Cisplatin and 5-fluorouracil with or without epidermal growth factor receptor inhibition panitumumab for patients with non-resectable, advanced or metastatic oesophageal squamous cell cancer: a prospective, open-label, randomised phase III AIO/EORTC trial (POWER).

BACKGROUND: Palliative chemotherapy of advanced oesophageal squamous cell cancer (ESCC) consists of cisplatin/5-fluorouracil (CF) to target epidermal growth factor receptor (EGFR) with panitumumab (P); chemotherapy enhanced overall survival (OS) in advanced colorectal or squamous cell head and neck cancers. With prospective serum and tumour biomarkers, we tested if P added to CF (CFP) improved OS in advanced ESCC. PATIENTS AND METHODS: Eligible patients with confirmed ESCC that was not curatively resectable or did not qualify for definitive radiochemotherapy, were randomised 1 : 1 to receive CF [cisplatin (C) 100 mg/m2 i.v., day 1; 5-fluorouracil (F) 1000 mg/m2 i.v., days 1-4] or CF plus P (9 mg/kg, i.v., day 1, each q3-week cycle) until progressive disease or unacceptable toxicity. Safety was reviewed by the Data Safety Monitoring Board after 40, 70 and 100 patients who completed at least one cycle. After 53 enrolled patients, cisplatin was reduced from 100 mg/m2 to 80 mg/m2. RESULTS: The trial was stopped early based on interim efficacy results triggered by the third safety analysis: median OS (mOS) favoured CF over CFP, regardless of cisplatin dose [hazard ratio (HR) 1.77, 95% confidence interval (CI) 1.06-2.98; P = 0.028]. In the final analysis, mOS was 10.2 versus 9.4 months for CF versus CFP, respectively (HR 1.17, 95% CI 0.79-1.75; P = 0.43). One hundred (70.4%) of 142 patients in the safety population died, 51 (51.0%) with CFP. Most deaths were related to disease progression [44/49 (90%) deaths in CF versus 34/51 (67%) deaths in CFP]; objective responses [27/73 (37.0%)] were identical. The most common serious adverse events were kidney injury [3 (4.3%) versus 7 (9.7%)], general health deterioration [5 (7.1%) versus 5 (6.9%)] and dysphagia [4 (5.7%) versus 4 (5.6%)] in CF versus CFP, respectively. There were three (4.3%) and 17 (23.6%) common terminology criteria for adverse events (CTCAE) grade 5 events in CF versus CFP, respectively. Low soluble (s)EGFR levels were associated with better progression-free survival; sEGFR was induced under CFP. CONCLUSION: EGFR inhibition added to CF did not improve survival in unselected advanced ESCC patients. The results support further liquid biopsy studies. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01627379) and EudraCT (2010-020606-15).

Tracing the evolution of the heterotrimeric G protein α subunit in Metazoa.

BACKGROUND: Heterotrimeric G proteins are fundamental signaling proteins composed of three subunits, Gα and a Gßγ dimer. The role of Gα as a molecular switch is critical for transmitting and amplifying intracellular signaling cascades initiated by an activated G protein Coupled Receptor (GPCR). Despite their biochemical and therapeutic importance, the study of G protein evolution has been limited to the scope of a few model organisms. Furthermore, of the five primary Gα subfamilies, the underlying gene structure of only two families has been thoroughly investigated outside of Mammalia evolution. Therefore our understanding of Gα emergence and evolution across phylogeny remains incomplete. RESULTS: We have computationally identified the presence and absence of every Gα gene (GNA-) across all major branches of Deuterostomia and evaluated the conservation of the underlying exon-intron structures across these phylogenetic groups. We provide evidence of mutually exclusive exon inclusion through alternative splicing in specific lineages. Variations of splice site conservation and isoforms were found for several paralogs which coincide with conserved, putative motifs of DNA-/RNA-binding proteins. In addition to our curated gene annotations, within Primates, we identified 15 retrotranspositions, many of which have undergone pseudogenization. Most importantly, we find numerous deviations from previous findings regarding the presence and absence of individual GNA- genes, nuanced differences in phyla-specific gene copy numbers, novel paralog duplications and subsequent intron gain and loss events. CONCLUSIONS: Our curated annotations allow us to draw more accurate inferences regarding the emergence of all Gα family members across Metazoa and to present a new, updated theory of Gα evolution. Leveraging this, our results are critical for gaining new insights into the co-evolution of the Gα subunit and its many protein binding partners, especially therapeutically relevant G protein - GPCR signaling pathways which radiated in Vertebrata evolution.

