Medullary sponge kidney in a 10-year-old Shih Tzu dog

Medullary sponge kidney was diagnosed in a 10-year-old male Shih Tzu dog with a long history of hyposthenuria, but with no other findings indicating renal failure or hormonal aberration. At the dog's death from heart failure, an autopsy was performed. On gross morphology, bilateral kidneys were normal size and had many cysts ranging from the corticomedullary junction to renal papillae. Histopathologic findings showed that almost all of the cysts were lined by monolayered or multilayered and columnar or cuboidal epithelium with chilium similar to epididymis. Immunohistochemically, all of these cells were strongly positive for AE1/AE3 and negative for vimentin. Many of these cells were positive for cytokeratin 7 (CK7), and only a few cells were positive for desmin. The results of staining are the same as those for epithelium of the collecting duct of normal canine kidney. This is the first report of this pathologic entity in the canine kidney.     

Potomac horse fever in Ontario: Clinical,geographic, and diagnostic aspects

Clinical findings, geographic locations, laboratory diagnoses, and culture isolation of Neorickettsia spp. in Potomac horse fever (PHF) cases diagnosed in Ontario between 2015 and 2019 are described. Forty-six confirmed PHF cases occurred from late June to early September. Of 41 horses admitted to the Ontario Veterinary College, 28 (68%) survived and 13 (32%) were euthanized due to poor prognosis or financial constraints. Most cases were in southern Ontario along the Canada-USA border. Blood and fecal samples from 43 suspect PHF cases were submitted to 2 laboratories for polymerase chain reaction (PCR) testing for Neorickettsia risticii. Agreement between both laboratories for detection of N. risticii DNA was excellent for feces [κ = 0.932, 95% confidence interval (CI): 0.80 to 1], and fair for blood samples (κ = 0.494, 95% CI: 0.13 to 0.85). Neorickettia spp. were isolated from 16 of 41 (39%) blood samples. DNA analysis confirmed 14 isolates were N. risticii and 2 were N. findlayensis, a novel species of Neorickettsia recently demonstrated to cause PHF.     

Hematological, osmotic, and scanning electron microscopic study of erythrocytes of dogs given beta-acetylphenylhydrazine

Hematologic examinations, osmotic fragility tests, and scanning electron microscopy of erythrocytes were done on blood of dogs given 5 mg/kg of beta-acetylphenylhydrazine for 5 weeks. Reticulocytes, Heinz bodies, and serum total bilirubin values increased in the 1st week. Reticulocyte numbers peaked in the 2nd week, and reticulocytosis persisted through the 5th week. Erythrocyte, packed cell volume, and hemoglobin values decreased markedly and became lowest in the 2nd week. Mean corpuscular volume increased in the 1st week and remained increased for the duration of treatment. Erythrocyte osmotic fragility was increased after 1 week of treatment. Echinocytes were increased with a peak level of 47.6% at week 1 of treatment. Increased numbers of acanthocytes and schizocytes also were detected.     

Neorickettsia risticii surface-exposed proteins: proteomics identification, recognition by naturally-infected horses, and strain variations

ABSTRACT: Neorickettsia risticii is the Gram-negative, obligate, and intracellular bacterial pathogen responsible for Potomac horse fever (PHF): an important acute systemic disease of horses. N. risticii surface proteins, critical for immune recognition, have not been thoroughly characterized. In this paper, we identified the 51-kDa antigen (P51) as a major surface-exposed outer membrane protein of older and contemporary strains of N. risticii through mass spectrometry of streptavidin-purified biotinylated surface-labeled proteins. Western blot analysis of sera from naturally-infected horses demonstrated universal and strong recognition of recombinant P51 over other Neorickettsia recombinant proteins. Comparisons of amino acid sequences for predicted secondary structures of P51, as well as Neorickettsia surface proteins 2 (Nsp2) and 3 (Nsp3) among N. risticii strains from horses with PHF during a 26-year period throughout the United States revealed that the majority of variations among strains were concentrated in regions predicted to be external loops of their β-barrel structures. Large insertions or deletions occurred within a tandem-repeat region in Ssa3. These data demonstrate patterns of geographical association for P51 and temporal associations for Nsp2, Nsp3, and Ssa3, indicating evolutionary trends for these Neorickettsia surface antigen genes. This study showed N. risticii surface protein population dynamics, providing groundwork for designing immunodiagnostic targets for PHF.     

