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Biomedical subjects

L E Becker

Publications and source records attributed to L E Becker.

At least 163 records · Page 9Linked to original sources
PubMed1988

Neurogenic arthrogryposis multiplex congenita: clinical and muscle biopsy findings.

Thirteen cases of arthrogryposis multiplex congenita without evidence of spinal muscular atrophy, congenital muscular dystrophy, or structural myopathy were reviewed. Family history, consanguinity, pregnancy, delivery, number and severity of contractures, and outcome were evaluated. Laboratory investigations had been performed and a biopsy of muscle from an affected limb had been examined histochemically and by electron microscopy. Five biopsies showed fiber type 1 predominance and three had type 2 predominance. Patterns of fiber-type predominance may have resulted from altered neural influence leading to impaired maturation of type 1 or 2 motor units. Nine patients had been followed up for 3-8 years. Two were still not walking at age 8 years. For the 6 who were walking, the mean age at ambulation was 4.7 years. There was no deterioration in power. Muscle biopsy is recommended in arthrogryposis multiplex congenita. Identification of a probable neurogenic arthrogryposis multiplex congenita is important because the condition is not progressive and is apparently not transmitted genetically.

Arthrogryposis↗
PubMed1988

Intensity and duration of amnesia from intravenous midazolam given for sedation.

A clinical study was performed investigating the ability of intravenous midazolam to cause amnesia for visual, auditory and painful stimuli presented during surgical removal of third molars. Various stimuli were presented prior to and after administration of a sufficient quantity of midazolam to produce profound sedation. Recall was then tested immediately after, one day, and one week following the surgery. The study found that midazolam produces at least 20 minutes of profound amnesia for all stimuli in 93 +/- 6% of individuals. However, little correlation was found between the dose of midazolam and the duration of amnesia. Anesthesia literally means the loss of sensation. In the clinical dental situation, the principle sensation lost, when using either regional or general anesthesia, is pain perception. Although prevention of pain sensation is the primary reason patients request local anesthesia prior to invasive dental care, for many patients, control of pain only partially prepares them to receive dental care. These patients request the adjunctive use of sedation or general anesthesia, not for further pain control, but rather requiring periodontal or oral/maxillofacial surgery in which such factors as the sight and taste of blood, the noise of bone-cutting equipment, or the pressure placed on the jaws is not eliminated by local anesthetics. Although effective anxiolytic oral, inhalational, or parenteral agents have been available for several decades, patients still usually retain their memory of events occurring during their dental care, particularly anxiety-provoking events. This memory of the uncomfortable portions of dental care stimulates additional anxiety so that patients may procrastinate when dental care is necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Amnesia↗
PubMed1987

Human brain dopamine receptors in children and aging adults.

Since spontaneous oral dyskinesias are more prevalent in the elderly, and since these movements may be controlled by the balance of brain dopamine D1 and D2 dopamine receptors, we measured the densities of these receptors in 247 postmortem brain striata. In childhood, the densities of D1 and D2 dopamine receptors in the brain striatum rise and fall together. After age 20 years, D1 receptors disappear at 3.2% per decade while D2 receptors disappear at about 2.2% per decade. Overall, therefore, the D1/D2 ratio falls with age. Since perioral motion in rats is dominated by a high D1/D2 ratio, the observed decline in the human D1/D2 ratio with age suggests that the perioral control mechanisms for humans and rats may be different.

Aged↗
PubMed1987

A Golgi study of the cerebral cortex in Fukuyama-type congenital muscular dystrophy, Walker-type "lissencephaly," and classical lissencephaly.

The cortical neuronal organization of the brain was studied and compared in three conditions. The neurons in the polymicrogyric cortex from a subject with Fukuyama-type congenital muscular dystrophy and from a child with ocular dysplasia (Walker-type lissencephaly) were large, irregularly aligned, and not completely mature. In the former condition, the abnormal neuronal arrangement was predominantly in the superficial cortex; in the latter both the superficial and deep cortex were involved. These two diseases may have a similar pathogenetic mechanism. In classical lissencephaly without evidence of other disease manifestations, the neurons were arranged in a radial pattern with heterotopia but no large neurons. The pathogenesis of these conditions is discussed.

Cerebral Cortex↗
PubMed1987

Malignant tumours in the neonate.

One hundred and two cases of neonatal cancers, representing 2% of all paediatric malignancies, were seen during a 60 year period at The Hospital for Sick Children, Toronto, Canada. The neonatal cancers included neuroblastoma (47%), retinoblastoma (17%), soft tissue sarcoma (12%), central nervous system tumours (9%), leukaemia (8%), and a few cases of Wilms' tumour, liver tumour, and miscellaneous tumours. The overall mortality from disease was 41%. Patients with retinoblastoma, Wilms' tumour, and neuroblastoma had the best prognosis. Forty three patients (42%) survived their neonatal cancers; all were treated with surgery or radiochemotherapy, or both, but none suffered long term major handicaps as a result of treatment. There was one instance of second malignancy of the thyroid gland induced by radiation. We conclude that although neonatal cancers are difficult management problems, many patients can be cured. Physicians should discuss with parents the possible risks associated with treatment before treatment is begun.

