Lignocaine versus bupivacaine for flank anaesthesia using multiport catheters via a caudal epidural approach in cattle

Objective To determine the anaesthetic and systemic effects of dorsolumbar epidural anaesthesia using non-stylet multiport catheters via the caudal approach to administer hypertonic 5% lignocaine (HL) or hypertonic 0.5% bupivacaine (HB) to the flank in standing cattle. Materials and methods Six healthy adult cattle weighing 310–455 kg received 0.2 mg/kg HL or 0.025 mg/kg of HB; control animals received 0.9% saline solution. All drugs were injected into the dorsolumbar epidural space via a caudal approach through a non-stylet multiport catheter. Each animal received each treatment at random. Evaluations of anaesthesia, ataxia, heart rate, arterial pressures, respiratory rate and rectal temperature were obtained at 0 (basal), 5, 10, 15, 30, 45, 60, 75, and 90 min after epidural injection and then at 30-min intervals until loss of anaesthesia. All animals received a standard noxious stimulus and a 4-point scale was used to score the response. A second scale was used to score ataxia. Results The duration of anaesthesia in the upper and lower flanks in cattle was 68 ± 12 and 110 ± 15 min (mean ± SD) after dorsolumbar epidural HL or HB, respectively. Both hypertonic local anaesthetics produced a mild ataxia. The systemic changes were within acceptable limits in these clinically healthy cattle. Conclusion In standing cattle the dorsolumbar epidural injection of hypertonic lignocaine provided faster onset of anaesthesia and fewer cardiovascular effects, but had a shorter duration of anaesthesia than hypertonic bupivacaine.     

Immunogenicity in dogs of three recombinant antigens (TSA, LeIF and LmSTI1) potential vaccine candidates for canine visceral leishmaniasis

Control of canine visceral leishmaniasis (VL) remains a difficult and serious problem mostly because there is no reliable and effective vaccine available to prevent this disease. A mixture of three recombinant leishmanial antigens (TSA, LeIF and LmSTI1) encoded by three genes highly conserved in the Leishmania genus have been shown to induce excellent protection against infection in both murine and simian models of cutaneous leishmaniasis. A human clinical trial with these antigens is currently underway. Because of the high degree of conservation, these antigens might be useful vaccine candidates for VL as well. In the present study, using the dog model of the visceral disease, we evaluated the immunogenicity of these three antigens formulated with two different adjuvants, MPL-SE and AdjuPrime. The results were compared with a whole parasite vaccine formulated with BCG as the adjuvant. In order to investigate if sensitization with the recombinant antigens would result in recognition of the corresponding native parasite antigens upon infection, the animals were exposed for four weeks after the termination of the immunization protocol with the recombinant antigens to a low number of L. chagasi promastigotes, an etiological agent of VL. Immune response was evaluated by quantitative ELISA in the animal sera before and after exposure to the viable parasites. Both antigen specific IgG1 and IgG2 antibody levels were measured. Immunization of dogs with the recombinant antigens formulated in either MPL-SE or AdjuPrime resulted in high antibody levels particularly to LmSTI1. In addition, this immunization although to low levels, resulted in the development of antibody response to the whole parasite lysate. Importantly, experimental exposure with low numbers of culture forms of L. chagasi promastigotes caused a clear boost in the immune response to both the recombinant antigens and the corresponding native molecules. The boost response was predominantly of the IgG2 isotype in animals primed with the recombinant antigens plus MPL-SE. In contrast, animals primed with the recombinant antigens formulated in AdjuPrime as well as animals vaccinated with crude antigen preparation responded with mixed IgG1/IgG2 isotypes. These results point to the possible use of this antigen cocktail formulated with the adjuvant MPL-SE in efficacy field trials against canine VL.     

Post-natal maturation of acinar cells of the guinea pig pancreas: an ultrastructural morphometric study

The morphological maturation of the acinar cells of the guinea pig pancreas during post-natal development was characterized morphometrically by determining the intracytoplasmic accumulation of rough endoplasmic reticulum (RER) and zymogen granules. The following results were obtained for the period analysed, i.e., from 2 to 70 days of post-natal life: (a) the acinar cell volume increased by 210% (P < 0.01); (b) the mostly cisternal RER occupied more than 30% of the cytoplasm at any age studied and their total volume and surface in the cell were increased by 300 and 534% (P < 0.01), respectively; (c) maturation in the morphological pattern of the RER was observed; (d) the mean number of zymogen granules per cell increased from 261 at 2 days to 422 at 70 days (P < 0.01), while their mean diameter increased from 0.52 to 0.94 micron (P < 0.01) during the same period; (e) these increases in granule number and size were responsible for a 500% (P < 0.01) increase in total volume from 2 to 70 days and for a 304% increase (P < 0.01) in total surface from 2 to 35 days; (f) the RER and the zymogen granules together occupied 44, 54, 55 and 57% of the cytoplasm at 2, 14, 35 and 70 days of age, respectively. We conclude that although the pancreatic acinar cells of the guinea pig are morphologically well differentiated at 2 days of age, with the cytoplasm already showing a large amount of RER and zymogen granules, they are still immature. Morphological maturation of the acinar cell occurs during the first months of post-natal life and is characterized by a substantial gain in cell volume and intracytoplasmic accumulation of RER and zymogen granules, which significantly increase of both their absolute volume and total surface, with a higher growth rate being observed during the period from 2 to 14 days of post-natal life.     

