Architectuur van het corpus spongiosum: een anatomische studie

Introduction: Detailed knowledge on the architecture of the corpus spongiosum is necessary for tissue engineering, but lacking. Methods: Two penises of male cadavers, who donated their bodies for research purposes, were dissected and frozen; one in flaccid state, the other artificially erected. Tissue sections in transverse and frontal (longitudinal) direction were obtained, stained and digitalized. Surfaces, shape and tissue density were measured and compared. Also, a digital and a stereolithografic 3D-reconstruction were made. Results: Area percentages of vascular sinuses in both directions indicated an increase with erection of 127% transversally and 140% frontally. The structure of the transverse sections was similar at all section sites, but the glans penis had a higher tissue density. Vascular spaces were larger in frontal sections, with more incomplete septae. 3D-models confirmed these findings. Conclusion: This study provides novel information on the architecture of the corpus spongiosum that is important in tissue engineering

Architecture of the Corpus Spongiosum : An Anatomical Study

PURPOSE: Urethral reconstruction is performed for urethral stricture or hypospadias correction. Research on urethral tissue engineering is increasing. Because the corpus spongiosum is important to support the urethra, urethral tissue engineering should ideally be combined with reconstruction of a corpus spongiosum. We describe a method to visualize and measure the architecture of the corpus spongiosum, which is needed for scaffold design. MATERIALS AND METHODS: The penis was dissected from 2 unembalmed male cadavers. One penis was flaccid and the other was erect, as induced by saline infusion. Both were frozen in ice. At 6 sites sections were obtained in the transverse and frontal directions. After digitalizing the stained sections the images were edited, area measurements were taken and a 3-dimensional reconstruction was made. RESULTS: In transverse sections the mean area of the vascular lumen was 60% and 77% in the flaccid and the erect corpus spongiosum, and in frontal sections it was 53% and 74%, respectively. This indicated a 129% transverse increase and a 140% longitudinal increase in erection. Section sites did not essentially differ except in the glans penis. Frontal sections showed larger vascular cavities and more incomplete septae than transverse sections. CONCLUSIONS: This study provides what is to our knowledge novel information on corpus spongiosum architecture, which is relevant for scaffold design in tissue engineering. The study protocol can be used in future research with a larger number of specimens and more extensive analyses

Synthesis of C-Glycosyl Amino Acid Building Blocks Suitable for the Solid-Phase Synthesis of Multivalent Glycopeptide Mimics

Five C-glycosyl functionalized lysine building blocks, featuring C-glycosidic derivatives of α-rhamnose, α-mannose, α-galactose, β-galactose, and β-N-acetyl glucosamine have been designed and synthesized. These derivatives, equipped with acid-labile protecting groups, are eminently suitable for solid-phase synthesis of multivalent glycopeptides. The lysine building blocks were prepared from C-allyl glycosides that underwent a Grubbs cross-metathesis with an acrylate, followed by a reduction of the C=C double bond in the resulting α,β-unsaturated esters, and liberation of the carboxylate to allow condensation with a lysine side chain. The thus obtained C-glycosides, five in total, were applied in the solid-phase peptide synthesis (SPPS) of three glycopeptides, showing the potential of the described building blocks in the assembly of well-defined mimics of homo- and heteromultivalent glycopeptides and glycoclusters

Interleukin-18 resistance in patients with obesity and type 2 diabetes mellitus.

Contains fulltext : 69672.pdf (publisher's version ) (Closed access)OBJECTIVE: Interleukin-18 (IL-18) has been recently demonstrated to improve experimental hyperphagia and insulin resistance. Paradoxically, concentrations of circulating IL-18 in obese subjects and in patients with type 2 diabetes are increased. The objective of this study is to provide an explanation for this paradox. DESIGN: We have hypothesized that cells from obese individuals or from patients with type 2 diabetes mellitus have a diminished response to stimulation with IL-18. IL-18 responsiveness was tested by stimulating blood monocytes of obese or diabetes patients with rIL-18 or microbial components. RESULTS: Obese individuals and patients with type 2 diabetes mellitus exhibit increased circulating concentrations of IL-18. More importantly, leukocytes isolated from obese or type 2 diabetes patients respond poorly after stimulation with IL-18, as reflected by defective interferon-gamma (IFN gamma) production. The defective response to IL-18 stimulation was accompanied by a 50% reduction in the expression of IL-18R alpha and beta chains. In addition, cells of patients with obesity and diabetes displayed an impaired release of IFN gamma after challenge with bacterial or fungal pathogens, which was due to defective IL-18-mediated signaling. CONCLUSION: Patients with obesity or type 2 diabetes mellitus are characterized by lower responses after stimulation with IL-18. This IL-18 resistance explains the association of obesity and diabetes with high IL-18 circulating concentrations, similar to hyperinsulinemia and hyperleptinemia. IL-18 resistance may represent an important mechanism of the increased susceptibility of these patients to a number of infections