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Biomedical subjects

J M Warter

Publications and source records attributed to J M Warter.

At least 73 records · Page 4Linked to original sources
PubMed1995

Antioxidant lazaroids enhance differentiation of C2 skeletal muscle cells.

We have examined the incidence of new antioxidant compounds, so-called lazaroids, on the morphological and biochemical aspects of differentiation of C2 mouse skeletal muscle cells. We show that three lazaroids (U-74006F, U-74389F and U-83836E) enhance fusion of myogenic cells when added at the day of fusion. A parallel increase in nicotinic acetylcholine receptor expression and skeletal muscle alpha-actin content was observed. This promoting effect of lazaroids on myogenesis could be related to inhibition of free radical-mediated muscle damage. Therefore, one could expect that lazaroids might be useful in the treatment of degenerating muscle diseases such as Duchenne muscular dystrophy.

Actins↗
PubMed1995

Striatal dopaminergic denervation in pallidopyramidal disease demonstrated by positron emission tomography.

Pallidopyramidal disease is a rare disease of young patients in which they manifest a parkinsonian syndrome and pyramidal signs. Pallidopyramidal disease has been attributed to a degeneration of the pallidum and the pyramidal tract, although only 1 patient has been studied postmortem. In the present report, [18F]fluorodopa positron emission tomography in 2 patients showed a marked dopaminergic denervation of the striatum, suggesting that this disease corresponds more to a nigropallidopyramidal dysfunction.

Adolescent↗
PubMed1995

Myasthenia gravis: comparative autoantibody assays using human muscle, TE671, and glucocorticoid-treated TE671 cells as sources of antigen.

The use of acetylcholine receptors (AChR) from the readily available TE671 cell line as a practical alternative to human muscle for monitoring the anti-AChR antibody assay in sera of Myasthenia gravis patients has been recently proposed. Most of the TE671 culture protocols include the use of glucocorticoids. Glucocorticoids were shown to upregulate the acetylcholine receptor expression in TE671 cells. To confirm the advantage of using AChR from TE671 cells (AChRTE) and to validate the use of AChR from glucocorticoid-treated cells (AChRGT) in AChR antibody measurement, the three different antigens (muscle AChR (AChRMU), AChRTE, and AChRGT) were compared for radioimmunoprecipitation assay. We found that, despite a slight underestimation of the antibody titers using AChRTE and AChRGT compared to AChRMU, and considering the rare cases of AChRMU antibody titer category permutations, the correlations between the values were satisfactory.

Adolescent↗
PubMed1995

Localization of Refsum disease with increased pipecolic acidaemia to chromosome 10p by homozygosity mapping and carrier testing in a single nuclear family.

Adult Refsum disease (ARD) is a rare autosomal recessive neurologic disorder associated with the accumulation in blood and tissues of phytanic acid, a natural compound of exogenous origin whose catabolism is impaired in patients. We present here genome wide linkage analysis of an atypical Refsum disease family where L-pipecolic acid level in blood was also increased, suggesting that the patients suffer from a new peroxisomal disorder intermediate between ARD and Infantile Refsum Disease (IRD, a peroxisomal deficiency disease). We were able to demonstrate significant linkage (lod score = 3.6) between Refsum Disease with increased Pipecolic Acidaemia (RDPA) and the interval defined by D10S249 and D10S466 on 10p in this single consanguineous family by combining lod score values obtained from analysis of the multiple affected sibs, haplotype homozygosity and from discrimination between healthy carriers and non carriers based on phytanate oxidase measurements. This illustrates the power of homozygosity mapping with a dense map of microsatellite markers. A similar strategy will allow testing for homogeneity/heterogeneity between RDPA and ARD or the rare complementation groups of IRD.

Cells, Cultured↗
PubMed1995

DNA analysis as a tool to confirm the diagnosis of asymptomatic hereditary neuropathy with liability to pressure palsies (HNPP) with further evidence for the occurrence of de novo mutations.

We performed DNA analysis in four families with hereditary neuropathy with liability to pressure palsy (HNPP). An interstitial deletion of the 17 p11.2 region was found in typically affected patients as well as in as yet asymptomatic patients. The opportunity for an individual genotyping permitted to ascertain a de novo deletion in one clinically affected case with no relevant familial history. DNA analysis thus becomes the most sensitive tool in diagnosing HNPP, since potentially affected patients may lack either informative familial history, or clinical symptoms or even suggestive EMG or histopathological data (tomaculas).

