The effect of under and over refractive correction on visual performance and spectacle lens acceptance.

As a follow-on from a previous study by Miller, Kris and Griffiths (1997, Optom. Vis. Sci. 84, 521-526), we investigated the effect of small prescription errors on spatial visual performance and spectacle lens acceptability. We included both negative and positive errors and binocular and monocular errors. Data were collected on 15 young adult subjects. Clinical measures were taken of pupil size, ocular dominance, binocular visual acuity, negative and positive relative accommodation, distance and near heterophorias, and stereopsis. Visual performance was measured with the best correction and for +/-0.50 D spherical binocular and monocular errors. Subjects wore spectacles, each containing a different error in turn, for 2 days and compared them with a reference pair. Following the wearing period subjects assessed the performance of the spectacles by completing a short questionnaire. The only ocular tests for which these small prescription errors had significant effects were binocular visual acuity and negative relative accommodation. No significant relationship was observed between any of the clinical test results and overall lens acceptance. Despite this, the reference pair was generally perceived as better than the test pairs containing errors, and a considerable proportion of subjects reported pairs with errors as being unacceptable. In conclusion, the questionnaire findings support the need for both accurate monocular and binocular refractions. Subjects differed in their criteria for judging lens acceptability.

Orthopedic trauma: pelvic fracture.

1. The incidence of pelvic fractures has greatly increased; automobile and motorcycle crashes, pedestrian accidents, and falls from great height are the most common causes. Pelvic fractures caused by high-energy trauma often result in significant morbidity and mortality with mortality rates variously reported at 10% to 50%, dependent upon fracture classification and associated injuries. Mortality occurs from associated trauma to viscera, abdominal organs, and abdominal vessels, and from early complications of hemorrhage. 2. The difficulty in management of patients with pelvic fractures is determining whether fractures are stable or unstable. Single breaks with no displacement in the pelvic ring, which includes injuries to the ischium, ilium, pubis, and sacrum, are stable fractures and account for one third of all pelvic fractures. 3. Increasingly widespread use of surgical stabilization internally via rigid fixation of pelvic fractures has helped reduce the morbidity and mortality related to these fractures. Other benefits that have resulted include shortened hospitalization, decreased complications, and earlier mobility.

Influence of 2-deoxy-D-glucose and energy substrates on guinea-pig sperm capacitation and acrosome reaction.

When guinea-pig spermatozoa were suspended in a minimal culture medium (MCM-PL), 2-deoxy-D-glucose (100 microM) and 2-amino-2-deoxy-D-glucose (100 microM) were potent inhibitors of the acrosome reaction without affecting the sperm motility, whereas the N-acetyl derivative 2-acetamido-2-deoxy-D-glucose (2 mM) had no inhibitory effect. The addition of D-glucose (2 mM) partly inhibited the percentage acrosome reaction of spermatozoa suspended in Medium MCM-PL, but DL-alpha-glycerophosphate (2 mM) and myo-inositol (2 mM) had no effect. In addition, DL-alpha-glycerophosphate (2 mM) did not overcome the inhibitory effect of 2-deoxy-D-glucose on the sperm acrosome reaction. The inhibitory action of 2-deoxy-D-glucose (100 microM) on the sperm acrosome reaction assessed after a 3-h incubation was irreversible and was only completely effective if the sugar was added within 30 min of the start of incubation. When spermatozoa suspended in Medium MCM-PL were treated with 2-deoxy-D-glucose (100-200 microM) for an extended incubation up to 6 h, the inhibitory effect of 2-deoxy-D-glucose was partly overcome. Spermatozoa treated with 2-deoxy-D-glucose had significantly reduced concentrations of ATP after incubation for 2 h in Ca2+-free media, compared with the ATP concentrations of spermatozoa preincubated for 2 h in Ca2+-free media that supported acrosome reactions. The addition of Ca2+ (5 mM) caused a rapid decrease in ATP concentrations of spermatozoa suspended in Medium MCM-PL, while the addition of the monovalent ionophore monensin (50 microM) and Ca2+ stimulated sperm acrosome reactions as well as an additional decline in the sperm ATP concentrations. However, monensin (50 microM) in the absence of Ca2+ caused only a slight decline in the sperm ATP concentrations over the 15-min incubation period. The depletion of the sperm ATP concentrations by 2-deoxy-D-glucose may retard completion of the capacitation process and the resultant acrosome reaction.