Capsular definition

Each laparoscopy should aim at a visual assessment of the spleen in terms of (7.) size, (2.) colour, (i.) shape, and (4.) identifiable spleen diseases. Special mention should be made of capsular fibrosis, hyalinosis ( sugar-coated spleen ), tumours (e. g. Hodgkin s disease, retothelial sarcoma), tuberculosis, splenic cysts, splenic infarction (s. fig. 35.10) and splenic haematoma. Given appropriate positioning, the spleen is visible in 80% of cases. In the case of myeloproliferative diseases, a biopsy of the spleen (e. g. by means of the Menghini technique) can provide a definitive diagnosis, (s. pp 135,253) (s. figs. 11.1 14.7) (see chapter 11)... 

Just 1 year later, in 1996, Bohmer and co-workers demonstrated, using H NMR spectroscopy, that combining two different tetraurea ca]ix[4]arenes (2 and 3 from Fig. 32.2) in benzene-dg provided a mixture of homodimers 2 2 and 3 3 in addition to the heterodimeric capsular assembly 2 3. The ratio of the three self-assembled containers was very close to the statistical distribution expected for three isoenergetic dimers (25 25 50 for 2 2,3 3, and 2 3 respectively) [15]. Immediately, following this report, Bohmer and co-workers described the first X-ray structure of a tetraurea cahx[4]arene homodimeric cOTitainer. This finding was perceived by the community of Supramolecular Chemists as the definitive proof of the self-assembly of tetraurea calix[4]arenes in dimeric capsular assemblies held together by hydrogen bonds [16]. 

Not all of the pneumococcal capsular polysaccharides have had their structures completely determined. Because of their antigenicity and use in producing vaccines, there has been great interest in this field of carbohydrate chemistry. We will consider only the structures of six types of 5. pneumoniae capsular polysaccharides that have had their structures definitively determined. 

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