Johne's disease in alpacas (Lama pacos) in Australia

SUMMARY: Johne's disease was diagnosed in 10 alpacas ( Lama pacos ) in Australia between February 1993 and May 1994. Eight of the animals were between 12 and 24 months of age, one was a 6-year-old female, and one was a 4-year-old male. Five, including the 6-year-old and the 4-year-old alpacas, showed weight loss and diarrhoea before death or slaughter. The other cases showed no clinical signs of Johne's disease but 4 gave a positive result on faecal culture and one gave a positive result on testing with the caprine ACID assay and had acid-fast organisms in its faeces. At necropsy, all cases had grossly enlarged mesenteric lymph nodes. Johne's disease was diagnosed after histological examination of the lymph nodes with conventional culture and polymerase chain reaction testing of tissue samples. This report outlines the clinical, epidemiological, and pathological findings in these cases.     

Analysis of swinepox virus antigens using monoclonal antibodies.

Seventeen monoclonal antibodies (MAbs) against swinepox virus (SPV) were produced and characterized. These MAbs were classified into eight groups (A through H) on the basis of the molecular weight of the polypeptides which they recognized and the staining patterns of antigens in SPV-infected cells by the indirect immunofluorescent (IF) technique. The MAbs belonging to groups A, B, C and G recognized late antigens in cytoplasmic inclusion bodies with molecular weights of 97 kD, 65 kD, 48 kD and 15 kD, respectively. The MAbs belonging to groups D and H respectively recognized 35 kD and 12 kD late antigens, which first appeared in cytoplasmic inclusion bodies and spread to the cytoplasms and surface membranes of the infected cells. The MAb of group F recognized an 18 kD late antigen with granular distribution in the cytoplasm. The MAbs of group E recognized a 32 kD early antigen. Although all the MAbs belonging to the six groups (A, D through H) were specific for SPV, some of those belonging to groups B and C showed cross-reactivity with members of the other genera of poxviridae. An MAb in group B, SP14, cross-reacted with orf and rabbit fibroma viruses. Two MAbs in group C, SP24 and SP32, cross-reacted with vaccinia, cowpox, ectromelia, and rabbit fibroma viruses. These findings indicate that at least two SPV antigens contain cross-reactive epitopes with different genera of poxviridae.     

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.     

Healing process of the wounds of the branches of the Japanese persimmon that were caused by girdling,scoring, and strangulation

Girdling is widely used for many crops, mainly in order to improve the fruit set, size, and quality and to increase the yield of flower buds. However, girdling may damage trees, and permanent injury can occur if callus bridges are not formed across the ring. We determined the regeneration of vascular bundles and the healing process of wounds caused by surgical treatments. It occurred as follows: necrosis of some cell layers on the edge of the cut, callus formation and dedifferentiation of the parenchyma cells, callus proliferation, contact between callus pads, callus bridge formation, and differentiation into the mature vascular bundle; however, the innermost callus cells remained undifferentiated. At 3 days after treatment (DAT), several phloem parenchyma cell layers showed symptoms of necrosis. At 10 DAT, callus formation started in the phloem tissue below the periderm. Initially, the callus cells were uniform; however, the callus tissue pad was distinguished into 2 layers based on color and firmness. After callus bridge formation, the inner callus differentiated into the mature xylem and the outer callus, into mature phloem. In strangulation, xylem elements were formed from the inner callus pad before callus bridge formation. The callus bridge formed within 6 weeks, 20–25 days, and 14 weeks after girdling, scoring, and strangulation, respectively.     

Vitrification procedure decreases inositol 1,4,5‐trisphophate receptor expression,resulting in low fertility of pig oocytes

Although cryopreservation of mammalian oocytes is an important technology, it is well known that unfertilized oocytes, especially in pigs, are highly sensitive to low temperature and that cryopreserved oocytes show low fertility and developmental ability. The aim of the present study was to clarify why porcine in vitro matured (IVM) oocytes at the metaphase II (MII) stage showed low fertility and developmental ability after vitrification. In vitro matured cumulus oocyte complexes (COCs) were vitrified with Cryotop and then evaluated for fertility through in vitro fertilization (IVF). Although sperm‐penetrated oocytes were observed to some extent (30–40%), the rate of pronuclear formation was low (9%) and none of them progressed to the two‐cell stage. The results suggest that activation ability of cryopreserved oocytes was decreased by vitrification. We examined the localization and expression level of the type 1 inositol 1,4,5 trisphosphate receptor (IP₃R1), the channel responsible for Ca²⁺ release during IVF in porcine oocytes. Localization of IP₃R1 close to the plasma membrane and total expression level of IP₃R1 protein were both decreased by vitrification. In conclusion, our present study indicates that vitrified‐warmed porcine COCs showed a high survival rate but low fertility after IVF. This low fertility seems to be due to the decrease in IP₃R1 by the vitrification procedure.     

Experimental verification of bandsaw roll-tensioning theory

The validity of a bandsaw roll-tensioning theory developed by the author is verified based on a model experiment. It is shown that the actual roll-tensioning process can be clearly explained by this theory. Roll-stretching force transmission coefficients are introduced in this theory. These coefficients, which indicate the magnitude of the compression force parallel to the bandsaw surface at the roll-stretching position, are affected by the thickness of the bandsaw blade, the radius of the bandsaw blade vent at the measurement of tension, and the straightness of the bandsaw blade at the measurement of crown back, among others. For the practical use of this theory, therefore, it is necessary to determine the proper magnitude of these coefficients based on tensioning experiments.     

ESR studies of radicals generated by ultrasonic irradiation of lignin solution. An application of the spin trapping method

 An electron spin resonance (ESR) method combined with a spin trapping reagent was successfully applied to trap and characterize unstable radicals which were generated by ultrasonic irradiation of dimethylsulfoxide (DMSO) solution of hardwood, Fagus crenata lignin. It was found, consequently, that a secondary carbon radical, ∼CH· was trapped as the nitroxide spin adduct when the DMSO solution was subjected to ultrasonic irradiation in the presence of a spin trapping reagent: 2, 4, 6-tri-tert-butylnitrosobenzene (BNB) at 50 °C for 60 minutes under vacuum. This means that the alkyl phenyl ether bonds known as lignin linkage bonds were homolytically scissoned by the ultrasonic irradiation, although the phenoxy radical, Ph-O· as the counter radical of the secondary carbon radical was not trapped by the BNB spin trap. Further, the data showed that the primary carbon radical, ∼OCH₂ · is trapped by the BNB to form the corresponding spin adduct, indicating that the hydrogen abstraction from the ortho methoxy group in the syringyl and/or guaiacyl moiety is induced by the secondary carbon radical when irradiated. Based on these findings it was concluded that the Ph-O· radicals produced by the homolytic rupture of the alkyl phenyl ether bonds were not trapped by the BNB spin trap. This suggests that large steric hindrances operate between the syringyl with two methoxy moieties and/or guaiacyl with a methoxy moiety at the ortho position, and the BNB molecule bearing two bulky ortho tert-butyl groups. Received 5 January 1999