J.M. de Meyer

Intracavernous injection of vasoactive drugs, an alternative for treating impotence in spinal cord injury patients

We report on our results with the intracavernous injection and self-injection of papaverine-phentolamine in a group of spinal cord injury patients with erectile impotence. This technique offers the possibility of achieving a full erection which continues for a few hours and disappears afterwards. In our limited experience no major complications have occurred. If our findings are confirmed, in future, the self-injection technique may become a valuable alternative to implanting a prosthesis in impotent paraplegics and tetraplegics.

Intracavernous injection of noradrenaline to interrupt erections during surgical interventions

Injection of a small dose of noradrenaline in one corpus cavernosum caused quick detumescence in 10 children and 7 adults with disturbing peroperative erections. The mode of administration is simple, and complications have not appeared. As this therapy has always been effective and avoids the need for deeper anesthesia, we dare to recommend it as first choice treatment for peroperative erections.

Head shape dimorphism in European glass eels (Anguilla anguilla)

The life cycle of the European eel (Anguilla anguilla) remained a mystery until the 20th century, when Schmidt discovered that the Sargasso Sea was its spawning area. However, many aspects of the eels life cycle remain poorly understood. Among these is the bimodal distribution in head shape, with broad- and narrowheaded phenotypes reported in the yellow eel stage. Although this has been linked to dietary preferences of the yellow eels, very little is known about why, how and when this dimorphism arises during their ontogeny. To determine whether this dimorphism indeed appears in relation to trophic niche segregation, we examined head shape variation at an earlier ontogenetic stage, the glass eel stage, as at this stage eels are considered to be non-feeding. Head shape was studied in a large dataset, containing glass eels captured from the Yser river mouth, the Leopold Canal (Belgium) and from the rivers Severn, Trent and Parret (UK), by both taking measurements (head width/head length) and using an outline analysis. Our results show that there is already considerable variation in broadness and bluntness of the head at the glass eel stage. In most cases, equal support for a unimodal and bimodal head shape distribution is found, whereas some cases support head shape bimodality in glass eels, suggesting that glass eel head shape might be shifting from a unimodal to a bimodal distribution. This, in combination with the observation that variation in head width/head length ratios in non-feeding glass eels shows a similar range as in feeding yellow eels, indicates that head shape in European eel might be at least partially determined through other mechanisms than trophic segregation.

Gravity Cavernosometry and Assessment of Complete Smooth Muscle Relaxation: Helpful in the Differential Diagnosis of Cavernous Leakage?

Objective: To establish whether the relationship between cavernosal pressures and gravitational pressures of infused liquid during gravity cavernosometry is linear when complete smooth muscle relaxation is achieved and whether the determination of this relationship could be helpful in the differential diagnosis between organic and functional cavernous leakage. Methods: Gravity cavernosometry was performed in 50 impotent patients. The cavernosal pressure was measured at at least four different gravitational pressures of the infused liquid. Results: A linear relationship was obtained in all patients with normal maximal cavernosal pressure at gravity cavernosometry. A flat or nonlinear relationship was found in those with abnormal maximal pressure, whatever the cause of cavernous leakage. Conclusions: A linear relationship between cavernosal and gravitational pressures characterizes complete smooth muscle relaxation during gravity cavernosometry. However, the usefulness of the determination of this relationship is not yet established.

Differential gene expression in narrow- and broad-headed European glass eels (Anguilla anguilla) points to a transcriptomic link of head shape dimorphism with growth rate and chemotaxis

One of the major challenges in evolutionary biology is to understand the mechanisms underlying morphological dimorphism and plasticity, including the genomic basis of traits and links to ecology. At the yellow eel stage of the European eel (Anguilla anguilla), two morphotypes are found: broad‐ and narrow‐heads. This dimorphism has been linked to dietary differences, with broad‐heads feeding on harder, larger prey than narrow‐heads. However, recent research showed that both morphotypes could be distinguished at the glass eel stage, the nonfeeding predecessor of the yellow eel stage, implying that nondietary factors play a role in the development of this head shape dimorphism. Here, we used transcriptome profiling (RNAseq) to identify differentially expressed genes between broad‐ and narrow‐headed glass eels. We found 260 significantly differentially expressed genes between the morphotypes, of which most were related to defence and immune responses. Interestingly, two genes involved in growth (soma and igf2) were significantly upregulated in narrow‐heads, while nine genes involved in chemotaxis showed significant differential expression. Thus, we found support for the observation that head shape is associated with somatic growth, with fast‐growing eels developing a narrower head. Additionally, observations in the wild have shown that slow‐growers prefer freshwater, while fast‐growers prefer brackish water. The differential expression of genes involved in chemotaxis seems to indicate that glass eel growth rate and habitat choice are linked. We hypothesize that two levels of segregation could take place in the European eel: first according to habitat choice and second according to feeding preference.

Broader head, stronger bite : in vivo bite forces in European eel Anguilla anguilla

This work examined three different phenotypes of the yellow-eel stage of the European eel Anguilla anguilla, broad-heads, narrow-heads and eels with an intermediate head shape. The aim was to see whether broad-headed A. anguilla, which generally consume harder, larger prey, such as crustaceans and fish, exerted greater bite force than the narrow-headed variant, which mainly consume soft, small prey such as chironomid larvae. It was found that in 99 yellow A. anguilla, in vivo bite force of broad-heads are higher compared with narrow-heads and intermediates.

Dimorphism throughout the European eel's life cycle: are ontogenetic changes in head shape related to dietary differences?

A well‐known link exists between an organisms ecology and morphology. In the European eel, a dimorphic head has been linked to differences in feeding ecology, with broad‐headed eels consuming harder prey items than narrow‐headed ones. Consequently, we hypothesized that broad‐heads should exhibit a cranial musculoskeletal system that increases bite force and facilitates the consumption of harder prey. Using 3D‐reconstructions and a bite model, we tested this hypothesis in two life stages: the sub‐adult yellow eel stage and its predecessor, the elver eel stage. This allowed us to test whether broad‐ and narrow‐headed phenotypes show similar trait differences in both life stages and whether the dimorphism becomes more pronounced during ontogeny. We show that broad‐headed eels in both stages have larger jaw muscles and a taller coronoid, which are associated with higher bite forces. This increased bite force together with the elongated upper and lower jaws in broad‐headed eels can also improve grip during spinning behavior, which is used to manipulate hard prey. Head shape variation in European eel is therefore associated with musculoskeletal variation that can be linked to feeding ecology. However, although differences in muscle volume become more pronounced during ontogeny, this was not the case for skeletal features.

Ulcerative Lesions and Hypervascularization of Glans penis

We describe two patients with painful ulcerations on the penis after surgical vascular anastomosis for impotence.