Corticospinal facilitation studied during voluntary contraction of human abdominal muscles.

Transcranial magnetic stimulation (TMS) of the human motor cortex was used to study facilitation of motor-evoked potentials (MEPs) in the rectus abdominis (RA) muscle, a trunk flexor, during voluntary activation. MEPs could be produced in the relaxed RA muscles of all six normal subjects studied. The MEPs had short latencies (18-22 ms) which are consistent with other studies suggesting a fast corticospinal input to the trunk muscles.

Free prostate-specific antigen 'in the field': a useful adjunct to standard clinical practice.

Objectives: To determine the clinical utility of the ratio of free to total prostate-specific antigen (f/tPSA), which may improve the discrimination of PSA testing in the assessment of patients with prostatic disease, in a busy clinical practice.

Patients And Methods: A series of 198 men undergoing transrectal ultrasonography (TRUS)-guided biopsy, because of a high total PSA level or an abnormal digital rectal examination or both, had blood samples taken for the assessment of both free and total PSA before any form of prostatic manipulation. The histological findings were compared with tPSA, fPSA and f/tPSA, evaluating three different thresholds of f/tPSA.

The effect of digital rectal examination, flexible cystoscopy and prostatic biopsy on free and total prostate specific antigen, and the free-to-total prostate specific antigen ratio in clinical practice.

Purpose: We evaluated the effects of common urological maneuvers on serum free prostate specific antigen (PSA) and established guidelines for clinical practice.

Materials And Methods: Total and free PSA, and free-to-total PSA ratio were determined in 82 men with lower urinary tract symptoms before and 30 minutes after 3 different prostatic manipulations: 1) digital rectal examination (36 cases), 2) flexible cystoscopy (26) and 3) transrectal ultrasound guided prostatic biopsy (20). PSA forms were measured with Hybritech Tandem-R assays.