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Biomedical subjects

B M Spiess

Publications and source records attributed to B M Spiess.

At least 19 recordsLinked to original sources
PubMed2000

Activities of NADPH-dependent reductases and sorbitol dehydrogenase in canine and feline lenses.

OBJECTIVE: To measure activities of NADPH-dependent reductases and sorbitol dehydrogenase in lenses from healthy dogs and cats. SAMPLE POPULATION: Lenses from 37 dogs and 23 cats. All animals were healthy and had serum glucose concentrations within reference limits. PROCEDURE: Lenses were homogenized, and activities of NADPH-dependent reductases and sorbitol dehydrogenase were measured spectrophotometrically. RESULTS: Activities of NADPH-dependent reductases and sorbitol dehydrogenase were significantly lower in lenses from cats than in lenses from dogs. However, the ratio of NADPH-dependent reductases activity-to-sorbitol dehydrogenase activity was significantly higher in lenses from cats than in lenses from dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that during periods of hyperglycemia, sorbitol would accumulate at a faster rate in the lenses of cats than in the lenses of dogs. Thus, the higher incidence of diabetic cataracts in dogs, compared with cats, is likely not attributable to a difference in the ratio of NADPH-dependent reductases activity-to-sorbitol dehydrogenase activity.

Aldehyde Reductase↗
PubMed1999

Systemic dexamethasone concentration in horses after continued topical treatment with an ophthalmic preparation of dexamethasone.

OBJECTIVE: To determine concentrations of dexamethasone in serum and urine of horses treated repeatedly with a topically administered ophthalmic dexamethasone preparation. ANIMALS: 4 clinically normal horses (2 mares, 2 geldings). PROCEDURE: 0.1% dexamethasone ophthalmic ointment was administered to the left eye of each horse every 5 to 9 hours for 8 consecutive days, yielding an estimated cumulative dexamethasone dose of 6.4 microg/kg of body weight. Serum and urine samples were obtained before the first dexamethasone treatment, on days 4 and 8 of treatment, and 24, 48, and 96 hours after cessation of treatment. To detect small concentrations of dexamethasone, serum and urine samples were analyzed by use of a competitive enzyme immunoassay. RESULTS: During the period of continued topical treatment, serum dexamethasone concentrations increased to between 0.10 and 0.49 ng/ml, then decreased below the limit of detection (0.06 ng/ml) within 24 hours after cessation of treatment. Dexamethasone also was detected in urine samples at concentrations of up to 0.98 ng/ml. CONCLUSIONS: Repeated topical administration of dexamethasone ophthalmic ointment generated low, but detectable glucocorticoid concentrations in serum and urine. CLINICAL RELEVANCE: Because treatment of performance horses with dexamethasone is prohibited for most types of competitions and because enhanced glucocorticoid detection methods may result in positive test results, owners and trainers may wish to reconsider entering horses in competitions during periods of treatment with ophthalmic dexamethasone preparations.

Administration, Topical↗
PubMed1997

[Intascleral silicone prosthesis in the dog: a retrospective study of 22 cases].

Over a period of five years 28 dog eyes were treated by evisceration and implantation of an intrascleral silicone prosthesis. During an average follow-up period of 2.93 years the only complication noted was a mild entropion in one case. The majority of dog owners were satisfied with the cosmetic result. All of them would again opt for this procedure and prefer it to an enucleation. The postoperative management was well tolerated by both animals and owners. After careful preoperative work-up and ruling-out of intraocular neoplasms, evisceration/prosthesis is a simple and practical method to salvage buphthalmic eyes and globes with beginning phthisis bulbi. Intraocular tumors and septic endophthalmitis are the two principal contraindications. In addition, eyes with deep or even perforated corneal ulcers should not be fitted with an intrascleral prosthesis.

Animals↗
PubMed1997

[Equine recurrent uveitis].

Equine recurrent uveitis is an important ocular disease and the most common cause for blindness in horses and mules worldwide. The anatomy, physiology, immunology and inflammatory reactions of the uveal tract are discussed. Possible etiologies and the clinical signs are described. A detailed description of possible therapies is given and the prognosis is discussed.

Animals↗
PubMed1996

[Goniodysplasia in the Bouvier des Flandres].

Ophthalmologic examination of 72 Bouvier des Flandres dogs revealed variable degrees of goniodysgenesis in 37.5% of the animals. All dogs examined were normotensive and asymptomatic. Tonography in 4 dogs showed normal c-values for out-flow facility in all of them. Pedigree analysis demonstrated a recessive inheritance. Although the frequency of goniodysgenesis appears to be very high in this breed, the incidence of glaucoma remains low. Genetic counseling and careful selection of breeding stock showed that gonioscopically normal animals can be produced.

Animals↗
PubMed1996

[Eye injuries in the dog caused by cat claws].

