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The temperature dependence of the resistivity rho(T) and of the dc magnetic susceptibility chi(T) were measured on high-quality LNiO3 (L = La,Pr,Nd,Nd0.5Sm0.5) samples synthesized under high oxygen pressure. Subtraction of the rare-earth contribution to chi(T) allows the presentation of the evolution of the susceptibility of the NiO3 array from Pauli to Curie-Weiss paramagnetism with decreasing bandwidth. A metal-insulator transition occurring at a temperature T(t) = T(N) is first order for L = Pr and Nd; it becomes second order and produces no anomaly in chi(-1)(T) at a T(t)>T(N) for L = Nd0.5Sm0.5. In the antiferromagnetic domain T

The authors discuss their own 14-year experience with surgical treatment of the chronic pancreatitis. They treated 64 patients of a mean age of 43 years. An abdominal pain, persisting in all patients, constituted the main indication to surgery. Forty patients underwent pancreatic enterostomy with Puestow technique, 19 patients resections of various extension, and 5 patients underwent pancreatic duodenostomy. Mortality rate in pancreatic enterostomy and pancreatic duodenostomy was 2.5% whereas mortality rate in resections was 5.3%. Complications were noted in 27.5% and 36.8% of patients, respectively. Pain was completely abolished or markedly reduced in 90% of patients. Forty eight (77.4%) out of 62 patients were identified and followed up. According to commonly used criteria, positive late results were achieved in 56.2% of patients, moderate in 29.2%, and poor result in 14.6% of the treated patients.

Compensatory hypertrophy of the rat plantaris muscle (PLT) was induced by ipsilateral gastrocnemius muscle ablation. Following 8 weeks (wks) of hypertrophy, hindlimbs were cast immobilized (HI) for 4 weeks after which weight bearing was unrestricted for 8 wks (recovery). Compensatory hypertrophy increased PLT wet weight/body weight ratio (83%), muscle fiber cross-sectional areas (1.5 to 2 fold), and the percent of slow oxidative (%SO) fibers (2 fold) in the experimental compared to the contralateral sham control muscle. PLT protein content and maximal activities of phosphofructokinase (PFK), mitochondrial glycerol phosphate dehydrogenase, and succinate dehydrogenase were unaltered with muscle hypertrophy. HI produced significant decreases in PFK activity (50%) and muscle fiber cross-sectional areas (50%) but did not significantly change the histochemical myofibrillar ATPase profile. Following remobilization, muscle weight/body weight ratio and maximal enzyme activities recovered to that of aged matched controls. Muscle fiber areas returned to pre-immobilization sizes but were approximately 25% smaller than aged matched control hypertrophy muscles. The %SO fibers in the hypertrophied muscle remained higher than controls but did not return to pre-immobilization values. These results indicate that biochemical and histochemical characteristics of hypertrophied rat PLT recover from HI during 8 wks of normal weight bearing similar to that of normal control muscle. However, the recovery time period was insufficient to allow complete compensation of fiber size to that of the age-matched control animals.

Chronic hypertrophy (X = 88%) of the fast-twitch rat plantaris muscle was induced by surgical ablation of the synergistic gastrocnemius. Alterations in the catalytic activity and the light chain composition of myosin extracted from the hypertrophied plantaris muscle were examined. The hypertrophied muscle exhibited a decreased Ca2+-activated myosin ATPase activity and an increase in the content of LCS1 and LCS2 light chains when compared to its contralateral control. These changes, which occur in the absence of a direct manipulation of the muscle's innervation, suggest that the histochemically observed increase in the percent of alkaline labile fibres found in hypertrophied muscle are the result of the expression of a different myosin phenotype.

Na+/K+-ATPase activity was determined in striated muscles with different aerobic capacities. The underlying hypothesis was that different aerobic capacities are reflective of different contractile activity which imposes greater demands on sarcolemmal ion translocation and may thus set Na pumping capacity. The added ion translocation demands required during exercise-training on Na+/K+-ATPase activity in different muscle fiber types may require an adaptation of this enzyme. The highest and lowest Na+/K+-ATPase activity was in the heart and white gastrocnemius muscle (WG), respectively. A high linear correlation existed between Na+/K+-ATPase activity and succinate dehydrogenase activity in the six muscles studied. Exercise-training did not increase Na+/K+-ATPase activity in any of the muscles, but did increase the aerobic capacity, except in the heart and WG. It was concluded that Na+/K+-ATPase activity has a high positive correlation with the aerobic capacity of striated muscles in the rat and that the Na pump capacity does not adapt to exercise-training of 1 hr X day-1 as does aerobic capacity.