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Biomedical subjects

V S Johnson

Publications and source records attributed to V S Johnson.

16 recordsLinked to original sources
PubMed2006

Diagnosis and surgical treatment of a nasopharyngeal cyst in a dog.

A 21-month-old boxer dog was presented with clinical signs caused by nasopharyngeal obstruction. A mineralised mass in the nasopharynx was identified by radiography. Computed tomography allowed accurate anatomical localisation of the cystic lesion and identification of an ossified wall. Surgical removal of the mass by a ventral approach resulted in complete resolution of clinical signs. Histopathological examination strongly suggested that the cyst was derived from remnants of Rathke's pouch.

Animals↗
PubMed2005

Thoracic high-resolution computed tomographic findings in dogs with canine idiopathic pulmonary fibrosis.

OBJECTIVES: To identify features of canine idiopathic pulmonary fibrosis (CIPF) using high-resolution computed tomography (HRCT), and to correlate these features with clinical stages of the disease. METHODS: Ten dogs with signalment, history and clinical signs highly suggestive of CIPF were investigated. Thoracic radiography, haematology and biochemistry profiles, bronchoscopy and bronchoalveolar lavage and HRCT were performed in each case. The dogs were classified as having mild, moderate or severe stages of the disease based on their clinical presentation and radiographic signs. Features identified by HRCT were correlated with these disease stages. RESULTS: HRCT showed a spectrum of pulmonary changes and it was possible to match some of these to the stage of CIPF. CLINICAL SIGNIFICANCE: HRCT is used extensively in humans in the diagnosis and treatment planning of idiopathic pulmonary fibrosis. This preliminary study identifies the high-resolution computed tomographic features of CIPF in a small group of dogs. With further work it may be possible to use HRCT as a non-invasive tool for diagnosing, staging and therapeutically monitoring CIPF.

Animals↗
PubMed2004

Thoracic high-resolution computed tomography in the diagnosis of metastatic carcinoma.

Three dogs were presented for investigation of recurrent pyrexia of unknown origin, chronic vomiting and respiratory distress, respectively. One dog was markedly underweight and the other two were cachexic. Physical examination and initial diagnostic tests failed to establish the underlying cause of the presenting signs. Thoracic radiographs were within normal limits for the age of the dog. In each case there was a high index of suspicion for an occult neoplastic process in view of the profound unexplained weight loss present. High-resolution computed tomography (HRCT) of the thorax was performed. The lung fields were divided into three zones for analysis and a novel classification scheme was used to describe the HRCT findings in each zone. Postmortem examination and histopathology confirmed the presence of an infiltrating metastatic carcinoma in all three cases. The HRCT changes correlated closely with the pathological findings. The authors conclude that HRCT of the lung should be considered for pulmonary metastatic screening in the dog and introduce a classification system for HRCT findings, based on terminology used in human medicine.

Adrenal Gland Neoplasms↗
PubMed2004

Bone scintigraphy in the investigation of occult lameness in the dog.

99mTechnetium methylene diphosphonate (99mTc-MDP) scintigraphy was performed in 14 dogs of different breeds after clinical lameness examination, radiography and synovial fluid analysis failed to localise lameness to a specific area of pain. The scintigraphic protocol included an intravenous injection of 17 MBq 99mTc-MDP/kg bodyweight and vascular, soft tissue and bone phase scans in standardised positions with a low-energy all-purpose collimator. Confirmation of diagnosis was achieved in nine dogs by arthroscopy, repeated lesion-orientated radiography, computed tomography and response to treatment. In seven cases, bone phase scans showed single elbow uptakes, in two cases unilateral limb uptake, and in one case each a single shoulder and tibia uptake; in three cases there was no increased uptake. Vascular and soft tissue phase images did not reveal additional information. Diagnosis of humeral condyle fissures, a fragmented medial coronoid process, panosteitis and arthropathy was possible in nine cases. Skeletal pathology was ruled out in three normal scintigrams. In two dogs with unilateral uptake of multiple joints, no diagnostic benefit was gained from scintigraphy. The highly sensitive and relatively specific uptake allowed localisation and characterisation or exclusion of skeletal lesions in most dogs.

