myelin-basic-protein and Vitamin-B-12-Deficiency

To investigate the association between subacute combined degeneration (SCD) and vitamin B(12) (VB(12)) deficiency and megaloblastic anemia (MA).. The serum level of VB(12), severity of anemia and lesions in CNS were analysed in 36 cases diagnosed as SCD. In addition, MRI neuro-electrophysiologic examination and CSF myelin basic protein (MBP) concentration were monitored dynamically. The prognosis of SCD was evaluated in relation to the time of the initiation of therapy.. Average ferrohemoglobin level in patients was (77.1 +/- 11.2) g/L and the average blood serum level of VB(12) was (87.0 +/- 21.4) ng/L before treatment with an abnormality rate of 47.2%. However, there was no linear correlation between the severity of lesions in CNS and ferrohemoglobin level or level of serum VB(12) (correlation coefficient: r = -0.1917, 0.0926, P > 0.5; r = 0.207, 0.101, P > 0.5, respectively). The comprehensive abnormal rate of evoked potential was 100%, which might occur prior to the clinical symptoms of SCD. The abnormal rate of MRI was 71.4%, and some lesions could diminish or disappear after treatment. The MBP levels in CSF were (3.96 +/- 1.66) ng/L, and (2.25 +/- 1.66) ng/L before and 3 months after the treatment. No significant improvement of symptoms and signs were seen when the treatment was initiated 6 months after the diagnosis.. SCD is associated with VB(12) deficiency and often accompanied by MA, but there is no linear correlation. Lesions of SCD in spinal cord or brain can be demonstrated in MRI. Evoked potential is critical for early diagnose and identification of silent cases of SCD. The level of MBP in CSF can reflect the severity of the lesion and prosthetic state of myelin sheath. Early diagnosis and treatment play an important role in decreasing the degree of the permanent dysfunction of CNS in SCD.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anemia, Megaloblastic; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myelin Basic Protein; Neurodegenerative Diseases; Vitamin B 12 Deficiency

We have demonstrated previously that chronic vitamin B12 [cobalamin (Cbl)] deficiency preferentially affects glial cells in the rat central nervous system (CNS) and severely affects peripheral glial cells independently of and concomitantly with the central neuropathy. In this study, we determined the mRNA levels for myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) in different CNS areas of rats made Cbl-deficient by total gastrectomy, as well as the mRNA levels for glycoprotein Po and peripheral myelin protein (PMP)22 in the sciatic nerve. GFAP-mRNA levels were significantly decreased in the spinal cord (SC) and hypothalamus, but not in the cortex, hippocampus, or striatum of totally gastrectomized (TGX) rats. No differences in GFAP protein levels were found in the SC and hypothalamus of the TGX rats treated or not with Cbl. MBP-mRNA levels were significantly decreased only in the hypothalamus, and the levels of mRNA for both glial markers returned to normal with Cbl replacement therapy. The levels of mRNA for the various myelin proteins in the sciatic nerve were not modified by Cbl deficiency. These results demonstrate that: a) the neurotrophic action of Cbl in rat CNS occurs in a zonal manner; and b) Cbl deficiency does not affect myelin synthesis (with the sole exception of the hypothalamus).

Topics: Animals; Central Nervous System; Gastrectomy; Gene Expression; Glial Fibrillary Acidic Protein; Hypothalamus; Myelin Basic Protein; Myelin Sheath; Peripheral Nervous System; Rats; RNA, Messenger; Sciatic Nerve; Spinal Cord; Vitamin B 12 Deficiency

It has been proposed that the biochemical lesion in subacute combined degeneration of the cord due to vitamin B12 deficiency, is impaired methylation of residue 107 (arginine) in myelin basic protein. We have examined myelin basic protein in brains of rats in which vitamin B12 was inactivated by exposure to nitrous oxide for up to 7 days. In addition brains of fruit bats in which vitamin B12 neuropathy had been produced by feeding washed, and hence vitamin B12-free fruit, were examined. There was no difference in the methylation of arginine 107 in myelin basic protein in these animals as compared to healthy control animals. Rats given an inhibitor of transmethylation reactions (cycloleucine) showed the expected fall in methylation of myelin basic protein.

Topics: Animals; Arginine; Brain Diseases; Chiroptera; Cycloleucine; Disease Models, Animal; Liver; Methylation; Myelin Basic Protein; Rats; Rats, Inbred Strains; Vitamin B 12; Vitamin B 12 Deficiency

Total particulate material prepared by homogenization in water and centrifugation at 100,000 g for 60 min from the brains of normal and vitamin B12-deficient fruit bats was fractionated on linear sucrose gradients (0.1 M-1.4 M sucrose). Animals were made vitamin B12-deficient by dietary deprivation or as a result of exposure to nitrous oxide. Based on absorbance at 280 nm three peaks were seen in material derived from the B12-deficient fruit bat brain and only two peaks in the normal animal. Myelin proteins were observed over a larger range of molarities of sucrose in the deficient brain than in the control tissue. Animals rendered vitamin B12-deficient by nitrous oxide treatment showed membrane protein patterns similar to those observed in the control animal.

Topics: Animals; Brain Chemistry; Chiroptera; Membrane Proteins; Myelin Basic Protein; Myelin Proteins; Subcellular Fractions; Vitamin B 12 Deficiency