Enzymes of nitrogen assimilation in maize roots

The enzymes nitrate reductase (NR), glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthetase (GS) and asparagine synthetase (AS) have been assayed in various regions along the seedling root ofZea mays L. In the intact attached root and calculated on a protein basis NR, GOGAT, and GS are found to have slightly higher specific activities in the apical 5 mm than in more mature regions of the root. GDH and AS, on the other hand, are much more active in extracts prepared from mature regions of the root than in the apical region. In excised root tips incubated in the presence of NH4 (+) and NO3 (-) there was a marked increase in GDH and AS, and a slight decrease in GOGAT and GS. Additions of NO3 (-) are required for NR activity but neither NO3 (-) nor NH4 (+) additions altered the activity levels of the other four enzymes. Additions of glucose to the medium inhibited the development of AS and GDH activities and resulted in higher activity levels of NR, GS and GOGAT. Glucose additions also enhanced the incorporation of acetate-(14)C and leucine-(14)C into protein. Additions of cycloheximide inhibit the development of NR, AS and GDH activities and also the incorporation of acetate-(14)C and leucine into protein.

Enzymes of nitrogen assimilation in maize roots

The enzymes nitrate reductase (NR), glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthetase (GS) and asparagine synthetase (AS) have been assayed in various regions along the seedling root ofZea mays L. In the intact attached root and calculated on a protein basis NR, GOGAT, and GS are found to have slightly higher specific activities in the apical 5 mm than in more mature regions of the root. GDH and AS, on the other hand, are much more active in extracts prepared from mature regions of the root than in the apical region. In excised root tips incubated in the presence of NH4 (+) and NO3 (-) there was a marked increase in GDH and AS, and a slight decrease in GOGAT and GS. Additions of NO3 (-) are required for NR activity but neither NO3 (-) nor NH4 (+) additions altered the activity levels of the other four enzymes. Additions of glucose to the medium inhibited the development of AS and GDH activities and resulted in higher activity levels of NR, GS and GOGAT. Glucose additions also enhanced the incorporation of acetate-(14)C and leucine-(14)C into protein. Additions of cycloheximide inhibit the development of NR, AS and GDH activities and also the incorporation of acetate-(14)C and leucine into protein.

Neuromuscular status in hypothyroidism

Twenty unselected patients with hypothyroidism were evaluated by clinical and electrophysiological techniques for neuromuscular dysfunction. On clinical examination, muscle weakness was observed in four, paraesthesia in 11, carpal tunnel syndrome in three, and peripheral neuropathy in two of the patients. The electromyograms were abnormal in 14 of the patients. The average duration of motor unit potentials and the mean amplitudes in these patients were reduced, compatible with myopathy. There were no denervation potentials. The nerve conduction abnormalities were found in 13 patients, predominantly affecting the median (10) than the peroneal nerve (one). Subclinical carpal tunnel syndrome was observed in six patients. This was evidenced by increased sensory in five and motor distal latencies in one patient.

A comparison of glutamate synthase obtained from maize endosperms and roots

Glutamate synthase (EC 2.6.1.53) has been examined in developing endosperms and roots of maize. KCl is required for maximum activity in each tissue. The effect with KCl is seen with buffer strength of 25 to 100 millimolar in the assay. The optimum concentration for the enzyme from endosperm is 20 millimolar and for the enzyme from root tissue the saturating concentration is about 20 millimolar. In root material the enzyme is labile but activity can be restored if KCl is added to the assay. Divalent cations such as Mg(2+) or Mn(2+) also activate the enzyme to some extent.In each case NADH or NADPH can serve as reductant. The reaction is insensitive to alpha-aminooxyacetate, but is inhibited by glutamate, the glutamate analogs methionine sulfoximine and methionine sulfone, and by the glutamine analogs azaserine and albizziin.

Profile of epilepsy in a developing country: a study of 1,000 patients based on the international classification

The present prospective study undertaken in a specialized neurological center of a developing country deals with 1,000 epileptic patients classified in accordance with the International Classification. Eighty-one percent of the patients could be classified, with a lower incidence in the younger age group. Partial epilepsy was found to be far more common than generalized epilepsy (80% versus 20%). Primary generalized epilepsy was seen in 15% and secondary generalized in 5%. Partial epilepsy with elementary symptomatology was seen in 58% and complex symptomatology in 7%. Secondarily generalized seizures were seen in the remaining 15%. Primary generalized epilepsy and partial epilepsy with complex symptomatology were more common in adults. Secondary generalized epilepsy and partial epilepsy with secondarily generalized seizures were more common in children. Partial epilepsy with elementary symptomatology, however, did not vary significantly with age. The higher incidence of partial epilepsy in our patients, compared to the West, could be due to greater frequency of CNS infections and birth injuries, which are common childhood hazards in the developing countries.

Plasma cortisol in glaucoma

Plasma cortisol level and intraocular tension were determined diurnally in 40 normal and 40 glaucomatous patients at 8 AM and 8 PM. It was observed that (1) plasma cortisol level was higher in glaucomatous patients at both the periods; (2) the diurnal variation in plasma cortisol was parallel to diurnal variation in intraocular tension in both glaucomatous and normal persons; and (3) the diurnal variation in plasma cortisol level also was more marked in glaucomatous patients as compared to normal persons.

Congestive cardiomyopathy in a family of Becker's X-linked muscular dystrophy

Ths dissociation of gross congestive cardiomyopathy and muscle disease in different members of a family affected with Becker's benign X-linked muscular dystrophy is described. The possibility that cardiomyopathy and muscular dystrophy may be the expressions of the same mutant gene has been suggested.