CHARACTERIZATION OF CANINE FOCAL LIVER LESIONS WITH CONTRAST-ENHANCED ULTRASOUND USING A NOVEL CONTRAST AGENT—SONAZOID

Contrast-enhanced ultrasound using Sonazoid, a novel contrast medium with a liver-specific Kupffer phase, was evaluated in canine focal liver lesions Twenty-five dogs with a liver mass were given intravenous Sonazoid, and the enhancement pattern in the arterial, portal, and parenchymal phase was characterized. An enhancement defect in the lesion in the parenchymal phase was observed in all malignant lesions, whereas only one of nine benign lesions had a filling defect. The diagnostic value of the presence of a filling defect for malignancy was statistically significant (100% sensitivity, 88.9% specificity, 94.1% positive predictive value, 100% negative predictive value), and was equal to that of hypoenhancement in the portal or delayed phase. The defect pattern (clear or irregular defect) was dependent ( P <0.05) on the types of malignancy (i.e., hepatocellular carcinoma and other types of malignancies). In the arterial phase, five of the six hepatocellular carcinomas had hypervascularity, whereas no other lesion was characterized by hypervascularity. In some dogs, additional lesions that could not be observed with conventional B-mode ultrasonography were detected in the parenchymal phase. The enhancement pattern of Sonazoid, especially in the parenchymal phase, has potential as a diagnostic tool for canine focal liver lesions.     

内毒素对山羊肝脏的病理损伤和654-2的保护效应

通过给山羊静注大肠杆菌内毒素（ＥＴ）诱导ＥＴ休克,探讨ＥＴ休克时山羊肝脏的病理损伤,并观察山莨菪碱（６５４－２）对其影响。结果表明,ＥＴ自理组在注射后５ｈ,肝脏表现出明显的病理变化,特征为实质细胞退行性变化,微血管淤血、有透明血栓形成,血管内有淋巴细胞和中性粒细胞粘聚,且肝脏有明显的超微结构变化。６５４－２能有效地缓解或减轻ＥＴ引起的毒性损伤。     

Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. 1. Study design,and clinical,nutritional, radiological and histological observations

AIMS: This is the first in a series of papers reporting studies in 2-year-old Thoroughbred racehorses that aimed to determine the response of musculoskeletal tissues to early training on grass and sand racetracks. In this paper, the experimental set-up of the whole study is described, and nutritional, workload, and clinical, radiographic and pathological outcomes are reported, including semi-quantitative assessment of macroscopic changes in articular cartilage.

METHODS: The study group comprised 14 two-year-old Thoroughbred fillies reared entirely at pasture. Of these, seven were selected by a licensed racehorse trainer to undergo a 4-week period of initial training in which they were taught to accept saddle and rider, followed by a 13-week period of flatrace training at a racetrack (Weeks 1–13); the other seven fillies were confined to large grass enclosures and were not trained. Nutrient, including macro- and trace-element intakes were estimated. Distances cantered or galloped and average velocities were quantified for the trained horses. All horses were observed daily, weighed approximately weekly, and underwent a clinical lameness examination at Weeks 5, 9 and 13. Distal forelimbs were radiographed prior to Week 1, during Weeks 7–8, and again at the end of the study, when macroscopic changes in articular cartilage of the proximal surface of the proximal phalanx were also scored after staining with India ink.

RESULTS: Dietary intakes met or exceeded recommended requirements for all nutrients except sodium, which was low in the trained horses. Bodyweight increased throughout the study in the untrained horses, and increased until Week 7 and then decreased slightly in the trained horses. Mean velocity data were used to define three stages of the training programme: Stage 1 comprised canter in Weeks 1–4; Stage 2 comprised canter in Weeks 5–8; and Stage 3 comprised canter in Weeks 9–13 and galloping twice weekly. Four of seven horses completed training. These covered a mean distance of 179.2 km at mean velocities (excluding gallops) of 7.63 m/sec (SD 0.58), 8.99 m/sec (SD 0.56), and 8.43 m/sec (SD 0.74) for Stages 1–3, respectively, and galloped 4.45 km at 14.4 (SD 0.1) m/sec. The three horses that did not complete training became lame in Weeks 9, 10 and 11, and covered 147.9 km at velocities of 7.38 m/sec (SD 0.44), 8.88 m/sec (SD 0.33) and 8.43 m/sec (SD 0.59) and galloped 2.1 km. Overall, slight or intermittent lameness in trained horses was noted on 76/655 (12%) of horse observation days. Swelling was evident on 284/655 (41%) of horse observation days in the metacarpophalangeal (MCPJ) and metatarsophalangeal (MTPJ) joints (92%), palmar metacarpal tendon region (7%) or carpus (1%). Swelling of the MCPJ or MTPJ was not associated with obvious lameness. Radiographic changes were minor and no gross lesions in bone or tendon tissue were evident except for one case of dorsal metacarpal disease. Post mortem, the cartilage of some MCPJ and MTPJ had obvious wear lines and high lesion scores, which were not consistently related to clinical evidence of pain, lameness or joint swelling. Mean lesion scores were not significantly different between the MCPJ and MTPJ, or between trained and untrained horses.