Female↗
PubMed1987

Subsarcolemmal vermiform deposits in skeletal muscle, associated with familial cardiomyopathy: report of two cases of a new entity.

Distinctive subsarcolemmal acid phosphatase-positive crescents were found in many muscle fibers of triceps muscle biopsies from 2 siblings with cardiomyopathy. The crescents appeared as dense osmophilic material in irregular vermiform arrays on electron microscopy. However, both patients had clinically normal skeletal muscle function. These 2 cases are believed to represent a rare familial myopathy affecting cardiac and skeletal muscle.

Cardiomyopathies↗
PubMed1987

Walker-Warburg syndrome with skeletal muscle involvement. A report of three patients.

Three patients with Walker-Warburg syndrome are reported. In all, severe hypotonia and ocular abnormalities were noted soon after birth, followed by a rapid increase of head size. Examination of the brain showed regions of complete agyria, cortical dysplasia of the cerebrum, cerebellar micropolygyria, marked hydrocephalus and aqueduct stenosis. In skeletal muscles, advanced myopathy consistent with dystrophic change was present. The cortical dysplasia in this syndrome is similar to the severest pattern of the cortical dysplasia seen in Fukuyama congenital muscular dystrophy, but ocular abnormalities are rare in the latter. These two syndromes may be genetically distinct, despite the presence of cortical dysplasia and myopathy in both.

Brain↗
PubMed1987

Choroid plexus tumors in children: immunohistochemical and scanning-electron-microscopic features.

The 30 choroid plexus tumors recorded in a large pediatric tumor registry were reviewed. The 22 choroid plexus papillomas and 8 choroid plexus carcinomas represented 2.1% of all brain tumors in the registry. The patients (19 boys, 11 girls) were aged 3 months to 12 years (mean: 2 years 9 months). All tumors and four samples of normal choroid plexus were examined with conventional histology, 9 tumors were examined with electron microscopy and 24 using immunohistochemical techniques with antisera against glial fibrillary acidic protein, S-100 protein, epidermal cytokeratin, internal organ cytokeratin and carcinoembryonic antigen. Seven of the tumors (1 carcinoma and 6 papillomas) had some positive cells with antiserum against glial fibrillary acidic protein. Twenty-seven of the tumors (90%) and all normal choroid plexus samples were positive with antiserum to S-100 protein. Some tumor cells from both types of tumor and the normal choroid plexus reacted positively with internal organ cytokeratin antiserum, but all tissue samples were nonreactive with epidermal cytokeratin antiserum. Ultrastructurally, both papillomas and carcinomas displayed cytoplasmic intermediate filaments. Transmission and/or scanning electron microscopy revealed cilia in all choroid plexus papillomas. Frequently, the cilia had an abnormal arrangement, varying from 5 + 0 to 8 + 1. This study demonstrates that tumor cells of choroid plexus origin are characterized by the presence of S-100 protein and internal organ cytokeratin antiserum. Cilia, either normal or abnormal, are consistently identified in papillomas but rarely and with difficulty in carcinomas. Carcinoembryonic antigen is seen in choroid plexus carcinomas but not papillomas.

Adolescent↗
PubMed1987

Surgical management of children with temporal lobe epilepsy and mass lesions.

In a review of 48 children who underwent temporal lobectomy for temporal lobe epilepsy, 16 patients had mass lesions in the temporal lobe. These mass lesions consisted of 12 tumors, 3 vascular malformations, and 1 arachnoid cyst. In 9 of 10 patients where the hippocampus was present in the pathological specimen and was not involved by tumor, there was concomitant mesial temporal sclerosis. All 16 patients have been followed for more than 1 year. Nine are free of seizures, with 4 of these 9 still on medication. Seven patients have had a greater than 50% reduction in seizures.

Adolescent↗
PubMed1986

Brain neurotransmitters in dystonia musculorum deformans.

We examined histologically and biochemically the brains of two patients with generalized childhood-onset dystonia musculorum deformans. We found no important histologic changes in the basal ganglia, cerebral cortex, higher brain-stem nuclei, locus ceruleus, or raphe nuclei. Similarly, the activity of choline acetyltransferase and the levels of gamma-aminobutyric acid and glutamic acid in the cerebral cortex and basal ganglia were within the control range. In contrast, the norepinephrine concentrations were markedly and consistently decreased in the lateral and posterior hypothalamus, mamillary body, subthalamic nucleus, and locus ceruleus. The serotonin level was subnormal in the dorsal raphe nucleus, as was the dopamine level in the nucleus accumbens and, in one of the two cases, in the striatum. Elevated concentrations of norepinephrine were found in the septum, thalamus, colliculi, red nucleus, and dorsal raphe nucleus; of serotonin, in the globus pallidus, subthalamic nucleus, and locus ceruleus; and of 5-hydroxyindoleacetic acid, in the globus pallidus, subthalamic nucleus, and nuclei raphe centralis inferior and obscurus. The level of homovanillic acid showed little consistent change in the regions examined. We conclude that some of these monoamine changes, especially the pronounced apparent disturbance of noradrenergic brain mechanisms, may represent a basic neurochemical abnormality in dystonia musculorum deformans and may thus be relevant to the pathoneurophysiology and treatment of this disorder.