Millifluidic magnetophoresis-based chip for age-specific fractionation: evaluating the impact of age on metabolomics and gene expression in yeast.

A novel millifluidic process introduces age-based fractionation of S. pastorianus var. carlsbergensis yeast culture through magnetophoresis. Saccharomyces yeast is a model organism for aging research used in various industries. Traditional age-based cell separation methods were labor-intensive, but techniques like magnetic labeling have eased the process by being non-invasive and scalable. Our approach introduces an age-specific fractionation using a 3D-printed millfluidic chip in a two-step process, ensuring efficient cell deflection in the magnetic field and counteracting magnetic induced convection. Among various channel designs, the pinch-shaped channel proved most effective for age differentiation based on magnetically labeled bud scar numbers. Metabolomic analyses revealed changes in certain amino acids and increased NAD+ levels, suggesting metabolic shifts in aging cells. Gene expression studies further underlined these age-related metabolic changes. This innovative platform offers a high-throughput, non-invasive method for age-specific yeast cell fractionation, with potential applications in industries ranging from food and beverages to pharmaceuticals.

Modeling conformational states of proteins with AlphaFold.

Many proteins exert their function by switching among different structures. Knowing the conformational ensembles affiliated with these states is critical to elucidate key mechanistic aspects that govern protein function. While experimental determination efforts are still bottlenecked by cost, time, and technical challenges, the machine-learning technology AlphaFold showed near experimental accuracy in predicting the three-dimensional structure of monomeric proteins. However, an AlphaFold ensemble of models usually represents a single conformational state with minimal structural heterogeneity. Consequently, several pipelines have been proposed to either expand the structural breadth of an ensemble or bias the prediction toward a desired conformational state. Here, we analyze how those pipelines work, what they can and cannot predict, and future directions.

Targeting in silico GPCR conformations with ultra-large library screening for hit discovery.

The use of deep machine learning (ML) in protein structure prediction has made it possible to easily access a large number of annotated conformations that can potentially compensate for missing experimental structures in structure-based drug discovery (SBDD). However, it is still unclear whether the accuracy of these predicted conformations is sufficient for screening chemical compounds that will effectively interact with a protein target for pharmacological purposes. In this opinion article, we examine the potential benefits and limitations of using state-annotated conformations for ultra-large library screening (ULLS) in light of the growing size of ultra-large libraries (ULLs). We believe that targeting different conformational states of common drug targets like G-protein-coupled receptors (GPCRs), which can regulate human physiology by switching between different conformations, can offer multiple advantages.

Which animals are at risk? Predicting species susceptibility to Covid-19.

In only a few months, the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic, leaving physicians, scientists, and public health officials racing to understand, treat, and contain this zoonotic disease. SARS-CoV-2 has made the leap from animals to humans, but little is known about variations in species susceptibility that could identify potential reservoir species, animal models, and the risk to pets, wildlife, and livestock. While there is evidence that certain species, such as cats, are susceptible, the vast majority of animal species, including those in close contact with humans, have unknown susceptibility. Hence, methods to predict their infection risk are urgently needed. SARS-CoV-2 spike protein binding to angiotensin converting enzyme 2 (ACE2) is critical for viral cell entry and infection. Here we identified key ACE2 residues that distinguish susceptible from resistant species using in-depth sequence and structural analyses of ACE2 and its binding to SARS-CoV-2. Our findings have important implications for identification of ACE2 and SARS-CoV-2 residues for therapeutic targeting and identification of animal species with increased susceptibility for infection on which to focus research and protection measures for environmental and public health.

Tip60 is a cell-type-specific transcriptional regulator.