A retrospective study of ocular cat claw injuries in the dog revealed an over-representation of very young dogs in our case material. Puppies up to the age of 12 weeks have no menace response. Thus, an important protective mechanism is missing in early life. This may be one reason for the frequently occurring severe ocular trauma caused by cat claw injuries in puppies. Older dogs are less likely to sustain such an injury. Cat claw injuries cause corneal and lens capsule perforation with ensuing severe phacoclastic uveitis. In our series phthisis bulbi or secondary glaucoma were the result in 50% of the cases. In large lens capsule tears early lens extraction may prevent severe uveitis and may retain functional vision.

Age Factors↗
PubMed1995

[Retrobulbar space-occupying lesions in dogs and cats: symptoms and diagnosis].

In the last five years 55 cases of orbital space-occupying lesions in dogs and cats were treated at the Veterinary Surgical Clinic of the University of Zurich. The most frequent diagnosis was orbital neoplasia (n = 29), followed by orbital abscesses or cellulitis (n = 17). Orbital hematoma (n = 5), salivary mucocele (n = 3), A/V-fistulas (n = 1), and eosinophilic myositis (n = 1) appear to be less frequent entities. The 55 cases comprised 42 dogs and only 13 cats, which seem to be less likely to suffer from orbital disease. This difference was particularly obvious in orbital inflammatory disease. The most important clinical sign is exophthalmos. Other symptoms are listed in tables. Special emphasis is put on the diagnostic work-up of orbital space-occupying lesions. An algorithm shall guide the practitioner to the correct diagnosis. The management of orbital disease is only briefly mentioned but will be the topic of a future article.

Abscess↗
PubMed1995

[Treatment of orbital abscesses and phlegmon in dogs and cats].

A diagnosis of orbital cellulitis or abscess was made in 13 dogs and four cats over the past five years. A foreign body was found in three of these cases. In five cases pasteurella spp. was isolated. In 15 of these cases the abscess was drained surgically. One dog was permanently blind due to inadequate surgical drainage of the abscess. In the remaining cases healing was uneventful. The surgical and medical therapy of orbital abscesses is illustrated by an exemplary case.

Abscess↗
PubMed1995

[Therapy of orbital neoplasms in small animals].

The incidence, clinical signs and diagnostic work-up of orbital neoplasms is briefly discussed. The surgical management of such tumors is discussed in detail on the basis of three clinical cases. Long-term functional and cosmetic results are shown. Intraoperative and postoperative complications are discussed.

Animals↗
PubMed1994

[Inherited eye diseases in the Entlebucher mountain dog].

Ophthalmoscopic examinations of 276 Entlebucher Mountain Dogs between 1987 and 1992 revealed a high incidence of inherited ocular diseases in this particular breed. A posterior polar cataract was seen in 42.4% of dogs examined. This cataract develops between one and two years of age and is in the majority of cases stationary. Development of mature cataracts was noticed in 8% of dogs with polar opacities. A progressive retinal degeneration (rod/cone-abiotrophy) was observed in 24.9% of the dogs examined. The fundus abnormalities are comparable to other forms of retinal degeneration, such as hyperreflectivity of the tapetal fundus, attenuation of the retinal vasculature, depigmentation of the non tapetal fundus, and pallor of the optic disc. Visual deficits were first seen at the age of 3 years, the majority of affected dogs going blind between 6 and 8 years of age. As a third suspected inherited ocular disease glaucoma was seen in 3.3% of the dogs examined. Glaucoma affects older animals. In the nine cases examined by gonioscopy goniodysgenesis was observed. Initially, glaucoma occurs unilaterally, but the opposite eye may also become affected, in which case animals go blind. Pedigree analysis revealed an autosomal recessive mode of inheritance for the cataracts and the PRA, whereas the mode of transmission is unclear for the glaucoma. 11.9% of the dogs examined had more than one inherited eye disease.

Animals↗
PubMed1992

[Oscillating potentials on the B-wave of the ERG in the dog].

The oscillatory potentials (OP) on the b-wave of the canine ERG are characterized. Normal values for an OP-index, implicit times and periodicity are given. The OP-index increases during dark adaptation as well as with increasing stimulus intensities for white light flashes. Scotopic blue and red stimuli, although balanced for the maximum b-wave amplitude, surprisingly result in higher OP-indices for red flashes. Implicit times decrease for all OP with increasing stimulus intensities. Scotopic balanced red light results in OP with markedly reduced implicit times compared to blue light stimulation. The intervals between two OPs remain constant during dark adaptation, however, intervals between OPs with longer implicit times tend to be shorter. In contrast, the b-waves for scotopic balanced stimuli show rhythmic oscillations with constant intervals between them, the intervals being shorter for blue light than for red light. The intervals between OPs tend to become shorter with increasing stimulus intensities. This investigation indicates that OPs are influenced but not generated by photoreceptors. The examination of a dog with optic nerve hypoplasia indicates that the ganglion cells do not contribute to the biogenesis of OPs. The prognostic value of OPs in the early diagnosis for hereditary retinal degenerations in the dog is discussed.

