Effects of the angiotensin converting enzyme inhibitor benazepril in cats with induced renal insufficiency

OBJECTIVE

To determine effects of the angiotensin converting enzyme inhibitor benazepril in cats with induced renal insufficiency.

ANIMALS

32 cats.

PROCEDURE

Renal mass was surgically reduced, and cats were assigned to 1 of 4 eight-cat groups. Group 1 received placebo, whereas groups 2, 3, and 4 received benazepril hydrochloride orally once daily for approximately 6.5 months at the following doses: group 2, 0.25 to 0.50 mg/kg of body weight; group 3, 0.50 to 1.00 mg/kg; and group 4, 1.00 to 2.00 mg/kg. Arterial blood pressures, glomerular filtration rate (GFR), and renal plasma flow were determined before treatment and during the treatment period. Other determinants of renal hemodynamics were measured by use of micropuncture techniques. Renal biopsy specimens were examined microscopically.

RESULTS

Compared with cats that received placebo, mean systolic arterial blood pressure was significantly less and GFR significantly greater in cats that received benazepril. Glomerular capillary pressure and the ratio of efferent to afferent arteriolar vascular resistance were also significantly less in treated cats. However, histologic differences in renal specimens were not detected.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with benazepril sustained single nephron GFR in remnant nephrons of cats with induced renal insufficiency. Administration of benazepril was also associated with a small but significant reduction in degree of systemic hypertension and an increase in whole kidney GFR. Benazepril may be an effective treatment to slow the rate of progression of renal failure in cats with renal disease.

Improved memory functioning and frontal lobe maturation between childhood and adolescence: a structural MRI study

Previous studies conducted by our group have provided evidence for age-related reductions in cortical thickness in dorsal frontal and parietal regions between childhood and adulthood, and gray matter volume increases of mesial temporal and anterior diencephalic structures. The purpose of this study was to describe neurobehavioral correlates of these brain maturational changes using morphometric analyses of brain magnetic resonance images (MRI) and two tests of cognitive abilities. Participants were 35 normal children roughly stratified by age (7 to 16 years) and sex (20 boys and 15 girls) and frontal and mesial temporal regions were anatomically defined in each subjects' MRI data. The California Verbal Learning Test-Children's Version and the Rey-Osterrieth Complex Figure test were used as measures of verbal and visuospatial memory and organizational abilities. Analyses designed to show regionally specific relationships between the brain and behavioral measures revealed interesting results. Specifically, frontal lobe gray matter thinning was more strongly predictive of delayed verbal memory functioning than was the mesial temporal lobe gray matter volume, and this relationship did not appear to be mediated by factors indexed in chronological age. Similar, but less regionally specific relationships were observed for measures of visuospatial memory abilities and frontal lobe maturation. Functional imaging studies in the literature consistently report activation in frontal regions in adults during retrieval tasks. The relationship between frontal lobe maturation and delayed recall observed here may be reflective of the children's development towards the more adult-like frontal lobe function revealed in the functional imaging studies.

Regional size reduction in the human corpus callosum following pre- and perinatal brain injury

This morphometric study examined two aspects of corpus callosum development: pediatric cortico-callosal topography and developmental neuroplasticity subsequent to perinatal brain injury. In vivo magnetic resonance imaging was used to quantify the total midsagittal cross-sectional area and five anterioposterior subregions of the callosum in 10 children with focal lesions and 86 healthy volunteer control subjects. Nine of the ten children with early injury showed a reduction in the total area of the callosum relative to matched controls. The area of the total callosum cross-section was inversely proportional to the size of lesion. All patients displayed region-specific size reduction. This regional thinning bore a topographical relationship to the lesion sites. Reduction in anterior subregions 1, 2 and 3 was respectively associated with lesions in the anterior inferior frontal area, the middle and superior frontal region, and the precentral area. Attenuation of subregion 4 corresponded to anterior parietal lesions, and thinning of subregion 5 occurred with posterior parietal injury. This cortical-callosal pattern coincides with adult and nonhuman primate mappings. Callosal thinning despite the early onset of the lesions suggests limits to developmental neuroplasticity.

Effects of 0.005% latanoprost solution on intraocular pressure in healthy dogs and cats

OBJECTIVE

To evaluate effects of daily topical ocular administration of latanoprost solution on intraocular pressure (IOP) in healthy cats and dogs.

ANIMALS

9 domestic shorthair cats and 14 dogs.

