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Biomedical subjects

L York

Publications and source records attributed to L York.

10 recordsLinked to original sources
PubMed1998

Two-year stability of free and total PSA in frozen serum samples.

OBJECTIVES: To investigate the stability of free and total prostate-specific antigen (PSA) in serum stored at -20 degrees C and -70 degrees C for 2 years. METHODS: Fresh blood from 29 patients was drawn and allowed to clot at room temperature. Serum was prepared by centrifugation 1 hour later and tested to determine the free and total PSA levels. Samples were aliquoted, frozen at -20 degrees C or -70 degrees C, and monitored for long-term stability over the course of 2 years. RESULTS: On average, 91% of the free PSA, 92% of the total PSA, and 89% of the percent free PSA values were recovered after 2 years of storage at -20 degrees C; and 96% of the free PSA, 101% of the total PSA, and 95% of the percent free PSA values were recovered after 2 years of storage at -70 degrees C. Seventy percent of the samples stored at -20 degrees C and 100% of the samples stored at -70 degrees C showed no statistically significant decline in free PSA values over the 2-year period. Only one total PSA sample (-20 degrees C) showed a statistically significant loss after 2 years of storage. CONCLUSIONS: Our results suggest that samples stored frozen for up to 2 years at -70 degrees C should give acceptable percent free PSA results.

Aged↗
PubMed1987

Topical fibronectin therapy in persistent corneal ulceration.

Fifteen patients with 20 episodes of persistent corneal ulceration, resistant to conventional therapy, were treated with topical autologous fibronectin. Thirteen corneal ulcers (eight patients) developed following penetrating keratoplasty, three patients had mucous membrane pemphigoid, two patients had herpetic keratitis and one each had Sjögren's syndrome and a trophic corneal ulcer. A standard protocol for fibronectin administration was followed. This therapy healed 16 of the 20 ulcers after a mean duration of treatment of 2.3 months. Corneal ulceration associated with mucous membrane pemphigoid failed to respond to fibronectin. Corneal ulcers which recurred after cessation of fibronectin responded to reintroduction of this therapy. Topical fibronectin is an effective therapy for refractory corneal ulceration and is free of major side effects.

Administration, Topical↗
PubMedDate not supplied

The CA 125 gene: an extracellular superstructure dominated by repeat sequences.

CA 125 has long presented problems to both clinicians and investigators because there was no definitive information on its structure and function. Here, we describe our work on cloning the CA 125 gene with the anticipation that such information will provide the basis for understanding its structure and its physiologic role in both normal and malignant tissues. The CA 125 protein core is composed of a short cytoplasmic tail, a transmembrane domain and an extraordinarily large glycosylated extracellular structure. This structure is dominated by a repeat domain composed of 156 amino acid repeat units which encompass the epitope binding sites. The molecule also includes an amino terminal domain of serine/threonine-rich sequences which would account for most of the O-glycosylation known to be present in CA 125. CA 125 is an unusually large transmembrane glycoprotein. Its release from the surface of the cell is most probably dependent on cytoplasmic phosphorylation followed by proteolytic cleavage. The extracellular domain is characterized by a large number of repeat units (probably 60+) which encompass an interactive disulfide bridged cysteine-loop and the site of OC125 and M11 binding. Sequencing the gene provides us with the ability to initiate the quest to understand the biological function of CA 125.

Amino Acid Sequence↗