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Biomedical subjects

H E Whiteley

Publications and source records attributed to H E Whiteley.

At least 19 recordsLinked to original sources

Clinical and histologic evaluation of the prolapsed third eyelid gland in dogs.

Eighteen prolapses of the gland of the third eyelid in 17 Beagles were randomly allocated to 3 groups, which included nontreated (group 1, n = 6), excised (group 2, n = 4), and surgically repositioned (group 3, n = 8) glands. A schirmer tear test (STT) was performed on affected and normal (control) eyes for 5 consecutive days on weeks 0 (baseline), 2, 4, 6, 8, 10, 12, 16, 18, 20, and 24. All prolapsed third eyelid glands were excised and examined histologically. Ten female and 7 male Beagles were used in the prospective study. Mean age at prolapse was 35.1 weeks (range, 6 to 89 weeks). Control STT data revealed a population mean of 22.2 +/- 2.1 mm/min. Complications developed in 4 of 6 eyes when the gland was allowed to remain in a prolapsed position. Complications for group-1 eyes were significantly (P < 0.005) greater than those for eyes in groups 2 and 3 (0 of 12). Comparison of affected and control eye baseline data revealed decreased STT values for eyes with prolapsed glands (P < 0.01). Mean differences between affected and control eyes were 2.2, 2.0, and 3.4 mm/min for groups 1, 2, and 3, respectively. A significant (P < 0.001) decrease in lacrimation (0.2 to 3.1 mm/min) in group-2 eyes was detected after removal of the gland. Tear production for affected eyes of nontreated dogs fluctuated above and below that of control eyes prior to excision of the prolapsed gland of the third eyelid; however, with time, affected and control eye STT values were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Platelet kinetics and other hematological profiles in experimental Plasmodium falciparum infection: a comparative study between Saimiri and Aotus monkeys.

Levels of platelets and other hematological values were monitored in 21 Saimiri and 12 Aotus monkeys over a period of three weeks post-infection with monkey-adapted Indochina CDC-1 strain of Plasmodium falciparum. In both Saimiri sciureus boliviensis and Aotus nancymai karyotype-1 monkeys the severest thrombocytopenia was observed at 14 days post-infection coinciding with peak parasitemia, neutropenia, lymphocytosis, and anemia associated with severe hemoglobinemia and elevated fibrinogen degeneration products(FDP's). MCH and MCV profiles in Aotus monkeys decreased with ascending parasitemia. In contrast, these parameters in Saimiri were characterized by a significant compensatory increase correlating with parasitemia. In general, thrombocytopenia was one of the earliest clinical manifestations of the infection with the platelets returning to normal levels shortly after peak parasitemia at 14 days. Platelet kinetics had a strong correlation with hematologic and parasitologic values in the Aotus model. No consistent associations were observed between platelet kinetics and other parameters in the Saimiri model. These data indicate that the Aotus model for malaria is more predictable than the Saimiri. Further, platelet turnover rates and recovery provide a useful prognostic parameter during malaria infection. The results are discussed in relation to the value of the two species of monkeys as models for the pathogenesis of human malaria.

Animals

Ocular infection with a murine neurovirulent retrovirus does not cause retinal degeneration.