PROCEDURE

Latanoprost solution (0.005%) was administered topically to 1 eye (treated) and vehicle to the other eye (control) of all animals once daily in the morning for 8 days. Intraocular pressure was measured twice daily for the 5 days preceding treatment, and IOP, pupillary diameter, conjunctival hyperemia, and blepharospasm were measured 0, 1, 6, and 12 hours after the first 4 treatments and 0 and 12 hours after the final 4 treatments. Measurements continued twice a day for 5 days after treatment was discontinued. Aqueous flare was measured once daily during and for 5 days after the treatment period.

RESULTS

Intraocular pressure and pupillary diameter were significantly decreased in the treated eye of dogs, compared with the control eye. Mild conjunctival hyperemia was also detected, but severity did not differ significantly between eyes. Blepharospasm and aqueous flare were not detected in either eye. Intraocular pressure in cats was not significantly affected by treatment with latanoprost. However, pupillary diameter was significantly decreased in the treated eye, compared with the control eye. Conjunctival hyperemia, aqueous flare, and blepharospasm were not detected in either eye.

CONCLUSIONS AND CLINICAL RELEVANCE

Once-daily topical ocular administration of latanoprost solution (0.005%) reduced IOP in healthy dogs without inducing adverse effects but did not affect IOP in healthy cats. Latanoprost may be useful for treating glaucoma in dogs.

Feline herpesvirus

Feline herpesvirus infection is extremely common and may lead to recurring ocular disease in the adult cat. Recognition of the history and clinical signs that are consistent with FHV-1 infection is critical because diagnostic tests may be negative. Although a variety of treatment options are available, no one therapy is successful in every cat, and a small percentage of cats respond poorly to any treatment.

Canine rickettsial infections

Dogs that live in tick-infested areas are at risk for contracting rickettsial infections. Clinical signs associated with ehrlichiosis or Rocky Mountain spotted fever may be dramatic or mild. Clinicians must consider the possibility of rickettsial diseases to request laboratory tests that will permit a proper diagnosis. Specific antimicrobial therapy usually brings about clinical improvement, although some dogs may not be cleared of rickettsial organisms, even with prolonged treatment. A small percentage of dogs die of rickettsial infections, either in the acute stage or owing to chronic bone marrow suppression and generalized debilitation. Ocular lesions are an important clinical sign in canine rickettsial infections and may aid the clinician in making a diagnosis and monitoring response to therapy.

Disseminated toxoplasmosis following T cell-depleted related and unrelated bone marrow transplantation

More than 95% of reported cases of disseminated toxoplasmosis following BMT have occurred following an unmodified transplant. Most have been fatal, diagnosed at autopsy and without antemortem institution of specific therapy. From 1989 to 1999, we identified 10 cases of disseminated toxoplasmosis, in 463 consecutive recipients of a T cell-depleted (TCD) BMT. Transplants were from an unrelated donor (n = 5), an HLA-matched sibling (n = 4) or an HLA-mismatched father (n = 1). In 40%, both the donor and recipient had positive IgG titers against T. gondii pre-transplant; in 30%, only the recipient was sero-positive. Three recipients of an unrelated TCD BMT developed toxoplasmosis despite both donor and host testing negative pretransplant. All 10 patients presented with high grade fever. CNS involvement ultimately occurred in seven patients, with refractory respiratory failure and hypotension developing in nine. Eight of 10 cases were found only at autopsy, involving the lungs (n = 7), heart (n = 5), GI tract (n = 5), brain (n = 8), liver and/or spleen (n = 5). The only survivor, treated on the day of presentation with fever and headache, was diagnosed by detection of T. gondii DNA by polymerase chain reaction (PCR) performed on the blood and spinal fluid. This study demonstrates the similar incidence of toxoplasmosis following TCD BMT and that reported post T cell-replete BMT, and underscores the need for rapid diagnostic tests in an effort to improve outcome.

Sino-orbital aspergillosis in a dog

Fungal rhinitis-sinusitis with orbital involvement was diagnosed in a dog with profuse unilateral ocular and bilateral nasal discharge, enophthalmos, and a corneal descemetocele. The descemetocele was treated with a conjunctival pedicle graft. Frontal sinusotomy was performed, and clotrimazole was infused through catheters placed in the frontal sinuses and nasal cavities to saturate the tissues for 1 hour. Successful resolution of orbital infection may have been aided by a fistula between the frontal sinus and orbit that allowed delivery of clotrimazole to the orbit. The dog retained sight in the affected eye, and clinical signs of infection were not detected 14 months later, although enophthalmos and medial strabismus may have been caused by persistent postinflammatory fibrosis.

