PubMed Health⌕ Search

Biomedical subjects

W D Singer

Publications and source records attributed to W D Singer.

31 records · Page 2Linked to original sources
PubMed1987

Effect of pyridoxine deficiency in the neuronally mature rat.

Pyridoxine deficiency was induced in neuronally mature rats by combination of dietary deprivation and ingestion of 4-deoxypyridoxine. Overt signs of deficiency were evident. At this time the activity of glutamic acid decarboxylase as also the content of serotonin decreased in several areas of the brain. Catecholamine contents were unchanged from controls. Light microscopic observations indicated no difference in CNS myelin between the deficient and control animals. There was no difference between deficient and control groups in their auditory evoked responses.

Animals↗
PubMed1986

Carbamazepine-erythromycin interaction. Case studies and clinical significance.

Because of significant and seemingly haphazard fluctuations in serum carbamazepine concentrations, we decided to investigate the possible link between erythromycin administration and potential changes in serum carbamazepine concentration. We studied four cases involving this combination. In every case, serum carbamazepine concentrations either rose dramatically (doubled or tripled previous steady-state concentrations) or dropped precipitously once erythromycin therapy was discontinued. In all cases, we report serum carbamazepine concentrations obtained before, during, and after concurrent erythromycin administration. We conclude that the combination of erythromycin and carbamazepine represents a clinically significant drug interaction and should be avoided where possible.

Adult↗
PubMed1984

Human serum teratogenicity studied by rat embryo culture: epilepsy, anticonvulsant drugs, and nutrition.

Epileptic women have a greater risk for spontaneous abortions and children with birth defects than do nonepileptics. In a unique approach to identifying causes of these problems, we have cultured whole rat embryos for 48 h on blood sera from epileptics. In the first part of the study, three embryos were cultured on each serum sample from 128 different epileptics being treated with either single anticonvulsants or no drug to compare the teratogenicity of these drugs. Sera from subjects receiving either phenobarbital or no drug had comparable frequencies of cultured embryo abnormalities, which were lower than those from subjects taking phenytoin, valproic acid, or carbamazepine. In the second phase of the study, attempts to identify causes for serum teratogenicity led to the finding that the abnormalities and reduced embryo growth produced by many serum samples could be completely overcome by adding vitamins and/or amino acids to the serum. Of 53 samples tested, 32 (60%) were corrected by supplementation (17 of 23 phenytoin, seven of nine phenobarbital, six of 12 carbamazepine, none of six valproic acid, and two of three no drug). Although the results of this study provided a general assessment of drug teratogenicity that agreed with other studies and emphasized the role of nutrition in fetal defects, the importance of individual differences in causes of teratogenicity was also noted.

Amino Acids↗
PubMed1982

The value of neuroradiology in infantile spasms.

The results of neuroradiologic studies of 71 children with infantile spasms treated with ACTH were correlated with the developmental outcome at follow-up (mean 62 months, range 14 to 207 months). Fifty-two (73%) patients had an abnormal NRS on initial evaluation; 49% had cerebral atrophy, 18% had congenital anomalies, and 6% had hydrocephalus. Twenty patients were normal on initial clinical evaluation. At follow-up only the eight (40%) with normal NRS were normal. Twelve (60%) who had unexpected abnormalities on NRS were retarded at follow-up. CAT scanning is necessary to predict the developmental outcome in developmentally normal children with infantile spasm. Eight of nine patients with normal NRS in the early treatment group were developmentally normal at presentation and follow-up. Ten patients who were developmentally normal before spasms began, and had normal NRS but were in the late treatment group, were retarded at initial evaluation and follow-up. This finding suggests that early treatment of children who have a normal NRS and normal development at onset of spasm prevents mental retardation.

Adrenocorticotropic Hormone↗
PubMed1981

Transient Gilles de la Tourette syndrome after chronic neuroleptic withdrawal.

A retarded 16-year-old male developed symptoms consistent with Gilles de la Tourette syndrome within one month of withdrawal from chronic neuroleptic treatment. The symptoms began to subside after six months and he was symptom-free after seven months. This suggests that symptoms of Gilles de la Tourette syndrome which appear after withdrawal of chronic neuroleptic therapy may be due to transient hypersensitivity of dopamine receptor sites.

Adolescent↗
PubMed1980

The effect of ACTH therapy upon infantile spasms.

Fifty-five infants with infantile spasms and hypsarrhythmia, who were treated with ACTH using 80 units im every other day for a mean period of ten months, were studied retrospectively and showed better results than infants using so-called nonsteroidal anticonvulsants or ACTH and steroids in other doses and with other time intervals. The study showed that the treatment with ACTH within the first month of onset of spasms produced a higher incidence of spasm-free state while on treatment, a shorter duration of spasms while on treatment, and a higher incidence of spasm-free state while on treatment, a shorter duration of spasms while on treatment, and a higher incidence of a spasm-free state when off treatment, compared to a similar regimen of ACTH begun after seizures had persusted for more than a month. The value of early treatment of infantile spasms suggests that the treatment of this disease should be regarded as a medical emergency.

Adrenocorticotropic Hormone↗
PubMed1975

Occlusive vertebrobasilar artery disease associated with cervical spine anomaly.

A 6-year-old boy developed a flaccid hemiplegia and dysarthria following several transient episodes of nausea, vomiting, and ataxia. An anomly of the dens was discovered, permitting subluxation of C-1 on C-2. A segmental occlusion of the right vertebral artery and an aneurysm of the left vertebral artery were found at the C-2 level, as well as a thromboembolic occlusion of the rostral end of the basilar artery. It appeared that the repeated cervical subluxation produced occlusive, aneurysmal, and embolic vascular disease, and that clinical symptoms were the result of ischemia in the territory perfused by the vertebrobasilar arteries.

Aneurysm↗
PubMedDate not supplied

Carbamazepine replacement of phenytoin, phenobarbital and primidone in a rehabilitation setting: effects on seizure control.

Most patients who receive anticonvulsants after traumatic brain injury are treated with the sedative anticonvulsants phenytoin and/or phenobarbital, or perhaps primidone. However, there is considerable evidence demonstrating that these medications have a deleterious effect on cognitive function. Thus, in a rehabilitation setting, alternatives should be sought. Carbamazepine has been found to be relatively free of such effects, and would be an optimum alternative if seizure control were comparable. We have studied the effects of withdrawing phenytoin, phenobarbital and primidone, and using carbamazepine as the primary anticonvulsant in 27 patients at the Greenery Rehabilitation and Skilled Nursing Center for whom ongoing anticonvulsant treatment was considered to be necessary due to previous seizures or a high risk of the occurrence of seizure. We compared a 3 month baseline period (just prior to carbamazepine introduction or sedative anticonvulsant tapering), to a 3 month post-withdrawal period immediately following sedative anticonvulsant withdrawal, when carbamazepine was the sole anticonvulsant. In 20 out of 21 patients in whom carbamazepine replaced sedative anticonvulsants seizure control was essentially similar or somewhat improved. In only one patient did the substitution with carbamazepine result in a loss of seizure control. Six patients were initially receiving carbamazepine in combination with phenytoin and/or phenobarbital. The removal of phenytoin and phenobarbital, leaving carbamazepine as sole therapy, resulted in improved seizure control in three patients and no change in the other three. In the light of carbamazepine's reportedly less detrimental effects on cognitive function and behaviour in other patient populations, it should perhaps be considered as a first line anticonvulsant, especially for patients in rehabilitation settings.

Adult↗