ABSTRACT
Data-mining of Reaxys and network analysis of the combined literature and in-house reactions set were used to generate multiple possible reaction routes to convert a bio-waste feedstock, limonene, into a pharmaceutical API, paracetamol. The network analysis of data provides a rich knowledge-base for generation of the initial reaction screening and development programme. Based on the literature and the in-house data, an overall flowsheet for the conversion of limonene to paracetamol was proposed. Each individual reaction-separation step in the sequence was simulated as a combination of the continuous flow and batch steps. The linear model generation methodology allowed us to identify the reaction steps requiring further chemical optimisation. The generated model can be used for global optimisation and generation of environmental and other performance indicators, such as cost indicators. However, the identified further challenge is to automate model generation to evolve optimal multi-step chemical routes and optimal process configurations.
ABSTRACT
Mycotoxins are naturally occurring environmental contaminants recognized worldwide in a variety of food and feed products. Produced as secondary metabolites by filamentous fungi, mycotoxins can have acute and chronic effects. Differing seasonal weather patterns and harvesting and storage conditions put corn grain at high risk for mycotoxin contamination. The objective of this study was to assess the risk of mycotoxin exposure posed to California livestock from whole corn. Random samples (n=50) of whole corn were collected and analyzed for 6 different mycotoxins, including aflatoxins, fumonisins, ochratoxins, trichothecenes (deoxynivalenol and T-2 toxin), and zearalenone. The samples represented a cross section of the corn entering California from various corn-growing states (n=43) as well as additional samples from California-grown corn (n=7). The experiment was a randomized sampling design. Over the course of a 6-mo period, 16 trains in California (100-110 railcars) and 5 California grain elevators were randomly sampled. Aflatoxins were detected in 14 samples, with 1 sample containing a concentration of 41.3 µg/kg (as-is basis), which was above the action level of 20 µg/kg for corn fed to dairy cattle. The average concentration of aflatoxins for the 13 samples below the regulatory action level was 8.69 µg/kg (range 4.67 to 13.82 µg/kg). Deoxynivalenol was found in 15 samples and averaged 553 µg/kg (range 340 to 1,072 µg/kg), which was below the federal advisory level of 5,000 µg/kg for grain fed to dairy cattle. Fumonisins were found in 38 samples and averaged 1,687 µg/kg (range 435 to 4,843 µg/kg), which was below the federal guidance level of 30,000 µg/kg in corn for dairy cattle. Ochratoxins, T-2 toxins, and zearalenone were not detected in any samples of whole corn. Fumonisins were the most prevalent mycotoxins found.
Subject(s)
Animal Feed/analysis , Food Contamination/analysis , Mycotoxins/analysis , Zea mays/chemistry , Aflatoxins/analysis , Animals , California , Cattle , Dairying , Female , Fumonisins/analysis , Livestock , Trichothecenes/analysisABSTRACT
Canine leishmaniosis (CL) can present with multiple clinical signs and ocular disease is reported to occur in almost 25% of affected dogs. The purpose of the present study was to characterize the nature of inflammation within the eyes of dogs with leishmaniosis and to determine whether parasites were present in these lesions. Eyes from 60 dogs with confirmed leishmaniosis that died or were humanely destroyed over a 4 year period were included in the study. Sections of formalin-fixed globes were stained with haematoxylin and eosin (HE) and subjected to immunohistochemistry using a Leishmania-specific antibody. Clinically evident ocular signs were present in 15 of 60 dogs (13 bilaterally and 2 unilaterally). Thirty-five of 60 dogs received some form of anti-protozoal treatment. In 36 of 120 eyes (30%) a granulomatous inflammatory infiltrate was found and in 32 of 120 eyes (26.6%) the parasite was identified immunohistochemically within the globe. Ocular tissues affected, in order of frequency, were conjunctiva and limbus, ciliary body, iris, cornea, sclera and iridocorneal angle, choroid and the optic nerve sheath. Different microscopical patterns were defined in each of these structures. Leishmania organisms and associated inflammation can be found in different ocular tissues, accounting for some of the ocular clinical signs described for this disease.
