New sites of ocular involvement in late-infantile metachromatic leukodystrophy revealed by histopathologic studies.
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Anterior Eye Segment↗
Biomedical subjects
S Naidu
Publications and source records attributed to S Naidu.
Increased very long chain fatty acids in patients on a ketogenic diet: a cause of diagnostic confusion.
We found an elevation of very long chain fatty acids in 13 of 22 plasma samples from patients on a ketogenic diet for the treatment of uncontrolled seizures. Because elevated values of very long chain fatty acids are a biochemical manifestation of peroxisomal dysfunction, this phenomenon might lead to diagnostic confusion. Thus the history and clinical status should be considered when plasma levels of very long chain fatty acids are interpreted.
Adolescent↗
HIV positivity and abnormal cervical cytology.
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Cervix Uteri↗
Proton NMR spectroscopy of Canavan's disease.
Proton Nuclear Magnetic Resonance (NMR) spectroscopy was used to quantitatively determine cerebral N-Acetyl Aspartate (NAA) concentrations in four patients with Canavan's disease and in four age-matched control subjects. Macroscopic NAA concentrations (mumol/gm wet weight) were not found to be significantly different from controls. Reduced levels of choline and creatine were observed in all patients, and increased levels of lactate and inositol in the eldest three patients.
Adolescent↗
The efficacy of phenytoin in relation to serum levels in severe pre-eclampsia and eclampsia.
OBJECTIVES: To investigate the efficacy of phenytoin in relation to total and free serum levels in patients with severe pre-eclampsia and eclampsia. DESIGN: Prospective descriptive study. SETTING: Labour Ward, King Edward VIII Hospital, Durban, South Africa. Tertiary referral centre serving an underprivileged community. SUBJECTS: Eleven patients admitted with a hypertensive crisis. Four patients had eclampsia and 7 had impending eclampsia. MAIN OUTCOME MEASURES: Free and total phenytoin levels; efficacy of phenytoin as an anticonvulsant and side-effects of therapy. RESULTS: Although total phenytoin levels were within the therapeutic range, free phenytoin levels were abnormally high in all patients. Three patients (2 with eclampsia and 1 with imminent eclampsia) each had a seizure after phenytoin treatment had been initiated. CONCLUSION: Neither total nor free phenytoin levels were good predictors of seizure control. It is postulated that the poor performance of phenytoin as an anticonvulsant in severe eclampsia may relate to inadequate distribution of the drug to the brain as a result of cerebral oedema and poor cerebral perfusion rather than paradoxical seizure activity associated with high free phenytoin levels.
Adolescent↗
Positron emission tomography in the Rett syndrome: clinical, biochemical and pathological correlates.
A consistent constellation of clinical signs and symptoms define the Rett syndrome, the most prominent of which are disorders of movement and tone. Preliminary pathologic and neurochemical data indicate predominant involvement of the nigrostriatal dopaminergic pathways and the cholinergic system of the basal forebrain region. The age of onset differentiates the Rett syndrome from Alzheimer and Parkinson disease with similar lesions. PET scanning makes it possible to relate the chemistry of the brain to function by measuring the number and affinity of neuroreceptors, metabolism in specific brain regions, and provide important determinants of the underlying mechanisms in disease states.
Adolescent↗
Tokyo symposium on the Rett syndrome: neurobiological approach--concluding remarks and epilogue.
Based on data presented at the Tokyo Rett Syndrome Symposium, November 1990, actual neurobiological knowledge and interpretations are compiled. The underlying biological concepts, as well as the potential origin of the condition are particularly discussed.
Female↗
Clinical aspects of adrenoleukodystrophy and adrenomyeloneuropathy.
