A surface acoustic wave (SAW)-enhanced grating-coupling phase-interrogation surface plasmon resonance (SPR) microfluidic biosensor.

A surface acoustic wave (SAW)-enhanced, surface plasmon resonance (SPR) microfluidic biosensor in which SAW-induced mixing and phase-interrogation grating-coupling SPR are combined in a single lithium niobate lab-on-a-chip is demonstrated. Thiol-polyethylene glycol adsorption and avidin/biotin binding kinetics were monitored by exploiting the high sensitivity of grating-coupling SPR under azimuthal control. A time saturation binding kinetics reduction of 82% and 24% for polyethylene and avidin adsorption was obtained, respectively, due to the fluid mixing enhancement by means of the SAW-generated chaotic advection. These results represent the first implementation of a nanostructured SAW-SPR microfluidic biochip capable of significantly improving the molecule binding kinetics on a single, portable device. In addition, the biochip here proposed is suitable for a great variety of biosensing applications.

[Risk factors for arteriosclerosis and diet of surgical patients. 10 years of outpatient activity]. / Fattori di rischio per arteriosclerosi e dieta in pazienti di interesse chirurgico. Attività ambulatoriale di 10 anni.

The follow-up of arteriopathic subjects who have already been hospitalized (abdominal-peripheral vascular district 79% of patient and supra-aortic branch district 21%) has been carried out for around 10 years using an out-patient regime at the Institute of General and Cardiovascular Surgery of Milan. During outpatient visit the main risk factors for arteriosclerosis are routinely checked and treated if required; among the various therapies for metabolic control particular emphasis is placed on diet since its influence on the metabolism is well known, above all in the long term. The efficacy of this treatment has been evaluated by evaluating blood chemical changes (total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, VLDL and glycemia) in a group of patients who followed the diet in comparison to a group which did not. The results obtained show that in dieting patients there was a statistically significant decrease in blood values for total cholesterol, LDL cholesterol, triglycerides and VLDL, together with a decrement, which failed to reach statistical significance, in glycemia and HDL cholesterol. In non-dieting patients it was found that all parameters increased but that this was only statistically significant for total cholesterol and HDL cholesterol. The control of risk factors for arteriosclerosis through diet therapy therefore appears to be satisfactory even for secondary prevention in surgical arteriopathic subjects. It is important to underline that these results were not obtained under conditions of clinical research but in the reality of day-to-day clinical and therapeutic activity whose efficacy is vitally important for scientific health.

Plasma steroid transport in subjects with tumors of hormonal target organs: a review.

Tumors derived from a hormonal target organ are assumed to be stimulated by the same hormone that stimulates the normal target tissue. In spite of attempts to acquire direct indications of a correlation between hormones and cancer, none have been definitive because studies of total and free hormone levels have given contradictory results. For this reason, attention has shifted to the study of plasma binding and transport of hormones, that is, of the proteins responsible for modulation of the hormone effect and thus of hormone bioavailability. The data reviewed indicate that in-depth study of the transport and binding system of sex steroids would give new information about the endocrine characteristics of cancer patients.

Current status of hormone receptor measurements in cancer patients.

Despite increasingly sophisticated techniques, improvements in the correlation between laboratory findings and tumor response to endocrine therapy have not been obtained by hormone receptor studies. A possible explanation is that present knowledge of the mechanisms of the endocrine stimulus is incomplete. Some aspects of the present model, (elevated conjugated steroid levels, multiplicity of the plasma proteins capable of binding hormones, pulsatility of the plasma protein bond and of the receptor system for steroids), are still unclear and thus are not used in diagnosis. By evaluating these factors it will probably be possible to correlate better laboratory data with clinical findings.