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N W Barton

Publications and source records attributed to N W Barton.

At least 55 records · Page 3Linked to original sources
PubMed1992

A clinical staging classification for type C Niemann-Pick disease.

Analysis of the temporal sequence of neurologic events, neurophysiologic abnormalities, and longevity in 36 Niemann-Pick type C patients revealed two clinical subgroups with five stages of severity within each group. Patients with a preschool onset (group I; n = 18) had a higher mortality than did patients with a school-age onset (group II; n = 18). An asymptomatic phase (stage 0) was defined by biochemical and histopathologic evidence of disease. The initial manifestations of stage 1 were a movement disorder (group I) and cognitive difficulties (group II) accompanied by impaired vertical saccadic eye movements and abnormal acoustic reflexes. Stage 2 was characterized by the sequential occurrence of vertical supranuclear gaze palsy (VSGP), cognitive difficulties, and dysarthria in group I and a movement disorder, VSGP, and dysarthria in group II. Pyramidal tract signs and abnormal brainstem auditory evoked responses defined stage 3 in both groups. Stage 4 culminated in a nonambulant, vegetative state.

Adolescent↗
PubMed1992

Ophthalmologic manifestations of type B Niemann-Pick diseases.

Type B Niemann-Pick Disease (NPB) is a rare lysosomal storage disease resulting from diminished activity or deficiency of sphingomyelinase and is characterized by multi-system involvement with visceromegaly. Rare ocular involvement (the Macula Halo Syndrome) has been reported. Eight patients (ages 4-36) with NPB underwent complete ophthalmologic evaluations. All patients had periorbital fullness, a hitherto unreported clinical feature. Two patients had a classic Macula Halo Syndrome. One patient developed peri-macular granular deposits forming an incomplete Macula Halo over 5 years. Another patient had macular granular deposits and developed deterioration of central vision and abnormal visual evoked potentials. Ophthalmologic involvement in NPB is more common than previously described. Complete ophthalmologic evaluation is recommended in all patients suspected to have NPB.

Adolescent↗
PubMed1991

Replacement therapy for inherited enzyme deficiency--macrophage-targeted glucocerebrosidase for Gaucher's disease.

BACKGROUND AND METHODS: Gaucher's disease, the most prevalent of the sphingolipid storage disorders, is caused by a deficiency of the enzyme glucocerebrosidase (glucosylceramidase). Enzyme replacement was proposed as a therapeutic strategy for this disorder in 1966. To assess the clinical effectiveness of this approach, we infused macrophage-targeted human placental glucocerebrosidase (60 IU per kilogram of body weight every 2 weeks for 9 to 12 months) into 12 patients with type 1 Gaucher's disease who had intact spleens. The frequency of infusions was increased to once a week in two patients (children) during part of the trial because they had clinically aggressive disease. RESULTS: The hemoglobin concentration increased in all 12 patients, and the platelet count in 7. Serum acid phosphatase activity decreased in 10 patients during the trial, and the plasma glucocerebroside level in 9. Splenic volume decreased in all patients after six months of treatment, and hepatic volume in five. Early signs of skeletal improvements were seen in three patients. The enzyme infusions were well tolerated, and no antibody to the exogenous enzyme developed. CONCLUSIONS: Intravenous administration of macrophage-targeted glucocerebrosidase produces objective clinical improvement in patients with type 1 Gaucher's disease. The hematologic and visceral responses to enzyme replacement develop more rapidly than the skeletal response.

Acid Phosphatase↗
PubMed1991

Gaucher's disease: lack of antibody response in 12 patients following repeated intravenous infusions of mannose terminal glucocerebrosidase.

An amplified ELISA has been employed for monitoring the safety of repeated intravenous infusions of modified human placental glucocerebrosidase. The enzyme infusions consisted of biweekly injections of macrophage targeted glucocerebrosidase over a 6 month duration. Serum samples collected throughout the study were assayed by use of an ELISA using alkaline phosphatase coupled to alcohol dehydrogenase for amplification. Using this protocol, 0.2-5 ng affinity purified immunoglobulin specific for glucocerebrosidase can be detected. Occasional false positives necessitate multiple repeat assays over time to accurately assess immunogenic response. Blinded ELISAs were performed on sera from both infused patients with Gaucher's disease and uninfused control patients and compared with apparent immunoglobulin concentration in 54 normal control sera. Although several samples showed apparently elevated immunoglobulin levels, repeat analyses failed to demonstrate high levels reproducibly. Furthermore, these sera were unable to neutralize enzyme or to precipitate radiolabelled enzyme, confirming the absence of antibody. Problems with high sensitivity ELISA formats are discussed.

