This study describes the anatomy of the musculocutaneous nerve (MCN) in the middle and lower thirds of the arm, with special reference to the motor branches to the biceps and brachialis muscles, given their importance in certain clinical, particularly surgical, procedures. In each dissection (46 upper limbs) we recorded the course of the MCN and its variations, and the number, type of distribution pattern and length of the motor branches to the biceps brachii and brachialis muscles. We also recorded the position at which those branches arose from the MCN trunk. We found three branching patterns for biceps brachii: 1) one branch (60.5%); 2) two branches, one for each biceps head (27.9%); and 3) two branches, one for the two biceps heads and one for the common belly (11.6%). The mean distance between the acromion and the motor branches to biceps brachii was 133.8 mm, 45.3% of the acromion-lateral epicondyle distance. The mean length of those branches was 31.2 mm. We found two branching patterns for brachialis: 1) one branch (72.1%); and 2) two branches (27.9%). These motor nerves to brachialis arose from the MCN at a mean distance of 185.3 mm, 61.5% of the acromion-lateral epicondyle distance, and their average length was 33.0 mm. The data were expressed as the percentage of the distance between the acromion and the lateral epicondyle of the humerus, to make their clinical use easy and to avoid errors caused by anthropometric differences.

A new strategy to obtain a single-mode fiber with a flattened intensity profile distribution is presented. It is based on the use of an OVD-made high index ring deposited on a silica rod having a refractive index slightly lower than the silica used for the microstructured cladding. Using this strategy, we realized the first single-mode fiber with a quasi-perfect top-hat intensity profile around 1 µm. Numerical studies clearly demonstrate the advantage of using a core index depression to insure the single-mode operation of the fiber at the working wavelength.

BIM 23014 (BIM) is a long-acting octapeptide somatostatin analog. We studied the effects of this analog on the secretion of GH, TSH, and gastroenteropancreatic hormones [secretin, motilin, and pancreatic polypeptide (PP)] in normal men. In the first protocol three BIM doses (125, 250, and 500 micrograms) and vehicle were administered sc in random order at 2000 h to eight normal young men. Plasma GH concentrations decreased during the first part of the night only after the highest dose (P less than 0.05). Plasma secretin levels did not change, while plasma motilin decreased after the 250- and 500-micrograms doses (P = 0.05 and P = 0.02, respectively), and plasma PP decreased after all three doses (P less than 0.05, P less than 0.01, and P less than 0.01, respectively) during the first part of the night. In the second protocol, eight men received BIM, administered by constant sc infusion during the night in a dose of 2 mg/12 h, or vehicle, either alone or in association with a 10 ng/kg.min iv GHRH or vehicle infusion. Nocturnal GH secretion was suppressed by the BIM infusion (P less than 0.001). GH secretion, stimulated by GHRH infusion (P less than 0.001), was reduced by concomitant BIM infusion (P less than 0.001) and was pulsatile during the combined infusions. BIM infusion suppressed the physiological nighttime rise in plasma TSH levels. Plasma motilin and PP levels were reduced by BIM, when administered either alone or in combination with GHRH. We conclude that: 1) BIM is capable of reducing GH secretion when administered sc in a dose of 500 micrograms and of abolishing nocturnal GH secretion when constantly infused at a dose of 2 mg/12 h; 2) BIM, constantly infused, reduces the nocturnal rise in TSH secretion; and 3) motilin and PP secretion are more sensitive than that of GH to BIM, as they are reduced by a lower dose.