Brow suspension for treatment of ptosis and entropion in dogs with redundant facial skin folds

Brow suspension surgery was performed on 7 dogs with redundant facial skin folds, associated ptosis, and entropion. The surgical technique involved subcutaneous placement of polyester mesh strips to suspend the upper eyelid from the dorsal frontalis muscle and the underlying periosteum of the skull. Visual impairment associated with ptosis was resolved in all dogs at the 2 week reevaluation period. Upper eyelid position was maintained in 4 of 7 dogs available for long-term follow-up. One dog developed persistent draining tracts in the region of the implant, and removal of part of the implanted mesh was eventually required. Upper eyelid height in this dog, however, was maintained following mesh removal, probably because of fibrosis around the implant. Brow suspension is an option for surgical management of upper eyelid ptosis and entropion in dogs with redundant skin folds and avoids the need for facial skin fold excision.

Spatial grouping activity in children with early cortical and subcortical lesions

Spatial construction skills were examined in 3- to 5-year-old children with prenatal or perinatal focal brain injury. In earlier work, a dissociation was reported between children with injury to the right hemisphere and the left hemisphere, right-hemisphere injury resulting in significantly lower levels of performance. In the current paper, the effect of isolated unilateral subcortical injury was explored. Thirty-four children with early focal brain injury were tested in a task which required them to copy a series of simple block constructions. There were approximately equal numbers of children with right-hemisphere and left-hemisphere injury; within each of these groups approximately half of the children had injury involving only subcortical regions. Consistent with the earlier work, children with right-hemisphere injury performed significantly below children with left-hemisphere injury and the normal controls. Importantly, no differences were observed between the children with isolated subcortical injury and children with injury involving both cortical and subcortical brain areas.

Comparison of nested polymerase chain reaction, virus isolation, and fluorescent antibody testing for identifying feline herpesvirus in cats with conjunctivitis

OBJECTIVE

To compare nested polymerase chain reaction (PCR), virus isolation (VI), and fluorescent antibody (FA) testing to detect feline herpesvirus (FHV) in cats with naturally acquired conjunctivitis or respiratory tract disease, or both.

SAMPLES

Swab and microbrush specimens from the conjunctiva and throat were taken from 46 cats, allotted to 3 groups (conjunctivitis only, respiratory tract disease and conjunctivitis, and clinically normal).

PROCEDURE

Cells from microbrush specimens were digested and herpesvirus DNA was amplified, using a double round of PCR. Products were detected by use of agarose gel electrophoresis. The VI and FA tests were performed in routine manner.

RESULTS

Of 16 cats with conjunctivitis only, conjunctival specimens from 8 and throat specimens from 8 were FHV positive by PCR. None had positive results of VI or FA testing. Of 15 cats with respiratory tract disease and conjunctivitis, conjunctival specimens from 13 and throat specimens from 12 were FHV positive by PCR. A conjunctival specimen from 1 cat and throat specimens from 3 cats were FHV positive by VI. A conjunctival specimen from 1 cat was FHV positive by FA testing. Of 15 clinically normal cats, conjunctival and throat specimens from 2 cats were FHV positive by PCR; neither conjunctival nor throat specimens from these cats were FHV positive by VI or FA testing.

CONCLUSION

For cats with respiratory tract disease and conjunctivitis, or with conjunctivitis only, nested PCR was more sensitive at detecting FHV than was VI or FA testing.

CLINICAL RELEVANCE

Nested PCR is a more sensitive test than the currently available VI and FA tests for identifying FHV in cats with conjunctivitis.

Hemispheric asymmetries in global and local processing: evidence from fMRI

Functional magnetic resonance imaging (fMRI) was used to explore the brain substrate associated with global and local processing of visuospatial patterns. Systematic differences in activation, consistent with differences observed in reaction time data collected under conditions of visual hemifield presentation, were found in occipitotemporal regions of the right and left hemispheres. Within the right hemisphere, area of activation and fractional signal changes were greater under conditions of global processing than under local processing conditions. In the left hemisphere, activation to global and local input was high and comparable.

Use of nested polymerase chain reaction to identify feline herpesvirus in ocular tissue from clinically normal cats and cats with corneal sequestra or conjunctivitis

OBJECTIVE

To use a nested polymerase chain reaction (PCR) to detect feline herpesvirus (FHV-1) DNA in conjunctiva or cornea from clinically normal cats and cats with conjunctivitis or corneal sequestra.