Subject(s)
Dog Diseases/pathology , Eye Diseases/pathology , Eye Diseases/veterinary , Leishmaniasis/pathology , Leishmaniasis/veterinary , Animals , Dog Diseases/microbiology , Dogs , Eye Diseases/microbiology , Female , MaleABSTRACT
Herein we report the synthesis and characterisation of a series of salalen and salan ligands derived from 2-(aminomethyl)piperidine. Depending on the choice of starting salicylaldehyde, a bicyclic salan type ligand (1-3H2) or imino salalen type ligand (4-6H, 7-9H2) were prepared. The ligands were successfully complexed to group 4 metals and aluminium; with hafnium and zirconium octahedral complexes, M(1-3)2, were realised; whilst with aluminium tetrahedral and trigonal bipyramidal complexes, Al(1-9)Mex (x = 1,2), were isolated. The complexes have been characterised in solution via(1)H and (13)C{(1)H} NMR spectroscopy and in the solid state by X-ray crystallography. The group 4 complexes were observed to have a fac-fac arrangement of ligands and there were two isomers present when 3H2 was ligated. The imino aluminium complexes Al(7-9)Me were isolated as a mixture of diastereoisomers. The resultant complexes were trialed in the ring opening polymerisation of rac-lactide with both heterotactic and isotactic PLA being demonstrated. Tacticity was found to be dependent on the nature of the ligand and metal used; the M(1-3)2 complexes were generally found to have a heterotactic preference (Pr = 0.67-0.76) and the aluminium polymerisation outcome was dictated more by the steric influence of the ligand, particularly for Al(4/6)Me2/Al(7/9)Me.
ABSTRACT
Feline immunodeficiency virus (FIV) is associated with feline acquired immunodeficiency syndrome (FAIDS) and has been suggested as a model for HIV-induced human AIDS. The most obvious immunological defect in HIV infection is a reduction in CD4+ cell numbers and an inversion of the CD4:CD8 ratio. To determine whether the same is true in FIV infection, we analyzed by flow cytometry using a panel of monoclonal antibodies to feline lymphocyte populations the CD4:CD8 ratios in cats naturally infected with the virus. We report that 13 of 19 FIV-infected cats had ratios below the 5th percentile of normal cats (0.57, established from analysis of 39 normal cats) and 18 of 19 had ratios below 1. Repeated analyses over a period of several months revealed the inverted ratios to be consistent. Analysis of lymphocyte numbers in FIV-infected cats shows that the inverted ratios are due to a decrease in CD4+ T cells, while CD8+ T and B cells remain relatively normal in number. Analysis of a group of cats with a variety of other chronic diseases, including feline leukemia virus (FeLV) infections, revealed a near-normal distribution of CD4:CD8 ratios. These findings are similar to those in HIV infections and indicate that, like HIV, FIV causes a selective reduction in CD4+ cells and should be an excellent model for studying retrovirus-induced AIDS.
