Relationship between the temperature and the overwintering of water lettuce (Pistia stratiotes) at Kowataike,a branch of Yodogawa River,Japan

The successful overwintering of water lettuce (Araceae, Pistia stratiotes L.) is reported in Kowataike, a pond in Kyoto Prefecture, Japan, in the temperate climate zone. Overwintering was observed in the northern zone of Kowataike, where warm water discharge flows from an upstream electrical appliance factory. From December 2007 to January 2008, several overwintering water lettuce plants were observed in the northern zone where the water temperature was abnormally high (average: 21.9°C; low: 19.5°C). Water in the central zone of Kowataike was isolated from the warm water discharge. The temperatures here were much lower (average: 8.2°C; low: 4.2°C) and no water lettuce plant survived here. The overwintering in the northern zone fluctuated annually. This fluctuation appeared to be correlated with the period of warm water discharge, which varied from year to year and resulted in higher water temperatures most, but not all, of the winter. The results suggest that artificial environmental factors, such as anthropogenic warm water discharge, could enable water lettuce to overwinter. In the northern zone of Kowataike under the influence of the warm water discharge, only small water lettuce plants overwintered. This may be attributed to the presence of older plants with larger leaves that seemed to protect the small rosettes from frost. Second, the air warmed by the warm discharge accumulated in the space under the piles of dead large leaves, which created conditions similar to those of a greenhouse. These two mechanisms apparently allow the small water lettuce plants to be surrounded by moderate atmospheric conditions.     

Experimental actinomycosis caused by Actinomyces-like bacteria in mice and a sow

The present experiment was performed to test the pathogenicity of Actinomyces-like bacteria in experimental animals and swine. Two rough (R) strains of Actinomyces-like bacteria isolated from a site of arthritis and from the tonsil in pigs were used as inocula. To investigate their susceptibility to Actinomyces-like bacteria, BALB/c, SS and ddY mice and guinea-pigs were inoculated intraperitoneally with the strains of Actinomyces-like bacteria. The ddY mice were used for the long-term observation of Actinomyces-like bacteria lesions and the mammary tissue of a sow was inoculated with Actinomyces-like bacteria isolated from swine tonsil. Macroscopic observation revealed many abscesses on the surfaces of the abdominal and/or thoracic organs in the mice, but not on those of the guinea-pigs. The sow developed firm nodules at the inoculation site in the mammary glands. Histopathologically, the lesions in the mice were characterized as actinomycotic abscesses in the early stage and as pus-forming granuloma (PFG) in the advanced stage; the lesions were accompanied by crystalloid particles. Actinomyces-like bacteria induced granulomatous mastitis in the sow, and the lesion was characterized as PFG. The characteristic actinomycotic lesions in swine mammary glands were reproduced by experimental infection.     

Volatile organic compounds from wood and their influences on museum artifact materials I. Differences in wood species and analyses of causal substances of deterioration

Wood is generally used as the interior material in museum storage rooms. Recently, however, the effects of volatile organic compounds (VOCs) from wood on artifacts has become a topic of great concern. The VOCs from four species of wood (western red cedar, spruce, kiri, and sugi) and their effects on artifact materials (two types of metal, seven types of pigment) were investigated using a deterioration-accelerating test, gas chromatography-mass spectrometry, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The results suggested that the influences on artifact materials varied greatly with wood species, and depended on specific components such as hinokitiol or acetic acid rather than the amount of total volatile organic compounds (TVOCs). It is a very serious problem that of the four species of wood, western red cedar (rich in hinokitiol), which has been recommended as an interior material for museum storage rooms, showed the heaviest deterioration on metal samples, and only this type of wood discolored enpaku (white lead) and rokushou (malachite, verdigris). In such storage rooms, museum artifacts should be carefully monitored. When selecting an interior material for a storage room or studying methods of preventing deterioration, it is very important to consider fully the characteristics of wood VOCs, not only the amount of TVOC.Part of this paper was presented at the 24th (Tokyo, June 2002) and 25th (Kyoto, June 2003) Annual Meeting of the Japan Society for the Conservation of Cultural Property     

The effect of body position on the 'hanging drop' method for identifying the extradural space in anaesthetized dogs

