Downy mildew resistance evaluation in 28 grapevine hybrids promising for breeding programs in Trentino region (Italy)

Downy mildew is a major grapevine disease caused by the biotrophic oomycete, Plasmopara viticola. Numerous disease resistance studies of diverse Vitis germplasm have been previously carried out to identify downy mildew resistance sources; however, ratings were mainly reported using leaf disc in vitro testing and foliage field assessment, or upon leaf and cluster field evaluations. In the current study, 28 grapevine hybrid cultivars were screened using leaf disc bioassay, for disease resistance characterization of both existing and wild-collected materials. 16 hybrids were identified as highly resistant or resistant, and will serve as relevant resistance donors in future pre-breeding and breeding programs. All grapevine hybrids were evaluated for foliar and cluster downy mildew resistance in an untreated field trial over three successive years. This study showed that the leaf disc bioassay provided some information on the resistance level of the genotypes under scrutiny, but it was a weak predictor of their resistance level under field conditions on leaves and even more on bunches. These findings are relevant to future applications in both traditional and marker-assisted breeding programs which promote sustainable viticulture.     

An AFLP-based assessment of the genetic diversity within Hibiscus rosa-sinensis and its place within the Hibiscus genus complex

Species within the genus Hibiscus (Malvaceae) are herbaceous or woody plants, annuals or perennials. Within the genus, most of the domesticated species are grown as ornamentals, and the most widely exploited is Hibiscus rosa-sinensis, which is particularly variable with respect to flower colour and shape. H. rosa-sinensis is thought to have originated following hybridization between two species complexes endemic to different geographic locations.     

Oxidative stress in the pathogenesis of canine zinc‐responsive dermatosis

Zinc deficiency causes skin diseases both in humans and in animals. The underlying pathogenic mechanisms remain unclear, but a growing body of evidence indicates a role for zinc in skin protection against free radical‐induced oxidative damage. The immunohistochemical expression of heat shock proteins (HSPs; Hsp27, Hsp72, Hsp73 and Hsp90), Cu/Zn superoxide dismutase (SOD), metallothionein (MT), Ki‐67 antigen and active caspase‐3 were evaluated in normal canine skin and in samples from eight dogs with zinc‐responsive dermatosis. All investigated HSPs showed intense cytoplasmic immunostaining in the affected epidermis. Focal nuclear positivity of Hsp72 was also detected in keratinocytes. Although Cu/Zn SOD expression was similar to that observed in normal skin, MT immunoreactivity occurred in both the cytoplasm and the nucleus of basal cells in normal skin but was absent from the affected epidermis. Caspase‐3 activation was also absent in the involved epidermis, which revealed a high Ki‐67 index (a 3.5‐ to 9‐fold increase compared with normal skin). These results support the hypothesis that cellular response to stress, particularly oxidative stress, is involved in the pathogenesis of skin lesions in canine zinc‐responsive dermatosis. The lack of MT immunoreactivity in the affected epidermis may be indicative of low zinc levels, thus resulting in vulnerability to oxidative damage. In contrast, high expression levels of HSPs in skin during zinc deficiency may confer protection against a variety of dangerous stimuli, contributing to inhibition of apoptosis and to cell cycle regulation of proliferating keratinocytes.     

Detection of Echinococcus multilocularis infection in a colony of cynomolgus monkeys (Macaca fascicularis) using serology and ultrasonography.

Five animals in a colony of cynomolgus monkeys (Macaca fascicularis) died or were euthanatized because of alveolar echinococcosis, during a period of 5 years. The remainder of the colony was screened for possible infection with Echinococcus multilocularis, using serology and ultrasonography. A total of 46 animals out of a group of 55 were examined. The presence of anti-Em2 antibodies analyzed with enzyme-linked immunosorbent assay was demonstrated in 3 monkeys. In 2 of these 3 monkeys, multilocular structures compatible with metacestodal cysts in the liver were identified, using ultrasonography. The presence of alveolar echinococcosis was subsequently confirmed at postmortem examination in 1 animal. The other animals are still alive. Two other monkeys were negative in the serological examination but had cystic structures in the liver, which were identified as bile duct cysts at postmortem examination in 1 animal. The other monkey is still alive. These findings suggest that serology for antibodies against the Em2 antigen may represent a useful method in identifying animals that might be infected with E. multilocularis and are therefore at risk of developing fatal alveolar echinococcosis.     

Guava (<Emphasis Type="Italic">Psidium guajava L</Emphasis>. cv. Red Suprema) Crude Extract Protect Human Dermal Fibroblasts against Cytotoxic Damage Mediated by Oxidative Stress

We analyzed guava fruits (Psidium guajava L. cv. Red Suprema) from Cuba to determine their chemical composition, total antioxidant capacity, as well as their protective effect against oxidative damage using an in vitro model of human dermal fibroblasts. The guava fruit is a natural source of bioactive compounds, such as polyphenols, vitamin C, folates and beta carotenes with proven health benefits. Human dermal fibroblasts were pre-incubated with different concentrations of guava crude extract and then subjected to oxidative stress using the AAPH stressor. The number of apoptotic and dead cells, as well as the markers of oxidative damage such as lipid and protein oxidation significantly decreased when cells were pre-incubated with guava crude extract and then exposed to the stressor. The activity of antioxidant enzymes also improved when cells were pre-incubated with guava crude extract in comparison to cells subjected to stress without prior pre-incubation with the guava extract. The results obtained in this study highlight the health benefits of guava regarding oxidative stress, proving it to be an important source of bioactive compounds associated with important biological properties.     

