Identification of responders to immune checkpoint therapy: which biomarkers have the highest value?

Evasion of immune recognition by the innate and acquired immune system is a major principle of tumour cells and belongs to the hallmarks of cancer. Immune checkpoint inhibitor-based cancer therapies targeting the co-inhibitory receptors CTLA-4 or PD-1 have received enormous scientific and clinical attention during the last few years, because of promising clinical results observed in the treatment of different cancer entities including melanoma and cutaneous squamous cell carcinoma. However, the enthusiasm about the effects of the immune checkpoint inhibitors is muted as only a subfraction of patients shows a stable clinical response. To predefine the patient cohorts that may benefit from immune checkpoint therapy, rigorous biomarker analyses, which predict the response to these novel therapies, need to be performed. In addition, combination of immune checkpoint therapy with classical DNA-damaging chemotherapy or radiotherapy, which positively affects tumour neo-antigen presentation, appears to be a promising approach in optimizing patients' response. In this review, we briefly summarize important biomarkers for patient stratification and discuss the current limitations of these biomarkers in defining responders vs. non-responders to immune checkpoint therapy.

Multi-color magnetic nanoparticle imaging using magnetorelaxometry.

Magnetorelaxometry (MRX) is a well-known measurement technique which allows the retrieval of magnetic nanoparticle (MNP) characteristics such as size distribution and clustering behavior. This technique also enables the non-invasive reconstruction of the spatial MNP distribution by solving an inverse problem, referred to as MRX imaging. Although MRX allows the imaging of a broad range of MNP types, little research has been done on imaging different MNP types simultaneously. Biomedical applications can benefit significantly from a measurement technique that allows the separation of the resulting measurement signal into its components originating from different MNP types. In this paper, we present a theoretical procedure and experimental validation to show the feasibility of MRX imaging in reconstructing multiple MNP types simultaneously. Because each particle type has its own characteristic MRX signal, it is possible to take this a priori information into account while solving the inverse problem. This way each particle type's signal can be separated and its spatial distribution reconstructed. By assigning a unique color code and intensity to each particle type's signal, an image can be obtained in which each spatial distribution is depicted in the resulting color and with the intensity measuring the amount of particles of that type, hence the name multi-color MNP imaging. The theoretical procedure is validated by reconstructing six phantoms, with different spatial arrangements of multiple MNP types, using MRX imaging. It is observed that MRX imaging easily allows up to four particle types to be separated simultaneously, meaning their quantitative spatial distributions can be obtained.

Stentgraft Implantation for the Treatment of Postoperative Hepatic Artery Pseudoaneurysm.

PURPOSE: Hepatic artery pseudoaneurysms are a rare but potentially life-threatening complication of major pancreaticobiliary surgery. We evaluated the safety and efficacy of endovascular stentgraft implantation for the management of such vascular lesions. MATERIALS AND METHODS: Between May 2013 and October 2015, ten patients with postoperative hepatic artery pseudoaneurysm, of which eight presented with active hemorrhage, were treated with endovascular stentgraft implantation. All patients had undergone major pancreatic or hepatic surgery before (pylorus-preserving pancreaticoduodenectomy, pancreatectomy, hemihepatectomy, extended hemihepatectomy). The pseudoaneurysms were diagnosed 13-202 days after surgery and were associated with postsurgical complications (e.g., leakage of pancreaticojejunal anastomosis). RESULTS: In 9/10 patients, the pseudoaneurysm was completely excluded via stentgraft implantation. In 1/10 patient, the pseudoaneurysm ruptured during the procedure and was successfully treated by immediate open surgery. In 1/10 patient, a second intervention was performed after 6 days because of rebleeding; this was successfully treated by implantation of a second overlapping stentgraft. Mean follow-up time is 51 days. None of the patients died due to stentgraft- or aneurysm-related complications. Further episodes of hemorrhage were not observed. In one patient, clinically asymptomatic complete occlusion of the stentgraft was discovered at follow-up imaging. CONCLUSION: Stentgraft implantation is a safe and effective technique to treat hepatic artery pseudoaneurysms related to major pancreatic or hepatic surgery, especially in the setting of acute hemorrhage.

HIPK2 restricts SIRT1 activity upon severe DNA damage by a phosphorylation-controlled mechanism.

Upon severe DNA damage a cellular signalling network initiates a cell death response through activating tumour suppressor p53 in association with promyelocytic leukaemia (PML) nuclear bodies. The deacetylase Sirtuin 1 (SIRT1) suppresses cell death after DNA damage by antagonizing p53 acetylation. To facilitate efficient p53 acetylation, SIRT1 function needs to be restricted. How SIRT1 activity is regulated under these conditions remains largely unclear. Here we provide evidence that SIRT1 activity is limited upon severe DNA damage through phosphorylation by the DNA damage-responsive kinase HIPK2. We found that DNA damage provokes interaction of SIRT1 and HIPK2, which phosphorylates SIRT1 at Serine 682 upon lethal damage. Furthermore, upon DNA damage SIRT1 and HIPK2 colocalize at PML nuclear bodies, and PML depletion abrogates DNA damage-induced SIRT1 Ser682 phosphorylation. We show that Ser682 phosphorylation inhibits SIRT1 activity and impacts on p53 acetylation, apoptotic p53 target gene expression and cell death. Mechanistically, we found that DNA damage-induced SIRT1 Ser682 phosphorylation provokes disruption of the complex between SIRT1 and its activator AROS. Our findings indicate that phosphorylation-dependent restriction of SIRT1 activity by HIPK2 shapes the p53 response.

Quantitative imaging of magnetic nanoparticles by magnetorelaxometry with multiple excitation coils.

