Sea urchin spine injuries of the hand.

Sea urchin spine injuries are common. They usually cause local pain and swelling that subsides. Chronic granulation is rare. We report two cases of sea urchin granulomata involving finger metacarpophalangeal joints. Both resolved following surgery.

Revision of an acetabular liner has a high risk of dislocation.

Polyethylene liners of modular acetabular components wear sometimes need to be replaced, despite the metal shell being well fixed. Replacing the liner is a relatively simple procedure, but very little is known of the outcome of revision. We prospectively followed up 1126 Harris-Galante I metal-backed, uncemented components for between nine and 19 years. We found 38 (3.4%) liners of 1126 acetabular components wore and required revision. These revisions were then followed up for a mean of 4.8 years. The rate of dislocation was 28.9%. Nine of the dislocations occurred once and two were recurrent. The overall secondary revision rate was three of 38 total hip replacements (7.9%) at a mean follow-up of 4.8 years. This gives a 92.1% survivorship (35 of 38) at under five years. In isolated revision of a liner, we had a complication rate of 23% (three of 13). In revision of a liner combined with revision of the femoral stem, there was a complication rate of 48% (12 of 25). We discuss possible reasons for the high dislocation rates. Leaving the well-fixed acetabular shell in situ leads to an increased risk of instability. However, this needs to be balanced against the otherwise low complication rate for revision of the liner. Patients should be consented accordingly.

Sexual behaviour in travellers abroad attending an inner-city genitourinary medicine clinic.

OBJECTIVE: To investigate frequency of sexual encounters with new partners abroad in patients attending a genitourinary clinic (GUM). METHODS: In a case series 464 attenders at a genitourinary medicine clinic completed an anonymous self-administered questionnaire, if they had been abroad recently, enquiring about sexual behaviour abroad. RESULTS: 28.4% of subjects admitted to sex with a new partner abroad with only 41.7 per cent consistently using condoms. There were no significant differences in condom use for gender, ethnicity or type of visit and relationship. Twenty-nine per cent of those admitting to sex abroad had more than one partner. The risk of multiple partners was not associated with gender, ethnicity, type of visit (holiday or business) or type of relationship (heterosexual or homosexual). The first partner abroad for 63% of men and 62.5% of women was of a nationality other than that of United Kingdom residents. Non-Caucasians and homosexuals were significantly more likely to have first partners abroad from outside the UK than Caucasians and heterosexuals respectively. CONCLUSION: The occurrence of casual sex abroad in GUM attenders suggests that further research is needed to establish targetable risk factors for this type of behaviour amendable to change through health promotion.

Stability of perfluorocarbon blood substitutes determined by sedimentation field-flow fractionation.

It is shown that the method known as sedimentation field-flow fractionation, which has been applied to the separation and characterization of many industrial and biological particles and recently to emulsions, can be used to obtain high-resolution droplet diameter profiles for perfluorocarbon blood substitutes. Following a description of the methodology, experiments are described for two commercial perfluorocarbon emulsions, Fluosol-DA 20% and Fluosol-43. The droplet diameter profiles for both of these blood substitutes are shown to shift to noticeably higher diameter values in less than 2 months. The diameter at the profile peak for Fluosol-DA 20%, for example, shifts from 0.19 to 0.27 micron in 56 days.

Physiological and behavioral effects of prolonged exposure to 915 MHz microwaves.

Long-Evans male adult rats were exposed for 16 weeks to 915-MHz CW microwaves at an average power density of 5 mW/cm2. The resulting dose rate was 2.46 (+/- 0.29 SEM) mW/g. The animals were exposed eight hours a day, five days a week, for a total of 640 h in a monopole-above ground radiation chamber while housed in Plexiglas cages. Daily measures of body mass and of food and water intake indicated no statistically significant effects of microwave irradiation. Measures by activity wheels and stabilimetric platforms of spontaneous locomotion indicate than mean activity levels increased about 25% after microwave exposure, but the findings are doubtful statistical significance (Ps < .10 but > .05). Studies of blood sampled after 2, 6, 10, and 14 weeks of exposure revealed alterations of free sulfhydryls. Measures of levels of urinary 17-ketosteroids at weeks 1, 5, 9, and 12 of exposure, and measures of brain hypothalamic tissue, and of mass of adrenals, heart, and liver at the end of the 16-week period, revealed no significant differences between irradiated and control animals. Cortical EEGs sampled after conclusion of microwave exposures also revealed no significant differences.

Physiological and behavioral effects of chronic exposure to 2450-MHz microwaves.

Long-Evans male adult rats were exposed for sixteen weeks to 2450-MHz CW microwaves at an average power density of mW/cm2. The resulting dose rate was 1.23 (+/- 0.25SEM) mW/g. The animals were exposed eight hours a day, five days a week, for a total of 640 h in a monopole-above-ground radiation chamber while housed in Plexiglas holding cages. Daily measures of body mass and of food and water intakes indicated no statistically significant effects of microwave irradiation. Biweekly stabilimetric tests immediately after exposure revealed a significant depression of behavioral activity by 15 microwave-exposed rats as compared with 15 sham-exposed animals. Measures of locomotor activity based on revolutions of a running wheel, which were obtained during 12-h periods between each 8-h exposure, showed no significant effect of irradiation. Blood sampled after 2, 6, 10, and 14 weeks of exposure indicated slight alterations of sulfhydryl groups, and of red and white blood-cell counts. Measures of levels of 17-ketosteroids in urine at weeks 1, 5, 9, and 12 of exposure, and mass of adrenals, heart, and liver at the end of the sixteen-week period of exposure, revealed no indications of stress.

A microelectronic pH sensor.

This paper presents preliminary data on a new integrated circuit microelectronic pH sensor. The device is extremely miniaturized by the use of integrated circuit technology, and uses the intrinsic hydrogen ion selective properties of the gate insulator material. In order to make the device compatible with aqueous solution monitoring, the silicon dioxide-silicon nitride gate insulator structure is used. The integrated circuit chip was designed, processed, and packaged by a variety of techniques which protect all metal parts from the aqueous solution. Test data are reported on leakage current, sensitivity, reproducibility, linearity, stability, response time, and life. The results indicate that this type of pH sensor may have many significant advantages for biomedical research and application.