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Biomedical subjects

C Agbo

Publications and source records attributed to C Agbo.

10 recordsLinked to original sources
PubMed2002

Transferrin regulates transcription of the MBP gene and its action synergizes with IGF-1 to enhance myelinogenesis in the md rat.

Myelin-deficient (md) rats and their unaffected littermates were injected at postnatal day 4 either with a single dose of transferrin (Tf) or insulin-like growth factor one (IGF-1) singly or combined. Two weeks later, their brains were perfused and coronal sections were analyzed for MBP by in situ hybridization and for transferrin and myelin basic protein (Tf and MBP) by double immunofluorescence. Each of the factors separately had an effect on mutant animals as seen by both increased OL maturation, and MBP mRNA and protein synthesis. The combination of factors resulted in a profound enhancement of the myelinogenic properties of oligodendrocytes (OL) with a consequent increase in the number of MBP-labeled fibers. The brains of unaffected littermates also responded to growth factor(s) injection either by increasing myelination in some brain areas or by regulating the synthesis of MBP in OL. Using rat OL cultures we studied the site of transferrin action for the expression of MBP gene. We found by run off transcription that the MBP mRNA was significantly increased at the nuclear level but the PLP message was unaffected. Thus, transferrin selectively regulates MBP at the transcriptional level and together with IGF-1 synergizes to increase both the maturation and myelinogenic properties of md and normal OL.

Animals↗
PubMed1995

Event-related auditory evoked potentials and amyotrophic lateral sclerosis.

OBJECTIVE: To study event-related potentials and particularly the P300 wave in a group of patients with amyotrophic lateral sclerosis (ALS), as changes in the P300 wave have been observed in many cases of brain damage-inducing cognitive impairment. DESIGN: Case series. SETTING: University hospital. PATIENTS: Twenty patients with ALS were compared with 20 healthy control subjects, with no significant age range and no significant difference in their education level. MAIN OUTCOME MEASURES: Amplitudes and latencies of long-latency auditory evoked potentials for the N100, P200, N200, and P300 waves were measured in the "odd-ball paradigm." Mental status was assessed by the Similarities subtest of the Wechsler Adult Intelligence Scale and by the Rapid Evaluation of Cognitive Function that allows for a mini-neuropsychological testing. The degree of disability was scored on the ALS Severity Scale, which rates bulbar and spinal functions. RESULTS: The latencies of the N100 and P200 waves did not appear to differ between normal and affected subjects; in contrast, the N200 and P300 latencies were significantly longer in the group with ALS. Sixty percent of the patients had a P300 latency more than 2 SDs above the theoretical norm that was established by the linear curve for control subjects. The N100, P200, N200, and P300 amplitudes showed no significant difference between the control subjects and the group of patients with ALS. There was no significant correlation between the N200 and P300 latencies and the disease duration or between the N200 and P300 latencies and the degree of motor impairment. The scores from the Rapid Evaluation of Cognitive Function were significantly lower in the group of patients with ALS than in the group of control subjects. CONCLUSIONS: A subtle cortical cognitive dysfunction is frequently observed in patients with ALS. These findings point also in the same direction as did previous neuropsychological, histological, and positron emission tomographic studies of ALS. Limb motor deficits and speech difficulties make it difficult to study the time course of changes in intellectual function in patients with ALS by using psychometric methods; thus, in the future, cognitive evoked potentials should constitute a fruitful method of testing cognitive function in patients with ALS to follow up their development over time.

Aged↗
PubMed1995

[Anosognosic graphomimia: an uncommon variety of hypergraphia in right sylvian infarction].

Following a massive infarction in the territory of the right sylvian artery, a right-handed patient with a left hemiplegia and anosognosia, developed a peculiar hypergraphia. It consisted of an inappropriate and permanent writing behaviour, disappearing only during sleep. Space-constructional components of writing were severely disturbed. Graphemes were poorly formed. The graphic disturbances were different from hypergraphia previously described in stroke patients who produced linguistically correct but semantically loose writing. They were also different from graphomania reported in a case of fronto-callosal glioma. Our case of anosognosic hypergraphia suggests a sudden loss of inhibition of writing activity of the left hemisphere. The term graphomimia is proposed to distinguish this writing behaviour from the cases of hypergraphia previously reported and from graphomania.

Aged↗
PubMed1993

[Cerebral infarction, cardiac myxoma and lentiginosis].

Occlusion of the middle cerebral artery in a 16-year old woman revealed a left atrial myxoma associated with a mucocutaneous lentiginosis. Two-dimensional transthoracic or transesophageal echocardiography should be performed in all patients with stroke and lentiginosis to look for cardiac myxoma. After treatment of the cardiac tumor, echocardiography should be repeated at regular intervals to detect a recurrence of the myxoma. As this cardio-cutaneous syndrome is a familial disorder with autosomal dominant inheritance, examination of all family members by echocardiography is recommended.

Cerebral Infarction↗
PubMed1991

[Significance of the blink reflex in the Wallenberg syndrome].

The blink reflex was studied in 38 cases with lateral medullary lesions (Wallenberg syndrome). Twenty-one blink reflexes were abnormal. The most common abnormality is an afferent delay in the late reflex on the side of the lesion with a normal early reflex. This abnormality is not pathognomonic of the Wallenberg syndrome. The physiopathogeny is discussed.

Adult↗
PubMedDate not supplied

Event-related auditory evoked potentials and multiple sclerosis.

Long latency event-related auditory evoked potentials, particularly the P300 wave, constitute an objective electrophysiological index of cognitive function. For this reason, these potentials have been studied in a series of 101 patients with multiple sclerosis (MS), classified according to McAlpine's criteria into definite, probable and possible cases. The patients were also classified as depressed or non-depressed according to the DSM-III and Research Diagnostic Criteria. They were also subjected to a battery of psychometric tests. In the patient population the N200 and P300 latencies were increased, as were the P200 latencies, when compared with a control population. This electrophysiological pattern had previously been observed in other conditions characterised by subcortical lesions. Partial correlations (at constant disease duration) between the disability score and the cognitive deficit were found to be significant. Patients with an increased P300 latency had a greater disability and the P300 latency was significantly correlated with the duration of the illness. The N200 and P300 latencies were increased in depressed MS subjects, but this increase did not reach the level of significance. Depression was more frequent in the more severely handicapped patients. This suggests that the origin of the depression seen in multiple sclerosis is only partly organic, and that it is one of the factors contributing to the subcortical cognitive deficit in multiple sclerosis. Progressive forms of the disease exhibited the most profound cognitive deficit, and the most marked increase in P300 latency.

Acoustic Stimulation↗
PubMedDate not supplied

[Late recurrence of Miller-Fischer syndrome. Physiopathogenic reflections about a case].

The physiopathology of the syndrome of ophtalmoplegia-ataxia-areflexia-hyperproteinorachia, firstly described by FISHER in 1956, remains a matter of controversy among neurologists. We report a new case of recurrence of a MILLER-FISHER's syndrome. The involvement of peripheral and central structures is discussed according to recent knowledges about the immunopathology of inflammatory polyneuropathies.

Cerebellar Ataxia↗