Animals↗
PubMed2004

Assessment of the efficacy of composite surgery for the treatment of dorsal displacement of the soft palate in a group of 53 racing Thoroughbreds (1990-1996).

REASONS FOR PERFORMING STUDY: There has been no objectively assessed case-control study of the efficacy of surgery to correct dorsal displacement of the soft palate (DDSP) previously reported. HYPOTHESIS: Composite surgery has a beneficial result on racing performance in horses affected with DDSP as compared to a matched control population. METHODS: Race records were obtained for 53 racing Thoroughbreds which underwent composite staphylectomy, sternothyrohyoideus myectomy and ventriculectomy for correction of idiopathic DDSP at the University of Bristol between 1990 and 1996. Each surgical case was matched for age, sex and training yard with 2 control horses. The racing performance, based on prize money won, of surgical cases and control horses were compared for 3 races run before and after the date of surgery. RESULTS: Ninety-two percent of the surgical cases returned to racing after surgery. There was a significant increase in earnings of the surgical group before and after surgery (P = 0.011), but there was no significant difference in earnings of the control group before and after the date of surgery (P = 0335). Sixty percent of the surgical group had higher earnings after surgery than before, compared to 40% of controls. When horses which underwent surgery were ranked relative to their 2 matched controls, surgical cases did not significantly change in rank (P = 033), whereas control horses significantly decreased in rank (P = 0.012). Additionally, horses within the surgical group were more likely (P < 0.01) to start in 3 post operative races than those in the control group. CONCLUSIONS AND POTENTIAL RELEVANCE: Composite surgery had a beneficial effect on racing performance of horses afflicted with idiopathic DDSP, and further studies to evaluate objectively the usefulness of other surgical techniques are warranted.

Animals↗
PubMed2003

Ultrasound imaging of the canine tympanic bulla.

A procedure for imaging the canine tympanic bulla, external ear canal and adjacent structures using currently available ultrasound equipment was established. Lateral and ventral transducer positions were identified for this purpose and a 6.5 MHz curvilinear transducer was considered to be optimal. The sonographic appearance of these structures in cadavers and live dogs unaffected by ear disease is documented. Fluid was introduced into the tympanic bullae of the cadavers and its presence could be identified through the bony wall of the bulla. The ability of ultrasound to differentiate between gas and fluid within the bulla has important clinical implications as this is a common occurrence in dogs with middle ear disease. Ultrasound has several advantages over other imaging modalities and the examination procedure was well tolerated by unsedated dogs.

Acoustic Impedance Tests↗
PubMed2003

Comparison of ultrasonography, radiography and a single computed tomography slice for the identification of fluid within the canine tympanic bulla.

Fluid accumulation within the tympanic bulla (TB) is an important diagnostic indicator in clinical cases of canine otitis media although its identification can be a challenge using currently available imaging techniques. The aim of this study was to compare ultrasound with radiography and a single computed tomography (CT) slice for the identification of fluid within the TB of canine cadavers. A random number of TB in 66 cadavers were filled with ultrasound gel. Rostrocaudal open mouth (RCdoM) radiographs and CT images were interpreted by 2 blinded radiologists and ultrasound examinations were performed by 2 blinded sonographers. The heads were then frozen and sectioned to confirm the contents of each TB. Although CT remained the most accurate method, comparable results were obtained by one of the sonographers and even the inexperienced sonographer produced results superior to radiography. Ultrasound has several advantages over the other imaging techniques and this study suggests that it may have an application in the investigation of canine otitis media although further work in live animals would be required to confirm this.

Animals↗
PubMed1975

The marked item technique: a practical procedure for litter control.

Unobtrusively marked items of litter were placed among existing trash on the grounds of a federal youth correctional facility. Inmates voluntarily collected trash and deposited it at a central location, where they were given money or special privileges for each piece of marked litter found. A multiple-baseline design with litter counts in three areas revealed successive reductions of 55%, 88%, and 71% after 17, 22, and 36 days of baseline, respectively. A fourth area served as a baseline-only control, and revealed no systematic changes. Advantages of the procedure over previously devised techniques were discussed and applications in other areas of pollution control suggested.

Journal Article↗