Adrenoleukodystrophy (ALD) is an X-linked recessive disorder that affects mainly the nervous system white matter and the adrenal cortex. It is associated with an abnormal accumulation of saturated very long chain fatty acids and can be diagnosed by demonstrating an excess of these substances in plasma or red cells. Our laboratory has identified more than 900 hemizygotes and 1,000 heterozygotes. Approximately 50% of the hemizygotes have a rapidly progressive childhood or adolescent form of the disease. Twenty-five percent of males have a slowly progressive paraparesis in adulthood, but often are not diagnosed correctly. The illness may also present as Addison disease without apparent neurological involvement. Approximately 15% of heterozygotes develop moderately severe spastic paraparesis. It is important to diagnose ALD promptly because of the urgent need for genetic counseling and the availability of promising therapeutic interventions.
Addison Disease↗
Quantitative magnetic resonance imaging in Rett syndrome.
Rett syndrome (RS) is a progressive neurological disorder of females, characterized by the early onset of autistic behavior, ataxia, and "handwringing" movements. The present magnetic resonance imaging study was undertaken with the purpose of investigating whether structural brain abnormalities of RS patients are similar to those recently reported in autism. The subject population consisted of eight patients and an equal number of age- and sex-matched controls. Area and shape measurements were taken at selected anatomical levels for the following structures: brain hemisphere, corpus callosum, midbrain, pons, lobules I-V and VI-VII of the cerebellum, and head of the caudate. Results revealed significant differences in area for the whole brain hemisphere (p < 0.05) and in both right and left caudate (p < 0.04). These morphological findings are different from those recently reported in autism and emphasize the involvement of the striatal system in RS.
Child↗
Altered neurochemical markers in Rett's syndrome.
Rett's syndrome (RS) is a neurologic disorder associated with severe mental deficiency and neurologic manifestations of cortical and extrapyramidal origin. The present report is a preliminary postmortem brain study that compares the levels of endogenous biogenic amines and selected neurotransmitter receptors in five cases with RS and six normal controls of similar age. The level of choline acetyltransferase activity was reduced in several cortical and subcortical regions. Endogenous levels of dopamine in the superior frontal and superior temporal gyri, occipital cortex, and putamen were reduced. The changes in specific neurotransmitter markers, particularly those associated with the basal ganglia and cortex, may underlie the progressive deterioration in motor and cognitive function characteristic of this progressive disorder.
Adolescent↗
Adrenoleukodystrophy.
X-linked adrenoleukodystrophy (ALD) is a disorder of very long chain fatty acid (VLCFA) metabolism that can be diagnosed by demonstrating increased levels of VLCFA in plasma and, prenatally, by similar assays in cultured amniocytes or chorionic vilus samples. ALD causes Addison disease frequently in men and occasionally in women. Prompt diagnosis is important for genetic counseling and for the institution of therapies aimed to prevent or ameliorate the progressive neurologic disability that often is associated with this illness.
Adrenoleukodystrophy↗
Cognitive impairment in adult-onset adrenoleukodystrophy.
Adrenoleukodystrophy (ALD) is a progressive X-linked disorder that produces pathological changes, mainly in the adrenal cortex and the white matter of the central nervous system. The main biochemical abnormality is the accumulation of saturated unbranched fatty acids with a chain length of 24 or more, referred to as very-long-chain fatty acids (VLCFA). Affected children develop large zones of demyelination associated with perivascular lymphoctyic infiltrations resembling those seen in multiple sclerosis. Adults show a more chronic form of the disease, referred to as adrenomyeloneuropathy (AMN). AMN mainly involves the spinal cord ad peripheral nerves, although the cerebral hemispheres may also be affected. Approximately 15% of female carriers have nervous-system involvement that resembles AMN. It is well known that ALD may initially appear as a psychiatric disorder. In the present study, we have assessed the prevalence of cognitive impairment in a group of AMN patients and neurologically symptomatic ALD heterozygotes initially presenting primarily physical complaints. Sixty percent of these patients demonstrated significant neuropsychological impairment, most commonly a pattern of spared and impaired functions typical of a subcortical dementia. We suggest that this progressive cognitive impairment may underlie other behavioral deficits, affirming the significance of the psychological features of this genetically determined disorder.
Adrenoleukodystrophy↗
The Rett syndrome: progress report on studies at the Kennedy Institute.