Allometric analysis of the postnatal development of the Syrian golden hamster pancreas

The objective of the present study was to analyse allometrically the growth of the Syrian golden hamster pancreas during days 2 to 70 of postnatal development. Body and pancreatic mass were determined, followed by stereological determination of the absolute volume of each morphological compartment of the pancreas. The marked pancreatic growth, by 4360%, was due to an increase in the absolute volume of all morphological compartments, mainly the acini which showed an increase of 10 431%. Bivariate allometric analysis of pancreatic mass and morphological compartmental volume in relation to body mass gain showed: (1) a biphasic pattern for pancreatic mass, acinar volume, excretory duct volume and stromal volume, with the first phase being observed from 2 to 21 days of age and the second from 21 to 70 days of age, with allometry coefficients of 1.537-0.513, 1.770-0.543, 1.651-0.506 and 0.967-0.258, respectively, and (2) a monophasic pattern from 2 to 70 days for intercalated duct volume and islet volume, with allometry coefficients of 0.913 and 1.727, respectively. These results show that during the growth of the pancreas in relation to that of the body some structures - acini and excretory ducts - follow the growth pattern of the organ, while others - intercalated ducts and islets - show a different pattern. This may be related to the genetic growth characteristics of each compartment itself or to some relationship between compartments during some stage of the ontogenetic development of this organ.     

Evaluation of Seed Transmission of Turnip yellow mosaic virus and Tobacco mosaic virus in Arabidopsis thaliana

ABSTRACT The mechanism of virus transmission through seed was studied in Arabidopsis thaliana infected with Turnip yellow mosaic virus (TYMV) and Tobacco mosaic virus (TMV). Serological and biological tests were conducted to identify the route by which the viruses reach the seed and subsequently are located in the seed. Both TYMV and TMV were detected in seed from infected plants, however only TYMV was seed-transmitted. This is the first report of transmission of TYMV in seed of A. thaliana. Estimating virus seed transmission by grow-out tests was more accurate than enzyme-linked immunosorbent assay due to the higher frequency of antigen in the seed coat than in the embryo. Virus in the seed coat did not lead to seedling infection. Thus, embryo invasion is necessary for seed transmission of TYMV in A. thaliana. Crosses between healthy and virus-infected plants indicated that TYMV from either the female or the male parent could invade the seed. Conversely, invasion from maternal tissue was the only route for TMV to invade the seed. Pollination of flowers on healthy A. thaliana with pollen from TYMV-infected plants did not result in systemic infection of healthy plants, despite TYMV being carried by pollen to the seed.     

Volatiles from the 1994 Eruptions of Rabaul: Understanding Large Caldera Systems

The 1994 eruption of Rabaul, in Papua New Guinea, involved a small plinian eruption at Vulcan and a vulcanian eruption on the opposite side of the caldera at Tavurvur. Vulcan's ash leachates indicate seawater interaction that is consistent with earlier observations of low sulfur dioxide emissions and the presence of ice crystals in the initial plinian eruption cloud. In contrast, Tavurvur ash leachates indicate no seawater interaction, and later sulfur dioxide emissions remained high despite low-level eruptive activity. Silicic melt inclusions indicate that the andesitic melt contained about 2 weight percent water and negligible carbon dioxide. Mafic melt inclusions in Tavurvur ash have water and carbon dioxide contents that vary systematically over the course of the eruption. The mafic melt inclusions suggest that a mafic dike intruded from below the silicic chamber and provide further evidence that mafic intrusions drive caldera unrest.     

Partial purification and characterization of pectin methylesterase from acerola (Malpighia glabra L.)

The enzyme pectin methylesterase (PME) is present in acerola fruit and was partially purified by gel filtration on Sephadex G-100. The results of gel filtration showed different PME isoforms. The total PME (precipitated by 70% salt saturation) and one of these isoforms (fraction from Sephadex G-100 elution) that showed a molecular mass of 15.5 +/- 1.0 kDa were studied. The optimum pH values of both forms were 9.0. The total and the partially purified PME showed that PME specific activity increases with temperature. The total acerola PME retained 13.5% of its specific activity after 90 min of incubation at 98 degrees C. The partially purified acerola (PME isoform) showed 125.5% of its specific activity after 90 min of incubation at 98 degrees C. The K(m) values of the total PME and the partially purified PME isoform were 0.081 and 0.12 mg/mL, respectively. The V(max) values of the total PME and the partially purified PME were 2.92 and 6.21 micromol/min/mL/mg of protein, respectively.