Fast-to-slow muscle conversion by chronic electrostimulation: effects on mitochondrial respiratory chain function with possible implications for the gracilis neosphincter procedure.

The effects of chronic, around the clock, low-frequency electrostimulation on the respiratory chain activity and cytochrome content of freshly isolated mitochondria were evaluated in rabbit skeletal muscle before and after 30 days of continuous or cyclical electrostimulation using a totally implantable system and a training programme now used in humans. The respiratory activity measured in state III increased strongly after electrostimulation. The efficiency of the respiratory chain increased significantly after electrostimulation but the activity of complex [(reduced nicotinamide adenine dinucleotide dehydrogenase) did not increase. The amount of cytochromes a and a3, b562, and c and c1 increased clearly after electrostimulation. The respiratory activity rate of mitochondria obtained after continuous electrostimulation was apparently higher than after cyclical electrostimulation. Chronic uninterrupted low-frequency electrostimulation, using a clinical training programme, induces an increase in mitochondrial respiratory chain activity in purified mitochondria of skeletal muscle. These changes are the basis of induced resistance to fatigue in fast-to-slow muscle conversion by chronic electrostimulation.

[Effect of the resection margin and the extrarectal spread on the recurrence following 2 types of surgical procedures in rectal cancer]. / Influencia del margen de sección y de la diseminación extrarrectal en la recidiva después de dos tipos de intervenciones por cáncer de recto.

A prospective unrandomized clinical study was conducted to determine the incidence of local recurrences after radical surgery and to ascertain whether the anterior resection could be an effective approach in cases of the tumours of the rectum, also in presence of the unsatisfied distal clearance and the extraparietal spread. For this purpose the length of the rectum below the tumor, mesorectum included, was cut in little cubes of 1 square cm and 10 microslices/cm at random were histologically examined to locate the intramural diffusion and extraparietal spread. Sixty-one patients undergoing curative surgery for rectal cancer entered the trial. Thirty-seven of them have been operated on by anterior resections (AR) and twenty-four by abdominal-perineal amputation. Thirteen local recurrences (21.3%) have been recorded during a five-year follow-up: 9 after AR and 4 after Miles operation. Nine relapses were among the cases with distal clearance less than 3 cm an eight of these have undergone anterior resections. No recurrence was seen in cases with distal clearance greater than 5 cm. Spread was found in 11 (18%) patients. Five recurrences were recorded all belonging to the group with anterior resection. No statistical difference exists between conservative surgical procedure and abdominal-perineal operation. We have been able to demonstrate only the direct relationship between relapse and Dukes C stage after curative rectal surgery.