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Biomedical subjects

A Simmons

Publications and source records attributed to A Simmons.

169 records · Page 10Linked to original sources
PubMedDate not supplied

Another example of a B variant.

A family in which five members has a weak B variant and one member had a normal A and weak B reaction is reported. It appears that these phenotypes arise by the inheritance of a variant allele of the ABO locus. Their cells react weakly when added to anti-B sera, and they have normal anti-A activity and an absence of anti-B in their sera. Additionally, all of the members tested had increased levels of cellular H substance and all of the affected secretor members of the family secreted normal amounts of both B and H substance. Transferase activity of the sera of these individuals confirmed the presence of the B-gene specific transferase.

ABO Blood-Group System↗
PubMedDate not supplied

Detection of HBsAg in coagulation Factor IX concentrates.

HBsAg was detected in two commercial clotting factor concentrates: Proplex (Hyland) and Konyne (Cutter). HBsAg was positive by RIA in samples of Proplex but not Konyne. Immune-electron microscopy, however, demonstrated clumped small spheres of HBsAg in both preparations, and lamellar-type strands were seen in several preparations.

Blood Transfusion↗
PubMedDate not supplied

Correction of nonuniformity in images of the spine and optic nerve from fixed receive-only surface coils at 1.5 T.

OBJECTIVE: Our goal was to analyze the sources of nonuniform image intensity of two surface coil configurations used on a General Electric 1.5 T Signa scanner and to correct the major source. MATERIALS AND METHODS: Correction of receive coil nonuniform sensitivity is achieved using division by images of a uniform phantom. Patient images are transferred to a network of Sun workstations for routine correction by technologists. Spinal cord images, originally 512 x 512, are truncated to 128 x 512 to allow four slices to be copied onto one X-ray film. RESULTS: Images of the spinal cord, collected using a four coil multiarray, show marked coil-to-coil nonuniformity and a high signal level from subcutaneous tissue near the coils. After correction the cord has uniform intensity, with improved visualization in the posterior fossa and upper thoracic region, enabling more reliable detection of small intrinsic lesions as occur in multiple sclerosis. Images of the optic nerves, collected using a two coil array, show bright signal in the brain and subcutaneous tissue. After correction the images are more uniform. CONCLUSION: Nonuniformity in images of the spine can be corrected using division by a phantom image. Water phantoms must be restricted in size to avoid standing wave effects; for the optic nerves a cylindrical oil phantom 20 cm in diameter was used.

Artifacts↗