Applicability of ERTS-1 to lineament and photogeologic mapping in Montana: Preliminary report

A lineament map prepared from a mosaic of western Montana shows about 85 lines not represented on the state geologic map, including elements of a northeast-trending set through central western Montana which merit ground truth checking and consideration in regional structural analysis. Experimental fold annotation resulted in a significant local correction to the state geologic map. Photogeologic mapping studies produced only limited success in identification of rock types, but they did result in the precise delineation of a late Cretaceous or early Tertiary volcanic field (Adel Mountain field) and the mapping of a connection between two granitic bodies shown on the state map. Imagery was used successfully to map clay pans associated with bentonite beds in gently dipping Bearpaw Shale. It is already apparent that ERTS imagery should be used to facilitate preparation of a much needed statewide tectonic map and that satellite imagery mapping, aided by ground calibration, provides and economical means to discover and correct errors in the state geologic map

Neoadjuvant letrozole in postmenopausal estrogen and/or progesterone receptor positive breast cancer: A phase IIb/III trial to investigate optimal duration of preoperative endocrine therapy

<p>Abstract</p> <p>Background</p> <p>In recent years, preoperative volume reduction of locally advanced breast cancers, resulting in higher rates of breast-conserving surgery (BCS), has become increasingly important also in postmenopausal women. Clinical interest has come to center on the third-generation nonsteroidal aromatase inhibitors (AIs), including letrozole, for such neoadjuvant endocrine treatment. This usually lasts 3–4 months and has been extended to up to 12 months, but optimal treatment duration has not been fully established.</p> <p>Methods</p> <p>This study was designed as a multicenter, open-label, single-arm, exploratory phase IIb/III clinical trial of letrozole 2.5 mg, one tablet daily, for 4–8 months. The primary objective was to investigate the effect of neoadjuvant treatment duration on tumor regression and BCS eligibility to identify optimal treatment duration. Tumor regression (by clinical examination, mammography, and ultrasound), shift towards BCS eligibility, and safety assessments were the main outcome measures. Standard parametric and nonparametric descriptive statistics were performed.</p> <p>Results</p> <p>Letrozole treatment was received by 32 of the enrolled 33 postmenopausal women (median (range): 67.0 (56–85) years) with unilateral, initially BCS-ineligible primary breast cancer (clinical stage ≥ T2, N0, M0). Letrozole treatment duration in the modified intent-to-treat (ITT; required 4 months' letrozole treatment) analysis population (29 patients) was 4 months in 14 patients and > 4 months in 15 patients. The respective per-protocol (PP) subgroup sizes were 14 and 11. The majority of partial or complete responses were observed at 4 months, though some beneficial responses occurred during prolonged letrozole treatment. Compared with baseline, median tumor size in the ITT population was reduced by 62.5% at Month 4 and by 70.0% at final study visit (Individual End). Similarly, in the PP population, respective reductions were 64.0% and 67.0%. Whereas initially all patients were mastectomy candidates, letrozole treatment enabled BCS (lumpectomy) in 22 ITT (75.9%) and 18 PP (72.0%) patients.</p> <p>Conclusion</p> <p>Over half of patients become BCS-eligible within 4 months of preoperative letrozole treatment. While prolonged treatment for up to 8 months can result in further tumor volume reduction in some patients, there is no clear optimum for treatment duration. Letrozole has a favorable overall safety and tolerability profile.</p> <p>Trial registration</p> <p>ClinicalTrials.gov identifier NCT00535418.</p

Proteomic Analysis of Neisseria gonorrhoeae Biofilms Shows Shift to Anaerobic Respiration and Changes in Nutrient Transport and Outermembrane Proteins

Neisseria gonorrhoeae, the causative agent of gonorrhea, can form biofilms in vitro and in vivo. In biofilms, the organism is more resistant to antibiotic treatment and can serve as a reservoir for chronic infection. We have used stable isotope labeling by amino acids in cell culture (SILAC) to compare protein expression in biofilm and planktonic organisms. Two parallel populations of N. gonorrhoeae strain 1291, which is an arginine auxotroph, were grown for 48 h in continuous-flow chambers over glass, one supplemented with 13C6-arginine for planktonic organisms and the other with unlabeled arginine for biofilm growth. The biofilm and planktonic cells were harvested and lysed separately, and fractionated into three sequential protein extracts. Corresponding heavy (H) planktonic and light (L) biofilm protein extracts were mixed and separated by 1D SDS-PAGE gels, and samples were extensively analyzed by liquid chromatography-mass spectrometry. Overall, 757 proteins were identified, and 152 unique proteins met a 1.5-fold cutoff threshold for differential expression with p-values <0.05. Comparing biofilm to planktonic organisms, this set included 73 upregulated and 54 downregulated proteins. Nearly a third of the upregulated proteins were involved in energy metabolism, with cell envelope proteins making up the next largest group. Of the downregulated proteins, the largest groups were involved in protein synthesis and energy metabolism. These proteomics results were compared with our previously reported results from transcriptional profiling of gonococcal biofilms using microarrays. Nitrite reductase and cytochrome c peroxidase, key enzymes required for anaerobic growth, were detected as highly upregulated in both the proteomic and transcriptomic datasets. These and other protein expression changes observed in the present study were consistent with a shift to anaerobic respiration in gonococcal biofilms, although changes in membrane proteins not explicitly related to this shift may have other functions

