Neuroaxonal dystrophy in raccoons (Procyon lotor) from Iowa.

During a 12-month period (1998-1999), microscopic evidence of neuroaxonal dystrophy (NAD) in medullae oblongata of raccoons (Procyon lotor) was observed in 17/39 (47% prevalence in adults) from Iowa, USA. Three of the animals were kits (<3 months), 26 were between 1 and 2 years, and 10 were over 7 years. Lesions were not seen in the medullae of the 3 kits. In young adults, the lesions were mild and were seen in 7 animals. More severe lesions were present in the 10 older raccoons. Grossly, the brains were unremarkable. Microscopically, NAD was confined to the dorsal caudal medulla, where certain nuclei (predominantly gracilis and cuneate) were bilaterally affected. Severely affected animals had vacuolar degeneration of neurons or neuronal loss and extensive areas of spongiosis. Tests for the presence of PrP(res) in the brain were negative. Spongiotic areas often contained axonal spheroids. Degenerate neurons and axons occasionally contained amphophilic periodic acid-Schiff-positive granular material. There was a paucity of inflammatory cells in the affected areas. Since lesions were not present in kits, were either absent or mild in young adults, and were severe in older raccoons, the findings may be related to advancing age. Neuroaxonal dystrophy has not been previously reported in raccoons. Retrospective examination of raccoon brains from the eastern and northwestern areas of the country revealed very low prevalence of NAD. Because of the apparently high prevalence of this condition at this geographic location, factors other than age (genetic, nutritional, and/or environmental) may influence this degenerative process in the brains of raccoons in Iowa.     

Hemoglobin adducts and mercapturic acid excretion of acrylamide and glycidamide in one study population

The aim of this study was to determine the relationship between the oxidative and reductive metabolic pathways of acrylamide (AA) in the nonsmoking general population. For the first time both the blood protein adducts and the urinary metabolites of AA and glycidamide (GA) were quantified in an especially designed study group with even distribution of age and gender. The hemoglobin adducts N-carbamoylethylvaline (AAVal) and N-( R, S)-2-hydroxy-2-carbamoylethylvaline (GAVal) were detected by GC-MS/MS in all blood samples with median levels of 30 and 34 pmol/g of globin, respectively. Concentrations ranged from 15 to 71 pmol/g of globin for AAVal and from 14 to 66 pmol/g of globin for GAVal. The ratio GAVal/AAVal was 0.4-2.7 (median = 1.1). The urinary metabolites were determined by LC-MS/MS. Of all urine samples examined 99% of N-acetyl- S-(2-carbamoylethyl)- l-cysteine (AAMA) levels and 73% of N-( R/ S)-acetyl- S-(2-carbamoyl-2-hydroxyethyl)- l-cysteine (GAMA) levels were above the LOD (1.5 microg/L). Concentrations ranged from 相似文献   

Morbilliviruses in Mediterranean monk seals.

Two morbilliviruses were isolated from Mediterranean monk seals (Monachus monachus), one from a stranded animal in Greece and the other one from carcasses washed ashore during a mass die-off in Mauritania. From both viruses N and P gene fragments were sequenced and compared to those of other known morbilliviruses. The monk seal morbilliviruses most closely resembled previously identified cetacean morbilliviruses, indicating that interspecies transmission from cetaceans to pinnipeds has occurred.     

Identifying dendroecological growth releases in American beech,jack pine,and white oak: Within-tree sampling strategy

The objective of this project was to identify the timing of growth release events detected from tree ring widths and compare whether two cores taken from the same tree reconstructed the same disturbance history. This research question is important because current dendroecological reconstructions of canopy disturbance rely on sampling one core per tree; however, the variation of releases from different cores from the same tree has never been evaluated. We sampled two increment cores from 20 jack pine, 17 white oak, and 19 American beech and identified release events with two commonly employed methods: radial growth averaging technique and boundary line criteria. In jack pine, 85% of the paired cores showed identical releases with the radial growth averaging technique, but 15% of the paired cores varied in reconstructed growth releases. In the jack pine, no releases were identified with the boundary line criteria for any of the paired cores. In the white oak, 65% had identical releases identified with the radial growth averaging technique and 35% of the pairs showed differences. The boundary line criteria for white oak had agreement between releases for 76% of the pairs and different release histories for 24% of the pairs. In the American beech, we were only able to use the radial growth averaging technique and this method showed identical release timing for 79% of the paired cores and differences in 21% of the paired cores. This level of within-tree growth variation is unlikely to influence identification of stand-wide disturbances; however, for reconstructions of small-scale disturbances it is likely to under-represent disturbance events. Therefore, for small-scale disturbance reconstructions, we recommend dendroecologists consider sampling two cores per tree instead of the standard sample of one core per tree.     

Impact of formulation and technological factors on the acrylamide content of wheat bread and bread rolls

This study clearly demonstrates that formulation and baking technology have strong influence on the acrylamide content in the baked products. NaCl plays an ambiguous role: Whereas low doses up to 2% lowered acrylamide by inhibition of the enzyme activities, higher addition remarkably increased the contents due to growth inhibition of the yeast. The results of previous model studies concerning the influence of cysteine could be confirmed in pilot plant experiments. Its addition to the dough resulted in significantly lower acrylamide content whereas its application to the crust proved to be ineffective. Furthermore, it was demonstrated that enzyme-bearing bakery improvers had no influence on acrylamide formation. In pilot plant experiments acrylamide was reduced with increasing fermentation time, and minimum acrylamide levels were already reached after 60 min thus avoiding flattened breads due to prolonged amylase activity. Besides formulation and fermentation also process technology is crucial. As shown by our data, reduced baking temperature and prolonged heat treatment is favorable. Furthermore, convection ovens seem to enhance acrylamide formation compared to deck oven.     

