Confounders for kidney carcinogenesis in rodent cancer bioassays

In the long-term safety testing of chemicals for carcinogenicity the toxicologist needs to be aware of a number of scenarios where renal tubule tumors, or their precursors, arise that are not due to a carcinogenic action of the test article. Situations producing false positive results in the kidney include exacerbation of chronic progressive nephropathy (CPN) in rats, confusion of atypical tubule hyperplasia (the obligate precursor of renal tubule tumor) with foci of benign CPN-related renal tubule cell proliferation, inclusion of spontaneous tumor entities, such as the amphophilic-vacuolar tumor, in the test article tumor count, the possibility of a link between spontaneous forms of tubule dilatation and renal tubule tumor formation in mice, and the supposed predictivity of chemically-induced karyomegaly for renal carcinogenicity in both rats and mice. Examples of these misleading situations are described and discussed.     

鸡肿瘤病快速鉴别诊断技术的建立

根据病毒基因组特征,以聚合酶链反应（PCR）为基础,建立一种能快速鉴别马立克氏病（MD）、禽白血病（AL）和网状内皮增生症（RE）3种常见鸡肿瘤病的诊断技术。研究确定以MDV的132－bpr及ALV和REV的LTRs作为PCR扩增的特异性基因片段,改进样品DNA的提取程序,优化PCR及三重PCR的反应条件及参数,并对该诊断技术的特异性、敏感性进行研究,结果表明：建立的诊断技术具有特异、敏感、快速、经济的优点,为开发鸡肿瘤病快速鉴别诊断试剂盒奠定了基础。     

Therapeutic pericardiocentesis in the dog and cat

Pericardial effusion is a potentially life-threatening problem leading to a rise in the intrapericardial pressure resulting in varying degrees of hemodynamic compromise. Cardiac tamponade occurs when the intrapericardial pressure equals or exceeds right ventricular diastolic filling pressures leading to a decreased cardiac output. In dogs, the most common causes of pericardial effusion that require pericardiocentesis are cardiac neoplasia and idiopathic pericardial effusion (IPE). The incidence of cardiac neoplasia in dogs is low, and it is rare in cats. In dogs, hemangiosarcoma and chemodectoma are the two most common types of cardiac neoplasia. In cats, lymphosarcoma is the most common form of cardiac neoplasia, but they are more likely to develop pericardial effusion secondary to congestive heart failure or feline infectious peritonitis. Common histories include lethargy, dyspnea, anorexia, collapse, and abdominal distension. Pericardiocentesis is used to stabilize animals with life-threatening cardiac tamponade, relieve the pressure leading to right-sided heart failure, and obtain fluid samples for diagnostic evaluation. The fluid should be quantified and characterized. Serious complications associated with pericardiocentesis are rare. Complications include cardiac puncture, arrhythmias, and laceration of a tumor or coronary artery resulting in intrapericardial hemorrhage or sudden death.     

A NINE-DAY ACCELERATED RADIATION PROTOCOL FOR FELINE SQUAMOUS CELL CARCINOMA

Nine cats with oral squamous cell carcinoma were treated with an accelerated radiation protocol (14 fractions of 3.5 Gy in 9 days). Radiation was administered twice daily with a 6hour break between treatments. Median overall survival was 86 +/- 110 days. Median survival for cats with a partial response (n=6) was 60 +/- 7 days, while median survival for cats with a complete response (n=3) was 298 +/- 187 days (P = 0.0639). The accelerated protocol was well tolerated and toxicity in the early and late period was manageable in all cats. Further modification of the protocol is warranted to extend survival.     

家养动物的睾丸肿瘤

本文简要地介绍了家养动物中常见睾丸肿瘤的发病与分布情况，病因学、病理变化及其临床症状与诊断方法，并对其治疗方法提出了意见。     

RADIUM-226-INDUCED BONE LESIONS IN BEAGLES

In a colony of Beagles that had received intravenous injections of ²²⁶Ra was a subgroup of 42 dogs that had limbs amputated because of the development of painful bone lesions. Information was gained from sequential radiographic studies plus examination of tissue harvested from the amputated limbs. Bone lesions that had their inception in bizarre, progressively expansile resorption cavities in which the process of normal bone tissue replacement was defective were identified. Some of these lesions were the site of development of bone sarcomas. This radiation-induced disturbance in bone repair was termed radiation osteodystrophy. The pathologic sequence in these Beagles in which a defect in the remodeling process of cortical bone leads to the development of lesions of radiation osteodystrophy and bone sarcoma was felt to be unique and thought to be a specific effect of chronic irradiation by ²²⁶Ra.     

Role of macrophage in the defense against intestinal cancers

The capability of activated macrophages to kill tumor cells in vitro is now well documented. The tumoricidal activation of macrophages against intestinal tumor cells by different agents is described and the main hypothesis on the mechanisms of tumor cell killing in vitro are discussed. These in vitro results suggest that the macrophage can constitute an efficient effector cell in the defense against intestinal tumors. The distribution and ratio of macrophages in normal intestine and intestinal tumors is described. At the moment, potent activators of macrophages studied in vivo on experimental and human intestinal tumors give poor results or even enhance the growth of tumors. Macrophages may also interfere with the specific immune response in two directions by enhancing the immune response or decreasing it by elaboration of mediators such as prostaglandins.