BACKGROUND

Sphingosine kinase (SKase) has been implicated in the protection of hearts from ischemia/reperfusion injury. This hypothesis was further examined.

MATERIAL/METHODS

Changes in SKase activity and cardiac function (left ventricular developed pressure, LVDP, and infarct size) in response to ischemia and reperfusion were studied in adult rat hearts by the ex vivo Langendorff method. Following initial equilibration or preconditioning, there was 45 min no-flow ischemia and then 45 min of reperfusion.

RESULTS

SKase activity declined 61% during ischemia and did not recover upon reperfusion. LVDP also did not recover upon reperfusion and the infarct size was 47%. A short 30 min period of ischemia was associated with variable recovery of SKase activity that directly correlated with LVDP recovery. Preconditioning of hearts reduced the decrease in SKase activity during ischemia by half, and upon reperfusion activity returned to normal. The LVDP recovered 79% and infarct size was small. Preconditioned hearts had higher S-1-P levels after ischemia/reperfusion relative to non-preconditioned hearts. The decline in SKase activity during ischemia of preconditioned hearts could not be mimicked in vitro by treatment with protein phosphatases. Attempts to alter activity of SKase from control, preconditioned, ischemic, or reperfused hearts by phosphorylation with ERK1/2 were unsuccessful. Treatment of non-preconditioned hearts at reperfusion with 100 nM S-1-P improved recovery of LVDP. The SKase inhibitor dimethylsphingosine blocked hemodynamic recovery in preconditioned hearts.

CONCLUSIONS

The data support a role for SKase activity in recovery of hemodynamic function after ischemic injury and also in the cardioprotective effect of preconditioning.

BACKGROUND

Caecal intubation is a necessary step in the complete endoscopic evaluation of the colon. Studies have estimated that experienced colonoscopists may fail to reach the caecum in up to 10% of cases.

AIMS

To evaluate the utility of the double balloon enteroscope used for complete examination of the colon in patients with incomplete standard colonoscopy.

PATIENTS

Twenty consecutive patients with incomplete colonoscopies within the Veterans Affairs Palo Alto Health Care System. Mean age of 66 years (S.D.+/-12 years, range 46-84), 16 men.

METHODS

Prospective single-centre case series on the caecal intubation rate using standard double balloon enteroscope technique in patients with previous incomplete conventional colonoscopy.

RESULTS

Use of the standard double balloon enteroscope technique permitted complete colonoscopy to be achieved in 95% of the patients (19/20). Seven patients (35%) had significant pathology beyond the extent of the prior incomplete colonoscopy. We performed endoscopic mucosal resection, polypectomy or biopsy. The mean time to reach the caecum was 28 min (S.D.+/-20 min, range 6-90 min). The sedation was similar to conventional colonoscopy. No complications occurred.

CONCLUSIONS

The double balloon enteroscope technology and technique can be used to complete examination of the colon in patients who were referred because of incomplete standard colonoscopy.