Displasia renal em cão da raça Rotweiller / Renal dysplasia in a dog breed Rotweiller

Descreveram-se os achados clínicos e patológicos de um caso de displasia renal em um cão da raça Rotweiller com oito meses de idade. O animal apresentou vômitos, emagrecimento, polidpsia e poliúria. Houve elevação sanguínea de creatinina, cálcio e da fosfatase alcalina. À necropsia, notaram-se os rins diminuídos de tamanho, com estruturas císticas proeminentes sobre a superfície natural do órgão e, ao corte, firmes e com estruturas císticas distribuídas pelo parênquima. Na avaliação histológica, havia glomérulos imaturos, fibroplasia intersticial e dilatação cística tubular.

In this study we describe the clinical and pathological findings of a case of renal dysplasia in a dog from the Rottweiler breed at 8 months of age. The animal presented vomiting, weight loss, polydipsia and polyuria. There was an increase of blood creatinine, calcium, and alkaline phosphatase. At necropsy it was noted that the kidneys were reduced in size, with prominent cystic structures on the natural surface of the body and the cutting and firm with cystic structures distributed throughout the parenchyma. The histological evaluation was immature glomeruli, interstitial fibroplasia and tubular cystic dilation.

Jaburetox-2Ec: an insecticidal peptide derived from an isoform of urease from the plant Canavalia ensiformis.

Canatoxin, a urease isoform from Canavalia ensiformis seeds, shows insecticidal activity against different insect species. Its toxicity relies on an internal 10 kDa peptide (pepcanatox), released by hydrolysis of Canatoxin by cathepsins in the digestive system of susceptible insects. In the present work, based on the N-terminal sequence of pepcanatox, we have designed primers to amplify by PCR a 270-bp fragment corresponding to pepcanatox using JBURE-II cDNA (one of the urease isoforms cloned from C. ensiformis, with high identity to JBURE-I, the classical urease) as a template. This amplicon named jaburetox-2 was cloned into pET 101 vector to obtain heterologous expression in Escherichia coli of the recombinant protein in C-terminal fusion with V-5 epitope and 6-His tag. Jaburetox-2Ec was purified on Nickel-NTA resin and bioassayed in insect models. Dysdercus peruvianus larvae were fed on cotton seed meal diets containing 0.01% (w/w) Jaburetox-2Ec and, after 11 days, all individuals were dead. Jaburetox-2Ec was also tested against Spodoptera frugiperda larvae and caused 100% mortality. In contrast, high doses of Jaburetox-2Ec were innocuous when injected or ingested by mice and neonate rats. Modeling of Jaburetox-2Ec, in comparison with other peptide structures, revealed a prominent beta-hairpin motif consistent with an insecticidal activity based on either neurotoxicity or cell permeation.

Insecticidal effects of canatoxin on the cotton stainer bug Dysdercus peruvianus (Hemiptera: Pyrrhocoridae).

Canatoxin (CNTX) is a variant form of urease isolated from Canavalia ensiformis (Leguminosaea) seeds. A possible role in the plant defense was proposed for CNTX, due to its toxicity upon feeding to the beetle Callosobruchus maculatus, and the hematophagous bug, Rhodnius prolixus. The toxic effect is caused by a canatoxin-derived peptide ( approximately 10kDa) formed by insect cathepsin-like digestive enzymes. In order to evaluate their potential as bioinsecticides, the effects of CNTX and its peptide were evaluated on a phytophagous hemipteran insect Dysdercus peruvianus, a pest of cotton culture. For the bioassays, the insects fed on gelatin capsules containing powdered cotton seeds, mixed with the freeze-dried protein and other test materials and were observed for survival rate, weight gain and molting. Ingestion of canatoxin, or a recombinant 10kDa peptide derived from it, severely affected young forms of the insects, delaying their development or leading to their death. In contrast, adults were insensitive to diets containing higher concentrations of canatoxin. Cathepsin-like proteinases predominated and showed distinct pattern of enzymatic activities in midguts homogenates according to the developmental stage of the insect, a fact which may explain the different susceptibility of nymphs as compared to adult D. peruvianus. The data presented confirm the potential use of canatoxin-like proteins and derived peptides as bioinsecticides.