Micromechanical models for the Brownian motion of hair cell stereocilia

Brownian motion of the hairs (stereocilia) of amphibian hair cells has been shown in experiments to be in the range of some nm. Our models of the Brownian motion of coupled harmonic oscillators with mechanical properties of stereocilia lead to similar displacements. Computer simulation shows that stochastic fluctuations enhance the encoding of low level acoustic signals. Stochastic resonance lowers the detection threshold of auditory signals to amplitudes one order of magnitude lower than that of the Brownian motion.     

An ESDIRK method with sensitivity analysis capabilities

A new algorithm for numerical sensitivity analysis of ordinary differential equations (ODEs) is presented. The underlying ODE solver belongs to the Runge–Kutta family. The algorithm calculates sensitivities with respect to problem parameters and initial conditions, exploiting the special structure of the sensitivity equations. A key feature is the reuse of information already computed for the state integration, hereby minimizing the extra effort required for sensitivity integration. Through case studies the new algorithm is compared to an extrapolation method and to the more established BDF based approaches. Several advantages of the new approach are demonstrated, especially when frequent discontinuities are present, which renders the new algorithm particularly suitable for dynamic optimization purposes.     

Permanent open shunt as a reason for impotence or reduced potency after surgical treatment of priapism in 26 patients

A permanent open shunt as a cause of impotence or impaired potency after a shunt operation for priapism is an unusual situation. In this series we studied the persistence of an open shunt in 26 patients who had developed impotence or impaired potency after operative treatment for priapism. All patients had been examined by cavernosography on the suspicion of an open shunt, giving a positive finding in five of 26 cases, in all of which impotence was cured by closure of the shunt. In five patients without a permanent open shunt potency returned to normal only after 6-12 months.     

Successful treatment of cutaneous Kaposi's sarcoma by the 585-nm pulsed dye laser

The clinical appearance of Kaposi's sarcoma (KS) can cause significant disfigurement and lead to functional impairment, particularly if the lesions ulcerate and become secondarily infected. We describe a patient with a KS plaque on the face that was successfully treated with 585-nm pulsed dye laser (PDL) therapy. No recurrence of the tumor was noted 12 months after the final laser treatment.     

Major haemorrhagic complications during oral anticoagulant therapy in a Danish population-based cohort

OBJECTIVE: To identify whether obstetric and perinatal factors are independent predictors of child behaviour at 5 years. METHODOLOGY: The Mater University Study of Pregnancy (MUSP) is a prospective cohort study of 8556 mothers enrolled in early pregnancy. The relationship of obstetric and perinatal factors, maternal lifestyle, age and gender of the child, and social disadvantage were examined as predictors of child behaviour in 5005 children completing a modified child behaviour checklist at 5 years. This checklist contained three independent groups of behaviour: externalizng, internalizing and SAT (social, attentional and thought problems). RESULTS: In the initial analysis a limited number of associations were present. After adjusting for measures of social disadvantage, only number of antenatal admissions was associated with child behaviour in all three scales, while maternal cigarette smoking in pregnancy and male gender were associated with externalising and SAT behaviours. CONCLUSIONS: Most common epidemiologic obstetric and perinatal risk factors were not independent predictors of behaviour problems in children at 5 years.     

Chemoprevention of pulmonary carcinogenesis by aerosolized budesonide in female A/J mice

This investigation is part of a continuing effort to develop effective chemoprevention for carcinogenesis of the lung. The present study explores the use of aerosol administrations for this purpose. The agent selected for initial study was the synthetic glucocorticoid budesonide. This selection was based on previous work in which budesonide added to the diet was found to inhibit pulmonary adenoma formation in female A/J mice. However, high dose levels were required, i.e., of the order of 300 microg/kg, of body weight [L. W. Wattenberg and R. D. Estensen, Carcinogenesis (Lond.), 18: 2015-2017, 1997]. For aerosol administration of budesonide, a nose-only technique has been developed that entails nebulization of the compound dissolved in ethanol and subsequent stripping off of the solvent (less than 3 microl ethanol/liter of air remaining at the site of inhalation). The budesonide particles produced by the apparatus had a mass median aerodynamic diameter of less than 1 microm. An experiment has been carried out in which the inhibitory effects of aerosolized budesonide, given for 1 min six times a week, were studied. Concentrations of budesonide of 26, 81, and 148 microg/liter of air (calculated doses of 23, 72, and 126 microg/kg of body weight) were used. The aerosols were started 1 week after three oral administrations of benzo(a)pyrene (2 mg/20 g of body weight) to female A/J mice. All three doses of budesonide resulted in more than 80% inhibition of pulmonary tumor formation compared to the aerosol control and 90% or greater compared to mice not exposed to aerosol. The difference in inhibition is due to the aerosol procedure itself, which produces a reduction in tumor formation. A decrease in splenic weight (evidence of a systemic effect) occurred at all doses of budesonide. To the best of our knowledge, this is the first published effort at the use of aerosol administration to prevent neoplasia of the respiratory tract. The results of the present study show that administration of a potential chemopreventive agent by aerosol at a low dose can inhibit the occurrence of pulmonary carcinogenesis in female A/J mice.