Does too much urology damage your eyesight? Study of macular function.

A study comparing the macular function of both eyes of 130 urological surgeons was carried out to investigate whether the increased light exposure to the endoscoping eye caused any deterioration of macular function. The non-endoscoping eye was used as a control. A sophisticated computer test of colour contrast sensitivity was used. The computer assesses the degree of brightness at which the subject is just able to detect a coloured grating, and for each eye this is expressed as a threshold for the red/green axis and the blue/yellow (tritan) axis. The subjects also completed a questionnaire about their working patterns and their general and ophthalmic history and had a brief examination of the fundus. The results do not suggest that urologists are suffering any significant macular damage as a result of their work with endoscopes.     

Upregulation of interleukin-1 receptors in mouse AtT-20 pituitary tumor cells following treatment with corticotropin-releasing factor.

Treatment of AtT-20 cell cultures with increasing concentrations of rat/human corticotropin-releasing factor (r/hCRF) for 24 h resulted in a dose-dependent 2-3 fold increase in specific 125I-labelled recombinant human IL-1 alpha (125I-IL-1 alpha) binding that was paralleled by a 70-80% decrease in 125I-Tyro-ovine CRF binding. Saturation analysis of 125I-IL-1 alpha binding in control and CRF-treated cultures indicated that CRF produced an increase in the density (Bmax) of IL-1 receptors without altering their affinity (KD). The CRF-induced upregulation of IL-1 receptors appears to be mediated through specific membrane receptors for CRF since the CRF receptor antagonist, alpha-helical oCRF (9-41), blocked the CRF-induced upregulation of IL-1 receptors without producing any effect on 125I-IL-1 alpha binding by itself. In summary, these data demonstrate complex interactions between CRF and IL-1 at the pituitary level and identify potential novel mechanisms for cytokines to alter neuroendocrine function.     

Dermal fillers. The next generation.

In today's busy and demanding world, we no longer have the luxury of taking weeks to recover from a surgical procedure and are more frequently seeking quicker alternatives. The use of dermal fillers meets this need but in no way replaces a surgical intervention. Previously, bovine collagen was the only approved dermal filler. However, today there are several options available including a human collagen, a variety of hyaluronic acids, and a permanent injectable product. Each of the products has different uses, indications, and adverse reactions. The experienced injector now has a wider selection of products from which to choose to ensure that the patient receives what is best suited for his or her particular situation. These new products are becoming increasingly popular, due to acceptability and affordability, but are not without potential complications and adverse reactions. This article discusses the use of Cosmoderm/Cosmoplast, Hylaform, Restylane/Perlane, and Artecoll dermal fillers.     

Effect of sodium hyaluronate (0.1%) on break-up time (NIBUT) in patients with dry eyes.

We evaluated the effect of 0.1% sodium hyaluronate (unpreserved) in 10 patients with dry eyes. The precorneal tear film break-up time was assessed by the non-invasive technique, and the severity of symptoms was recorded before and after treatment on a 0 to +3 scale. It was found that the tear film stability was significantly increased (p less than 0.05) in eyes treated with sodium hyaluronate. The symptoms of grittiness and burning were also significantly alleviated in the treated eyes.     

Tolerance of Pseudomonas aeruginosa to killing by ciprofloxacin, gentamicin and imipenem in vitro and in vivo

In the rat croton oil pouch model, treatment with ciprofloxacin, gentamicin or imipenem caused a sharp reduction in the numbers of Pseudomonas aeruginosa when applied 24 h after infection but treatment had little or no effect when delayed until 48 h after infection. Surviving bacteria from treated animals were fully susceptible on subculture in vitro. Between 24 h and 48 h after infection there was an increase in the concentration of magnesium and a decrease in the concentration of oxygen but no significant change in the pH of the pouch fluid. In-vitro, the MBC of gentamicin was increased four-fold by the addition of magnesium ions and eight-fold under anaerobic conditions whereas these variables had no significant effect upon the MBC of ciprofloxacin and imipenem. However, cells of P. aeruginosa incubated in batch culture for 4, 24 and 48 h became progressively more tolerant to killing by all three drugs. We conclude that the tolerance of P. aeruginosa in vivo was only partly explained by biochemical changes at the site of infection. The stationary growth phase was associated with progressive tolerance to killing by ciprofloxacin, gentamicin and imipenem both in vivo and in vitro.     

Test for assortative mating between Boophilus microplus and Boophilus annulatus (Acari: Ixodidae).

The closely related cattle ticks, Boophilus microplus (Canestrini) and B. annulatus (Say), were tested for possible assortative mating under conditions designed to mimic those in the field. Patterns in the numbers of the four possible types of matings were generally indicative of a preference for conspecific mates in both species. There were significantly more conspecific and fewer interspecific matings than would be predicted from the observed frequencies of males and females among the two species had they mated at random.