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Biomedical subjects

M Jefferson

Publications and source records attributed to M Jefferson.

13 recordsLinked to original sources
PubMed1998

Effect of pancreatic enzymes on zinc absorption in cystic fibrosis.

BACKGROUND: The trace metal zinc has a wide range of important physiologic roles. Indirect evidence suggests that fat malabsorption is associated with malabsorption of zinc. The objective of this study was to evaluate the effect of pancreatic enzyme replacement on zinc absorption in children and adolescents with cystic fibrosis. METHODS: Subjects were four boys and four girls ranging in age from 7 to 17 years of age. All were pancreatic insufficient. Stable isotope labels, 70Zn and 67Zn, were administered orally in divided doses on consecutive days with meals. Meals were identical on the first 2 study days. Subjects were randomized to have pancreatic enzyme replacement withheld on the first or second day. All fecal samples were collected quantitatively for 10 days after label administration and were analyzed individually for total zinc and isotopic enrichment using atomic absorption spectrophotometry and fast atom bombardment mass spectrometry, respectively. Fractional absorption of zinc was calculated from cumulative fecal excretion of unabsorbed label. RESULTS: Fractional absorption while receiving enzymes was 0.50 +/- 0.29 versus 0.38 +/- 0.24 while not taking enzymes (p = 0.05). CONCLUSIONS: These results indicate that fractional absorption of zinc is impaired by pancreatic insufficiency in patients with cystic fibrosis, and is improved by exocrine pancreatic enzyme replacement.

Adolescent↗
PubMed1985

Astrocytes secrete basal lamina after hemisection of rat spinal cord.

Basal lamina is reconstructed over the lesioned surface of the spinal cord. The following experiment (90 rats) studies the ultrastructure of the formation of this membrane and the immunohistochemistry of laminin production (a major secreted component of basal lamina). After hemisection of the spinal cord at T6 animals were prepared for electron microscopy or antilaminin-biotin-avidin-peroxidase incubation. Three-5 days posthemisection, antilaminin reaction product was observed in astrocytes and their processes which faced the lesion, endothelia of blood vessels or pia. Ultrastructurally (3 days), basal lamina was polymerizing as small projections on the surface of astrocytic membranes facing the lesion, endothelia or pia. By 5 days the basal lamina was a single membrane, folded multiple sheets or in swirls. At 6-10 days the antilaminin reaction and the basal lamina (except for duplications) did not differ from normal. Reactive astrocytes secrete laminin for at least 3-5 days after hemisection and form basal lamina on the lesioned surface of the spinal cord after spinal cord hemisection.

Animals↗
PubMed1984

Ultrastructure of fetal spinal cord and cortex implants into adult rat spinal cord.

The ultrastructure of cortex and spinal cord from 11-, 12-, and 15-day-old fetuses implanted into the spinal cord of adult rats was studied over 3 months. Under deep Chloropent anesthesia, a 0.5 X 1.0-mm square of fetal cortex or a 1.0-mm segment of fetal spinal cord was implanted subpially between the left dorsal column and the dorsal horn of 70 adult rats. Implants grew toward gray matter, usually interfacing with the host at the isthmus between the horns of the spinal cord. However, implants were observed that occupied the entire left dorsal and ventral horns of the left half of the host spinal cord. Implants had concentric zones: A central zone with basal lamina lined joined channels and subjacent neuroglia; a zone of differentiating implant nervous system; a zone with basal lamina lined implant with overlying pial cells on the dorsal and lateral surfaces of the implant; a zone that interfaced with the host with overlapping neuropil on the lateral and ventral surfaces of the implant. Neuron types were typical for cortical or spinal implants. Implants survived for 3 months and reached stages of neuronal and neuroglial maturation similar to controls. Both fetal spinal cord and brain were successful as implants, had delayed differentiation, and formed complex neuropils. The zone of overlapping interface of the donor and host is an anatomical indication of physiological and functional integration.

Animals↗
PubMed1980

Gliomatous transformation and demyelinating diseases.

The clinical and pathological details are described of three patients with demyelinating diseases associated with a glioma, the effects of which proved fatal. The findings suggest that the tumours developed from neoplastic transformation of glia in areas of established demyelination.

Brain↗
PubMed1973

Syringomyelia.

Explore the source record for details and available documents.

Adult↗
PubMed1971

Chorea and the oral contraceptives.

The case histories are reported of six women who developed chorea while taking oral contraceptive drugs. The chorea that results from taking compounds containing oestrogen and progestogen has many features in common with chorea gravidarum, and the pathogenesis is probably similar. In some of the patients, however, the sudden onset of symptoms suggests a vascular aetiology.

Adult↗
PubMed1971

Fatal encephalopathy complicating lymphoid interstitial pneumonia.

The case is reported of a young woman who suffered from lymphoid interstitial pneumonia. Involvement of the brain by what appeared to be an identical pathological process led to her death, and the orbital tissues were also involved at one stage. The cause of this condition is unknown, but the hypotheses are put forward that it may represent one facet of delayed hypersensitivity or that a slow virus is the responsible aetiological agent. Although lymphoid interstitial pneumonia has previously been reported as an isolated entity, the evidence from this case suggests that it might represent part of pluri-systemic disease.

Adult↗