Post-imperialism, postcolonialism and beyond: towards a periodisation of cultural discourse about colonial legacies

Taking German history and culture as a starting point, this essay suggests a historical approach to reconceptualising different forms of literary engagement with colonial discourse, colonial legacies and (post-) colonial memory in the context of Comparative Postcolonial Studies. The deliberate blending of a historical, a conceptual and a political understanding of the ‘postcolonial’ in postcolonial scholarship raises problems of periodisation and historical terminology when, for example, anti-colonial discourse from the colonial period or colonialist discourse in Weimar Germany are labelled ‘postcolonial’. The colonial revisionism of Germany’s interwar period is more usefully classed as post-imperial, as are particular strands of retrospective engagement with colonial history and legacy in British, French and other European literatures and cultures after 1945. At the same time, some recent developments in Francophone, Anglophone and German literature, e.g. Afropolitan writing, move beyond defining features of postcolonial discourse and raise the question of the post-postcolonial

GacA-controlled activation of promoters for small RNA genes in Pseudomonas fluorescens.

The Gac/Rsm signal transduction pathway positively regulates secondary metabolism, production of extracellular enzymes, and biocontrol properties of Pseudomonas fluorescens CHA0 via the expression of three noncoding small RNAs, termed RsmX, RsmY, and RsmZ. The architecture and function of the rsmY and rsmZ promoters were studied in vivo. A conserved palindromic upstream activating sequence (UAS) was found to be necessary but not sufficient for rsmY and rsmZ expression and for activation by the response regulator GacA. A poorly conserved linker region located between the UAS and the -10 promoter sequence was also essential for GacA-dependent rsmY and rsmZ expression, suggesting a need for auxiliary transcription factors. One such factor involved in the activation of the rsmZ promoter was identified as the PsrA protein, previously recognized as an activator of the rpoS gene and a repressor of fatty acid degradation. Furthermore, the integration host factor (IHF) protein was found to bind with high affinity to the rsmZ promoter region in vitro, suggesting that DNA bending contributes to the regulated expression of rsmZ. In an rsmXYZ triple mutant, the expression of rsmY and rsmZ was elevated above that found in the wild type. This negative feedback loop appears to involve the translational regulators RsmA and RsmE, whose activity is antagonized by RsmXYZ, and several hypothetical DNA-binding proteins. This highly complex network controls the expression of the three small RNAs in response to cell physiology and cell population densities

LrhA as a new transcriptional key regulator of flagella, motility and chemotaxis genes in Escherichia coli

Lehnen D, Blumer C, Polen T, Wackwitz B, Wendisch VF, Unden G. LrhA as a new transcriptional key regulator of flagella, motility and chemotaxis genes in Escherichia coli. Molecular Microbiology. 2002;45(2):521-532.The function of the LysR-type regulator LrhA of Escherichia coli was defined by comparing whole-genome mRNA profiles from wild-type E. coli and an isogenic lrhA mutant on a DNA microarray. In the lrhA mutant, a large number (48) of genes involved in flagellation, motility and chemotaxis showed relative mRNA abundances increased by factors between 3 and 80. When a representative set of five flagellar, motility and chemotaxis genes was tested in lacZ reporter gene fusions, similar factors for derepression were found in the lrhA mutant. In gel retardation experiments, the LrhA protein bound specifically to flhD and lrhA promoter DNA (apparent K-D approximate to 20 nM), whereas the promoters of fliC , fliA and trg were not bound by LrhA. The expression of flhDC (encoding FlhD(2)C(2)) was derepressed by a factor of 3.5 in the lrhA mutant. FlhD(2)C(2) is known as the master regulator for the expression of flagellar and chemotaxis genes. By DNase I footprinting, LrhA binding sites at the flhDC and lrhA promoters were identified. The lrhA gene was under positive autoregulation by LrhA as shown by gel retardation and lrhA expression studies. It is suggested that LrhA is a key regulator controlling the transcription of flagellar, motility and chemotaxis genes by regulating the synthesis and concentration of FlhD(2)C(2)