We describe a system in which proliferating human breast cancer cells are monitored by NMR spectroscopy for at least 6 days in basement membrane gel (BMG)1 threads. The cells are perfused under ...standard sterile cell culture conditions. 31P-NMR spectra obtained continuously for up to 64 h showed an increase in the signals owing to an increasing number of cells. Cell division in the BMG is easily observed by microscope or by the human eye as the gel opacifies. Spectra of cells in the BMG threads at 20% confluency show a more rapid signal increase than at 60% confluency. Cells grown in vivo in nude mice show a spectrum markedly similar to in vitro spectra in BMG threads, whereas the same cells in agarose threads lack peaks owing to Pi, glycerophosphocholine, and glycerophosphoethanolamine. With the high resolution obtained from this system we distinguished intracellular from extracellular Pi in vitro, and found that the intracellular pH is equal to that observed in the same cell line in vivo. This cell-BMG system is in effect a model tumor, but it is composed of a homogeneous cell population that can be observed indefinitely as the cells reproduce. The material needed is inexpensive, the technique is simple and efficient, and no adaptation of the spectrometer is required. This model will be useful for studying intracellular metabolism and the interaction of cells with the basement membrane.
We present the first VLTI/MIDI observations of the Be star Alpha Ara, showing
a nearly unresolved circumstellar disk in the N band. The interferometric
measurements made use of the UT1 and UT3 ...telescopes. The projected baselines
were 102 and 74 meters with position angles of 7 degres and 55 degres,
respectively. These measurements put an upper limit to the envelope size in the
N band under the Uniform disk approximation of $\phi_{\rm max}= 4\pm1.5$ mas,
corresponding to 14 $R_{\star}$, assuming $R_{\star}$=4.8${\rm R}_\odot$ and
the Hipparcos distance of 74pc. On the other hand the disk density must be
large enough to produce the observed strong Balmer line emission. In order to
estimate the possible circumstellar and stellar parameters we have used the
SIMECA code developed by Stee (1995) and Stee & Bittar (2001). Optical spectra
taken with the echelle instrument Heros and the ESO-50cm telescope, as well as
infrared ones from the 1.6m Brazilian telescope have been used together with
the MIDI spectra and visibilities. These observations put complementary
constraints on the density and geometry of Alpha Ara circumstellar disk. We
discuss on the potential truncation of the disk by a companion and we present
spectroscopic indications of a periodic perturbation of some Balmer lines.
The authors have studied the effects on the metallic content of sediments of some sieving procedures such as water chemistry, size and pH of samples, test duration, mesh size and sieve material. It ...is shown that sediment samples are severely contaminated by stainless steel sieves but the effects are insignificant when the mesh size is greater than 40 u. The contamination comes mainly from welds, so that stainless steel sieves with mesh size lower than 40 u can be used except for determination of those metals found in welds (tin, zinc, cadmium of lead) . For these metals nylon sieves are recommended, and it is considered that nylon is a safer material for sediment analysis in general. (Full translation 18 pounds sterling).
AMBER is the first near infrared focal instrument of the VLTI. It combines
three telescopes and produces spectrally resolved interferometric measures.
This paper discusses some preliminary results of ...the first scientific
observations of AMBER with three Unit Telescopes at medium (1500) and high
(12000) spectral resolution. We derive a first set of constraints on the
structure of the circumstellar material around the Wolf Rayet Gamma2 Velorum
and the LBV Eta Carinae.
A 74-year-old woman developed a generalized pustular dermatosis with erythema-multiforme-like and vesiculobullous lesions 10 days after beginning a treatment by nadoxolol. Despite the clinical ...polymorphism of the eruption, histology constantly revealed the presence of subcorneal pustules, even within the epidermis overlying subepidermal bullae. The eruption spontaneously healed after discontinuation of nadoxolol.
