Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The paralytic tremor (pt) rabbit is an X-linked recessive mutant characterized by hypomyelination of the CNS. The onset of myelin mutants' neurological symptoms typically occurs about the tenth postnatal day. A partial recovery is often observed; thus, the life-span of affected animals is almost normal and they can breed successfully. Mutants presenting this phenotype were chosen for our study. Because proteins can serve as excellent markers for the myelin formation process, we examined the developmental expression of several important myelin proteins (PLP/DM-20, MBP, CNP, MAG, and MOG) in both pt mutant and control rabbit brain homogenates. Expression of the investigated proteins occurs in rabbits as follows: CNP and MAG are already present at the early postnatal stage; PLP/DM-20 and MBP appear about the 10th postnatal day; MOG, expressed last, has been detected on the 28th postnatal day. Whereas the MBP, CNP, MAG, and MOG content is only slightly reduced in mature pt mutant brain homogenates (80-90% of control values), the amount of PLP corresponds to approximately 30-40% of that present in controls. Expression of all of the examined proteins is substantially retarded in maturing brains, which leads to the conclusion that besides severe PLP deficiency, retardation of oligodendrocyte maturation is another probable feature of pt mutation.
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PMID:Expression of myelin-specific proteins during development of normal and hypomyelinated Paralytic tremor mutant rabbits. I. Studies on the brain homogenates. 858 24

An X-linked, recessive paralytic tremor (pt) mutation is characterized by CNS hypomyelination. In our previous work, we presented developmental studies on the expression of several myelin-specific proteins (PLP/DM-20, MBP, CNP, MAG, and MOG) in the brain homogeates of both pt mutant and age-matched control Chinchilla rabbits aged 1-120 postnatal days. A moderate reduction in all examined proteins and a striking PLP deficiency were observed in the pt mutant rabbits. In the present study, we investigated isolated and purified myelin fractions. A severe (approximately 30% of control values) and approximately constant hypomyelination of pt mutant CNS was observed during the entire investigated development (28-120 postnatal days). Although the neurological symptoms gradually regressed and a partial recovery of the affected animals usually occurred, no tendency toward regression of the hypomyelination was noticed. Whereas the content of CNP, MBP, and MAG in isolated myelin membrane fractions seemed close to normal, a drastic PLP deficiency was observed. A significantly elevated amount of MOG was found in the myelin of pt mutant rabbits. The controversy between the high degree of hypomyelination and the slight reduction in myelin protein marker expression (except for PLP) in mature brain homogenates is discussed with respect to retarded oligodendrocyte maturation and deficient processing of myelin membranes in pt mutant rabbits.
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PMID:Expression of myelin-specific proteins during development of normal and hypomyelinated Paralytic tremor mutant rabbits. II. Studies on the purified myelin. 858 25

The optimal time for treating congenital hydrocephalus is still unknown. The following study tries to answer this question by shunting hydrocephalic rats around the 10th day of life when the brain development corresponds to that of humans at birth. The animals were allocated to 4 groups: normal, hydrocephalic, normal sham-operated and hydrocephalic-shunted rats (groups 1-4). Body weight and neurological development was tested every 2nd-3rd day. X-rays of the skull were performed in groups 2, 3 and 4 at 10 days and in all at 20 days. In groups 2 and 4 0.1 ml lohexolum was instilled into the lateral ventricle at 10 days and in all at 20 days. X-rays were used to calculate the volume of the neurocranium and to identify ventriculomegaly and its grade (1-3). The x-rays and shunting were performed under general anesthesia, the latter using Kausch's technique. At 20 days of age the animals were sacrificed, the homogenized brain tissue was used to measure Protein, DNA, GAD and CNP by photometry, fluorometry and enzymatically. Time-course of neurological development in group 1: The locomotor patterns were attained gradually up to the ability to hold on to a bar. In group 2 there were larger variations and holding on to a bar was possible only in 6/13. In addition, a distinct tremor was observed in 34%. In group 4 holding on to a bar was possible in all, tremor was observed in 20% of examinations and diminishing following surgery. The volume of the neurocranium in groups 2 and 4 was significantly larger than in groups 3 at 10 days; and in group 2 significantly larger than in groups 1, 3 and 4 at 20 days. In group 4 the ventriculomegaly was distinctly reduced in 7 and remained the same in 1. Protein was significantly lower in group 4. DNA was the same in all groups. GAD was the lowest and the CNP significantly low in group 2. The study shows that an effective shunt may reverse the progressive clinical, radiological and neurochemical changes of hydrocephalus, and that surgery must not be performed necessarily earlier (e.g. prenatally in humans).
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PMID:Clinical, gross morphological and neurochemical follow-up in normal, hydrocephalic and hydrocephalic-shunted rats. 982 33

Paralytic tremor (pt), a hereditary neurological disorder of rabbits, is a recessive, X-linked point mutation in exon 2 of the plp gene, responsible for substitution of 38 His by Glu in the PLP molecule. Pt genotype is expressed in a range of phenotypes, distinguished by the severity of neurological symptoms. Variable course of the disease, from totally asymptomatic to serious disorder, is observed even within the offspring of one breeding pair. The two most typical phenotypes have been chosen for the studies: one representing mild course of the disease and the other reflecting the most severe course. Since previous developmental studies proved that myelination is not only deficient but also delayed in pt rabbits, the age groups of animals have been selected with the aim of spanning the period of most active myelinogenesis. As revealed by experiments, the degree of CNS hypomyelination, which is the main future of pt mutation, is highest in the most affected animals. The amounts of mutated gene products, PLP and DM-20, examined both at mRNA and protein levels, exhibited a strong dependence on phenotype. Down-regulation of MBP and CNP was also observed. In contrast, MAG expression was normal or only slightly changed in mutants. The results lead to the conclusion that pt mutation in the plp gene affects a panel of events that governs myelinogenesis and is modulated in each individual that is manifested by gradation of neurological symptoms.
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PMID:Phenotypic diversity resulting from a point mutation. 1718 50