Animals↗
PubMed1992

[Clinical electroretinography in the dog. Part 3].

In this last part the preparation of the patient for the ERG is shown. Anesthesia, positioning, and retrobulbar injection technique are discussed. The protocol for recording the ERG is presented. The dog is dark adapted for 30 minutes. The level of adaptation is examined using a single flash of dim red light at various times. Rods and cones are stimulated separately by scotopically balanced red and blue flashes. After a single flash of bright white light the rods and cones are studied with flicker trains at 5, 12.5, 15 and 30 Hz. During dark adaptation the maximum b-wave amplitude increased from 13.8 +/- 8.4 microV to 49.3 +/- 16.3 microV. Bright white light stimuli resulted in b-wave amplitudes of 167.7 +/- 75.3 microV. There were always 6 oscillatory potentials visible on the b-wave. Scotopically balanced stimuli produced b-waves of 104 microV (red) and 116 microV (blue). It was found that older dogs had reduced b-wave amplitudes and longer peak times than younger dogs. The most common artefacts in electroretinography are discussed.

Acepromazine↗
PubMed1991

Kinetics of uptake and effects of topical indomethacin application on protein concentration in the aqueous humor of dogs.

The pharmacokinetic properties of indomethacin and its effects on aqueous protein values were studied in 15 clinically normal Beagles. The dogs were treated every 6 hours with 1% indomethacin suspension in 1 eye, with the other eye serving as a control. After 24 hours, the dogs were anesthetized and samples of aqueous humor (AH) were drawn by aqueocentesis at 0, 15, 30, 60, and 90 minutes after initial paracentesis. Additional samples were drawn at the time of euthanasia, 180 (6 dogs) and 360 minutes (9 dogs) minutes after initial paracentesis. Blood samples were obtained at each treatment and at each aqueocentesis. The eyes were enucleated after dogs were euthanatized. Aqueous protein concentrations and indomethacin concentrations in AH, plasma, and different ocular tissues were determined. Topical indomethacin administration had no effect on baseline protein concentrations of AH. It reduced protein concentrations in AH significantly at all times after initial aqueocentesis. This reduction was approximately 30%. Indomethacin in the AH is mostly protein-bound. Concentrations were 350 ng/ml in primary AH and 1,305 ng/ml in secondary AH, 90 minutes after initial aqueocentesis. Free-drug concentrations were relatively constant at about 220 ng/ml. Indomethacin administered topically is readily absorbed by the ocular adnexae, reaching a steady-state concentration of 25 ng/ml in blood plasma 18 hours after the start of treatment. Plasma concentrations were 50 times lower than therapeutically effective concentrations. High indomethacin concentrations were found in the cornea only. Low concentrations were found in the iris and ciliary body, the lens, and in the choroid.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1991

[Clinical electroretinography in the dog. Part 1].

In the first of three parts of this investigation the clinical importance and the principal indications for electroretinography are presented. The histology and ultrastructure of the retina with special emphasis on the photoreceptors and the second order neurons are discussed. A section is devoted to the history of electroretinography in man and animals. The components of the ERG and their origin are discussed.

Animals↗
PubMed1991

[Clinical electroretinography in the dog. Part 2].

The second part of this study deals primarily with the technical aspects of electroretinography. A custom made dark chamber for the patient is presented. The requirements for an optical stimulator are discussed in detail and the recording instrumentation--electrodes, amplifiers, averager, digitalizer--are presented. The display of the signals on a monitor and plotter concludes this technical description. The remainder of part 2 is devoted to the many factors influencing the recording of an ERG, notably pupillary diameter, anesthesia, oxygen and glucose supply to the animal, body temperature of the patient, its intraocular pressure and level of retinal adaptation, and finally the age of the patient. On the technical side the intensity, wavelength and frequency of stimulation play an important role.

Animals↗
PubMed1991

[Chronic eosinophilic keratitis in the cat].

A special form of keratitis in the cat is described on the basis of 8 clinical cases. The disease has been known in the United States and the United Kingdom for some time, however, it has, to our knowledge, never been described in Switzerland. This keratitis is characterized by chronicity and infiltration of the cornea by mast cells and eosinophils. It is usually an unilateral and painless condition. We describe the clinical features and diagnostic examinations of the disease. Cytology of a corneal scraping is usually diagnostic. As in the cases described in the literature the cats were successfully treated with oral megestrol acetate. The aetiology of the disease is unknown.

Animals↗
PubMed1987

Glioma of the optic nerve with intraocular and intracranial involvement in a dog.

An anaplastic glioma of the optic nerve, involving the globe, optic chiasma and brain in a 3 1/2-year-old Labrador Retriever is described. The tumour consisted of lobules of small, dark cells intersected by a delicate fibrovascular stroma. There was a high degree of anaplasia and an average of 19 mitoses per x 200 field. The clinical signs were exophthalmos and mydriasis, followed several months later by blindness and, only terminally, by signs of brain involvement.

Animals↗