Adolescent↗
PubMed1995

[Neurologic manifestations following accidental exposure to pyralene and its thermal degradation products].

After five young women were exposed to pyralene and its thermal degradation products all developed a rich functional syndrome which could be explained by the traumatic effect of the accident. Nevertheless, in 3 of the women, abnormal somesthetic evoked potentials were observed including 2 with neurological lesions detectable radiologically. Polychlorobiphenyl derivates are toxic for the peripheral nervous system as has been observed in several recent exposure situations. Inversely, any effect on the central nervous system is still under debate.

Accidents, Occupational↗
PubMed1995

[Idiopathic Parkinson disease and mitochondrial functions].

Work on the molecular mechanisms of MPTP neurotoxicity have inspired search into the function of mitochondria in idiopathic Parkinson's disease. All the studies show a decrease of 30 to 40% in the activity of the respiratory complex I in the mitochondria of the nigra substantia. This decreased activity is not found in other degenerative Parkinsonisms treated with L-Dopa and cannot be explained simply by age. It is not found in other tissues including muscles and platelets. The causal mechanism of this mitochondrial dysfunction is unknown but it is not related to a mutation in mitochondrial DNA.

Humans↗
PubMed1994

Intranasal sumatriptan for the acute treatment of migraine. International Intranasal Sumatriptan Study Group.

Two double-blind, placebo-controlled, randomised, multicentre, multinational, parallel-group studies were carried out to identify the optimum dose of intranasal sumatriptan for the acute treatment of migraine. Study medication was taken as a single dose through one nostril in the first study, and as a divided dose through two nostrils in the second study. Totals of 245 and 210 patients with a history of migraine were recruited into the one- and two-nostril studies, respectively. In both studies, headache severity had significantly improved at 120 min after doses of 10-40 mg sumatriptan compared to placebo (P < 0.05) and the greatest efficacy rates were obtained with 20 mg sumatriptan. With 20 mg sumatriptan 78% and 74% of patients experienced headache relief in one- and two-nostril studies respectively. Sumatriptan was generally well tolerated, the most frequently reported event being taste disturbance. The results of the two studies are similar and indicate that administering sumatriptan as a divided dose via two nostrils confers no significant advantage over single-nostril administration.

Acute Disease↗
PubMed1994

Lazaroids enhance skeletal myogenesis in primary cultures of dystrophin-deficient mdx mice.

Growing evidence suggests a role for free radicals in the degeneration of dystrophin-deficient muscle (as observed in Duchenne muscular dystrophy). We therefore decided to test the action of the lazaroid antioxidant compounds on primary skeletal muscle cell cultures derived from an animal model of Duchenne muscular dystrophy, the mdx mouse. Both vitamin E-derived U-83836E and glucocorticoid-derived U-74389F enhanced myogenesis of dystrophin-deficient cultures as determined by the number of myotubes, the amount of nicotinic acetylcholine receptor, skeletal muscle alpha-actin levels and myosin light chain. U-83836E enhanced myogenesis of control congenic C57BL/10 mouse-derived muscle cultures whereas U-74389F had no detectable effect. This enhanced myogenesis was in most respects similar to the one triggered by alpha-methylprednisolone which is the only drug known to be beneficial in Duchenne muscular dystrophy.

Animals↗
PubMed1994

Neurobehavioral changes following bilateral infarct in the caudate nuclei: a case report with pathological analysis.

A patient presenting with loss of psychic self activation (LPSA) was studied clinically and at autopsy. Clinically, the patient showed changes that can be ascribed to the interruption of frontal-subcortical circuits. Pathological analysis revealed bilateral lesions of the caudate nuclei. This case extends others based on radiological findings and confirms the importance of the caudate nuclei in behavioral functions.

Aged↗
PubMed1994

Presence of anti-CSL antibodies in the cerebrospinal fluid of patients: a sensitive and specific test in the diagnosis of multiple sclerosis.

The carbohydrate-binding protein (lectin) CSL is an antigen involved in the stabilization of the myelin structure by interacting with the carbohydrate moiety of myelin glycoproteins. Since anti-CSL Fab fragments were able to produce destruction of CNS myelin in vitro, CSL was considered as a potential immunological target in multiple sclerosis. The presence of anti-CSL antibodies has been examined in the cerebrospinal fluid of 1388 different patients with various neurological diseases. It is concluded that the presence of anti-CSL antibodies in the cerebrospinal fluid of patients less than 50 years old constitutes a very sensitive and specific test for multiple sclerosis.

