Hepatobiliary cystadenoma. A study of five cases with reference to histogenesis

Hepatobiliary cystadenoma is a rare hepatic lesion characterized by a multiloculated cyst lined by cuboidal or columnar epithelial cells. Four cases of hepatobiliary cystadenoma with mesenchymal stroma (HCMS) and one case of hepatobiliary cystadenoma with intracystic epithelial component were studied by light microscopy, immunohistochemical methods, and electron microscopy. Similar studies were conducted on six fetal gallbladder tissues, representing the biliary tree, and two adult ovarian tissues. By light microscopy, the columnar epithelium of the five cases of hepatobiliary cystadenoma was similar to the epithelium of the developing gallbladder. The spindle cell stroma of the HCMS and the subepithelial spindle cells of the developing gallbladders showed similar reactivity to smooth-muscle actin. Vimentin reactivity was strongly positive in the stroma of the HCMS, and in the fetal gallbladders it was only noted in the subepithelial spindle cells of the 15-week gestation fetal gallbladder tissues. By electron microscopy, the epithelium lining the hepatic lesions showed characteristic gastrointestinal features and was identical to the epithelia lining the embryonic gallbladders. Furthermore, the mesenchymal stroma of the HCMS recapitulated the features found in subepithelial tissues in developing gallbladders. Although the ovarian stroma resembled the stroma of the HCMS by light microscopy, the immunohistochemical reactions and the electron microscopic studies showed dissimilarities. This study supports the hypothesis that the hepatobiliary cystadenomas arise from ectopic embryonic tissues destined to form the adult gallbladder.     

A survey of the training of computer users in Swedish companies

This study concerns how user training on newly introduced computer application programs is carried out. Questionnaire data from the computer managers of 265 Swedish companies were analysed. The results show that formal training, i.e., teacher-directed group instruction, and self-studies using instruction manuals represented nearly two-thirds of all reported training forms. For the most recently introduced program, classes (group instruction) with simultaneous computer exercises was the form of formal training that was nearly always used. When formal training was given it was compulsory in over half of the cases. However, substitutes for users attending a training course were only provided by the company in very few of these cases. The implications of these findings for effective user training are discussed.     

Ultrastructural and immunocytochemical features of a case of neuroendocrine carcinoma developing in a prior ileostomy site

A patient who developed a mixed neuroendocrine carcinoma and adenocarcinoma at the site of a previous long-standing ileostomy is reported. The neuroendocrine features are documented by both ultrastructural and immunocytochemical findings. Carcinoma arising in an ileostomy site is rare but has been recorded in patients with long-standing ileostomies after colectomy for chronic inflammatory bowel disease, as in this patient. Neuroendocrine carcinoma developing in this setting apparently has not been described before, however.     

Nonlinear distortion generated by DSF-based optical-phase conjugators in analog optical systems

In this paper, the nonlinear distortion induced by dispersion-shifted-fiber-based optical-phase conjugators (OPCs) in intensity-modulated subcarrier multiplexing optical systems is evaluated. In this study, it is shown that the nonlinear distortion mainly arises from the four-wave mixing (FWM) process during the phase conjugation, although there also exists influences from other nonlinear effects. Closed expressions for calculating the second- and third-order harmonic distortions due to FWM, self-phase modulation, cross-phase modulation and group-velocity dispersion effects in the dispersion-shifted-fiber-based OPC are also reported for the first time. The influence of several system design parameters, such as the optical modulation index, the number of channels, the input optical powers, and the effective area of the dispersion-shifted fiber on the compensation of fiber-induced nonlinear distortions employing the optical-phase conjugation technique, is considered.     

Identification of aroma components of Spanish ‘Verdejo’ wine

Aroma components of ine resulting from fermentation of grape must from the Verdejo cultivar ere isolated by continuous liquid-liquid extraction and further fractionation on a silica gel column. One hundred and thirty-to substances, including alcohols, esters, carbonyl compounds, terpenes, acids and sulphur compounds, ere identified by using GC-MS; some had not been previously detected in ines. Data are given hich could lead to the characterisation of the Verdejo cultivar and the effect of the elaboration of young ines. The sensory contribution of some volatile compounds to the flavour of Verdejo ine is also studied.     

Functionalized Nanostructures with Liquid‐Like Behavior: Expanding the Gallery of Available Nanostructures

Recently, we have developed a novel family of functionalized nanostructures that exhibit liquid‐like behavior in the absence of solvents and preserve their nanostructure in the liquid state. The gallery of nanostructures developed so far includes functionalized silica and magnetic iron oxide nanoparticles, layer‐like organosilicate nanoparticles, polyoxometalate clusters, and organic–inorganic hybrid networks. In an effort to demonstrate the wider applicability of this concept and to provide a deeper insight into this class of materials, the present work cites additional paradigms of functionalized nanostructures with similar behavior as above. In one case, surface functionalization of anatase nanoparticles (TiO₂, an inorganic nanostructure) with a quaternary ammonium organosilane leads to ionically modified nanoparticles that, when electrostatically combined with a poly(ethylene glycol) (PEG)‐tailed sulfonate anion, exhibit liquid‐like behavior in the absence of solvents. In a different but quite interesting case of a bionanostructure, ion‐exchange functionalization of a DNA oligonucleotide with a PEG‐tailed quaternary ammonium cation leads to an easily separable liquid derivative with attractive features. These examples show the versatility of this concept over a range of nanostructures.