Animals↗
PubMed1991

Neurologic complications of nonneuronopathic Gaucher's disease.

We describe eight patients with type 1 Gaucher's disease who developed neurologic complications that were secondary to systemic features of the illness. Four patients experienced neurologic difficulties because of coagulopathy, and the other four patients had involvement of the nervous system secondary to skeletal disease. Early recognition of these complications in patients with type 1 Gaucher's disease may lead to improved neurologic outcome.

Aged↗
PubMed1991

Hematologic improvement in a patient with Gaucher disease on long-term enzyme replacement therapy: evidence for decreased splenic sequestration and improved red blood cell survival.

We describe here an investigation of the hematologic response of a child with Gaucher disease to a six-year therapeutic trial of human placental mannose-terminated glucocerebrosidase. While on enzyme replacement therapy, the patient's hemoglobin and platelet count significantly increased (6.9 g/dl to 12.2 g/dl, and 39,000/microliters to 74,000/microliters, respectively). Over the same time interval his absolute reticulocyte count decreased (88.1 x 10(3)/microliters to 31.5 x 10(3)/microliters). The patient's splenic volume decreased by over 60% (2108ml to 797ml) and his bone marrow demonstrated a dramatic clearing of Gaucher cell infiltration. Serum erythropoietin levels were at the lower range of normal at points in time when he was severely anemic and did not change with improvement in hemoglobin. Coincident with the improvement in the patient's hemoglobin, in vivo survival of autologous radiolabeled RBCs increased 34%. The improved hematopoietic profile appeared to result primarily from an increase in the in vivo survival of mature hematopoietic elements secondary to a decrease in splenic sequestration. Improved marrow function secondary to the clearing of Gaucher cell infiltrates may also play a role in his improved hematologic status.

Biopsy↗
PubMed1991

The use of titanium dioxide as an inert marker for digestion studies in raptors.

1. TiO2 is not a suitable marker for digestibility studies involving raptors. 2. Complete recovery of the 'inert' marker was not achieved. 3. Total collection of faeces is a more accurate method to determine food absorption. 4. Freezing sample solutions prior to colorimetric analysis can produce misleading results. 5. The percentage food absorbed from the intestine in Falconiformes is about 85% by dry weight.

Absorption↗
PubMed1991

Late onset globoid cell leukodystrophy.

A 29 year old male with onset of globoid cell leukodystrophy at age 14 is described. This is the first case of enzymatically confirmed globoid cell leukodystrophy with onset of symptoms after the age of ten. This patient is unique because of the late onset and slow progression and extends the clinical spectrum of globoid cell leukodystrophy.

Adult↗
PubMed1990

Therapeutic response to intravenous infusions of glucocerebrosidase in a patient with Gaucher disease.

Enzyme replacement has been under consideration as a therapeutic strategy for patients with Gaucher disease for more than two decades. Previous studies indicated that single injections of purified glucocerebrosidase reduced the amount of storage material in the liver. It was important to determine whether administration of exogenous enzyme on a regular basis would be of clinical benefit. We report here that weekly i.v. infusions of a macrophage-targeted preparation of human placental glucocerebrosidase in a child with type 1 Gaucher disease increased hemoglobin from 6.9 +/- 0.8 g/dl (+/- 1 SD) to 10.2 +/- 0.4 g/dl (+/- 1 SD) over a 20-week period. The platelet count also increased from a pretreatment value of 30,000 +/- 7000/mm3 (+/- 1 SD) to 54,000 +/- 11,000/mm3 (+/- 1 SD). Phagocytic activity in the spleen decreased during the period of enzyme administration, and there was radiographic evidence of skeletal improvement. These observations document objective clinical responses to enzyme supplementation in a patient with a sphingolipid storage disorder.

Bone and Bones↗
PubMed1990

Clinical expression of Menkes syndrome in females.

Three female patients with Menkes syndrome are described. Clinically, they have typical Menkes syndrome. Biochemically, they have significantly increased 64Cu-uptake in cultured fibroblasts. The chromosomal analysis was normal for two of the patients and abnormal for one patient (45X/46XX mosaicism).

Child, Preschool↗
PubMed1989

Tetrahydrobiopterin administration in biopterin-deficient progressive dystonia with diurnal variation.

We administered tetrahydrobiopterin (BH4) to 4 patients with progressive dystonia with diurnal variation (PDDV). One patient improved clinically. Deficient CSF concentrations of HVA and 5-HIAA were unchanged despite marked elevation of CSF biopterin concentration. Variable effectiveness of BH4 in PDDV may reflect reduced number or function of biopterin-metabolizing neurons or variable entry of BH4 into these neurons.