Clinical, biochemical and pathological studies in patients with the Rett syndrome (RS) are presented. The neuropathological changes and alterations in neurotransmitter markers are particularly interesting and provide valuable information that may be helpful in understanding the behavior and neurological phenotype of RS.
Adolescent↗
Further EEG observations in children with the Rett syndrome.
In four cases of the Rett syndrome (RS) (age 3 1/2, 6, 11 and 12 years), paroxysmal activity and especially spike discharges over the central region could be blocked or attenuated by passive finger movements. This response, however, is not demonstrable in the majority of children with RS. The blocking or attenuating effect of passive movements is compared with earlier observations of central spike discharges occurring in children with benign Rolandic epilepsy. In some of these children, central spikes could be blocked by active hand movements. It was assumed that such a positive blocking response underscores the "functional" ("dysfunctional") character of the Rolandic spikes and the lack of local structural damage. In children with cerebral palsy, seizures and central spike (and evidence of structural brain damage), such a blocking response was not obtainable. Taking into consideration these earlier observations, there is reason to presume that the central spike activity found in RS is based on dysfunction rather than on structural impairment.
Brain↗
Ipsiversive eye deviation and epileptic nystagmus.
We studied an 11-year-old boy with focal seizures in the right temporo-occipital cortex. During the seizure, there was a 1- to 2-second period of ipsiversive (rightward) conjugate eye deviation, followed by 10 to 15 seconds of horizontal jerk nystagmus with slow phases that were directed to the right and appeared linear. The patient was conscious throughout the seizure. These findings fit the description of epileptic nystagmus. We postulate that the eye deviation and slow phases of the nystagmus in this patient were induced by epileptic activation of a cerebral smooth pursuit pathway originating from temporoccipital cortex.
Child↗
Peroxisomal disorders.
Although peroxisomes were once considered a vestige, their importance in cellular metabolism is clearly established by the many inherited diseases that have been described in the past two decades. Unfortunately there is no definitive treatment for the various disorders, but based on the recognition of the biochemical abnormalities, prenatal testing and appropriate genetic counseling can be provided. It is essential for clinicians to be aware of this group of diseases, as diagnosis and further study of these patients are essential in understanding the basic etiologic mechanisms underlying these complex groups of disorders. Clearly, there is much to be learned about the relationship between biochemical abnormalities and the phenotypic variability of the peroxisomal disorders.
Brain Diseases, Metabolic↗
Risk involvement with Staphylococcus aureus exotoxins among pyogenic skin infections with special reference to toxic shock syndrome.
The sera of three patients involved in a non-menstrual toxic shock syndrome outbreak showed TSST-1 at a concentration above 40 ng/ml and no antibodies of IgG class against the toxin. A Staphylococcus aureus strain producing TSST-1 was isolated from one of the patients. S. aureus strains showing similar phage type and biotype patterns were isolated from 473 out of 876 close contacts with the patients involved in this outbreak. This carriage and spread was traced to pyogenic skin infections (mainly "folliculitis") among this population. Serological studies indicated that during the early phase of the outbreak anti TSST-1 titres were low then rose gradually. In a further related study the frequency of enterotoxin production was found 48.5% among staphylococci isolated from pyogenic skin infections. Our data indicated that pyogenic skin infections are potential source for toxic shock syndrome.
Antibodies, Bacterial↗
Incidence of enterotoxin producing Staphylococcus aureus among pyogenic skin infections.
Out of the total 68 S. aureus strains isolated and studied from pyoderma patients, 33 (48.5%) strains produced enterotoxin. Isolates from IED, impetigo and folliculitis exhibited high degree of enterotoxigenicity. SE-C and its combinations with other enterotoxins was common. 60.6% of the SE producers were found phage nontypable. Typable enterotoxigenic strains were associated with III, IV and mixed phage groups. S. aureus var. hominis and S. aureus var. bovis are the prevalent subspecies types and potent SE producers among pyogenic skin infections.
Bacteriophage Typing↗