Browsing by Author "Rai, A N"
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Item Characteristics of the methylammonium/ammonium transport systems of the nitrogen-fixing cyanobacterium Anabaena 7120 (ATCC 27893).(1989-08-01) Rai, A N; Prakasham, RNH4(+)-transport in Anabaena 7120 was studied using the NH4+ analogue, 14CH3NH3+. At pH 7, two energy-dependent NH4(+)-transport systems were detected in both N2- and NO3(-)-grown cells, but none in NH4(+)-grown cells. Both transport systems showed a low and a high affinity mode of operation depending on the substrate concentration. One of the transport systems showed Km values of 8 microM (Vmax = 1 nmole min-1mg-1protein) and 80 microM (Vmax = 7 nmole min-1mg-1protein), and was insensitive to L-methionine-DL-sulphoximine, a glutamate analogue and irreversible inhibitor of glutamine synthetase. The other transport system showed Km values of 2.5 microM (Vmax = 0.1 nmole min-1mg-1protein) and 70 microM (Vmax = 0.7 nmole min-1mg-1protein), and was sensitive to L-methionine-DL-sulphoximine. Intracellular accumulation of free 14CH3NH3+ showed a biphasic pattern in response to variation in external 14CH3NH3+ concentrations. A maximum intracellular concentration of 2.5 mM and 7.5 mM was reached in the external 14CH3NH3+ concentration range of 1-50 microM and 1-500 microM, respectively. At pH 9, an energy-independent diffusion of 14CH3NH2 leading to a higher intracellular accumulation and assimilation rate, than that at pH 7, was observed.Item Herniation of stomach simulating as hydropneumothorax.(1973-04-01) Vaish, S K; Khanna, N N; Ansari, Z A; Rai, A N; Mohan, M; Singh, R BItem Influence of different forms of nitrogen on uptake of ammonium, glutamate and glutamine in the cyanobacterium Nostoc muscorum.(1991-08-01) Prakasham, R; Rai, A N; Singh, A K; Singh, H NEffect of various types of nitrogen nutrition was studied on the uptake of ammonium, glutamate and glutamine by Nostoc muscorum and its Het-Nif- mutant. Ammonium nitrogen acted as a potent inhibitor/repressor of ammonium, glutamate and glutamine transport. Nitrate nitrogen was found to be a strong inhibitor/repressor of ammonium transport, a partial inhibitor/repressor of glutamate transport but, caused a partial stimulation of glutamine transport.Item Risk factors of digoxin intoxication.(1975-01-16) Singh, R B; Vaish, S K; Rai, A N; Dube, K PItem A study of embolism in rheumatic heart disease.(1974-07-01) Rai, A N; Somani, P N; Katiyar, B CItem An unusual presentation of hepatic cirrhosis (a case report).(1973-04-01) Singh, S S; Vaish, S K; Rai, A N; Mehrotra, M L; Gupta, S