Isolation and tyrosinase inhibitory effects of polyphenols from the leaves of persimmon, Diospyros kaki

The main polyphenols were isolated from the leaves of six selected persimmon cultivars. Seven compounds were obtained by reverse-phase HPLC, and their structures were elucidated by multiple NMR measurements. These compounds are hyperoside, isoquercitrin, trifolin, astragalin, chrysontemin, quercetin-3-O-(2'-O-galloyl-β-D-glucopyranoside) (QOG), and kaempferol-3-O-(2'-O-galloyl-β-D-glucopyranoside) (KOG). Their inhibitory activity was tested against tyrosinase for the oxidation of L-DOPA, and only chrysontemin showed inhibitory activity. To investigate the differences of their inhibitory effects, the tyrosinase inhibitory activities of their aglycons, cyanidin, quercetin, and kaempferol, were also tested. As a result, it was confirmed that the most influential moiety for tyrosinase inhibition was the 3',4'-dihydroxy groups of the catechol moiety. Moreover, the tyrosinase inhibitory activity of chrysontemin, which was identified in persimmon leaves for the first time, is supported by a simulated model of chrysontemin docking into mushroom tyrosinase.     

Traffic jams reduce hydrolytic efficiency of cellulase on cellulose surface

A deeper mechanistic understanding of the saccharification of cellulosic biomass could enhance the efficiency of biofuels development. We report here the real-time visualization of crystalline cellulose degradation by individual cellulase enzymes through use of an advanced version of high-speed atomic force microscopy. Trichoderma reesei cellobiohydrolase I (TrCel7A) molecules were observed to slide unidirectionally along the crystalline cellulose surface but at one point exhibited collective halting analogous to a traffic jam. Changing the crystalline polymorphic form of cellulose by means of an ammonia treatment increased the apparent number of accessible lanes on the crystalline surface and consequently the number of moving cellulase molecules. Treatment of this bulky crystalline cellulose simultaneously or separately with T. reesei cellobiohydrolase II (TrCel6A) resulted in a remarkable increase in the proportion of mobile enzyme molecules on the surface. Cellulose was completely degraded by the synergistic action between the two enzymes.     

Yield and chemical composition of red clover and ladino clover as affected by phosphorus and calcium

In Japan red clover and ladino clover are a popular forage. These clovers are adaptable to a wide range of soil conditions, and respond well to fertilization. They are often grown on relatively infertile soils with the aid of complete fertilizers.¹     

Effect of mineral nutrition on metabolic change induced in crop plant roots (V)

In the previous work concerning the effect of potassium nutrition on glycolysis in sweet potato roots (1), monoiodoacetic acid (MIA) and sodium fluoride (NaF) inhibited more strongly respiration in younger roots and root tip parts, and yet a potassium deficiency enhanced its inhibition. The inhibition of MIA, which inhibits triose phosphate dehydrogenase (2), may indicate the importance of the EMP pathway and the Krebs cycle (3,4). The inhibition of NaF, which in higher concentrations inhibits enolase (2), may suggest the importance of the metabolism following phosphoglycerate → phosphoenolpyruvate or the Krebs cycle (3,4). It is of interest, therefore, to elucidate the role of the Krebs cycle in respiration in sweet potato roots, and what significance potassium nutrition has in the Krebs cycle operation. This paper deals with experiments bearing on respiration in roots of sweet potato plants grown at varying degrees of potassium application, especially in the presence of various inhibitors and / or substrates.     

Glycolic acid oxidase activity in crop plant leaves

Many workers have revealed the possible role of glycolic acid oxidase in the photosynthesis and the respiration of plant leaves (1, 5) and in the organic acid metabolism of rice plant roots (6). There is also abundant evidence that α-hydroxysulfonates, the bisulfite addition compounds of aldehydes and ketones, are the specific and competitive inhibitors of the enzyme (7, 8). The pevious works (9, 10) showed that a deficient application of potassium increased the content of amino-N and reducing sugars and concomitantly the respiratory activity in sweet potato roots. Such a derangement in the metabolic status of plant roots would be expected to be intimately connected with any changes in the photosynthesis and the respiration of the leaves. This paper, as a preliminary, describes some results from investigations into the glycolic acid oxidase activity in leaves of rice plant- and barley seedlings, sweet potato plants, and taro plants which were grown in solution culture at varying potassium application : the effects of light and plant age on enzyme activity, the activation of the enzyme by FMN addition, the stability of the enzyme during a prolonged incubation of sap from leaves, and the inhibitory effects of specific inhibitors on the enzyme in vitro and in vivo.