CONCLUSIONS: Workload can be readily quantified in racehorses under semi-commercial training conditions. Obvious lesions in cartilage of the MCPJ or MTPJ were present in some trained and some untrained horses and not consistently associated with clinical evidence of lameness, joint swelling or change in other connective tissues.

CLINICAL RELEVANCE: Workload data in racing horses are likely to be highly relevant for studying the pathogenesis of changes in bone, tendon and cartilage during training, for training management and for risk analysis in racehorse populations. Although obvious cartilage lesions produced little clinical effect, such lesions have previously been shown to be progressive and to prejudice athletic capability. Detection of such occult lesions in young horses will require more sophisticated detection methods.     

Immunogenic properties of Landrace pigs selected for resistance to mycoplasma pneumonia of swine

Mycoplasma pneumonia of swine (MPS) lung lesions and immunogenic properties were compared between a Landrace line that was genetically selected for reduced incidence of pulmonary MPS lesions, and a non‐selected Landrace line. The MPS‐selected Landrace line showed significantly lower degrees of pulmonary MPS lesions compared with the non‐selected Landrace line. When changes in immunity before and after vaccination were compared, the percentage of B cells in the peripheral blood of the MPS‐selected Landrace line was significantly lower than that of the non‐selected line. Furthermore, the concentration of growth hormone and the mitogen activity of peripheral blood mononuclear cells in the MPS‐selected Landrace line showed significantly (P < 0.05) lower increases after vaccination than the non‐selected line. Conversely, the concentration of peripheral blood interferon (IFN)‐γ and salivary immunoglobulin A (IgA) after Mycoplasma hyopneumoniae vaccination was significantly higher in the MPS‐selected Landrace line than in the non‐selected line. Gene expression of toll‐like receptor (TLR)2 and TLR4 was significantly higher in the MPS‐selected Landrace line in immune tissues, with the exception of the hilar lymph nodes. The present results suggest that peripheral blood IFN‐γ, salivary IgA TLR2, and TLR4 are important immunological factors influencing the development of MPS lesions.     

在中国新发现的一种羊的巴贝斯虫(Babesia)未定种

在中国甘肃某地自然感染发病绵羊的血液涂片中，观察到一种大型的巴贝斯虫（Ｂａｂｅｓｉａ）。虫体形态具多形性，有双梨籽形、单梨籽形、圆环形、棒状、不规则形、逗点形和三叶形。典型双梨籽形虫体的大小为１．８～２．５μｍ×０．９～１．８μｍ，平均（２．２１±０．１２）μｍ×（１．１７±０．１８）μｍ。个别红细胞中寄生有４个或８个虫体。该虫种特征性的形态是三叶形。它是相连的双梨籽形虫体两尖端的核质延伸（出芽），并生出原生质，发育成一个完整的梨籽形虫体，与母体共同排列形成三叶形的。该虫种可引起绵羊严重发病和死亡。本研究对自然感染发病羊的临床症状和死亡羊的病理变化进行了观察。该虫种的形态大小和致病力，与莫氏巴贝斯虫（Ｂ．ｍｏｔａｓｉ）和粗糙巴贝斯虫（Ｂ．ｃｒａｓｓａ）明显不同。     

