Differential swimming performance of two natricine snakes exposed to a cholinesterase-inhibiting pesticide.

Environmental contaminants have direct effects on organisms at the molecular, cellular, and tissue levels, but the net results of these sub-organismal effects are only consequential to exposed populations if they alter organism-level traits that ultimately influence fitness (e.g., growth, locomotor performance, reproduction, and survival). Here, we explore the possibility that the swimming performance of neonate black swamp snakes (Seminatrix pygaea) and diamondback water snakes (Nerodia rhombifer) may be affected by exposure to carbaryl (2.5 and 5.0 mg/L). The highest concentration of carbaryl caused greater reductions in swim velocity in S. pygaea than in N. rhombifer. Most individuals recovered from the effects of carbaryl on swimming performance within 96 h, but recovery was significantly slower in S. pygaea than in N. rhombifer. We hypothesize that the sensitivity of S. pygaea may arise from its highly permeable integument compared to other natricines. Our findings suggest that performance can serve as an ecologically relevant response to contaminant exposure in reptiles and warrants further study.

Botryoid odontogenic cyst. Report of a case with histologic evidence of multicentric origin.

Histologic examination of an excisionally biopsied botryoid odontogenic cyst (BOC) documented that it was composed of at least 2 separate cysts, the location of which suggested that both originated within the alveolar bone rather than from within the periodontal ligament. These observations provide evidence for a multicentric origin of this example of BOC, and are consistent with a previous suggestion that lateral periodontal cysts of non-inflammatory origin arise from remnants of the dental lamina.

Hemodialysis-associated amyloidosis presenting as lingual nodules.

Hemodialysis has permitted long-term survival of patients with kidney failure, but not without many complications, such as mineral loss from bones, secondary hyperparathyroidism, and increased risk of infection. Recently a new form of amyloidosis, AB2M, has been characterized that is specifically associated with long-term dialysis. The tissues and organs affected by deposits of AB2M appear to differ from those affected by the other major types of amyloidosis; AB2M affects mainly the carpal ligament, synovia of large joints, juxtaarticular bone, and intervetebral disks, while involvement of the oral tissues has been rare. We present here a case in which the biopsy of superficial lingual deposits of AB2M led to the recognition that the patient had developed hemodialysis-associated amyloidosis. It is suggested that periodic inspection of the oral soft tissues for signs or symptoms of amyloidosis should become a part of the dental care of patients undergoing dialysis.