Antibodies↗
PubMed1994

[Type II Charcot-Marie-Tooth and dopa-sensitive Parkinson disease].

The occurrence of a dopa-sensitive parkinsonian syndrome 25 years after a neuropathy suggestive of Charcot-Marie-Tooth disease type II raised the possibility of a relationship between these two diseases. Apart from Machado-Joseph-Azorean disease, an association of this kind seems to be exceptional and it can not be excluded that it was fortuitous. However, the recent description of 7 familial and sporadic cases of a syndrome characterized by a peripheral neuropathy, familial in 5 of the 7 cases, followed, a few years later, by a dopa-sensitive parkinsonian syndrome, makes it possible to consider that this association might have a common genetic origin.

Charcot-Marie-Tooth Disease↗
PubMed1993

[Intravenous immunoglobulins in neurology].

Immunoglobulins, used at first empirically in the treatment of thrombocytopenic purpura, occupy a prominent place not only in the treatment of antibody deficiencies, but also in that of antoimmune diseases. Their indications in neurology are ever extending; they include myasthenia, chronic inflammatory polyneuropathies with or without monoclonal gammopathy, polymyositis, dermatomyositis and, more recently, disseminated sclerosis and Guillain-Barré syndrome. Even the therapeutic priority of plasmapheresis in this syndrome is disputed by some authors. Immunoglobulins are costly, but they are well tolerated and easy to use. Their effectiveness must be confirmed by controlled, double-blind trials. In neurology such trials are still rare, but those recently published are devoid of methodological errors. Once the effectiveness of immunoglobulins is confirmed, their dosage must be established, and attempts should be made at a better understanding of their mechanisms of action.

Dermatomyositis↗
PubMed1993

Prednisolone enhances myogenesis and dystrophin-related protein in skeletal muscle cell cultures from mdx mouse.

The differentiation of skeletal muscle cells from mdx mice which lack dystrophin expression was examined after glucocorticoid treatment, namely alpha-methylprednisolone (PDN). Primary skeletal muscle cell cultures were established from newborn mdx, congenic C57BL/10, and allogenic BALB/C mice. We show that PDN promotes the myogenesis of both mdx- and control mice-derived cultures as determined by 1) the number of myotubes, 2) acetylcholine receptors, and 3) dystrophin and dystrophin-related protein levels. These results support the hypothesis that PDN could enhance the myogenesis of satellite cells and increase dystrophin-related protein expression in DMD treated patients.

Animals↗
PubMed1993

alpha-Methylprednisolone promotes skeletal myogenesis in dystrophin-deficient and control mouse cultures.

We have examined the influence of the glucocorticoid alpha-methylprednisolone (PDN) on the morphological differentiation of skeletal muscle cells derived from dystrophin-deficient C57BL/10 mdx, congenic C57BL/10 and allogenic Balb/c newborn mice. We show that PDN enhances myogenic cell numbers in dystrophin-deficient cultures as well as in matched controls. A parallel increase in the fusion rate of myoblasts into myotubes occurs while the size of myotubes, as determined by nuclei per myotube, is slightly increased. This promoting effect of PDN on myogenesis could be related to the enhanced muscular function observed in PDN-treated Duchenne's muscular dystrophy-affected boys.

Animals↗
PubMed1993

alpha-Bungarotoxin sensitization in experimental autoimmune myasthenia gravis.

A mouse model of MG, termed experimental autoimmune myasthenia gravis (EAMG), can be obtained after immunization with Torpedo acetylcholine receptor (AChR). Although many studies have detailed the consequence of AChR antibodies binding at the neuromuscular junction and the difficulty in obtaining obvious clinical signs, less attention has been focused on the possibility of amplifying the muscular block in order to discriminate between immunized and healthy animals. In the present studies we observe that a single inoculation of alpha-bungarotoxin (alpha-bgt) can amplify the neuromuscular block revealed by repetitive nerve stimulation, and induce in EAMG mice a stable muscular weakness state lasting for at least 169 hours instead of 95 hours in normal mice. This model could provide an excellent tool for evaluating drugs active on neuromuscular transmission.

Animals↗