The developing eyes of CFW/D mice inoculated at birth with a neurovirulent mutant (ts1) of Moloney murine leukemia virus (MoMuLV), nonneurovirulent wild type (wt) MoMuLV, and conditioned virus-free medium were studied comparatively by immunohistochemistry, lectin histochemistry and light microscopy. Cellular targets for viral antigen expression in the eye were identical in both ts1 and wt MoMuLV-infected mice. Viral antigen first was observed in endothelial cells of the retina and subsequently spread in a spatial and temporal pattern consistent with normal vascularization of the developing retina. The virus also was observed in (1) epithelial cells of the bulbar and palpebral conjunctiva, ora ciliaris retinae, and lacrimal gland; (2) endothelial cells of the ciliary body, iris, choroid, and sclera; (3) amacrine cells of the retina; and (4) smooth muscle cells and endothelia of the periocular muscle. Although ts1 MoMuLV induced a spongiform encephalopathy in the brain and spinal cord, structural lesions were not observed in the retina or other ts1 MoMuLV-infected ocular structures; differentiation of the retina was normal. The lectin Ricinus communis agglutinin-I (RCA-I) labeled (1) endothelial cells of the hyaloid vessels, tunica vasculosa lentis, retina, ciliary body, iris, choroid, and sclera; (2) epithelial cells of the cornea, bulbar and palpebral conjunctiva, ora ciliaris retinae, and lacrimal gland; (3) smooth muscle cells and endothelia of the periocular muscle; (4) inner segments of the photoreceptor layer; and (5) amacrine cells of the retina.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Black walnut (Juglans nigra) toxicosis: a model for equine laminitis.

Twelve light horse geldings developed laminitis within 8 to 12 h of being dosed by nasogastric tube with an aqueous extract of black walnut (Juglans nigra). Four of the 12 horses developed the severe signs of grade 3 laminitis (lame at a walk, refused to lift feet). Laminitis was accompanied by mild depression and limb oedema. There was no evidence of shock or colic. The horses developed neutropenia by 4 h after dosing with the extract, which shifted to a relative neutrophilia by 8 to 12 h. Minimal increases in plasma epinephrine and cortisol concentrations were suggested in severely affected horses. Severe laminitis was characterized by necrosis of dermal tips of dorsal primary epidermal laminae. A proliferative epithelial response in these laminae was distinguished by numerous mitotic figures and clusters of epithelial cells. This evidence suggests that black walnut toxicosis is not only a consistent clinical model, but is also a reliable clinico-pathological and pathological model for study of the pathogenesis and treatment of laminitis.

Animals

Effects of temperature, amebic strain, and carbohydrates on Acanthamoeba adherence to corneal epithelium in vitro.

An in vitro coincubation assay was used to measure adhesion of radiolabeled Acanthamoeba trophozoites to corneal epithelium. Adhesion of amebae to corneal epithelium was higher at 25 degrees C than at 37 or 4 degrees C, did not consistently correlate with the reported pathogenicity of the strain of Acanthamoeba, and was inhibited by mannose and by methyl-alpha-D-mannopyranoside.

Acanthamoeba

Intramembranous particle distribution and filipin binding in dysplastic canine retina.

We examined dysplastic canine retina for changes in intramembranous particle (IMP) density and filipin binding to sterols. Differences in IMP density were identified in incipiently dysplastic fetal retina and also in the degree of filipin binding near the onset of the dysplastic process. The data suggest that there are temporal differences in IMPs and filipin-sterol complexes that may be related to the formation of retinal folds and disorganized dysplastic retina proliferation.

Animals

Dysplastic canine retinal morphogenesis.

Retinal dysplasia is a failure in normal retinal development. The morphologic sequence of the dysplastic processes was examined in fetuses and neonates from dogs affected with an inherited form of retinal dysplasia. The dysplastic change has its onset at 45-50 days' gestation and is most prominent in the dorsal peripapillary retina. Morphologic characteristics of involved sensory retina include the focal loss of cell junctions forming the external limiting membrane, folding of the sensory retina, disorganized proliferation of neuroblasts in the retina and subretinal space, and formation of rosettes composed of multiple layers of neuroblasts. These morphologic changes suggest that there is an intrinsic abnormality of neural retinal differentiation.

Animals

Lectin binding patterns in developing canine retina.

