Fine Mapping the Spatial Distribution and Concentration of Unlabeled Drugs within Tissue Micro-Compartments Using Imaging Mass Spectrometry

Readouts that define the physiological distributions of drugs in tissues are an unmet challenge and at best imprecise, but are needed in order to understand both the pharmacokinetic and pharmacodynamic properties associated with efficacy. Here we demonstrate that it is feasible to follow the in vivo transport of unlabeled drugs within specific organ and tissue compartments on a platform that applies MALDI imaging mass spectrometry to tissue sections characterized with high definition histology. We have tracked and quantified the distribution of an inhaled reference compound, tiotropium, within the lungs of dosed rats, using systematic point by point MS and MS/MS sampling at 200 µm intervals. By comparing drug ion distribution patterns in adjacent tissue sections, we observed that within 15 min following exposure, tiotropium parent MS ions (mass-to-charge; m/z 392.1) and fragmented daughter MS/MS ions (m/z 170.1 and 152.1) were dispersed in a concentration gradient (80 fmol-5 pmol) away from the central airways into the lung parenchyma and pleura. These drug levels agreed well with amounts detected in lung compartments by chemical extraction. Moreover, the simultaneous global definition of molecular ion signatures localized within 2-D tissue space provides accurate assignment of ion identities within histological landmarks, providing context to dynamic biological processes occurring at sites of drug presence. Our results highlight an important emerging technology allowing specific high resolution identification of unlabeled drugs at sites of in vivo uptake and retention.     

Effects of cultural conditions on the production of phenylalanine from a plasmid-harboring E. coli strain

Summary Phenylalanine production from E. coli KA 197/pJN6 (plasmid harboring genes for aro F, phe A^FBR, Amp^R and Tc^R) was studied under varying nutritional conditions in batch and continuous cultures. In batch culture experiments where growth was deliberately interrupted by limiting concentrations of sulphate and phosphate the phenylalanine production continued from the non-growing cells. However, the depletion of phosphate resulted in an immediate cessation of phenylalanine production but thereafter a low specific rate of phenylalanine formation resumed, while the decrease in specific rate of product formation was less after sulphate depletion. In the chemostat experiments, however, phosphate limitation was the only case where the specific rate of phenylalanine formation remained constant, while at the corresponding time in sulphate and glucose limited chemostats it was declining respectively had ceased.     

Seed and tuber banks of aquatic macrophytes in the Askö area, northern Baltic proper

Sediment samples from 5 stations in the northern Baltic proper, 6.5 o/oo S, were collected in April 1987 and the emergence of seedlings was recorded over 120 days in a greenhouse at 20°C. Total seedling densities varied from 0 to 3328 m^-2: and of seven species, Zannichellia palustris and Chara spp. were the most abundant among seedlings and sporelings, respectively. Several common macrophytes in the area were rare as seedlings and no seedlings were recorded for the most abundant angiosperms, Potamogeton pectinatus, Potamogeton perfoliatus and Ranunculus baudotii. Except for the few annual species, reproduction by seeds contributed little to the dynamics of the vegetation in the area and no correlation was found between vegetation composition and the seed bank. For perennial species the winter survival of vegetative propagules is the most important factor for vegetation dynamics.     

Induction of interleukin-2 receptor by tumor necrosis factor α on cultured ovarian tumor-associated lymphocytes

Summary We have recently reported that autologous tumor-specific cytotoxic T lymphocyte (CTL) lines and clones can be developed from lymphocytes infiltrating ovarian malignant ascites (TAL). In this study, we investigated the biological effects of tumor necrosis factor (TNF) in the induction, expansion, long-term proliferation and lytic function of CD8⁺ TAL. TNF up-regulated the IL-2 receptor (IL-2R) chain (Tac antigen) on the surface of CD3⁺ CD8⁺ CD4^– TAL, enhanced the proliferation of autologous tumor-specific CTL, and potentiated their lytic function in long-term cultures. Furthermore, in the induction and expansion phase of CD8⁺ TAL, the presence of TNF was associated with a selective increase in CD8⁺ IL-2R⁺ (Tac⁺) cells, and subsequent decrease in CD4⁺ IL-2R⁺ (Tac⁺) cells. These results suggest that the observed facilitation of the outgrowth of CD8⁺ cells in TAL cultures may be due, at least in part, to the up-regulation of IL-2R, and indicate the usefulness of TNF in the analysis of signalling in autologous tumor-reactive CTL.     

On the activity of γ-aminobutyric acid and glutamate transporters in chick embryonic neurons and rat synaptosomes

The uptake of radioactive -aminobutyric acid (GABA) andd-aspartate and the effect of SKF 89976-A, a non-substrate inhibitor of the GABA transporter, on this uptake have been investigated. Neuronal cultures from eight-day-old chick embryos grown for three or six days in vitro, were used as a model. For comparison, we also used the P₂-fraction from rat. Neuronal cultures grown for three and six days expressed high-affinity uptake systems for [³H]GABA and ford-[³H]aspartate with an increasing V_max during this period. The lipophilic non-substrate GABA uptake inhibitor, SKF 89976-A, inhibited transporter mediated uptake of GABA both in cell cultures from chicken, and in P₂-fractions from rat. The results also showed that SKF 89976-A was a poor inhibitor of the uptake ofd-aspartate. We found no non-saturable uptake ofd-aspartate.     

Saccharification and protein enrichment of sugar beet pulp byPleurotus florida

Summary Pleurotus florida was grown in submerged culture with different concentrations of sugar beet pulp with a view to its nutritional upgrading. Micelial growth, protein enrichment and dry weight loss of the solid residues of cultures, as well as the evolution of reducing sugars in the liquid medium, were followed for 14 days. A product with 45% (w/w) protein and a saccharification extent as high as 35% (w/w) were obtained after 7 days with 1% (w/v) sugar beet pulp.