Subject(s)
Feline Acquired Immunodeficiency Syndrome/immunology , T-Lymphocyte Subsets/immunology , Animals , Antibodies, Monoclonal , Antibodies, Viral/blood , B-Lymphocytes/immunology , Blotting, Western , CD4-Positive T-Lymphocytes/immunology , Cats , Female , Flow Cytometry , Immunodeficiency Virus, Feline/immunology , Leukocyte Count , Male , T-Lymphocytes, Regulatory/immunologyABSTRACT
This preliminary study was designed to evaluate the effectiveness and dosage of oral use of interferon-alpha (IFN-alpha) in the treatment of naturally occurring, immune-mediated, canine keratoconjunctivitis sicca (KCS). Dogs with chronic immune-mediated KCS were selected from the two clinic populations. All medication, except topical artificial tears, was discontinued at least 2 weeks prior to beginning the clinical trial. IFN-alpha was administered orally once daily to the dogs by their owners as the sole therapy for the KCS. Examinations of the dogs were performed every 2 weeks for the duration of the trial (12 weeks). Each dog was given either two or three separate, escalating doses (20, 40, 80 IU of the IFN-alpha. A favorable response was observed in 55% (11/20) of all dogs treated. Clinical findings of those dogs that responded included increased wetting of the eyes, decreased mucus discharge, and fewer signs of discomfort. There was a nearly significant difference (p = 0.08) in pretreatment mean Schirmer's tear test (STT) between the dogs that responded (6.4 +/- SEM 0.62 mm/min) and those that did not respond (4.7 +/- SEM 0.69 mm/min) to the orally administered IFN-alpha. Seven of 11 dogs with favorable outcomes had an increased STT of at least 5 mm/min after treatment with oral IFN-alpha and the group had a post-treatment STT (10.5 +/- SEM 1.4 mm/min) significantly greater than baseline (p = 0.0004). The post-treatment STT of the dogs that did respond was significantly greater (p < 0.01) than the post-treatment mean STT of dogs that did not respond. All dogs that responded did so with the 20 or 40 IU dose of IFN-alpha. No side effects were noted and all dogs tolerated the treatment well.
Subject(s)
Interferon-alpha/therapeutic use , Keratoconjunctivitis Sicca/veterinary , Administration, Oral , Animals , Dogs , Dose-Response Relationship, Drug , Female , Interferon-alpha/adverse effects , Keratoconjunctivitis Sicca/drug therapy , Keratoconjunctivitis Sicca/immunology , Male , Treatment OutcomeABSTRACT
UNLABELLED: PURPOSE. This study was performed to characterize the clinical, serologic, histopathologic, and immunohistochemical features of an experimental model of ocular toxoplasmosis in cats. METHODS: Seven specific pathogen-free cats were inoculated in the right carotid artery with 5 x 10(3) tachyzoites of the ME49 strain of Toxoplasma gondii. Control cats received heat-killed tachyzoites. RESULTS: Progressive, bilateral, multifocal retinal, and choroidal inflammatory foci developed in the principal cats, beginning 5 to 8 days postinoculation (PI). Lesion development peaked 3 weeks PI, and the lesions varied in size from pinpoint to 5 mm, had a predilection for the central tapetal fundus, and were more numerous ipsilateral to the side of inoculation. Resolution of the lesions 21 to 70 days PI was characterized by foci of tapetal destruction and retinal degeneration. Fluorescein angiography showed disruption of the blood-retinal barrier at the level of the retinal pigmented epithelium, and occasional retinal vasculitis and perivasculitis. Mild anterior uveitis developed in four cats 10 to 13 days PI. Aside from a slight febrile response 2 to 3 days PI, no physical abnormalities were observed. T. gondii antigens were detected intermittently in the serum of four of seven cats as early as 8 days PI. T. gondii-specific immunoglobulin M titers were present on day 7 PI and continued to increase until 28 days PI. Immunoglobulin G production was documented on day 13 PI, and titers continued to increase throughout the study. Evidence of anterior uveal antibody production (mean Goldmann-Witmer coefficient [C value], 80.7; range, 13.4 to 236.6) was present in 11 of 14 eyes on day 70 PI. On histopathologic evaluation 70 days PI, multifocal granulomatous chorioretinitis, with retinal degeneration, retinal vasculitis, and lymphocytic-plasmacytic anterior uveitis, was documented. Tissue cysts in the retina and choroid were found with mouse inoculation of tissue suspensions, immunohistochemical studies, and histopathologic examination. CONCLUSIONS: This nonfatal, noninvasive method of inducing ocular toxoplasmosis may prove to be a useful model for investigation of toxoplasmi retinochoroiditis, particularly with the recent characterization of a naturally occurring, immunosuppressive feline lentivirus with properties similar to human immunodeficiency virus.
