Protein binding in deactivation of ferrylmyoglobin by chlorogenate and ascorbate.

Kinetics of reduction of iron(IV) in ferrylmyoglobin by chlorogenate in neutral or moderately acidic aqueous solutions (0.16 M NaCl) to yield metmyoglobin was studied using stopped flow absorption spectroscopy. The reaction occurs by direct bimolecular electron transfer with (2.7 +/- 0.3) x 10(3) M(-)(1).s(-)(1) at 25.0 degrees C (DeltaH( )(#) = 59 +/- 6 kJ.mol(-)(1), DeltaS(#) = 15 +/- 22 J. mol(-)(1).K(-)(1)) for protonated ferrylmyoglobin (pK(a) = 4.95) and with 216 +/- 50 M(-)(1).s(-)(1) (DeltaH( )(#) = 73 +/- 8 kJ. mol(-)(1), DeltaS( )(#) = 41 +/- 30 J.mol(-)(1).K(-)(1)) for nonprotonated ferrylmyoglobin in parallel with reduction of a chlorogenate/ferrylmyoglobin complex by a second chlorogenate molecule with (8.6 +/- 1.1) x 10(2) M(-)(1).s(-)(1) (DeltaH( )(#) = 74 +/- 8 kJ.mol(-)(1), DeltaS( )(#) = 59 +/- 28 J.mol(-)(1).K(-)(1)) for protonated ferrylmyoglobin and with 61 +/- 9 M(-)(1).s(-)(1) (DeltaH( )(#) = 82 +/- 12 kJ.mol(-)(1), DeltaS( )(#) = 63 +/- 41 J. mol(-)(1).K(-)(1)) for nonprotonated ferrylmyoglobin. Previously published data on ascorbate reduction of ferrylmyoglobin are reevaluated according to a similar mechanism. For both protonated and nonprotonated ferrylmyoglobin the binding constant of chlorogenate is approximately 300 M(-)(1), and the modulation of ferrylmyoglobin as an oxidant by chlorogenate (or ascorbate) leads to a novel antioxidant interaction for reduction of ferrylmyoglobin by ascorbate in mixtures with chlorogenate.

[Postgastrectomy dumping treated with octreotide (Sandostatin)]. / Postgastrektomibetinget dumping behandlet med octreotid (Sandostatin).

Somatostatin and the long acting somatostatin analogue Sandostatin have been shown to be effective in the management of dumping syndrome. We describe a patient with early dumping in whom this management provided total symptomatic relief. The doses was reduced from 50 micrograms to 12.5 micrograms s.c., t.i.d. At this dose clinical and biochemical parameters (blood pressure, pulse rate, packed cell volume, hematocrit, and blood glucose) were found to be within normal levels.

[Benign pneumoperitoneum and scrotal emphysema after colonoscopy]. / Benignt pneumoperitoneum og skrotalt emfysem efter koloskopi.

A case of benign pneumoperitoneum and subcutaneous emphysema of the scrotum after elective colonoscopy with polypectomy is reported. The development and treatment of benign pneumoperitoneum is discussed.