The prepuce: specialized mucosa of the penis and its loss to circumcision.

OBJECTIVE: To assess the type and amount of tissue missing from the adult circumcised penis. MATERIALS AND METHODS: The gross and histological features of the prepuces of 22 adults obtained at autopsy were assessed, primarily focusing on the inner or mucosal surface of the prepuce. RESULTS: Skin and mucosa sufficient to cover the penile shaft was frequently missing from the circumcised penis. Missing tissue included a band of ridged mucosa located at the junction of true penile skin with smooth preputial mucosa. This ridged band contains more Meissner's corpuscles than does the smooth mucosa and exhibits features of specialized sensory mucosa. CONCLUSION: The amount of tissue loss estimated in the present study is more than most parents envisage from pre-operative counselling. Circumcision also ablates junctional mucosa that appears to be an important component of the overall sensory mechanism of the human penis.

Microtubule systems associated with the septate junctions of the gill cells of four gammarid amphipods.

The microtubular systems associated with the septate junctions of the gill epithelial cells of four species of gammarid amphipod are described. The four species examined included two relatively stenohaline marine forms, Chaetogammarus marinus and Gammarus locusta; a highly euryhaline species, Gammarus duebeni, and a stenohaline freshwater species, Gammarus pulex. Of these amphipods, G. locusta and C. marinus maintain only a limited osmotic gradient between their haemolymph and the medium and have a poorly developed junctional microtubular system; G. pulex has haemolymph which is some 300 mOsmol hypertonic to freshwater and has a well ordered system of microtubules on both sides of fairly long septate junctions; G. duebeni from brackish water tend to have a somewhat shorter length of septate junctions lined by one or occasionally by a double row of microtubules. The most complex junctional microtubular systems are shown by specimens of the freshwater race of G. duebeni celticus which have been acclimated to seawater. These can take the form of multiple arrays in which some microtubules are linked to the plasma membrane by dense strands. It is suggested that these findings are consistent with the hypothesis that one role of these microtubules is to provide mechanical stability to enable the integrity of the septate junctions to be maintained during osmotic stress.

Structural changes in the gill cells of Gammarus duebeni (Crustacea, Amphipoda) under osmotic stress; with notes on microtubules in association with the septate junctions.

The amphipod crustacean Gammarus duebeni (Lilljeborg) tolerates salinities in the range freshwater to seawater. Such tolerance requires the ability to respond to the varying degrees of osmotic stress imposed on the single layer of epithelial cells separating the outside medium from the haemolymph space in the gills. Following transfer of individuals from low salinities to seawater, changes occur in the fine structure of the epithelial cells. These changes involve the configuration of the apical border of the cells, the mitochondria and cytoplasmic lacunae. Despite such variation in cell organisation, the association between neighbouring epithelial cells appears unaffected. Attention is drawn to a well developed system of microtubules in association with the septate junctions. The possible mechanical role of these microtubules in protecting the integrity of the septate junctions from the effects of osmotically induced changes in cell volume is discussed.