Subject(s)
Toxoplasmosis, Animal/pathology , Toxoplasmosis, Ocular/pathology , Animals , Antigens, Protozoan/analysis , Cats , Chorioretinitis/pathology , Disease Models, Animal , Female , Fluorescein Angiography , Fundus Oculi , Specific Pathogen-Free Organisms , Toxoplasmosis, Animal/immunology , Toxoplasmosis, Ocular/immunologyABSTRACT
Experimentally induced ocular feline herpesvirus 1 (FHV-1) infection was studied in 30 specific pathogen-free cats. In ten cats, the ability of five field isolates of FHV-1 to replicate in the epithelium and substantia propria of cornea and conjunctiva was demonstrated by histochemical techniques. Feline herpesvirus 1 was found to preferentially infect and induce necrosis of conjunctival epithelium. Although significant histologic lesions were not induced, all FHV-1 strains were observed to replicate in corneal epithelium; minimal viral antigen was detected in the corneal stroma. The course and clinical features of ocular FHV-1 infection were then studied over a period of 60 days in two groups of ten cats: in one group, infection was preceded by administration of subconjunctival betamethasone. In each of these groups, a distinct clinical syndrome developed. In cats not receiving corticosteroids, a course of epithelial keratitis, characterized by the formation of punctate and dendritic epithelial lesions, persisted for up to 24 days postinfection. In the corticosteroid treated group, a chronic (greater than 60 days) stromal keratitis developed, characterized by geographic epithelial ulceration, interstitial edema and deep vascularization. Other complications observed in corticosteroid-treated animals included decreased tear production, calcific-band keratopathy and a unique stromal disorder of cats termed corneal sequestration. The results of this study indicate that while epithelial keratitis may occur during primary infection, stromal keratitis does not, unless immune responsiveness to FHV-1 is concomitantly suppressed. This feature is similar to naturally occurring HSV-1 keratitis of humans, but contrasts to other animal model systems in which stromal keratitis predictably occurs during primary infection. Study of this animal model, therefore, may allow unique insights into the events preceding the establishment of stromal keratitis.
Subject(s)
Betamethasone/therapeutic use , Cat Diseases , Eye Diseases , Herpesviridae Infections , Animals , Antigens, Viral/analysis , Cat Diseases/drug therapy , Cat Diseases/microbiology , Cat Diseases/pathology , Cats , Conjunctiva/microbiology , Cornea/blood supply , Corneal Diseases/drug therapy , Corneal Diseases/microbiology , Corneal Diseases/pathology , Edema/complications , Epithelial Cells , Eye Diseases/drug therapy , Eye Diseases/microbiology , Eye Diseases/pathology , Fixatives , Fluorescent Antibody Technique , Herpesviridae Infections/drug therapy , Herpesviridae Infections/pathology , Herpesvirus 1, Canid , Keratitis/complications , Neovascularization, Pathologic/complications , Time FactorsABSTRACT
PURPOSE: To compare the effect of different cataract extraction surgical techniques on residual lens epithelial cell (LEC) density and cell regrowth rates using an in vitro model of posterior capsule opacification (PCO). SETTING: Comparative Ophthalmology Research Laboratories, North Carolina State University, Raleigh, North Carolina, USA. METHODS: Lens capsule explants were prepared from freshly enucleated canine globes after extracapsular cataract extraction (ECCE), phacoemulsification, or phacoemulsification followed by capsule vacuuming. Initial cell density on the capsule and cell proliferation were determined by phase contrast microscopy. The effects of the surgical technique on time to confluent growth of the cells across the posterior lens capsule were determined. RESULTS: Residual cell density on the remaining anterior capsule immediately after lens removal was 31.6% +/- 19.3%, 16.1% +/- 8.9%, and 7.7% +/- 5.7% in the ECCE, phacoemulsification, and phacoemulsification/capsule-vacuuming groups, respectively. Time to confluence (range 5.0 to 6.3 days) was not significantly different among the 3 groups when the lens capsules were cultured in serum-supplemented media. The confluence rate was significantly longer (by approximately 5 to 7 days) in the phacoemulsification/capsule-vacuuming group than in the other 2 groups when the capsules were cultured in serum-free media. CONCLUSIONS: Phacoemulsification with and without anterior and equatorial capsular vacuuming led to less initial LEC density in the capsular bag than ECCE. However, because cell proliferation rates among the 3 groups were only marginally affected, near 100% removal of LEC at the time of cataract extraction may be necessary to prevent PCO.
