione rapida che dà origine ai normali prodotti di fermentazione, fra cui acidi grassi volatili. Questi provocano una caduta del pH, che può scendere al di sotto del valore critico di 5,5; a ciò conseguono alterazioni della popolazione microbica: vengono uccisi i protozoi, vengono inibiti i batteri metanogeni e i microrganismi che fermentano il lattato, mentre gli streptococchi e, da ultimo, i lattobacilli subiscono un aumento selettivo. In molti batteri anaerobi e aerobi facoltativi, la formazione di acido lattico aumenta selettivamente all'interno della cellula durante la fermentazione rapida dei carboidrati. Nel caso di un elevato tasso di glicolisi, si può verificare l'attivazione dell'enzima deidrasi del lattato in seguito all'aumento dei livelli intercellulari di fruttosio-1 e 6-bifosfato. Viene sottolineata l'importanza, come tampone, del contenuto del rumine, della saliva e del tasso di salivazione nel prevenire l'instaurarsi di uno stato di acidità nel rumine stesso. Il bicarbonato rappresenta l'elemento tampone principale capace di prevenire la caduta del pH.La capacità di fermentazione del lattato del contenuto del rumine e determinata dalla concentrazione del substrato e dalla dieta somministrata agli animali da cui vengono prelevati i campioni di contenuto ruminale. Durante il periodo di adattamento ad una dieta concentrata, o ad una dieta contenente acido lattico, si verifica un aumento dei batteri lattolitici. La somministrazione di lattati, o di foraggi contenenti lattati, benché capace di potenziare la capacità di fermentazione dell' acido lattico da parte del contenuto del rumine, non si è tuttavia dimostrata misura adatta per abituare i ruminanti ad una alimentazione ad alto tenore energetico. Ciò può essere in relazione al fatto che, nel caso di una alimentazione ricca di lattato, il gruppo dei microrganismi CO₂-dipendenti viene selettivamente favorito in luogo diMegasphaera elsdenii, il solo importante microrganismo fermentatore del lattato capace di svilupparsi in presenza di bassi valori del pH. Tale impotesi, e proposte per ulteriori ricerche sul problema sono oggetto di discussione.

     

An extended deletion map of the Lr19 translocation and modified forms

A physical deletion map of the Lr19 translocated chromosome segment was extended by mapping three additional Thinopyrum RFLP loci. The relative locations of the marker loci on the translocated segment were determined as: centromere, Sd1, Xpsr165, Xpsr105, Xpsr129, XcsIH81-1, Xwg380, Xmwg2062, Lr19, Wsp-D1, Sr25/Y. Various recombinants, putative recombinats and mutants of the Lr19 segment were also characterised with respect to the additional markers. This revised version was published online in August 2006 with corrections to the Cover Date.     

Distribution of methyl bromide in soils treated for nematode control in replant vineyards

Methyl bromide was applied with and without polyethylene covers at rates of 337, 449, 673 and 898 kg/ha to replant vineyard soils to control plant parasitic nematodes. Distribution of the gas in the soil atmosphere at different depths was measured by gas chromatography. Higher doses, low soil moisture and deeper placement of methyl bromide resulted in more rapid soil penetration and higher concentrations of the gas at the deeper soil levels. Placement of methyl bromide in the soil at 0.76-0.81 m without polyethylene cover resulted in gas distribution at concentrations sufficient for nematode kill as deep as 2.44 m.     

Impeded Thrips Transmission of Defective Tomato spotted wilt virus Isolates

Two defective RNA-containing isolates (Pe-1 and 16-2) and an envelope-deficient (env ) isolate of Tomato spotted wilt virus (TSWV) were tested for their transmissibility by Frankliniella occidentalis. The Pe-1 isolate contained a truncated L RNA segment that barely interfered with symptom expression and replication of the wild-type (wt) L RNA segment. This isolate was transmitted with an efficiency of 51%, a value comparable to that found for wt TSWV (54%). Isolate 16-2, which contained a genuine defective interfering L RNA as concluded from its ability to suppress wt L RNA synthesis and attenuation of symptom expression, was not transmitted at all. The midguts of all larvae that ingested Pe-1 became infected, whereas limited midgut infections were found in 24% of the larvae that ingested 16-2. This difference in infection could be explained by the presence of a low number of infectious units in the inoculum ingested from plants as demonstrated in infection experiments and verified by northern blot analysis. The env isolate failed to infect the midgut after ingestion and could not be transmitted by any thrips stage. This isolate also cannot infect primary thrips cell cultures. Taken together, these results suggest that the envelope of TSWV contains the determinants required for binding and subsequent infection of thrips cells.     

Application of Phage Display in Selecting Tomato spotted wilt virus-Specific Single-Chain Antibodies (scFvs) for Sensitive Diagnosis in ELISA

ABSTRACT A panel of recombinant single-chain antibodies (scFvs) against structural proteins of Tomato spotted wilt virus (TSWV) was retrieved from a human combinatorial scFv antibody library using the novel phage display technique. After subcloning the encoding DNA sequences in the expression vector pSKAP/S, which allowed the scFvs to be expressed as alkaline phosphatase fusion proteins, 17 different scFv antibodies were obtained. Of these, 12 scFvs were directed against the nucleoprotein (N) and 5, putatively, against the glycoproteins (G1 and G2). Five of the N-specific antibodies cross-reacted with two other tospoviruses (Tomato chlorotic spot virus and Groundnut ringspot virus), but none recognized the more distantly related tospoviruses Impatiens necrotic spot virus, Watermelon silverleaf mottle virus, Iris yellow spot virus, or Physalis severe mottle virus. The successful use of one of the antibodies as coating and detection reagent in a double-antibody sandwich enzyme-linked immunosorbent assay showed the potential of the phage display system in obtaining antibodies for routine TSWV diagnosis.     

The immune response against Chlamydia suis genital tract infection partially protects against re-infection

The aim of the present study was to reveal the characteristic features of genital Chlamydia suis infection and re-infection in female pigs by studying the immune response, pathological changes, replication of chlamydial bacteria in the genital tract and excretion of viable bacteria. Pigs were intravaginally infected and re-infected with C. suis strain S45, the type strain of this species. We demonstrated that S45 is pathogenic for the female urogenital tract. Chlamydia replication occurred throughout the urogenital tract, causing inflammation and pathology. Furthermore, genital infection elicited both cellular and humoral immune responses. Compared to the primo-infection of pigs with C. suis, re-infection was characterized by less severe macroscopic lesions and less chlamydial elementary bodies and inclusions in the urogenital tract. This indicates the development of a certain level of protection following the initial infection. Protective immunity against re-infection coincided with higher Chlamydia-specific IgG and IgA antibody titers in sera and vaginal secretions, higher proliferative responses of peripheral blood mononuclear cells (PBMC), higher percentages of blood B lymphocytes, monocytes and CD8⁺ T cells and upregulated production of IFN-γ and IL-10 by PBMC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0095-6) contains supplementary material, which is available to authorized users.