Acetyltransferases↗
PubMed1986

Infantile bilateral striatal necrosis. Clinicopathological classification.

Two cases of infantile bilateral striatal necrosis (IBSN) were studied retrospectively, and the literature was reviewed. The two children had presented with progressive neurologic signs of involuntary movements or muscle hypertonia from infancy. Initial computed tomography scans showed mild atrophy of the caudate nuclei or basal ganglia, and the neuropathologic examination revealed diffuse neuronal loss with some patchy preservation and marked astrogliosis in the striatum and globus pallidus. The 27 reported cases of IBSN were divided into three groups with characteristic clinical and pathologic features: early, acute onset (four cases); early, gradual onset (16 cases); and late onset (seven cases). Although metabolic changes in the developing corpus striatum may be important in the pathogenesis of IBSN, the origin is uncertain.

Brain↗
PubMed1986

Dendritic atrophy in children with Down's syndrome.

Dendritic branching was evaluated in the visual cortex of 8 children with Down's syndrome and 10 controls, ranging in age from 4 months to 7 years and divided into infantile, late-infantile, and juvenile groups. Camera lucida drawings of Golgi-impregnated neurons were used for examining the following dendritic aspects: dendritic intersections as a function of distance from the cell body, point of maximum dendritic branching, number of branch orders, total number of branch segments, and total dendritic length. The number of intersections and the total dendritic length were above normal in the infantile period (6 months old or less) and dropped steadily to significantly below normal in the juvenile group (older than 2 years). These reductions contrasted with expanding dendritic arborization in normal children. The results suggest that the dendritic tree atrophies in early childhood in Down's syndrome.

Child, Preschool↗
PubMed1986

A specific histochemical marker (lectin Ricinus communis agglutinin-1) for normal human microglia, and application to routine histopathology.

Microglia were demonstrated in paraffin-embedded human nervous tissues with an avidin-biotin peroxidase method and Ricinus communis agglutinin-1 (RCA-1). Specific staining was observed in cell bodies and processes of microglia. Although endothelial cells and blood cells reacted with RCA-1, they were easily distinguished morphologically from microglia. Astrocytes, oligodendrocytes, and neurons did not react with RCA-1. These results suggest that RCA-1 can be used as a new histochemical marker for microglia in normal human brain.

Adolescent↗
PubMed1986

Glial fibrillary acidic protein (GFAP) in oligodendrogliomas: a reflection of transient GFAP expression by immature oligodendroglia.

Fourteen pure oligodendrogliomas were studied by light- and electronmicroscopy and immunohistochemistry to examine glial fibrillary acidic protein (GFAP) positivity in the tumors. To compare the immunohistochemical staining patterns of neoplastic oligodendroglia and immature oligodendroglia, myelination glia in the white matter of eight normal brains from children under 6 months of age were studied. The tumors possessed light microscopic and ultrastructural features characteristic of oligodendrogliomas. Microtubules were found in the cytoplasm of nine tumors on electronmicroscopy. In one, intermediate filaments and microtubules were observed in occasional tumor cells with polygonal crystalline structures in the cytoplasm. Using the peroxidase-antiperoxidase technique, all specimens were stained for GFAP, vimentin, S-100 and neuron-specific enolase (NSE). In nine tumors, variable numbers of cells with an oligodendroglial morphology reacted positively for GFAP. All tumors were positive for S-100 and negative for vimentin and NSE. The myelination glia in the eight normal brains stained positively for GFAP but not for vimentin. Vimentin is expressed by developing, reactive and neoplastic astrocytes. Thus, GFAP positivity combined with vimentin negativity in both neoplastic and immature oligodendroglia suggests that GFAP positivity in oligodendrogliomas may reflect the transient expression of this intermediate filament by immature oligodendroglia.

Brain↗
PubMed1986

Prenatal and postnatal maturation of medullary 'respiratory centers'.

During infancy respiratory patterns change with maturation. However, there is no documentation of the development of the neurons thought to be related to respiratory control. Relevant neurons in the medulla oblongata were examined using Golgi impregnation methods. Dendritic spines increased prenatally and decreased postnatally in the medullary respiratory centers (i.e., dorsal vagal nucleus, nucleus tractus solitarii and reticular formation). The prenatal neuronal maturation is earlier in the reticular formation than the vagal nucleus. These changes in neuronal dendrites may be related to the development of central respiratory control and the occurrence of primary apnea in prematurity and sleep apnea in sudden infant death syndrome.

Humans↗