The International Plant Sentinel Network: a tool for Regional and National Plant Protection Organizations

Botanic gardens and arboreta are valuable but currently under‐utilized resources in plant health research. Within their vast collections of living plants, gardens play host to expatriate plant species from across the world. These plants offer unique opportunities to study damaging pest and pathogen threats before their introduction into a region where they would be considered invasive aliens. Through these studies, scientists can determine vital information related to these organisms, which can in turn be used to strengthen understanding, contribute to pest risk analysis activities and put in place appropriate quarantine measures or other management programmes. The International Plant Sentinel Network (IPSN) has been working for the last 3 years to provide the support and resources needed for gardens to contribute to such research. The next phase of the IPSN will be to coordinate this research; it will identify, facilitate and provide the already developed tools to contributing gardens. In this way, the IPSN will provide meaningful and valuable information to plant health experts which could help mitigate, or stop altogether, the damaging impacts of new and emerging invasive alien organisms.     

Effects of medetomidine-midazolam-fentanyl IV bolus injections and its reversal by specific antagonists on cardiovascular function in rabbits

The objective of this study was to investigate the short-term cardiovascular effects of intravenous (IV) medetomidine-midazolam-fentanyl (MMF) injections in the rabbit using vascular ultrasonography and echocardiography.Anesthesia with MMF was induced intramuscularly (IM) in 8 female New Zealand White rabbits before 3 defined bolus injections of MMF were given IV. Before and for 10 min after each MMF injection the following vascular variables [at the left common carotid artery (ACC) after the first injection and at the abdominal aorta (AA) after the second injection]: vessel diameter (D), peak systolic, minimum diastolic, end-diastolic and average blood flow velocities (psBFV, mdBFV, edBFV, Vave), average volumetric flow (VFave), resistance index (RI) and pulsatility index (PI) and other clinical variables: mean arterial pressure (MAP), heart rate (HR), peripheral arterial oxygen saturation and end-tidal CO₂ were recorded. Echocardiography was used after the third injection to investigate changes in cardiac parameters. Additionally, hemodynamic effects were observed at the ACC after complete subcutaneous antagonism of anesthesia by atipamezole-flumazenil-naloxone (AFN) until recovery of the animals.Medetomidine-midazolam-fentanyl IV caused a significant decrease of blood flow velocity in both investigated vessels which was associated with a significant decrease of HR and cardiac performance indicated by the decrease of FS and average volumetric blood flow. Mean arterial pressure significantly increased after each MMF injection; whereas, it significantly decreased after AFN injection. Therefore, MMF and AFN should be carefully used in rabbits and may not be suitable in patients with ventricular dysfunction.     

Squamous cell carcinoma invading the right temporomandibular joint in a Belgian mare

This report describes a rare case of squamous cell carcinoma invading the right temporomandibular joint, right guttural pouch, and calvarium. Radiography, computed tomography, and histopathology were performed in the diagnostic workup. Computed tomography depicted more accurately than radiography the invasive nature, exact location, and extent of the lesion.     

Regeneration of different Cyclamen species via somatic embryogenesis from callus,suspension cultures and protoplasts

The present study is the first report of the establishment of embryogenic callus cultures from seedling tissue, the regeneration of plants via somatic embryogenesis and the development of a regeneration system from protoplast to plant, using three wild species of Cyclamen, Cyclamen graecum Link, Cyclamen mirabile Hildebrand, Cyclamen trochopteranthum Schwarz (syn. Cyclamen alpinum hort. Dammann ex Sprenger). The ability to form embryogenic callus and to regenerate via somatic embryogenesis was strongly genotype-dependent for each species. From 0.5 g callus, up to 1461 somatic embryos were formed in the case of C. mirabile. Culture media with different concentrations of plant growth regulators, CaCl₂ and activated charcoal significantly influenced embryo formation in this species. Up to 1.4 × 10⁶ protoplasts were isolated from 1 g of C. graecum cell suspension. Diverse growth responses of the protoplasts in two embedding agents, agarose and alginate, were observed for the different Cyclamen species. These specific growth characteristics could be used as a selection marker for future fusion experiments. From both protoplast culture systems, somatic embryos were regenerated, grown to plantlets and acclimatised to greenhouse conditions.     

Estimating soil turnover rate from tree uprooting during hurricanes in Puerto Rico

Soil turnover by tree uprooting in primary and secondary forests on the island of Puerto Rico was measured in 42 study plots in the months immediately after the passage of a Category 3 hurricane. Trunk basal area explained 61% of the variability of mound volume and 53% of the variability of mound area. The proportion of uprooted trees, the number of uprooted trees, or the proportion of uprooted basal area explained 84–85% of the variation in hurricane-created mound area. These same variables explain 79–85% of the variation in mound volume. The study indicates that the soil turnover period from tree uprooting by Puerto Rican hurricanes is between 1600 and 4800 years. These rates are faster than soil turnover by landslides and background treefall in the same area and provide a useful age constraint on soil profile development and soil carbon sequestration in these dynamic landscapes.