An unbiased method for estimation of total epidermal nerve fibre length.

It is of interest to quantify accurately lineal biological features such as nerve fibres, capillaries, and tubules for studies of development and diseases such as sensory neuropathy, and for evaluation of therapeutic regimens in humans and animal models. An unbiased stereological method to sample and estimate total length of immunostained epidermal nerve fibres by using vertical sections of punch skin biopsies from two human volunteers is presented. The essential steps in the procedure are as follows: (1) serially section the skin punch in a random plane perpendicular to the cutaneous surface; (2) immunostain a known fraction of total sections with antibody specific for nerve fibres; (3) orient a test line-grid over the epidermis; and (4) count intersections between test lines and immunostained epidermal nerve fibres. The optical fractionator method is employed to estimate total length of immunostained epidermal nerve fibres in the biopsy. By using these techniques the total length of nerve fibre in a defined region can be determined without methodological bias, assumptions or correction factors.

An analysis of feeding regimens after pyloromyotomy for hypertrophic pyloric stenosis.

We retrospectively reviewed 223 infants who underwent pyloromyotomy for hypertrophic pyloric stenosis (HPS) at our institution from January 1984 to May 1990. Each patient's postoperative feeding regimen was determined by the attending surgeon. The four distinct regimens used were as follows: A (n = 66): NPO overnight (> 10 h) with cautious feeding advancement every 4 hours x 2, then every 2 hours x 2, then every 1 1/2 hours x 8, then ad lib; B (n = 46): NPO until 6 to 8 hours postoperatively with the same cautious feeding advancement as in A; C (n = 42): NPO until 6 hours postoperatively with accelerated feeding advancement every 2 hours x 8, then ad lib; D (n = 69): NPO until 6 hours postoperatively with accelerated feeding advancement every 1 hour x 12, then ad lib. There were no significant differences in age at diagnosis or degree of dehydration among groups. From group A to group D, there was a progressive increase in amount and incidence of postoperative vomiting, both after the first three feedings and in the total postoperative period. However, patients in groups C and D had a shorter postoperative hospital stay and lower charges than did patients in groups A and B. Following discharge, no patient was readmitted for vomiting or dehydration. We conclude that feedings started 6 hours after pyloromyotomy for HPS with accelerated feeding advancement every 2 hours increases the incidence and frequency of postoperative vomiting, but not unacceptably, and results in a significantly shorter postoperative stay.