Clinical profile of PanIN lesions in tropical chronic pancreatitis

BACKGROUND

Chronic pancreatitis (CP) found in the tropical countries is known to have a higher risk for carcinoma of the pancreas. This study aimed to explore the clinical profile of pancreatic intraepithelial neoplasia (PanIN), one of the precursors of carcinoma of the pancreas, in tropical CP and to identify the possible clinical predictors of the same.

METHODOLOGY

A retrospective study was done enrolling patients who underwent either Frey's procedure or pancreatic resection for symptomatic CP, between January 2008 and December 2012. They were grouped into PanIN positive and PanIN negative based on histopathology. Their clinical and laboratory parameters were compared statistically to identify the predictors of the PanIN status.

RESULTS

Sixty-two tropical CP patients who had Frey's procedure or pancreatic resection were enrolled into this study; 38.7 % cases showed PanIN changes and 61.29 % had no PanIN changes. Majority of the clinical and laboratory parameters were found comparable between the two groups except obstructive jaundice and CA 19-9 value >137.5 which were there in 54.2 % of PanIN-positive cases. On histopathology, 54.83 % cases were benign CP and 45.16 % were malignant CP. Among the benign CP, 33.3 % were PanIN positive and among those with malignancy 66.7 % were PanIN positive. Low-grade PanINs were seen in 73 % cases of benign CP and in 26.1 % of malignancy whereas high-grade PanIN-3 lesions were seen exclusively in patients with malignancy.

CONCLUSION

High-grade PanIN-3 lesions showed significant association with pancreatic malignancy. Obstructive jaundice and CA 19-9 ≥ 137.5 could predict PanIN positivity.

Diazepam, gamma-aminobutyric acid, and progesterone open K(+) channels in myocytes from coronary arteries

Benzodiazepines enhance coronary blood flow and lower blood pressure, but the cellular basis of this action remains unclear. The present study now demonstrates a direct effect of diazepam, gamma-aminobutyric acid (GABA), and progesterone on the large conductance, Ca(2+)- and voltage-activated K(+) channel (BK(Ca)) in single myocytes isolated from porcine coronary arteries. These GABA receptor agonists significantly increased whole-cell (perforated patch) K(+) currents and stimulated the activity of single BK(Ca) channels in cell-attached patches dramatically. This effect is not mediated via cyclic AMP or cyclic GMP, but involves stimulation of Ca(2+) influx in response to activation of a bicuculline-sensitive GABA(A)-like receptor. We propose that localized, subsarcolemmal increases in Ca(2+) levels open BK(Ca) channels, thereby promoting K(+) efflux, membrane repolarization, and coronary relaxation. This transduction pathway can now account, at least in part, for the direct vasodilatory effects of diazepam, progesterone, and GABA.