Effect of drug-eluting bead transarterial chemoembolization loaded with cisplatin on normal dogs

Transcatheter arterial embolization (TAE) and transcatheter arterial chemoembolization (TACE) are standard treatments for advanced hepatocellular carcinoma (HCC) and particularly for unresectable tumors or liver metastases in humans. However, reports on TACE used in veterinary medicine are few. This study aimed to evaluate the feasibility and safety of drug-eluting bead transarterial chemoembolization (DEB-TACE). We performed DEB-TACE in four clinically normal dogs and pharmacokinetically compared the results against hepatic arterial infusion (HAI) of cisplatin in two dogs. Drug-eluting beads (DEB) loaded with cisplatin were injected through a microcatheter for selective embolization of the left hepatic artery. After embolization, computed tomography (CT) images and histological examination findings were obtained during a 4-week observation period. Serum platinum concentrations were measured to evaluate cisplatin after each procedure. Biochemical analysis was performed during a 12-week observation period. Embolization was successful in all dogs, and there were no clinically apparent abnormalities. Embolization was confirmed up to 4 weeks after DEB-TACE in two of the four dogs and up to 1 week in the other two dogs using postoperative CT images. Cisplatin was not detected in peripheral veins in all dogs after DEB-TACE, but it was detected in trace amounts after HAI. DEB-TACE using cisplatin was safe and well tolerated by normal dogs. DEB-TACE may be useful in terms of determining systemic toxicity and drug concentration within tumors.     

Involvement of nitric oxide generation in hypersensitive cell death induced by elicitin in tobacco cell suspension culture

Recent studies suggest that nitric oxide (NO), an important signaling and defense molecule in mammals, plays a key role in activating disease resistance in plants. We characterized NO production by tobacco Bright Yellow-2 cells pharmacologically after treatment with INF1, the major elicitin secreted by the late blight pathogen Phytophthora infestans, prepared from Escherichia coli. NO production rapidly occurred within 1h and reached a maximum level 3–6h after the addition of INF1. Carboxy-PTIO, a NO-specific scavenger, abolished INF1-induced NO production in a dose-dependent manner. Pretreatment of protein synthesis inhibitor cycloheximide and protein kinase inhibitor K252a blocked NO production 3–12h after INF1 treatment, indicating that NO production requires de novo protein synthesis and protein phosphorylation. In an investigation of the relations between NO generation and several defense responses induced by INF1, carboxy-PTIO completely suppressed activation of a 41-kDa protein kinase and cell death by INF1. Carboxy-PTIO also suppressed the induction of hypersensitive-related (hsr) genes HSR515 and HSR203J, the expression of which is strongly correlated with the hypersensitive response in plants. The results suggest that NO plays a crucial role in the induction of hypersensitive cell death.     

Usefulness of an early diagnosis for the favorable prognosis of fibrocartilaginous embolism diagnosed by magnetic resonance imaging in 10 Small- to Middle-Sized Dogs

Fibrocartilaginous embolism (FCE), a disorder of rapid onset featured by nonprogressive paralysis and paresis of four legs, shows clinical symptoms very similar to those of other disorders, e.g., disk herniation. We examined 10 animals diagnosed with FCE based on clinical symptoms and magnetic resonance imaging (MRI) findings in a retrospective study to examine the relationship between onset-to-diagnosis/treatment initiation time and prognosis of FCE. Statistical procedures, including Fisher’s exact probability test, were conducted. All animals in a group, in which the diagnosis was made and treatment was initiated after an elapse of <15 days after onset, showed improved symptoms; the group showed a positive correlation (r = 0.76) between “onset-to-symptom improvement time” and “onset-to-diagnosis/treatment initiation time”. Furthermore, the mean onset-to-diagnosis/ treatment initiation times were 2.67 days and 10.25 days in groups without and with sequelae, respectively; the time was significantly (P < 0.02) shorter in the group without sequelae. A significant difference was found between the groups in early diagnosis and treatment initiation. Our study indicates that the early precise diagnosis for acutely developed paralysis and paresis of four legs through testings including MRI, as well as the early onset of their treatment are important to obtain a favorable prognosis.     

