Long-term clinical outcomes following surgery for spontaneous pneumothorax caused by pulmonary blebs and bullae in dogs - a multicentre (AVSTS Research Cooperative) retrospective study.

OBJECTIVES: To report the clinical characteristics and recurrence rate of spontaneous pneumothorax secondary to pulmonary blebs and bullae following surgical management in a large cohort of dogs. To explore potential risk factors for recurrence and describe outcome. MATERIALS AND METHODS: Medical records were retrospectively reviewed for cases with spontaneous pneumothorax managed surgically between 2000 and 2017. Signalment, clinical presentation, diagnostic imaging, surgery, histopathology findings and patient outcomes were recorded. Follow-up was performed via patient records and telephone contact. RESULTS: Records of 120 dogs with surgically treated pneumothorax were identified and reviewed, with 99 cases appropriate for exploratory statistical analysis. Median follow-up was 850 days (range: 9-5105 days). Two- and 5-year survival rates were 88.4% and 83.5%, respectively. There was recurrence in 14 of 99 dogs (14.1%) with adequate follow-up, with a median time to recurrence of 25 days (1-1719 days). Univariable Cox regression analysis suggested increased risk for recurrence in giant breeds (hazard ratio = 11.05, 95% confidence interval: 2.82-43.35) and with increasing bodyweight (HR = 1.04, 95% confidence interval: 1.00-1.09). Of 14 dogs with recurrence, six were euthanased, two died of causes related to pneumothorax and six underwent further treatment, of which five were resolved. CLINICAL SIGNIFICANCE: Long-term survival for dogs with surgically managed spontaneous pneumothorax was good and associated with a low risk of recurrence. Giant breed dogs and increased bodyweight were the only variables identified as possible risk factors for recurrence. The outcome for dogs with recurrence undergoing a second intervention was also favourable.

Surgical management of a recurrent spinal meningioma in a cat.

A 13-year-old male neutered Persian crossbred cat was evaluated for hindlimb paresis, ataxia and urinary incontinence that had been progressing over the previous 3 months. Neurologically, the cat had thoracolumbar spinal cord deficits and a myelogram detected the presence of a mass compressing the thoracic spinal cord. A hemilaminectomy was performed to excise the soft tissue mass, subsequently identified histologically as a psammomatous meningioma. The cat regained ambulatory function and continence following surgery until a recurrence of paresis and ataxia 36 months later. A second myelogram suggested local recurrence of the tumour, which was confirmed by histological examination of the tumour after its removal at a second laminectomy. The cat again regained normal neurological function, until a further recurrence 16 months after the second surgery. The meningioma was surgically debulked a third time and the cat regained ambulation and continence postoperatively. This case demonstrates the successful use of repeated surgical resection in the management of a recurrent spinal meningioma in a cat. The cat was ambulatory and continent at a follow-up examination 63 months after the initial presentation.

Regulation of plasma membrane V-ATPase activity by dissociation of peripheral subunits.

The plasma membrane V-ATPase of Manduca sexta larval midgut is an electrogenic proton pump located in goblet cell apical membranes (GCAM); it energizes, by the voltage component of its proton motive force, an electrophoretic K+/nH+ antiport and thus K+ secretion (Wieczorek, H., Putzenlechner, M., Zeiske, W., and Klein, U. (1991) J. Biol Chem. 266, 15340-15347). Midgut transepithelial voltage, indicating net active K+ transport, was found to be more than 100 mV during intermoult stages but was abolished during moulting. Simultaneously, ATP hydrolysis and ATP-dependent proton transport in GCAM vesicles were found to be reduced to 10-15% of the intermoult level. Immunocytochemistry of midgut cryosections as well as SDS-polyacrylamide gel electrophoresis and immunoblots of GCAM demonstrated that loss of ATPase activity paralleled the disappearance of specific subunits. The subunits missing were those considered to compose the peripheral V1 sector, whereas the membrane integral V0 subunits remained in the GCAM of moulting larvae. The results provide, for the first time, evidence that a V-ATPase activity can be controlled in vivo by the loss of the peripheral V1 domain.