Subject(s)
Cataract/prevention & control , Lens Capsule, Crystalline/pathology , Phacoemulsification/methods , Postoperative Complications/prevention & control , Animals , Cataract/etiology , Cataract/pathology , Cell Count , Cells, Cultured , Culture Media, Serum-Free , Dogs , Lens Capsule, Crystalline/surgery , Postoperative Complications/etiology , Postoperative Complications/pathologyABSTRACT
OBJECTIVE: To identify predictors of burnout in pediatric nurses and to compare the incidence of burnout, job stress, anxiety and perceived social support in acute and nonacute care pediatric nurses. DESIGN: Prospective correlational-descriptive methodology was used to predict high, moderate or low burnout from length of work experience, perceived work stress and social support and anxiety. SUBJECTS AND SETTING: Registered nurses (n = 121) employed full-time in neonatal and pediatric intensive care units and pediatric intermediate care units. MEASUREMENTS AND RESULTS: Measures of job stress, anxiety, experience, social support and burnout were compared in acute and nonacute care pediatric nurses. The overall mean incidence of burnout was in a moderate range for both acute and nonacute care pediatric nurses for the emotional exhaustion and depersonalization subscales and in the high range of personal accomplishment subscales of the Maslach Burnout Inventory. Analysis of variance revealed no differences between groups. However, when nurses were grouped by high, moderate and low burnout scores, chi-square analysis revealed significant differences. More acute care nurses reported high burnout and more nonacute care nurses reported low burnout. Discriminant function analysis revealed that job stress was the strongest significant predictor of burnout, followed by state anxiety, coworker support, trait anxiety and experience on the unit. CONCLUSIONS: Even though high burnout levels are more frequent in acute care pediatric nurses, burnout is a problem in both acute and nonacute care pediatric nurses. The pattern of results suggests that efforts directed toward reducing anxiety and job stress and increasing coworker support, particularly for less experienced nurses, might reduce burnout.
Subject(s)
Burnout, Professional/epidemiology , Intensive Care Units, Neonatal , Intensive Care Units, Pediatric , Nursing Staff, Hospital/psychology , Pediatric Nursing , Progressive Patient Care , Adult , Analysis of Variance , Anxiety/complications , Anxiety/epidemiology , Burnout, Professional/diagnosis , Burnout, Professional/prevention & control , Burnout, Professional/psychology , Chi-Square Distribution , Depersonalization , Discriminant Analysis , Female , Humans , Incidence , Interprofessional Relations , Prospective Studies , Risk Factors , Severity of Illness Index , Social SupportABSTRACT
Forty-nine nurses working in neonatal intensive care were surveyed by using measures of job stress, burnout, anxiety, and perceived social support. On the Maslach Burnout Inventory, they scored in a moderate range of burnout for emotional exhaustion and depersonalization and in a high range of burnout for sense of personal accomplishment. Stepwise regression analyses revealed that higher job stress scores, higher anxiety scores, perception of less supervisor (head nurse) support, and less experience were associated with higher burnout subscale scores.
Subject(s)
Intensive Care Units, Neonatal , Maternal-Child Nursing , Nurses/psychology , Stress, Psychological/diagnosis , Adult , Anxiety , Burnout, Professional/diagnosis , Female , Humans , Infant, Newborn , Social Support , Stress, Psychological/etiologyABSTRACT
Direct immunofluorescence reaction for Rickettsia rickettsii was performed on formalin-fixed, paraffin-embedded cutaneous biopsy specimens collected from dogs with experimental Rocky Mountain spotted fever (RMSF). A technique of trypsin digestion of deparaffinized, rehydrated sections was successful in demonstrating discrete, immunofluorescent organisms in endothelia and adjacent vessel walls in the dermis. R rickettsii was identified only in grossly evident dermal lesions (macular rash or oral vesicles) and was not apparent in randomly collected biopsy specimens from clinically normal inguinal skin. These results suggest that clinical application of this technique for diagnosis of RMSF may be limited in dogs without cutaneous lesions.