SAMPLES

Conjunctival snip biopsy specimens from 50 cats with conjunctivitis and 50 clinically normal cats; 28 keratectomy specimens from 26 cats with sequestra, and 13 specimens from clinically normal cats.

PROCEDURE

Tissue specimens were digested, and FHV-1 DNA was amplified, using a double round of PCR. Products were visualized by use of agarose gel electrophoresis.

RESULTS

Polymerase chain reaction was positive in 27 of 50 (54%) conjunctival specimens from cats with conjunctivitis and 6 of 50 (12%) specimens from clinically normal cats. Difference in the results between cats with conjunctivitis and clinically normal cats was statistically significant. Polymerase chain reaction was positive in 5 of 28 (18%) corneal specimens from cats with sequestra and 6 of 13 (46%) clinically normal cats. Distribution of positive results between clinically normal cats and those with sequestra was not significant.

CONCLUSION

Cats with conjunctivitis were more likely to have a positive PCR result than were clinically normal cats, making it likely that FHV-1 was associated with the disease state. Herpesvirus DNA could not be detected in most corneas from cats with sequestra.

CLINICAL RELEVANCE

Polymerase chain reaction is a useful clinical test for identifying FHV-1 DNA in cats with conjunctivitis, yielding greater sensitivity over that of current available tests. Herpesvirus may be less of a cause of corneal sequestration in the commonly affected breeds, Himalayan and Persian, than other factors, such as lagophthalmos or corneal metabolic defects.

The development of drawing in children with congenital focal brain injury: evidence for limited functional recovery

Children with pre- or perinatal injury to right hemisphere (RH) brain regions show impairment of spatial integrative functions similar to that observed among adults with comparable injury. Unlike adults, children show considerable improvement with development on a range of spatial construction tasks which require spatial integration. Such gains could reflect true recovery of spatial integrative abilities. Alternatively, the improvement could be more limited in scope, reflecting the development of compensatory strategies which are task specific and allow the children to circumvent, rather than overcome, their primary spatial disorders. The studies presented here examined this distinction within the context of drawing tasks in which the child was first asked to draw a house and then an impossible house. The impossible house task was designed to examine the extent to which children rely on graphic formulas in generating organized drawings. The results showed that while all of the children with RH injury make considerable progress in free drawing into the school age period, they are very reliant on the use of graphic formulas. When given a task which requires them to alter their drawings, they did not change the spatial configuration of the depicted object. Rather they found alternate ways to render the object 'impossible'.

Children's analysis of hierarchical patterns: evidence from a similarity judgment task

Three experiments in this study examined the development of young children's analysis of spatial patterns, specifically hierarchical letter and geometric forms. In a forced choice task, 4- and 6-year-olds and adult subjects chose one of two choice forms as most similar to a target form. Specific stimulus manipulations were introduced to assess children's ability to segment and integrate hierarchically organized information under different conditions. In Experiment 1 adults served as subjects in a computerized version that provided both choice and response latency data. In Experiments 2 and 3 children and adults participated in a pencil and paper version of the forced choice task. Results showed that although children as young as 4 years of age demonstrated substantial analytic competence, their ability to integrate the parts of the spatial array to form a coherent whole was weaker and more easily disrupted than that of the older children and adults.

The influence of pattern type on children's block design performance

This study sought to determine what factors contribute to normal developmental changes in performance on the block design task. The target models were systematically varied to emphasize global, intermediate, and local pattern structures. One hundred children between 4.5 and 9 years of age were tested in the first experiment. Correct performance and error types differed significantly as a function of age and pattern type. Broken configuration errors were particularly common for the global patterns. In the second experiment, 48 children between 4.5 and 8 years of age were tested using designs with a superimposed grid (cued condition). Error rates were lower in the cued condition and broken configuration errors were less frequent. These results suggest that children have more difficulty parsing more cohesive patterns, but they can modify their strategies when the square matrix is provided by the pattern structure.