ObjectivesTo assess the accuracy of the ‘hanging drop method’ for identifying the extradural space in anaesthetized dogs positioned in sternal or lateral recumbency.Study designProspective randomized-experimental study.AnimalsSeventeen clinically healthy adult dogs, 10 females and seven males weighing 8.4–26.2 kg.MethodsDogs were positioned in either sternal (n = 8) or lateral (n = 9) recumbency under general anaesthesia. A 20 SWG spinal needle pre-filled with 0.9% saline was advanced through the skin into the lumbosacral extradural space and the response of the saline drop recorded, i.e. whether it: 1) was aspirated from the hub into the needle; 2) remained within the hub, or 3) moved synchronously with i) spontaneous respiration, ii) heart beat or iii) manual lung inflation. The position of the needle tip was ultimately determined by positive contrast radiography.ResultsOne dog positioned in lateral recumbency was excluded from the study because bleeding occurred from the needle hub. Saline was aspirated into the needle in seven of eight dogs held in sternal recumbency but in none of the dogs positioned in lateral recumbency. Accurate needle tip placement in the extradural space was confirmed by positive contrast radiography in all dogs.Conclusion and clinical relevanceThe ‘hanging drop’ method, when performed with a spinal needle, appears to be a useful technique for identifying the location of the extradural space in anaesthetized medium-sized dogs positioned in sternal, but not in lateral recumbency. The technique may yield ‘false negative’ results when performed in dogs positioned in sternal recumbency.     

Morphometric evaluation of canine hepatocellular carcinoma using computed tomography: a promising tool for predicting malignancy

The size of canine focal liver lesions (FLLs) is known to be one of the predicting criteria for malignancy. However, there are discrepancies for the measurement of maximum lesion size, resulting in contradicting results among studies and incidences of false positive outcomes. Thus far, the morphometric changes of FLLs for distinguishing malignancy from benignancy remains undocumented. This study aimed to investigate morphometric characteristics of FLLs using computed tomography (CT). CT images of 40 dogs with histopathological confirmation of 49 liver lesions, including 39 hepatocellular carcinomas and 10 nodular hyperplasias were retrospectively reviewed. The morphometric parameters including size (long and short axis diameters measured on transverse image), shape (measured by long to short axis (L/S) ratio), volume, and surface appearance of a liver lesion were evaluated using univariate and stepwise multivariate analyses, respectively. The results of univariate analysis showed that long and short axis diameters, L/S ratio, volume, and surface appearance of a lesion were significantly different between hepatocellular carcinomas and nodular hyperplasias. Multivariate analysis revealed that short axis diameter (>3.30 cm; odds ratio (OR): 36.1, 95% confidence interval (CI): 3.36–387.05, P=0.0031) and L/S ratio (>1.23; OR: 18.1, 95% CI: 1.61–205.12, P=0.0191) were independent predictors of malignancy, with the area under the curve of 0.9154. These results suggest that the combination of short axis diameter and L/S ratio is a promising tool for predicting liver malignancy with outstanding discriminating ability.     

Primary hemangiosarcoma of the humerus in a Maltese dog

A 14-year-old intact male Maltese dog was presented with a history of pain and swelling of the left upper forelimb and lameness for 3 weeks. Hematological and radiographical examinations showed regenerative anemia and osteolysis of the humerus. Fine needle aspiration biopsy detected epithelioid- and fibroblast-like anaplastic cells with blood components. A hemorrhagic and osteolytic malignant tumor was suspected, and the affected forelimb was amputated. Histopathologically, the dog was diagnosed with primary hemangiosarcoma of the humerus. Thereafter, metastatic lesions appeared in the skin, and the dog was euthanized 1 month after the operation.     

Plasma free amino acid profiles of canine mammary gland tumors

The purpose of this study was to elucidate the relationship between plasma free amino acid (PFAA) levels and the clinical stages of mammary gland tumors (MGT) in dogs. PFAA levels in canines with malignant mammary tumors were decreased compared to those of healthy animals. The levels of aspartate and ornithine, in the dogs with tumor metastasis were significantly decreased when compared to those of dogs that did not have metastases. Results of this study indicate that PFAA levels could be a risk factor or biomarker for canine MGT metastasis.     

Effects of low-dose G-CSF formulation on hematology in healthy horses after long-distance transportation

The present study evaluated the effects of single-dose filgrastim on hematology in 16 healthy horses after long-distance transportation. Horses were assigned to receive filgrastim (0.23 µg/kg, SC, once; G-CSF group; n=8) or saline (0.9% NaCl) solution (0.3 ml, SC, once; control group; n=8) ≤ 1 hr before transportation. Horses were transported 2,530 km using commercial vans over the course of approximately 44 hr. Clinical examinations and hematologic analyses were performed on all horses before and after transportation. Because the post-transportation white blood cell counts and bacillary neutrophil to segmented neutrophil ratio were significantly higher in the G-CSF group, filgrastim may have promoted the mobilization of neutrophils from marrow. Filgrastim deserves a further study for efficacy in preventing horse shipping fever.