Subject(s)
Dog Diseases/microbiology , Rickettsia rickettsii/isolation & purification , Rocky Mountain Spotted Fever/veterinary , Skin/microbiology , Animals , Biopsy/veterinary , Dog Diseases/diagnosis , Dogs , Fluorescent Antibody Technique , Predictive Value of Tests , Rocky Mountain Spotted Fever/diagnosis , Rocky Mountain Spotted Fever/microbiologyABSTRACT
Ocular infection with Toxoplasma gondii is a well-recognized and important clinical entity in many animal species. In the cat, ocular toxoplasmosis is commonly associated with systemic infection, yet its role in causing anterior uveitis in an otherwise healthy cat is unclear. The purpose of this article is to review the salient epidemiological, clinical, and histopathologic features of systemic and ocular toxoplasmosis in the cat. Additionally, pathogenesis and possible immunopathogenic mechanisms of ocular toxoplasmosis, which may account for the higher prevalence of anterior uveitis in cats seropositive for T. gondii, are discussed. Finally, diagnosis, treatment and prevention of feline toxoplasmosis are reviewed.
ABSTRACT
The purpose of this retrospective study was to determine the prevalence, type, and prognosis of ocular lesions associated with leishmaniasis in dogs. One hundred and five dogs (24.4% of all cases of leishmaniasis diagnosed during the study period) had ocular or periocular leishmaniasis, and 16 dogs (15.2% of ocular cases) had only ocular lesions and systemic signs were not apparent. Anterior uveitis was the most common manifestation and other prevalent findings included blepharitis and keratoconjunctivitis. Several distinct variations of eyelid lesions were seen including a dry dermatitis with alopecia, diffuse blepharedema, cutaneous ulceration, and discrete nodular granuloma formation. In some cases with keratoconjunctivitis, corneal lesions clinically resembled nodular granulomatous episclerokeratitis. Twenty-seven of the 34 cases with ocular lesions had improvement in signs following systemic antiprotozoal and topical anti-inflammatory therapy, although many cases with anterior uveitis required long-term topical therapy. Response of ocular signs correlated highly with overall, systemic response to therapy. Ophthalmic manifestations of systemic leishmaniasis are common in the dog, and this disease should be considered in the differential diagnosis of most adnexal and anterior segment ocular inflammatory lesions in dogs in endemic areas.
ABSTRACT
The objective of the study was to determine the incidence and estimated median time to cataract formation in dogs with diabetes mellitus. The animals studied were 200 dogs with diabetes mellitus which were referred to a university teaching hospital between 1985 and 1995. Medical records from dogs with a diagnosis of diabetes mellitus were reviewed and, where necessary, further follow-up information was gathered from the referring veterinarian. Incidence rate and median time to diabetic cataract formation was calculated using survival-analysis techniques in a retrospective cohort study design. Among the 200 dogs in the study population, 23 had cataracts at the time of diabetes diagnosis that were presumed to be related to other disease processes. Of the remaining 177 dogs, 132 had documented cataract development with features suggestive as being secondary to diabetes. Twenty-three dogs did not have obvious cataracts at the time of their last examination while 22 dogs did not have cataracts at the time they were lost to follow-up. These 55 cases contributed to the statistical models as noncases of cataracts until the last date for which an examination was available. Half of the population had developed cataracts by the 170th day postdiagnosis of diabetes mellitus, while 75% and 80% of the population developed cataracts by 370 days and 470 days, respectively. The results of this study suggest that the majority of dogs with diabetes will develop cataracts within 5-6 months from the time of diagnosis of the disease, and that approximately 80% of dogs will develop cataracts within 16 months of diagnosis.
