Lack of effect of flurothyl, a non-anesthetic fluorinated ether, on rat brain synaptic plasma membrane calcium-ATPase

Vitamin B-12 deficiency and hyperhomocysteinemia are partly ameliorated by cobalt and nickel supplementation in pigs

Vitamin B-12 deficiency and hyperhomocysteinemia alter the metabolism of trace elements. This study tested the hypothesis that there is a reverse relationship in which diets high in iron, copper, nickel and cobalt would influence vitamin B-12 deficiency outcomes including hyperhomocysteinemia. Piglets (German Landrace x Pietrain) were assigned to six groups of 8 and fed one of the following diets for 166 d: a vitamin B-12-adequate and folate-fortified diet (30 microg/kg vitamin B-12 and 0.5 mg/kg folate) with normal trace element concentrations or one of five vitamin B-12-free, folate nonsupplemented diets (0.36 mg/kg), with either normal trace element concentrations or high concentrations of iron (300 mg/kg), copper (30 mg/kg), cobalt (1 mg/kg) or nickel (6 mg/kg). Feed intake and weight gain did not differ significantly among the groups. Vitamin B-12-deficient pigs developed diminished serum and liver concentrations of vitamin B-12 and folate, an accumulation of iron in the liver and hyperhomocysteinemia. The magnitude of changes differed among vitamin B-12-deficient groups. Vitamin B-12-deficient pigs fed 6 mg/kg nickel had distinctly higher vitamin B-12 concentrations in liver and serum and 45% lower serum concentration of homocysteine than the corresponding deficiency group fed 1 mg/kg nickel; iron concentration in liver was completely normalized. Vitamin B-12-deficient pigs fed 1 mg/kg cobalt had 47% lower homocysteine concentrations in serum than the vitamin B-12-deficient group fed 0.13 mg/kg cobalt, but the vitamin B-12 status was unaffected. Supplementation of iron and copper did not affect these variables. The dietary manipulations had no detrimental effects on variables symptomatic of oxidative stress. The findings indicate a collaborative relationship between vitamin B-12 metabolism and the trace elements nickel and cobalt.

Xenon does not induce contracture in human malignant hyperthermia muscle

Xenon has many characteristics of an ideal anaesthetic agent. It is not known whether xenon is a safe alternative to the potent inhalational anaesthetics in patients susceptible to malignant hyperthermia (MH). We investigated the effect of xenon, halothane and caffeine on muscle specimens of 31 individuals, referred to the MH Unit of the University of Ulm, and performed genetic epidemiology. Thirteen individuals were classified as MH susceptible and 18 as MH negative. Xenon 70% did not cause an increase in baseline tension of any MH-susceptible muscle specimen in contrast to halothane and caffeine. The evoked twitch response increased transiently in MH-susceptible and normal specimens indicating a mechanism independent of MH susceptibility. These results suggest that xenon, in concentrations up to 70% may be a safe anaesthetic for MH-susceptible patients.