Use of thermal imaging for identification of foot lesions in dairy cattle

The objective of this study was to investigate the use of infrared thermography (IRT) for detection of foot lesions in dairy cattle. Thermal images of the rear feet of 139 lactating dairy cows were taken with a thermal camera and evaluated using imaging software. Foot lesions identified in the study included white line disease (WLD), sole ulcer (SU) and digital dermatitis (DD). Temperatures at the coronary band (CBT) and the skin (ST) were recorded. Cows were scored for locomotion on a scale of 1–5 (1?=?normal and 5?=?severely lame). CBT was higher for all types of foot lesion (34.1?±?2.3, 33.8?±?1.6 and 33.1?±?1.6°C for WLD, SU and DD, respectively) than for healthy (32.6?±?1.9°C) feet. ST was higher only for WLD (33.2?±?2.0°C) compared to healthy feet (31.5?±?1.7°C). ΔT (temperature difference between CBT and ST) was higher for SU (2.1?±?0.8°C) than healthy feet (1.1?±?0.9°C). Locomotion scores (LSs) were similar between healthy cows (2.2?±?0.7) and DD (2.4?±?0.7) but greater for SU and WLD cows (3.0?±?0.9, 3.0?±?0.8) than healthy cows. The threshold values established for CBT and ST were 33.5°C (sensitivity?=?77.8%, specificity?=?65.2%) and 33.7°C (sensitivity?=?44.4%, specificity?=?92.9%) for SU, and 34.4^oC (sensitivity?=?28.1%, specificity?=?88.6%) and 31.8°C (sensitivity?=?60.7%, specificity?=?55.4%) for overall lesion, respectively. These results indicate that IRT can be a useful tool for detection of SU, but not WLD and DD. In addition, CBT and ΔT were the best indicators for the detection of foot lesions.     

Liquoid-induced arterial lesions and the generalized Shartzman reaction.

Mural necrotic lesions were produced in renal afferent arteries in rabbits, pigs and blue foxes, by intravenous injections of Liquoid. These lesions were frequently accompanied by thrombosis in the affected arterial segments and invariably by “microthrombosis” in glomerular capillaries. Mural arterial lesions were always present in cases with evident macroscopic necrotic changes of the renal cortex. Necrotic arterial lesions, with thrombosis, were also observed in pulmonary arteries in all the animal species used in these experiments, i.e. rabbit, pig, blue fox, mouse and ferret.     

First Steps Towards an Understanding of a Mode ofCarcinogenic Action for Vanadium Pentoxide

Inhalation of vanadium pentoxide clearly increases the incidence of alveolar/bronchiolar neoplasms in male and female B6C3F1 mice at all concentrations tested (1, 2 or 4 mg/m³), whereas responses in F344/N rats was, at most, ambiguous. While vanadium pentoxide is mutagenic in vitro and possibly in vivo in mice, this does not explain the species or site specificity of the neoplastic response. A nose-only inhalation study was conducted in female B6C3F1 mice (0, 0.25, 1 and 4 mg/m³, 6 h/day for 16 days) to explore histopathological, biochemical (α-tocopherol, glutathione and F2-isoprostane) and genetic (comet assays and 9 specific DNA-oxo-adducts) changes in the lungs. No treatment related histopathology was observed at 0.25 mg/m³. At 1 and 4 mg/m³, exposure-dependent increases were observed in lung weight, alveolar histiocytosis, sub-acute alveolitis and/or granulocytic infiltration and a generally time-dependent increased cell proliferation rate of histiocytes. Glutathione was slightly increased, whereas there were no consistent changes in α-tocopherol or 8-isoprostane F2α. There was no evidence for DNA strand breakage in lung or BAL cells, but there was an increase in 8-oxodGuo DNA lesions that could have been due to vanadium pentoxide induction of the lesions or inhibition of repair of spontaneous lesions. Thus, earlier reports of histopathological changes in the lungs after inhalation of vanadium pentoxide were confirmed, but no evidence has yet emerged for a genotoxic mode of action. Evidence is weak for oxidative stress playing any role in lung carcinogenesis at the lowest effective concentrations of vanadium pentoxide.     

Slaughterline records of various postmortem pathological lesions and their influence on carcass and meat quality in slaughtered pigs

The aim of this study was to identify the prevalence of pathological lesions in pigs from small‐scale farms and to determine associations between pathological lesions and hematological parameters, and carcass and meat quality in slaughtered pigs. The study was conducted on 625 pigs (~115 kg) originating from 20 small‐scale farms. Any signs of pneumonia, pleurisy, pericarditis, and liver milk spots were recorded as present or absent. Complete blood count was investigated. The following carcass quality parameters were measured: live, hot and cold carcass weights, cooling loss, dressing percentage, backfat thickness, and meatiness. Meat pH and temperature were measured 45 min postmortem. Of the 625 examined pigs, 41.8% had pneumonia, 23.5% pleurisy, 2.7% pericarditis, and 29.9% liver milk spots. The presence of pathological lesions in slaughtered pigs adversely affected hematological parameters, reduced live, hot and cold carcass weights, and meatiness and had deleterious effects on meat quality (higher pH_45min and higher prevalence of dark, firm and dry meat). In conclusion, this study showed a high prevalence of pathological lesions in slaughtered pigs, indicating serious health problems in smallholder pig production systems. The presence of single and, especially, multiple pathological lesions in slaughtered pigs negatively affected hematological parameters, and carcass and meat quality.