SUMMARY
One hundred and fourteen cases of paratesticular tumour are reviewed.
The young patient with a rapidly growing tumour usually has a rhabdomyosarcoma, many of which have already metastasised at the time of presentation. Of the other malignant paratesticular tumours approximately 25 per cent, are manifestations of generalised malignant disease and are often metastases.
The presence of a hydrocele in association with a paratesticular tumour is usually an indication that the tumour is malignant.
In patients where the history and clinical findings are indicative of an adenomatoid tumour, there may well be a place for local excision of the tumour.
CYSTS communicating with the renal calyces were first described by Rayer (1841), who called them " cystes urinaires ". Since then the various names given them-calyceal cyst, calyceal diverticulum, megacalycosis, and hydrocalycosis-all signify variations on the same theme (Fig. 1). FIG. 1 Communicating cysts and diverticula of the renal pelvis showing their variations with their alternative names.
Poly(vinyl chloride) (PVC) plasticized with a phthalate ester was photodegraded with both farultraviolet (λ mainly 254 nm) and near‐ultraviolet (λ > 280nm) light. Multiple changes in the infrared spectra of the films were thus induced. The PVC underwent oxidation, dehydrochlorination, and simultaneous chain scission and crosslinking. Some of the phthalate ester was split along the aliphatic side chains, leading to lower‐molecular‐weight analogs, while a further fraction became firmly bound to the crosslinked part of the PVC. Reaction sequences to account for this complicated series of changes are suggested.
A comparison has been made of the effect of ultraviolet and solar radiation on plasticised and unplasticised PVC. It has been shown that, when the polymer, plasticised with either a phthalate or trimellitate ester, is exposed to short-wavelength ultraviolet radiation (<292 nm), the photodehydrochlorination of the polymer is retarded by the plasticiser. It has also been shown that, when longer-wavelength radiation is used, the dehydrochlorination is accelerated by the plasticiser. In each case, the effect of the trimellitate is greater than that of the phthalate. Possible mechanisms for the reactions at both long and short wavelengths are considered, and the role of the plasticiser is explained in terms of its electronic absorption spectrum.
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