Alan Stevens

Differences in the vascular patterns of basal and squamous cell skin carcinomas explain their differences in clinical behaviour

Tumour angiogenesis is essential for tumour growth and appears to play an important role both at the transition from hyperplasia to invasive growth and at a late stage in the dissemination process. Basal cell carcinomas (BCCs) and trichoepitheliomas (TEs) are related tumours that share the properties of invasive growth but without the capacity to metastasize. Squamous cell carcinomas (SCCs) of the skin are derived from a similar cell type and they have both invasive and metastatic potential. The aim of this study was to investigate whether the behaviour of these tumours could be explained by differences in their microvasculature. The study looked both qualitatively and quantitatively at the microvasculature of BCCs (n = 50) and TEs (n = 33) and compared them with normal skin (n = 6) and with SCCs of the skin (n = 22). Vessel counts were performed using a standard graticule count method after immunohistochemical staining for CD31. Counts were made of blood vessels in the stroma surrounding the tumour and also for vessels in the body of the tumour. The stromal counts for all the tumour groups differed significantly from normal skin. The SCC counts differed significantly from the counts for the BCCs and TEs. There was no significant difference between the counts for different subtypes of BCC or TE groups. While vessels could be found in the body of the SCCs, none was seen in the nodular BCC or the TE groups. There was no correlation between the vascular density and the depth of invasion. Overall, invasive growth correlated with an angiogenic response in the stroma, while metastatic potential correlated with microvessels being present in the body of the tumour. Copyright

Acute graft-versus-host disease with unusual cutaneous intracellular vacuolation in an infant with severe combined immunodeficiency

Abstract: We report an infant with severe combined immunodeficiency (SCID) who had cutaneous manifestations of acute graft‐versus‐host disease (GVHD) due to maternofetal lymphocyte engraftment. Histologic and ultrastructural examinations of the skin revealed intracellular vacuoles resembling lipid droplets in the epidermis and dermis, which is not a recognized feature of acute GVHD or SCID.

PREFACE TO THE FIFTH EDITION

The second volume of “Laser Spectroscopy” covers the different experimental techniques, necessary for the sensitive detection of small concentrations of atoms or molecules, for Doppler-free spectroscopy, laser-Raman-spectroscopy, doubleresonance techniques, multi-photon spectroscopy, coherent spectroscopy and timeresolved spectroscopy. In these fields the progress of the development of new techniques and improved experimental equipment is remarkable. Many new ideas have enabled spectroscopists to tackle problems which could not be solved before. Examples are the direct measurements of absolute frequencies and phases of optical waves with frequency combs, or time resolution within the attosecond range based on higher harmonics of visible femtosecond lasers. The development of femtosecond non-collinear optical parametric amplifiers (NOPA) has considerably improved time-resolved measurements of fast dynamical processes in excited molecules and has been essential for detailed investigations of important processes, such as the visual process in the retina of the eye or the photosynthesis in chlorophyl molecules. In particular, the applications of laser spectroscopy in chemistry, biology medicine and for the solution of technical problems have made rapid progress. This is illustrated by several examples in the last chapter. In this new edition some recent developments are discussed, as for instance the application of optical combs to precision molecular spectroscopy and its extension into the far UV region, to metrology, to astronomy and as frequency normal for the global positioning system. The progress in the controllable generation of high harmonics with frequencies up into the X-ray region and with a time resolution in the attosecond time scale are outlined and also new techniques of cooling and trapping of atoms or molecules in various realizations of optical traps are presented. For several sections of Vol. 2 some basic knowledge of spectroscopic techniques or instrumentation is necessary. Therefore, cross links to Vol. 1 are given, where the fundamentals of laser spectroscopy are discussed. At the end of each chapter some problems are given, which should help the students to check their understanding of the subject treated in the corresponding chapter. The solutions are given at the end of the book.