Accumulation mechanism of γ-aminobutyric acid in tomatoes (Solanum lycopersicum L.) under low O2 with and without CO2

The storage of ripe tomatoes in low-O(2) conditions with and without CO(2) promotes γ-aminobutyric acid (GABA) accumulation. The activities of glutamate decarboxylase (GAD) and α-ketoglutarate-dependent GABA transaminase (GABA-TK) were higher and lower, respectively, following storage under hypoxic (2.4 or 3.5% O(2)) or adjusted aerobic (11% O(2)) conditions compared to the activities in air for 7 days at 25 °C. GAD activity was consistent with the expression level of mRNA for GAD. The GABA concentration in tomatoes stored under hypoxic conditions and adjusted aerobic conditions was 60-90% higher than that when they are stored in air on the same day. These results demonstrate that upregulation of GAD activity and downregulation of GABA-TK activity cause GABA accumulation in tomatoes stored under low-O(2) conditions. Meanwhile, the effect of CO(2) on GABA accumulation is probably minimal.     

Experimental inoculation of beagle dogs with Ehrlichia species detected from Ixodes ovatus

Three beagle dogs were inoculated with mice spleen/liver homogenate infected with Ehrlichia species detected from Ixodes ovatus (EIO) and one dog was used as a control. All three infected dogs did not show clinical signs of disease except for mild pyrexia throughout the 41-day study period. Splenomegaly was observed from Day 7 post-inoculation (p.i.) in two of the dogs. Hematological and biochemical abnormalities included mild thrombocytopenia, hypoproteinaemia, hypoalbuminaemia and increased C-reactive protein values. One of the dogs' splenic aspirate sample was PCR-positive for Ehrlichia Day 7 p.i. and another dogs' blood and bone marrow aspirate sample was PCR-positive Day 41 p.i. Sequence analysis of the PCR products showed 100% homology with the 16SrRNA partial gene sequence of Ehrlichia sp. HF565. Antibody titers to EIO were observed in all three experimentally infected dogs starting from the first week p.i. and cross-reactivity with Ehrlichia canis was detectable in one of the dogs starting Day 7 p.i. These data suggest that infection of dogs with EIO is possible, though is probably of low pathogenic importance. Cross-reactivity of EIO infected dog serum with E. canis raises the likelihood of false E. canis seropositive dogs.     

Sulfate and Nitrate Loads on a Forest Ecosystem in Kochi in Southwest of Japan

To assess the influence of acidic deposition on the forest ecosystem, it is necessary to evaluate the gross amount of acidic deposition. In this paper, we discuss the variation of sulfate (SO₄ ^2?) and nitrate (NO₃ ^?) loads as well as related concentration from 1991 to 1999 in the Hinoki (Chamaecyparis obtusa) plantation in Kochi, southwest Japan. The annual precipitation varied significantly from 1,700 to 3,900 mm during the study period. The annual sulfate concentration of rainfall was about 15 µmol L^?1, including about 80% non sea salt sulfate, while the annual nitrate concentration of rainfall was increased. The sulfate and nitrate concentrations of the through fall and the nitrate concentration of the stem flow were equal to or slightly higher than those of rainfall. However, the sulfate concentration of the stem flow was higher than that of rainfall, 21 to 55 µmol L^?1. The sulfate and nitrate loads of rainfall were measured to be 27 to 46 and 14 to 43 mmol m^?2 y^?1, respectively. The sulfate and nitrate loads of the through fall were the same or slightly higher than those of rainfall. In contrast, the sulfate and nitrate loads of the stem flow were less than those of rainfall. Combined sulfate loads of the through fall and the stem flow reached about 1.5 times that of the sulfate load of rainfall.     