ABSTRACT
The objective of the research was to characterize the clinical, fluorescein angiographic, pathologic and microscopic features of feline pulmonary carcinoma with ocular metastasis that resulted in ischemic chorioretinopathy. Four cats with confirmed or presumed primary pulmonary neoplasia with posterior segment metastasis were studied. The medical records from four cats with a diagnosis of bronchogenic carcinoma and intraocular metastasis were reviewed. Physical and ophthalmic examinations and thoracic radiographs were performed in all cases, and fluorescein angiography was performed in two cases. Classification of the neoplasms was determined by fine-needle aspiration and biopsies of peripheral metastatic lesions, and/or complete necropsies. All four cases had unilateral or bilateral blindness and ophthalmoscopic lesions characterized by a wedge-shaped, tan discoloration in the tapetal fundus, variable but mild serous exudation under the retina, and profoundly attenuated retinal vasculature. Painful swelling and necrosis of the distal extremities and/or mass lesions in the appendicular musculature were also present. Clinical findings, along with microscopic findings from biopsy specimens or complete postmortem examination, documented widespread metastasis of variably differentiated, neoplastic, columnar epithelial cells presumed to be of bronchial origin. Tumor cells were predominately located within the systemic vasculature, consistent with classification of angioinvasive pulmonary carcinoma. Fluorescein angiographic and histopathologic findings in the affected globes suggested that the posterior segment lesions resulted from invasion and growth of neoplastic cells within the chorioretinal vasculature, resulting in secondary ischemic necrosis of the retina and choroid. Ischemic chorioretinopathy and necrosis of the distal extremities, associated with primary bronchogenic carcinoma, appear to be a unique neoplastic syndrome in the domestic cat.
ABSTRACT
The objective of the study was to characterize the morphologic and immunohistochemical features of lens epithelial-derived proliferative membranes from the anterior segment of canine globes. These features were correlated with those previously identified for diseases resulting from lens epithelial cell (LEC) proliferation including posterior capsular opacification, traumatic subcapsular cataract, and subcapsular plaques associated with hypermature cataracts. Sixteen canine globes were removed as a result of glaucoma or other complications following cataract extraction. Light microscopic and immunohistochemical analysis was performed on sections from formalin-fixed, paraffin-embedded globes. The tissues were stained with a variety of antibodies for cellular markers for LECs, growth factors or other cellular constituents relevant to cellular metaplasia and proliferation. The membranes were composed of monolayers or multilayers of spindle-shaped cells on the external surfaces of the anterior and posterior lens capsule, ciliary processes, iris leaflets, and iridocorneal angle, and they could be seen extending from an obvious monolayer of LEC within the capsular sac. Variably, scattered pigment cells, presumably of uveal origin, were concurrently present. Cellular components of the membranes stained positive for vimentin, transforming growth factor-beta, basic fibroblast growth factor, and smooth muscle actin. An amorphous eosinophilic extracellular matrix consisting predominately of collagen was associated with the membranes. Proliferative anterior segment membranes following cataract surgery were morphologically and immunohistochemically similar to cellular and matrix components of posterior capsular opacification and capsular plaques seen with hypermature cataracts, both of which result from metaplasia and proliferation of LEC. The presence of these LEC-derived membranes in association with secondary glaucoma suggests that exuberant proliferation of LEC outside the confines of the lens capsular sac may cause pathologic alterations in the eye following cataract surgery in the dog.
ABSTRACT
Pancuronium bromide, a neuromuscular blocking agent, was evaluated in canine cataract surgical patients under general anesthesia to determine its effects on respiratory function and globe position. Two paralytic, anesthetic regimes were studied: one using a standard dosage of 0.066 mg kg-1 pancuronium bromide, given intravenously while providing the patient with ventilatory support, and one using a dosage of 0.022 mg kg-1 in which no ventilatory support was provided. Eye position and anterior vitreal position/displacement were recorded by a surgeon who was blinded as to treatment group. Physiological parameters indicative of respiratory function were monitored. Both dosages of pancuronium produced comparable, neutral globe position within 30 s following administration which lasted for 20-30 min. All patients in the standard dose group experienced uneventful anesthetic episodes with physiological parameters well within the normal ranges. Within 5 min after administration, all patients in the low-dose group developed a pronounced respiratory acidosis (mean arterial pH = 7.07 +/- 0.08; mean PaCO2 = 79.8 +/- 10.7 mmHg), which exceeded a set of predetermined safety limits, and subsequently these dogs received ventilatory support. We conclude that 0.022 mg kg-1 pancuronium rapidly produces an unacceptable level of respiratory acidosis and, as a result, patients receiving neuromuscular blocking agents should routinely receive ventilatory support.
