Somatic modulation of tinnitus: test reliability and results after repetitive muscle contraction training.

OBJECTIVES: We sought to study the reliability of tinnitus modulation by muscle contractions and to observe the effect of their prolonged repetition. METHODS: Thirty-eight patients with tinnitus underwent 9 maneuvers of muscle contractions in test and retest situations. After a 2-month training period of repeating the maneuvers, tinnitus modulation and daily perception were evaluated. RESULTS: There was no difference between the occurrence of tinnitus modulation in test (57.9%) and retest (63.2%) situations. After 2 months, the occurrence of modulation during the maneuvers was similar (55.3%), but a new pattern showed an increase in tinnitus improvement and a decrease in tinnitus worsening. The daily perception of tinnitus was unchanged. CONCLUSIONS: Maneuvers of head and neck muscle contractions evoked tinnitus modulation in a frequent and reliable manner. Also, the repetition of such maneuvers for 2 months altered the pattern of modulation.

Preconcentration system for cadmium and lead determination in environmental samples using polyurethane foam/Me-BTANC.

In this work, polyurethane foam (PUF) loaded with 2-(6'-methyl-2'-benzothiazolylazo)chromotropic acid (Me-BTANC) was packed in a minicolumn and it was used in an on-line preconcentration system for cadmium and lead determination. Optimum hydrodynamic and chemical conditions for metal sorption were investigated. The effects of several foreign substances on the adsorption of cadmium and lead were also reported. The enrichment factor obtained was 37 (Cd and Pb) for 180 s preconcentration time. The proposed procedures allowed the determination of metals with detection limits (3 sigma) of 0.80 and 3.75 microg L(-1) (0.10 and 0.47 microg g(-1) of solid sample) for cadmium and lead, respectively. The precision of the procedures was also calculated: 3.1 (Cd 10 microg L(-1)) and 4.4% (Pb 100 microg L(-1)). The accuracy of the procedure was checked by analysis of the certified reference materials Spinach Leaves and Fish Tissue. Cadmium and lead contents in environmental samples (black tea, spinach leaves, natural and tap water) were determined by applying the proposed procedure.