Characterization of neuron-like cells derived from canine bone marrow stromal cells

Regenerative therapy using bone marrow stromal cells (BMSCs) has begun to be clinically applied in humans and dogs for neurological disorders such as spinal cord injury. Under appropriate conditions in vitro, BMSCs differentiate into neuronal cells, which may improve the effects of regenerative therapy. In this study, we evaluated canine neuron-like cells (NLCs) derived from BMSCs. We speculated on their suitability for neuro-transplantation from the point of view of their morphological features, long-term viability, abundant availability, and ability to be subcultured. Canine NLCs were differentiated as follows: third-passage BMSCs were maintained in pre-induction medium containing 2-mercaptoethanol and dimethylsulfoxide for 5 h, and then cells were transferred to neuronal induction medium containing fetal bovine serum, basic fibroblast growth factor, epidermal growth factor, dibutyryl cyclic AMP, and isobutylmethylxanthine for 7 or 14 days. Canine NLCs fulfilled the transplantation criteria and expressed markers of both immature neurons (nestin, 84.7 %) and mature neuronal cells (microtubule-associated protein-2, 95.7 %; βIII-tubulin protein, 12.9 %; glial fibrillary acidic protein, 9.2 %). These results suggest that canine BMSCs can be induced to differentiate into neuronal cells and may be suitable for neuro-transplantation. This study may provide information for improving cellular therapy for neurological diseases.     

Antifungal activity of a novel compound purified from the culture filtrate of <Emphasis Type="Italic">Biscogniauxia</Emphasis> sp. O821 against the rice blast fungus <Emphasis Type="Italic">Magnaporthe oryzae</Emphasis>

Rice blast is a devastating fungal disease resulting in major losses to rice crops. Owing to continuous acquisition of resistance by the causal fungus, several fungicide chemicals are no longer effective. Therefore, there is a need to identify natural components and develop new agents to control fungal pathogens. We previously demonstrated that the culture filtrate of Biscogniauxia sp. O821 inhibited infection behavior of Magnaporthe oryzae and subsequent blast lesion formation. In the present study, we isolated a new compound, (3aS,4aR,8aS,9aR)-3a-hydroxy-8a-methyl-3,5-dimethylenedecahydronaphto[2,3-b]furan-2(3H)-one (HDFO), from the culture filtrate of Biscogniauxia sp. O821 and determined its molecular weight as 248. The HDFO structure was determined by electrospray ionization-mass spectrometry and nuclear magnetic resonance spectroscopy after purification with column chromatography and high-performance liquid chromatography. The structure of this antifungal compound was similar to that of alantolactone and isoalantolactone. The growth inhibition zone against M. oryzae in presence of HDFO was observed at Rf 0.5–0.6 on a thin layer chromatography plate. HDFO inhibited conidial germination of M. oryzae in a dose-dependent manner (1–200 ppm). Furthermore, blast lesion formation was significantly suppressed by HDFO at over 5 ppm. These results suggest that HDFO from the culture filtrate of Biscogniauxia sp. O821 can protect rice from rice blast disease caused by M. oryzae. This is the first report that HDFO produced by Biscogniauxia sp. can serve as an antifungal compound against M. oryzae.     

Detoxification of phytotoxic compounds by TiO2 photocatalysis in a recycling hydroponic cultivation system of asparagus

TiO 2 photocatalytic decomposition and detoxification of phytotoxic compounds released by the roots of asparagus ( Asparagus officinalis L.) were investigated from the viewpoint of conservation-oriented cultivation. The phytotoxically active fraction was extracted either from dried asparagus roots or from the recycled nutrient solution of an asparagus hydroponic cultivation system. We found that the phytotoxic activity gradually decreased in the fraction with TiO 2 powder under irradiation with ultraviolet (UV) light at an intensity of 1.0 mW/cm (2). The growth of asparagus plants under actual cultivation conditions was also investigated by comparing asparagus grown in a hydroponic system where recycled waste nutrient solution was photocatalytically treated with solar light and a system with untreated recycled waste nutrient solution. The results showed, as measured by growth indices such as stem length and stem thickness, that asparagus growth in the photocatalytically treated system was superior to the untreated one. Furthermore, the yield of asparagus spears was 1.6-fold greater in the photocatalytically treated system, demonstrating the detoxification effect on the phytotoxic compounds and also the killing effect on pathogenic microorganisms.