Cutaneous plasmacytomas with amyloid in six dogs.

Cutaneous plasmacytomas associated with local deposition of amyloid were diagnosed by light microscopy in a series of six older dogs (mean age 10.7 years) consisting of two Cocker Spaniels, a Poodle, a Weimeraner, and two mixed-breed dogs. The neoplasms occurred on the digits (2 dogs), forelimb (2 dogs), lip (1 dog), and ear (1 dog). In most cases, groups of neoplastic plasma cells were widely separated by large homogeneous islands of amyloid. The neoplastic cells had characteristic plasmacytoid features, but the degree of pleomorphism varied greatly between different neoplasms. In four of the six tumors, the diagnosis of plasmacytoma was confirmed by the demonstration of a monoclonal plasma cell population using immunofluorescent staining for anti-canine immunoglobulins. In these tumors, the neoplastic cells reacted with only one class of immunoglobulins (IgG). The amyloid did not react with any of the reagents used. The suspicion that the amyloid was of immunoglobulin origin (primary amyloid) was supported by its retention of birefringence under polarized light after treatment with potassium permanganate and staining with Congo red.     

Equine congenital papilloma: pathological findings and results of papillomavirus immunohistochemistry in five cases

Abstract Congenital cutaneous papillomas were identified in five foals. Age at diagnosis ranged from 305 days' gestation to 2 days of age. Breeds were thoroughbred (2), standard-bred (1), warmblood (1) and paint (1). Two were female, one was male and the gender of two cases was not specified. Masses were pedunculated with a roughened, wart-like (verrucous) or a smoother, cauliflower-like surface. Masses occurred as single lesions on the forelimb, lip and face, or as multiple lesions on the trunk. Histological features included relatively uniform epidermal papillary hyperplasia with variable melanin pigment within basal layers and vacuolization of keratinocytes in all layers, but with no evidence of nuclear or cytoplasmic changes (koilocytes) characteristic of viral infection. One case showed epidermal proliferation with proliferation of pilosebaceous units. Results of immunohistochemical studies for the detection of papillomavirus antigens were negative in all cases. These results suggest that equine congenital papilloma may be a hamartomatous lesion (epidermal nevus) and not a viral-induced growth.     

Isotopic and Zoogeographic Paleotemperatures of Californian Pleistocene Mollusca

Pleistocene paleotemperatures inferred from zoogeographic evidence are based on temperatures at species' range limits at present. Paleotemperatures inferred from isotopic evidence are based on average former shell-growth temperatures which commonly, but not exclusively, lie between present range-limiting temperatures. With allowance for these differences, the two lines of evidence suggest similar thermal patterns.     

Marine fossils at rancho la brea

Marine assemblages of foraminifera, ostracods, mollusks, and echinoids were recovered from deposits stratigraphically beneath the classic vertebrate assemblages from the tar pits at Rancho La Brea. The marine fossils indicate deposition in quiet, shallow water and suggest that accumulation of the type Rancholabrean material began during Wisconsin time.     

Molecular biology of osmoregulation

The drought of 1983 resulted in some 10 billion dollars in agricultural losses and has focused attention on the vulnerability of our major crops to this devastating form of environmental stress. This article is concerned with the molecular biology of a new class of genes, called osm (osmotic tolerance) genes, that protect bacteria like Escherichia coli against osmotic stress and may work in a similar manner in plants and animals. Osm genes govern the production of a class of molecules, such as betaine and proline, that protect the cell and its constituents against dehydration. These osmoprotectant molecules have been known for many years to accumulate in plants but have only recently been shown to have potent antistress activity for bacteria.     

Anatomic and volumetric characterization of the cisterna chyli using CT lymphangiography and computer‐assisted design software in dogs with idiopathic chylothorax

The objectives of this retrospective, observational study were to characterize the anatomical features of the cisterna chyli (CC) in a cohort of dogs diagnosed with idiopathic chylothorax that underwent CT lymphangiography (CTLa), and to evaluate the feasibility of computer‐assisted design (CAD) software to quantify volumetric measurements of the CC. Twenty‐three client‐owned dogs with idiopathic chylothorax were included. Additionally, CTLa was performed in three canine cadavers to assess the ability of CAD software to accurately acquire volumetric measurements. Injection sites, attenuation values, anatomic location, dimensions, and aortic diameter to CC ratio (Ao:CC) were recorded. Video records of video‐assisted thoracic surgery (VATS) thoracic duct ligation (TDL) were reviewed in eight out of 23 dogs to compare operative and CTLa findings. The CC was dorsal and right‐sided in 18 out of 23 dogs, located between L1 and L4 in 21 dogs, and extended as far cranially as T11 in two dogs. The median measurements for length, height, and width were 150.0, 5.5, and 13.3 mm, respectively. Median total volume was 1.82 mL. Median volumes to the right and left of the aorta were 1.46 and 0.49 mL, respectively (P = .014). Median total CC volume to body weight ratio (CC:bw) was 0.07 mL/kg. The presence of an intrathoracic CC was observed intraoperatively in six out of eight cases that underwent VATS TDL. Findings supported the use of CTLa and CAD as feasible methods for characterizing the CC in dogs diagnosed with chylothorax. These methods may facilitate interventional planning involving the CC such as embolization.