Adult↗
PubMed1989

Carbamazepine in Fabry's disease: effective analgesia with dose-dependent exacerbation of autonomic dysfunction.

Seven patients with Fabry's disease and severe pain received carbamazepine (CMZ). Five of 7 patients had moderate to complete relief based upon self-assessment of pain levels. Preexisting autonomic dysfunction was exacerbated by CMZ in 2. Complications encountered were ileus, urinary retention, and gastrointestinal disturbance. Although CMZ was useful in treatment of pain, caution should be employed in this disease.

Adult↗
PubMed1989

Niemann-Pick disease types C and D.

Patients grouped into categories termed type C Niemann-Pick disease and the Nova Scotia isolate called type D Niemann-Pick disease are characterized by mild to moderate hepatosplenomegaly, sea-blue histiocytes in the bone marrow, supranuclear gaze paresis in the vertical plane, slowly progressing ataxia, and mental deterioration. These signs are caused by abnormal intracellular cholesterol homeostasis. Cholesterol that enters cells from the circulation through the LDL receptor is not processed in a timely, normal manner by cells in parenchymal organs and the CNS. It therefore accumulates in toxic quantities as unesterified cholesterol causing cellular and tissue damage. Knowledge of the primary, consistent disturbance in cholesterol disposition has led to the development of tests to diagnose patients, identify heterozygotes, and assure the prenatal detection of these disorders. Therapeutic strategies include reduction of dietary cholesterol, apheresis techniques designed to reduce LDL cholesterol available to cells, and reduction of formation of LDL and increase of synthesis of HDL to lower cellular uptake of cholesterol and enhance egress of this lipid from intracellular storage sites. The development of procedures that block cholesterol formation but do not up-regulate LDL receptors on plasma cell membranes is considered to be highly important for the therapy of types C and D Niemann-Pick disease.

Adult↗
PubMed1985

Vascular involvement in type 3 neuronopathic Gaucher's disease.

A 6 3/4-year-old boy with neuronopathic Gaucher's disease died unexpectedly. Autopsy demonstrated unusual vascular findings with the presence of Gaucher's cells and intimal-medial fibrosis in the ascending aorta and widespread acute hemorrhagic necrosis of the left ventricular myocardium. The combination of eccentric, intimal fibrosis of coronary arteries, left ventricular hypertrophy, pulmonary involvement, and anemia probably accounted for this child's death.

Aorta↗
PubMed1984

Molecular weight characterization of beta-D-glucocerebrosidase in mononuclear white blood cells in Gaucher's disease.

Cross-reacting material (CRM) to human beta-D-glucocerebrosidase has been demonstrated in circulating mononuclear white blood cells of normal controls, heterozygotes, and homozygotes for Gaucher's disease. The major CRM in both normal and mutant cells corresponds to a species with Mr approximately equal to 63,000 Da. Traces of CRM at Mr approximately equal to 61,000 and 56,000 Da are also present. In contrast, the CRM in other human tissues differs markedly from that found in circulating mononuclear cells. Evidence is presented to support the hypothesis that the CRM found in white cells is a precursor of the enzyme. The significance of these results is discussed in relation to the problems of subtype determination and heterozygote detection.

Gaucher Disease↗
PubMed1984

Occurrence of multiple dentigerous cysts in a patient with the Maroteaux-Lamy syndrome (mucopolysaccharidosis, type VI).

The mucopolysaccharidoses (MPS) are a group of genetic lysosomal storage diseases. These diseases result from a defect in specific lysosomal enzymes required for the degradation of specific mucopolysaccharides. These incompletely degraded saccharides accumulate in tissues and are excreted in the urine. A general characteristic of these diseases is dysostosis multiplex. Dental complications can be severe and include unerupted dentition, dentigerous cystlike follicles, malocclusions, condylar defects, and gingival hyperplasia. This report examines multiple dentigerous cysts in a patient with a deficiency in N-acetylgalactosamine-4-sulfatase, Maroteaux-Lamy syndrome (MPS VI). The inability to hydrolyze the sulfate group from N-acetylgalactosamine-4-sulfate residue of dermatan sulfate due to a deficiency in this enzyme results in the accumulation of dermatan sulfate in tissues and its excretion in the urine. Examination of dentigerous cyst fluid revealed glycosaminoglycan content of 397 microgram per milliliter. Compositional analyses revealed 60% hyaluronic acid, 30% chondroitin 4- and -6-sulfate, and only 10% dermatan sulfate. This was consistent with dentigerous cyst fluid derived from persons without mucopolysaccharide-storage disorders but distinctly different from glycosaminoglycans assayed from other body fluids of this patient.

Child, Preschool↗