ABSTRACT
OBJECTIVE: To measure postoperative anterior chamber depth (ACD), corneal curvature, and refractive state of feline eyes after lens removal and implantation of a prosthetic intraocular lens (IOL) and determine appropriate IOL use in cats. ANIMALS: 8 clinically normal adult cats. PROCEDURE: A-scan ultrasonic biometry, keratometry, and streak retinoscopy were performed on both eyes of each cat before and after lens removal and implantation of a prosthetic IOL. Three diopter (D) IOL strengths were used: 48, 51, and 60 D. Measurements were recorded for 12 weeks after surgery. RESULTS: IOL were well tolerated by cats, with no serious complications attributable to implantation or presence of the IOL. The ACD was significantly greater after (8.30 mm) than before (4.97 mm) surgery; however, it became slightly more shallow during the 4 weeks after surgery, suggesting that the IOL shifted anteriorly in the eye. Significant difference in corneal curvature was not detected before or after surgery among eyes with various IOL. Twelve weeks after surgery, eyes with 48-, 51-, and 60-D IOL had mean +/- SD refractive state of +2.1 +/- 0.49, +0.42 +/- 0.20, and -2.6 +/- 0.78 D, respectively. Linear regression analysis of refractive state on IOL power for all eyes at 12 weeks after surgery predicted that +52.8-D IOL was necessary to best approximate emmetropia in these cats. CONCLUSION AND CLINICAL RELEVANCE: IOL of substantially higher diopter strength than that needed in dogs was required to achieve emmetropia after lens extraction in cats. A 52- to 53-D IOL is required to correct feline eyes to near emmetropia after lens removal.
Subject(s)
Anterior Chamber/diagnostic imaging , Cats/surgery , Cornea/anatomy & histology , Lens Implantation, Intraocular/veterinary , Refraction, Ocular/physiology , Animals , Anterior Chamber/anatomy & histology , Biometry/methods , Cats/anatomy & histology , Cats/physiology , Dogs , Linear Models , Ultrasonography , Visual AcuityABSTRACT
The effects of mitomycin-C on intraocular pressure (IOP), facility of outflow (C), and Tenon's capsule fibrosis were studied over 60 days in 10 clinically normal dogs. A-1-piece, silicone glaucoma implant was surgically implanted into both eyes; the filtration site of one eye was treated with a single, 5-minute intraoperative application of mitomycin (0.5 mg/ml), and the fellow eye was treated in a similar manner with balanced salt solution. There were no significant differences in preoperative IOP or C-values between treatment groups. Mean IOP in eyes of both groups initially decreased from the preoperative value, but returned to the baseline value by day 21. Mean facility of aqueous outflow (C-value) increased in all eyes during the first 14 days (mitomycin-C-value = 2.26 +/- 0.72; control C-value = 2.38 +/- 0.81), then reached a plateau that was significantly higher than the baseline value in mitomycin (P = 0.039) and control (P = 0.041) eyes. Histologic evaluation revealed all implants surrounded by a connective tissue capsule composed of regular dense collagen and fibroblasts that was significantly (P = 0.003) thinner in the mitomycin-treated (scleral side = 167 +/- 62 microns; conjunctival side = 122 +/- 41 microns) than the control (scleral side = 261 +/- 92 microns; conjunctival side = 180 +/- 48 microns) group. There were, however, no significant differences in IOP or C-values between groups at any postoperative time interval. Results of this study indicate that intraoperative treatment with mitomycin suppresses, but does not prevent fibrosis around silicone filtering implants.