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H Evans

Publications and source records attributed to H Evans.

11 recordsLinked to original sources
PubMed1978

The structural requirements for immunoglobulin aggregates to localize in germinal centres.

The capacity of non-heat-aggregated monoclonal human immunoglobulins of different classes, to localize in murine splenic germinal centres within 24 h of intravenous injection has been investigated. It has been shown that at least trimerization of polyclonal IgG must occur before any germinal centre trapping is manifest. Studies of complement fixation by these IgG preparations in vivo, together with studies of the germinal centre trapping of various monoclonal immunoglobulins, have indicated that the sole structural requirement for germinal centre localization of immunoglobulin aggregates is the ability to fix complement. Results suggest that immunoglobulin aggregates are transported to germinal centres via membrane C3 receptors of mobile cells, and then are released with loss of complement to become fixed to dendritic macrophages by a separate mechanism.

Animals↗
PubMed1976

Klinefelter's syndrome and extragenital seminoma.

An extragenital metastatic seminoma in a patient with Klinefelter's syndrome is described. The increased incidence of many types of malignancies in patients with this chromosomal abnormality and the increased susceptibility of XXY cells to transformation by oncogenic SV-40 virus are discussed. A relationship is suggested circumstantially by these observations.

Adult↗
PubMedDate not supplied

Buckthorn neuropathy: effects of intraneural injection of Karwinskia humboldtiana toxins.

Ingestion of the endocarp of the coyotillo fruit, Karwinskia humboldtiana, a shrub of the buckthorn family, causes "Buckthorn neuropathy" in man and animals. Two neurotoxic compounds T496 and T544 were isolated from the endocarp and each toxin was dissolved in sesame oil and injected into the sciatic nerve of rats. The nerves were subsequently examined by teasing and as sections by light and electron microscopy. During the first 3--4 days after injection, oil droplets, probably containing toxin, were observed in the cytoplasm of Schwann cells with intact myelin sheaths. Clinical signs of weakness in the limb first appeared at 5--6 days and were accompanied by segmental demyelination mainly of the larger fibres. These observations suggest that the toxins have a primary action on Schwann cell metabolism. The results of local injection of purified toxins are discussed in relation to reports of nerve damage in animals following oral administration of the endocarp where intramyelin vacuole formation and segmental demyelination are prominent features.

Animals↗