Effect of gemcitabine on the tolerance of the lung to single-dose irradiation in C3H mice.

In an early phase II trial combining gemcitabine (dFdC) and radiotherapy for lung carcinomas, severe pulmonary toxicity was observed. In this framework, the objective of this study was to investigate the effect of dFdC on the tolerance of the lungs of C3H mice to single-dose irradiation. The thoraxes of C3H mice were irradiated with a graded single dose of 8 MV photons; dFdC (150 mg/kg) or saline (control animals) was administered i.p. 3 or 48 h prior to irradiation. Lung tolerance was assessed by the LD50 at 7-180 days after irradiation. For irradiation alone, the LD50 reached 14.45 Gy (95% CI 13.33-15.66 Gy). With a 3-h interval between administration of dFdC and irradiation, the LD50 reached 13.29 (95% CI 12.26-14.44 Gy); the corresponding value with a 48-h interval reached 13.01 Gy (95% CI 11.92-14.20 Gy). Our data also suggested a possible effect of dFdC on radiation-induced esophageal toxicity. dFdC has a minimal effect on lung tolerance after single-dose irradiation. However, a proper phase I-II trial should be designed before any routine use of combined dFdC and radiotherapy in the thoracic region.     

The effect of pH on the OsO4-revealed structure of the plasma membrane of Chara corallina

Statistically average absorbance profiles were obtained of the membrane image in electronmicrographs of OsO₄ stained cells of Chara corallina, cultured and fixed pH 7 and pH 9. At pH 7 the membrane appeared to be symmetrical about a central plane. At pH 9 the membrane showed a marked asymmetry in its structure. At pH 9 the central electron-lucent region on the cytoplasmic side of the centre of the membrane was approx. 35% smaller than at pH 7. The corresponding region in the outer half of the membrane was the same at both pH values. At pH 9 the overall thickness of the membrane was also approx. 10% smaller than at pH 7.     

An original approach for quantification of blood vessels on the whole tumour section.

Relative abundance of tumour angiogenesis has been shown to be of clinical relevance in cancers of various locations such as the ovary. Nevertheless, several problems are encountered when quantifying tumour microvessels: (i) as many other tumour markers, vascularity pattern is often heterogeneous within the tumour mass and even within the same histological section. As a consequence, an adequate acquisition method must be developed for accurate field sampling. (ii) Manual microvessel counting is long, tedious and subject to poor reproducibility. Introduction in routine practice requires a fast, reproducible and reliable automatic image processing. In this study we present an original procedure combining a slide scanner image acquisition and a fully automatic image analysis sequence. The slide scanner offers the advantage of recording an image of the whole histological section for subsequent automatic blood vessel detection and hot spot area location. Microvessel density and surface fraction were measured for the whole section as well as within hot spots. Different immunostaining methods were tested in order to optimise the procedure. Moreover, the method proposed was submitted to a quality control procedure, with reference to interactive identification of microvessels at scanner level. This experiment showed that 93 to 97% of blood vessels were detected, according to the staining protocol used. Colour figures can be viewed on http://www.esacp.org/acp/2003/25-2/kim.htm.     

Die Geschwindigkeit des Transpirationsstromes

Ohne Zusammenfassung