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Biomedical subjects

G A Lewbart

Publications and source records attributed to G A Lewbart.

25 records · Page 2Linked to original sources
PubMed1997

Orbital exenteration and placement of a prosthesis in fish.

OBJECTIVE: To develop a procedure for orbital exenteration and prosthesis placement in fish. DESIGN: Prospective study. ANIMALS: 5 cultured hybrid striped bass (Morone saxatilis x M chrysops) ranging from 30 to 50 cm in length. PROCEDURE: Exenteration was performed, using a dorsal approach in which blunt dissection was performed in the circumorbital sulcus. The orbit was then dried, and simple interrupted sutures were placed, leaving 2 suture loops within the orbit. The orbit was filled with polyvinylsiloxane, and a prosthetic glass eye was seated in the polyvinylsiloxane. RESULTS: All fish retained the prosthesis and had satisfactory cosmetic results at the end of the 8-week study period. CLINICAL IMPLICATIONS: The increase in popularity of pet fish and abundance of valuable aquarium and show fish have led to heightened awareness of piscine ocular disease. Aquarium fish are often euthanatized because of disfiguring ocular problems. The technique described here for surgical exenteration and cosmetic orbital prosthesis placement in fish may extend the captive life of public display fish.

Animals↗
PubMed1995

Microsurgical excision of an abdominal mass in a gourami.

A female, sunset, thick-lipped gourami (Colisa labiosa) that weighed 8 g and was 5.4 cm from the snout to the end of the vertebral column was examined because of a 5-mm-diameter, midventrally located mass that had developed suddenly 1 month earlier. Cytologic examination of a sample obtained by use of fine-needle aspiration, survey radiography, positive-contrast radiography of the gastrointestinal tract, and Doppler ultrasonography were performed to evaluate the mass. These procedures were not able to provide a definitive diagnosis, but did facilitate surgical planning. The mass was excised, and the abdominal musculature was repaired, using microsurgical techniques. Redevelopment of the mass was not detected during the 5-month period after surgery. Histologic evaluation of the mass revealed an organized hematoma of undetermined cause. Successful management of this gourami illustrated that size should not be a deterrent to diagnostic evaluation and surgical intervention in diminutive fish.

Abdomen↗
PubMed1995

Pneumocystectomy in a Midas cichlid.

A pet Midas cichlid with a 2-year history of a distended abdomen and inadequate buoyancy control was found, radiographically, to have an abnormally large swim bladder. A recirculating anesthesic machine was constructed, and the fish was anesthetized with tricaine methanesulfonate prior to removing a portion of the swim bladder. The entire procedure lasted 71 minutes. Buoyancy problems in pet fishes are common. Causes include subcutaneous air accumulation, infectious disease of the swim bladder inner ear disease, and gastroenteritis. Reduction of the volume of the swim bladder improved this fish's ability to maintain a normal posture in the aquarium.

Air Sacs↗
PubMed1985

The fate of larval chondrocytes during the metamorphosis of the epibranchial in the salamander, Eurycea bislineata.

The metamorphosis of the epibranchial cartilage, a skeletal component of the hyobranchial apparatus, in the salamander Eurycea bislineata entails a combination of the reabsorption of a larval cartilaginous element with the simultaneous genesis of an adult cartilage in the same place. In this study we focus on the fate of the larval chondrocytes. Two hypotheses are considered: one, larval cells simply die off during metamorphosis, or, alternatively, they dedifferentiate and participate in the formation of the adult element. Thyroxine treatment and experimental tissue manipulation coupled with measurements of thyroxine levels using radioimmunoassay show that, within 24 h after T4 treatment, larval chondrocytes in the epibranchials exhibit large autophagocytic vacuoles, disruption of the rough endoplasmic reticulum, abnormally shaped mitochondria, abundance of lysosomes and nuclear degeneration, all symptoms of the onset of cell death. In conclusion, evidence from light microscopy, TEM and SEM show that the larval chondrocytes in response to rising levels of thyroid hormones undergo a process of lysosomal autophagocytosis and do not participate in the formation of adult structures.

Animals↗
PubMedDate not supplied

Pet fish radiography: technique and case history reports.

Radiography can be used to aid in the diagnosis and treatment of pet fish diseases. Handling, restraint and radiographic technique for the radiographic examination of pet fish is described. Quality diagnostic images can be obtained with standard radiographic equipment and radiographic techniques. Fishes with undifferentiated sarcoma, swim bladder herniation and scoliosis are three clinical examples that are described where radiography was used in the management of the patient. Conventional radiography appears to be best for evaluating skeletal and swim bladder diseases. Alternate imaging techniques such as computed tomography and magnetic resonance imaging may enhance the evaluation of coelomic soft tissue structures.

Air Sacs↗
PubMedDate not supplied

Imaging a spinal fracture in a Kohaku Koi (Cyprinus carpio): techniques and case history report.

An ornamental pet fish was diagnosed with a spinal fracture and subluxation involving truncal vertebrae 5 and 6 (T5-T6) using conventional radiography, nuclear scintigraphy, and computed tomography. Attempts to evaluate the dynamic nature of the lesion using conventional fluoroscopy in the unanesthetized, moving patient were unsuccessful. Adaptation of imaging techniques to accommodate a fish patient was not difficult and diagnostic images were obtained. The use of multiple imaging techniques was useful in the diagnosis and determination of the treatment plan of the spinal fracture in this patient.

Animals↗