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Biomedical subjects

S Harbottle

Publications and source records attributed to S Harbottle.

3 recordsLinked to original sources

Recruitment of sperm donors: the Newcastle-upon-Tyne experience 1994-2003.

BACKGROUND: The demand for sperm donors has continued despite the introduction of ICSI. This study was undertaken in the light of impending changes in donor anonymity laws to evaluate the recruitment process of sperm donors. METHODS: Retrospective analysis of 1101 potential sperm donors in a tertiary referral centre between January 1994 and August 2003. The main outcome measures were to determine the demographic details, recruitment rate and reasons for rejection of donors. RESULTS: The majority of the applicants were aged <36 years (88.07%), students (54.88%), without a partner (53.47%), unmarried (85.38%) and without proven fecundity (78.67%). Only 3.63% of the applicants were released as donors, 30.79% defaulted, whilst 64.48% were rejected. The most common reason for rejection was suboptimal semen quality (85.07%). Over the years, the numbers of the applicants and released donors have declined significantly. The overall clinical pregnancy rate from donor sperm during this period was 23.52%. CONCLUSIONS: In this successful anonymous sperm donor programme only a small proportion of the applicants are released as donors. The significant decline in released sperm donors coupled with the potential effects of loss of donor anonymity means that new strategies for sperm donor recruitment are urgently required.

Adult↗

Surface alterations in dialysis roller pump inserts: a scanning electron microscopy study.

Scanning electron microscopy has been used in a study of particle spalling from silicone and PVC elastomer inserts of dialysis roller pumps. In an experimental circuit using Isoton II, pump occlusion, pressure, pump revolutions and temperature were monitored. Scanning electron microscopy was performed on inserts exposed to 1-10 h of pumping using Silastic (medical grade) and a Watson-Marlow MHRE pump, with PVC and Pivipol, a polyurethane coated PVC (Bellco) using a Bellco BL705N pump. Changes included longitudinal splits (single and multiple), superficial cracks (random and orientated), deformations of normal surface pattern, holes, craters and detaching particles. There was an increase in these abnormalities with time for all types of pump insert, the changes being most marked for the Silastic/Watson-Marlow pump combination and least prevalent with the PVC/Bellco pump combination.

Humans↗

Particle spallation induced by blood pumps in hemodialysis tubing sets.

The repeated flexion and compression of pump segments by the rollers of peristaltic pumps results in cracking and abrasion of the inner surfaces of the pump segment, leading to shedding of particles into the extracorporeal circuit. A series of studies to assess the rate of particle release from silicone rubber, polyvinyl chloride (PVC), and Pivipol, a coextruded polyurethane-coated PVC tubing, when these materials were used with blood pumps of the type found in hemodialysis units, was undertaken. The studies show that with all tubing/pump combinations there is an overall increase in the total number of particles released, but an analysis of the particle size distribution indicates that the majority of the particles are less than 16 micron in diameter. The rate of increase may be reduced, however, by decreasing the occlusion pressure.

Analysis of Variance↗