Developmental change in spatial grouping activity among children with early focal brain injury: evidence from a modeling task

Spatial construction skills were assessed in children with left (LH) or right (RH) hemisphere focal brain injury and control children. Children copied simple and complex block models which were rated on accuracy and spatial strategy. The accuracy of simple and complex constructions for 4- to 5-year-old children with LH injury was indistinguishable from 4-year-old controls. However, although they were able to produce accurate complex constructions, the processes used by children with LH injury differed from those of normal children. On both simple and complex constructions, 4- to 5-year-old children with RH injury showed evidence of developmental delay. For both accuracy and process measures, children with RH injury performed at a level comparable to normal children at 3 years. A second group of children with LH and RH injury were tested at 5 to 6 years of age. Both lesion groups were indistinguishable from 4-year-old controls in terms of accuracy. However, both children with LH and RH injury used different spatial processes than did controls. This study emphasizes the importance of distinguishing between products of behavior and the processes which underlie them. It is in the dissociation of products and process of behavior that the subtle spatial construction deficits in this population of brain-injured subjects is revealed.

Detection of Toxoplasma gondii in feline and canine biological samples by use of the polymerase chain reaction

OBJECTIVE

To develop a polymerase chain reaction (PCR) technique to identify Toxoplasma gondii DNA in biological samples from cats and dogs.

DESIGN

To artificially create samples that would mimic those acquired in a clinical setting from animals with naturally acquired toxoplasmosis. Using these samples, a PCR test to identify T gondii DNA was developed.

SAMPLE POPULATION

Feline and canine aqueous humor, CSF, serum, and blood samples.

PROCEDURE

Tachyzoites of several strains of T gondii grown in cell culture were added to feline and canine aqueous humor, CSF, serum, and blood samples. Protocols for identifying T gondii DNA by use of the PCR were developed.

RESULTS

The DNA from as few as 10 tachyzoites of T gondii could be identified in feline and canine aqueous humor, CSF, and serum samples. One hundred tachyzoites could be identified in blood samples.

CONCLUSIONS

Toxoplasma gondii can be identified in feline and canine biological samples by use of the PCR.

CLINICAL RELEVANCE

Correlation of clinical disease to T gondii serum antibodies provides only a presumptive diagnosis of toxoplasmosis. Use of PCR to detect T gondii DNA in biological samples from cats and dogs may provide a sensitive tool for the antemortem diagnosis of toxoplasmosis and may be most beneficial when used in conjunction with serum antibody titers.

Treatment of cats with ocular disease attributable to herpesvirus infection: 17 cases (1983-1993)

Medical records of 17 cats with ocular disease attributable to herpesvirus injection were reviewed. Herpesvirus infection was confirmed by a positive result on an immunofluorescent antibody test or by detection of dendritic corneal ulcers. Cats were 3 months to 23 years old (mean, 4.8 years). Sex or breed predilections were not evident. Vaccination history was available for 13 cats, 9 of which had been adequately vaccinated against feline viral rhinotracheitis, calici, and panleukopenia viruses. Six cats had a history of respiratory tract disease. Twelve cats were tested for FeLV, and 3 had positive results; 7 cats were tested for feline immunodeficiency virus, with 1 positive result. The most common ocular abnormality seen was conjunctivitis (13/17 cats), followed by dendritic corneal ulcers (10/17 cats). Keratitis was detected in 6 of 17 cats, and nondendritic corneal ulcers in 3 of 17 cats. Corneal sequestra were evident on initial examination or developed during the follow-up period in 4 of 17 cats. Keratoconjunctivitis sicca was diagnosed in 2 of 17 cats, and anterior uveitis was evident in 1 of 17 cats. All cats had 2 or more clinical ocular abnormalities associated with herpesvirus infection. Treatment with topically applied antiviral medications was instituted in 14 cats, including idoxuridine in 7, vidarabine in 4, and trifluridine in 3. Antibiotics were used topically in 10 cats, and atropine was used in 3 cats. Topical administration of corticosteroids was used in 2 cats. Recombinant human alpha-interferon was given orally to 3 cats in conjunction with topical administration of antiviral agents. In addition to medical treatment, 4 cats were treated surgically.(ABSTRACT TRUNCATED AT 250 WORDS)

Affective facial expression in infants with focal brain damage

Children are fluent affective communicators by their first birthday. The development of affective facial expression in infants with focal brain damage thus provides a promising context in which to investigate the developing neural substrates of emotions. We examined both positive and negative affective expression in 12 infants (6-24 months) with pre- or perinatal unilateral focal brain damage (6RHD and 6LHD) and their age- and gender-matched controls. Infants were videotaped in free and semi-structured tasks. Interactions were microanalytically coded, including the use of FACS. Both normal and babies with posterior LHD exhibited the full range of appropriate affective expressions. In contrast, infants with posterior RHD showed marked affective impairment to positive, but not to negative simulation.