Antioxidant systems and lymphocyte proliferation in the horse,sheep and dog

To better define the species-specific antioxidant systems and to ascertain the influence of the intracellular redox status on the immune system of different animal species, we determined lymphocyte glutathione peroxidase (GSHPx) activity, plasmatic glutathione levels (GSH) and the effect of H2O2 on the responsiveness of lymphocytes to proliferative stimuli. Among the three species considered, sheep presented the lowest plasmatic GSH and the highest lymphocyte GSHPx activity. On the contrary, dogs showed an inverted pattern (high GSH - low GSHPx). Horses displayed intermediate values for both parameters analysed. The effect of H2O2 on the proliferative capacity of lymphocytes was the same for all three species; the 200 microM dose in particular was strongly inhibiting. Each species, however, showed different rates of inhibition: sheep exhibited the highest sensitivity to the antiproliferative effect of H2O2. Our results confirmed that high H2O2 concentrations (200 microM) are noxious for the cellular functions of all animals; however this effect is mediated by a rigorously species-specific relationship between the intracellular reactive oxygen species (ROS) and the molecular systems involved in cell proliferation.     

Recurrent syncope associated with paroxysmal supraventricular tachycardia in a Devon Rex cat diagnosed by implantable loop recorder

A 9-year-old male neutered Devon Rex cat was presented for continued investigations following a 7-year history of recurrent syncope. Previous diagnostic tests, including 24h (Holter) electrocardiographic monitoring, had failed to identify the aetiology of such episodes, and former empirical treatment with atenolol had not provided satisfactory control of the clinical signs. A conclusive diagnosis was eventually achieved using an implantable loop recorder (Reveal), which identified paroxysmal supraventricular tachycardia (SVT) associated with a syncopal episode. Treatment with oral sotalol was instituted and, 18 months after initiation of anti-arrhythmic therapy, no further syncopal episodes have been observed by the cat's owners.     

Glycohistochemical characterization of histologically normal nasal mucosa and enzootic nasal tumor of sheep

Objective-To determine glycohistochemical characteristics of enzootic nasal tumors (ENTs) of sheep, compare results for ENT with those of histologically normal nasal mucosa of sheep, and identify the histologic origin of ENT. Sample-ENT and nasal mucosa samples obtained from cadavers of 5 adult Lacaune sheep with ENT and 5 Lacaune sheep unaffected by ENT, respectively. Procedures-Samples of ENT and nasal mucosa were collected from cadavers of sheep and sectioned. Conventional and lectin histochemical analyses were used to identify glycoconjugates in tissue sections on the basis of their principal chemical groups and principal terminal or internal oligosaccharidic glucidic residues, respectively. Results-ENTs had papillary and tubular portions. Cells in the papillary portion of ENTs had secretion and surface glycoconjugates, which included sulfated glycosaminoglycans and neutral and sialilated glycoproteins. Cells in the tubular portion of ENTs had surface glycoconjugates, which included neutral and sialilated glycoproteins. Both portions of ENTs had C(4)-acetylated sialoderivatives that were not detected in sections of histologically normal nasal mucosa. Conclusions and Clinical Relevance-The papillary portion of ENTs in sheep may originate from respiratory glands and goblet cells. The tubular portion of ENTs in sheep may originate from olfactory glands. Presence of C(4)-acetylated sialoderivatives in cells of ENTs could confer resistance against pathogens to those cells.     

Paraneoplastic leukocytosis in a dog with a renal carcinoma

A 7-year-old male German Shepherd dog in poor body condition had a 3-month history of intermittent hematuria. Nonregenerative anemia, mild leukocytosis, marked hypoalbuminemia, and hematuria were observed. Subsequently, marked neutrophilia and moderate monocytosis were noted; anemia, hypoalbuminemia, and hematuria persisted; and the dog developed disseminated intravascular coagulation. Ultrasonographic examination of the abdomen revealed the presence of an enlarged and irregularly shaped right kidney with a large area of cavitation, and a nephrectomy was performed 30 days after initial examination. Cytologic examination of fine-needle aspirates and imprints of the right kidney revealed a neoplastic cell population suggestive of renal carcinoma. The histopathologic diagnosis was chromophobic cystic-papillary renal carcinoma. The tumor cells expressed granulocytic/macrophage-colony-stimulating factor (GM-CSF), detected by immunohistochemical staining, and elaboration of GM-CSF by the tumor may have mediated the leukocytosis in this dog. Following excision of the tumor, neutrophil and monocyte counts were only mildly increased. The dog died 135 days after initial presentation, and a necropsy was not permitted. Paraneoplastic neutrophilic leukocytosis is an uncommon finding and may be caused by elaboration of CSF by neoplastic cells.