Developing canine retina, fixed in Bouin's or Tellyesnizky's acetic alcoholic formalin, was examined with a battery of biotinylated lectins. ConA and WGA consistently bound to all retinal layers including the tapetum cellulosum, retinal pigment epithelium, inner and outer segments, plexiform layers and ganglion cells. Binding became more intense with increased age. S-WGA bound to apical portions of the retinal pigment epithelium and to outer segments. Outer segments also bound ConA, WGA and RCA. DBA preferentially labelled all inner segments, while PNA bound to a subpopulation of inner segments. RCA bound intensely to retinal vessels as did PNA after neuraminidase treatment. UEA did not consistently bind to any layers. There was transient binding by some lectins at different developmental stages. This study indicates that canine retina demonstrates differential expression of glycoproteins, as indicated by lectin binding, during development and that this expression is temporally and topographically regulated.

Animals

Papillomavirus infection of aged Persian cats.

Papillomavirus infection was confirmed in 2 Persian cats with sessile hyperkeratotic skin lesions. Skin lesions were not typical papillomas as found in other species. Papillomavirus were demonstrated in negative stain preparations of homogenized tissue and within nuclei of cells in the stratum granulosum. Papillomavirus group-specific antigens were detected within nuclei corresponding to those containing virions. Attempts to transmit this disease to other cats or propagate the virus in tissue cultures were unsuccessful. A 7.8-kilobase DNA molecule was present in low-stringency Southern blots using a bovine papillomavirus type 1 cloned DNA probe. In reverse Southern blots, the cat papillomavirus hybridized under conditions of low stringency with all papillomavirus genomes tested. Combined with limited restriction endonuclease restriction mapping, the above information indicates that the feline cutaneous papillomavirus is a unique virus type and thus expands the list of hosts known to be infected by papillomaviruses.

Animals

Effects of inflammation and aqueous tear film deficiency on conjunctival morphology and ocular mucus composition in cats.

An experimental model of keratoconjunctivitis sicca (KCS) was produced by removing the lacrimal gland and the gland of the third eyelid from the left eye of 6 cats. The right eye of each cat was left intact and used as a control. After 2 weeks, cats were euthanatized and the central portion of the upper eyelid from both eyes of each cat was excised. Histologic sections were stained with either hematoxylin and eosin or with a battery of biotinylated lectins including concanavalin A (conA), soybean agglutinin (SBA), wheat germ agglutinin (WGA), succinylated wheat germ agglutinin (S-WGA), Ulex europaeus agglutinin I (UEA), Dolichos biflorus agglutinin (DBA), Ricinus communis agglutinin (RCA), peanut agglutinin (PNA), and PNA pretreated with neuraminidase. Consistent differences in histologic features were not observed between conjunctivas with KCS and control conjunctivas. A variable degree of mononuclear cell infiltration of the substantia propria was observed in control conjunctivas and those with KCS. In both groups, conjunctival goblet cell density decreased and epithelial stratification increased as the degree of submucosal inflammatory cell infiltration increased. Lectin binding sites for DBA, WGA, S-WGA, UEA, PNA, and PNA pretreated with neuraminidase were detected on conjunctival goblet cells of conjunctivas with KCS and control conjunctivas. The mucus/glycocalyx layer of conjunctival epithelial cells in both groups of conjunctivas bound lectins RCA, WGA, UEA, and conA, but inconsistently bound S-WGA. In both groups, DBA principally bound to the mucus layer overlying normal epithelium, whereas PNA pretreated with neuraminidase consistently bound to the mucus layer of stratified epithelial surfaces free of goblet cells. Binding of SBA to goblet cells and the mucus/glycocalyx layer was variable.

Animals

Fractured capital femoral epiphysis in twin ewes.

Capital femoral physeal fractures occurred simultaneously in twin 2-year-old Shropshire ewes. The fractures resulted in gradual, progressive lameness and recumbency. There was no history of trauma and no other ewes in the flock were affected. The fractures occurred at an age when the capital physis should have been closed. Clinical and postmortem examination of the ewes and evaluation of the ration did not reveal predisposing factors for the condition. A familial tendency for fractured capital femoral epiphysis is well documented in human beings, but there is no known familial tendency in sheep.