Tip60 was originally identified as cellular HIV-Tat interacting protein and has been shown to augment Tat-dependent transcription. It has also been shown to interact with various cellular transcription factors and to belong to the nuclear histone acetyltransferase (HAT) family. To further elucidate the function of Tip60 and its HAT domain in transcription regulation, we compared Tip60 activity in HeLa and Jurkat T lymphoma cells. Here we show that Tip60 augments the HIV-1 Tat activity at the HIV-LTR promoter in HeLa but inhibits it in Jurkat cells. Moreover, we isolated two new variants of the Tip60 protein (Tip60Delta1, Tip60Delta2) from Jurkat cells. The Tip60Delta2 variant lacks the entire HAT domain but modulates HIV-1 Tat activity like full-length Tip60. In addition, Tip60 and the transcriptional repressor ZEB (zinc finger E box binding protein) interact specifically in the yeast two-hybrid system and additively inhibit the CD4 enhancer/promoter activity in Jurkat cells. Thus, Tip60 may function as corepressor of the ZEB protein. In summary, these data show that Tip60 functions as a cell-type-specific transcriptional regulator and that the HAT domain is not required for either transcriptional activation or inhibition. This indicates that Tip60 may function by recruiting additional cell-type-specific cofactors.

[Effective prefilter and patient dosage]. / Effektives Vorfilter und Patientendosis.

The dose of incidence at a distance of 1 m from the focus is stated as pre-filtration characteristics of modern x-ray tube assemblies for estimating the patient dose. The examinations cover a constant d.c. voltage range from 40 to 150 kV and the exposure range that is of practical interest.

[Limitations of detail recognition in radiographs due to threshold contrast values (author's transl)]. / Die Begrenzung der Detailerkennbarkeit im Röntgenbild durch den Schwellenkontrast.

The minimal contrast was studied which can be recognised by the eye, using similar, neighbouring images under varying conditions of brightness. Subsequently the effect of contrast thresholds on the recognition of detail in radiographs has been examined.

[The effect of increased performance of modern x-ray tubes on improvements in picture quality, particularly of moving organs (author's transl)]. / Die Auswirkungen der gesteigerten Leistungsfähigkeit moderner röntgenröhren und der Verbesserungen in den Abbildungssystemen, auf die Bildqualität von Röntgenaufnahmen, insbesondere bewegter Organe

The deleterious effect of organ movement on radiographic quality is examined. In connection with this, the performance of various focal spots is discussed, particularly of a modern high speed tube with focal spots of 1.2, 1.5 and 1.8, with a resolution in the region of 3 to 6 lp/mm. A detailed discussion of the results is given with examples derived from various techniques used for the stomach and lungs. The results indicate that there is considerable improvement to be derived from high performance tubes with small focal spots. A further significant advance is also due to the high resolution image intensifiers. These have resulted in a marked increase in the use of 70 and 100 mm. film.

[Modulation transfer function of the radiograph (author's transl)]. / Die Modulationsübertragungsfunktion des Röntgenbildes

Individual modulation transfer functions of the recording system were related to total modulation transfer function; examples derived from radiographs of the lungs, stomach and gall bladder were used to show that proper evaluation of the radiograph requires consideration of the relationship between original contrast and detailed size. The total transfer function shows a rapid decline of the contrast factor with increasing point frequency. It has been shown that the pseudo record which could be expected from the usual transfer functions of the recording system does not, in fact, appear.

[Modulation transmission function and detail recognition in tomograms (author's transl)]. / Modulationsübertragungsfunktionen und Detailerkennbarkeit beim Tomogramm.

Tomograms with linear movements and 40 degrees swing have shown that the usual T-modulation transmission function is inadequate and that the I-modulation transmission function is as significant as for plain films. Moreover, several selected modulation transmission functions are necessary. Even if resolution is high, detail recognition is reduced in relation to the threshold contrast. This is particularly true for the level of the cut and its close vicinity. On the other hand, pseudoimages are supressed by the threshold contrast.

[Factors influencing radiation exposure in radiography]. / Abhängigkeiten der Strahlenexposition bei Röntgenaufnahmen.

After explaining how to correct total prefiltration of an x-ray-tube assembly, and of the factors influencing radiation exposure when taking x-rays, the article shows how at a known voltage radiation exposure is determined from the mAs values. Comparative radiation exposure values are given for various types of prefiltration.

[The value of the x-ray spectrum with regard to x-ray filtration (author's transl)]. / Die Aussagefähigkeit des Röntgenspektrums zur Strahlenfilterung.

After some preliminary remarks on the production and spectral composition of X-Rays it is demonstrated, how the total filtration of the X-Rays including the filtration in the anode can be found from the X-Ray Bremsspektrum. The curves for determining this filtration include filters up to 50 mm AI-Equivalent for 40 to 150 kV constant direct voltage.