Animals

Atypical contagious ecthyma in a sheep after extensive cutaneous thermal injury.

An atypical case of contagious ecthyma in a wether, following severe thermal injury to the skin, is reported. Histologically, extensive verrucous growths at the edges of the burned skin were areas of severe epidermal hyperplasia and hyperkeratosis. Intracellular viral particles were present, and sections of skin were positive for ovine contagious ecthyma virus by a fluorescent antibody test.

Animals

Argyrophilic, intracellular bacteria in some cats with idiopathic peripheral lymphadenopathy.

Lymph node biopsy specimens from several previously reported cases of unusual feline peripheral lymphadenopathies were re-examined by a modified Dieterlé silver-impregnation staining technique. In a proportion of these specimens, the Dieterlé stain revealed tiny pleomorphic, intensely argyrophilic coccobacilli. These organisms were predominantly located within macrophages. The infected cells were focally distributed, particularly in the interfollicular regions of the nodes. They were inconspicuous in sections stained by other, more conventional staining methods. It is possible that these coccobacilli represent yet another, previously unidentified, cause of chronic lymph node hyperplasia in the cat.

Animals

Expression of lectin binding in cutaneous papillomas of animals.

A group of spontaneously occurring animal papillomas which were negative or positive for papillomavirus group-specific antigen were examined with a battery of biotinylated lectins including Con A, WGA, succinylated-WGA, PNA and UEA-I. Canine papillomas, equine papillomas, white-tailed deer fibromas, mule deer fibromas, and bovine fibropapillomas were examined. Each lectin had a specific staining pattern. No obvious differences in staining patterns between normal skin, viral antigen-positive and -negative neoplasms were identified. This may be due to the well-differentiated and organized nature of these tumours.

Animals

Glomerulopathy in squirrel monkeys with acute Plasmodium falciparum infection.

The renal pathology of 9 squirrel monkeys (Saimiri sciureus) with acute Plasmodium falciparum infection was studied by light and electron microscopy. Endocapillary proliferative glomerulonephritis was the major pathological change observed. The peroxidase anti-peroxidase method demonstrated the presence of IgG, IgM, and P. falciparum antigens in the mesangium and basement membrane. These findings were consistent with those seen in humans with acute P. falciparum infection and indicates that squirrel monkeys are likely to be a good model for the study of renal pathology in malaria research.

Acute Disease

Intraocular findings in three dogs and one cat with chronic glaucoma.

Intraocular neoplasia may cause secondary glaucoma. If an intraocular prosthesis is placed in an eye with glaucoma secondary to intraocular neoplasia, the neoplasm frequently regrows around the prosthetic ball, resulting in recurrence of buphthalmos and signs of pain. Histologic examination of eviscerated intraocular contents of 4 animals resulted in diagnosis of intraocular neoplasia in 2 glaucomatous eyes and ruled out neoplasia as the cause of glaucoma in 2 eyes.

Animals

Glaucoma associated with a high number of mast cells in the uveal tract of an African lion cub.

An 8-week-old male lion cub (Panthera leo) was referred for evaluation of an enlarged and reddened left eye. Ocular examination revealed a buphthalmic left globe, with corneal edema, superficial neovascularization, moderate episcleral injection, a fixed dilated pupil, and an intraocular pressure of greater than 41.5 mm of Hg as measured by the Schiotz tonometer and a human conversion chart. A diagnosis of glaucoma was made. A silicone prosthesis was implanted after evisceration of the intraocular contents. Histologic examination of the eviscerated uveal tissue revealed numerous congested and dilated vessels of various sizes. Neutrophils were marginated along the vascular endothelium, and the uveal stroma was infiltrated by a few lymphocytes and numbers (3 to 30/hpf) of widely disseminated, well-differentiated mast cells with abundant, well-granulated cytoplasm.

Animals