New therapies against cancer based on magnetic nanoparticles (MNPs) require a quantitative spatially resolved imaging of MNPs inside a body. In magnetorelaxometry (MRX), a distribution of nanoparticles can be quantified non-invasively by measuring its relaxation after removal of an external magnetizing field. Conventionally, in MRX the sample is exposed to a homogeneous magnetizing field resulting in a quantitative reconstruction with rather poor spatial resolution. Theoretical work suggests an improvement of spatial resolution may be achieved by a sequential application of inhomogeneous fields magnetizing only parts of a sample. Here, we experimentally demonstrate the feasibility of this approach by reconstructing a nanoparticle distribution inside a compact three-dimensional volume phantom made of 54 gypsum cubes (1 cm(3) cube(-1)), of which 12 gypsum cubes were filled with MNPs. Using 48 small excitation coils surrounding the phantom, a sequence of MRX signals was obtained where only those MNPs near an individual coil contribute. By combined evaluation of these 48 MRX measurements, the positions and content of the 12 MNP-filled cubes could be determined accurately with a deviation below 4%, while by conventional homogeneous MRX only the MNP content was reconstructable with a deviation of about 9%. The results demonstrate the improvement of quantitative MRX imaging by using sequential activation of multiple magnetizing fields.

Evaluation of the activated clotting time and activated partial thromboplastin time for the monitoring of heparin in adult extracorporeal membrane oxygenation patients.

INTRODUCTION: Historically, the activated clotting time (ACT) has been the preferred monitoring test of the heparin effect in extracorporeal membrane oxygenation (ECMO) patients. However, few adult studies have evaluated its correlation to the heparin dose or other monitoring tests, such as the activated partial thromboplastin time (aPTT). This retrospective study sought to evaluate the correlation between the heparin dose and these monitoring tests. METHODS: Patients administered a heparin drip during ECMO were included in this study. The primary endpoints were the correlation between heparin dose and ACT or aPTT and the relationship between paired ACT and aPTT samples. RESULTS: Forty-six patients met the criteria for study inclusion. A better correlation was observed for heparin dose and aPTT (Pearson product-moment correlation coefficient (r) = 0.43 - 0.54) versus ACT (r = 0.11 - 0.14). Among the paired sample data, ACT values did not differ significantly between Groups two (aPTT 60 - 75 seconds) and three (aPTT >75 seconds). CONCLUSION: The heparin dose correlated better with aPTT relative to ACT and, thus, may be considered a more effective tool for the dosing of heparin in adult ECMO patients. Paired ACT and aPTT sample data suggested a poor relationship between these two anticoagulant monitoring tests.

Adult height and epigenotype in children with Silver-Russell syndrome treated with GH.

AIMS: To compare adult heights of GH-treated and GH-untreated patients with Silver-Russell syndrome (SRS) who were epigenotyped. METHODS: This was a nonrandomized retrospective study with matched controls at a single center. Molecular analysis of 32 out of 37 GH-treated patients (16 females) revealed IGF2-H19 epimutations in 12 and maternal uniparental disomy of chromosome 7 (matUPD7) in 5 patients; 15 were negative. At start of GH, mean age was 7.2 years and mean height -3.34 standard deviation score (SDS). Mean GH dose used was 51 µg/kg·day, mean duration of therapy was 5.6 years. Puberty was blocked by GnRH analogs in 16 patients. The untreated group comprised 13 individuals (5 females, mean age 6.8 years and mean height -3.34 SDS). End points were adult height and overall height gain. RESULTS: GH-treated patients reached an adult height of -2.12 ± 0.98 SDS gaining 1.22 SDS in comparison to baseline. Adult height SDS of the untreated was -3.13 ± 1.37 SDS. The matched treated patients were significantly taller than their untreated counterparts. Outcome was dependent on height at start of GH and duration of therapy. Height gain was highest in the shortest patients. CONCLUSIONS: GH improved adult height in SRS to a comparable degree as reported in nonsyndromic SGA children. A trend toward a better outcome in matUPD7 needs confirmation in larger cohorts.

[Physical medicine in hospital. Minimum standards in a physical medical department in acute inpatient areas in rheumatology]. / Physikalische Medizin im Krankenhaus. Minimalstandards in einer physikalisch medizinischen Abteilung im akutstationären Bereich in der Rheumatologie.

Standards for what should be available in terms of equipment and services in a department of physical medicine caring for acute inpatients do not exist in Germany. The profile of a department determines the therapeutic services it focuses on and hence the technical facilities required. The German catalogue of operations and procedures defines minimum thresholds for treatment. In the opinion of the authors a department caring for inpatients with acute rheumatic diseases must, as a minimum, have the facilities and equipment necessary for offering thermotherapeutic treatment. Staff trained in physical therapeutic procedures and occupational therapy is also crucial. Moreover, it is desirable that the staff should be trained in manual therapy.

[Effect of clothing on sphygmomanometric and oscillometric blood pressure measurement in hypertensive subjects]. / Der Einfluss von Bekleidung auf die sphygmomanometrische und oszillometrische Blutdruckmessung bei Hypertonikern.

BACKGROUND AND OBJECTIVE: The few studies published on this subject have shown that blood pressure measurements give similar results whether the patients' arm is covered by clothing or not. But it has not been clarified whether this is also true in the case of hypertensive persons, Yet, in practice the correct measurement is of critical importance in the diagnosis of hypertension. METHODS: 203 hypertensive patients were examined with the auscultatory sphygmomanometry and the automatic oscillometry by measuring the pressure three times with each method. These tests were carried out in a randomized sequence on a covered arm (the patient's own clothing of maximally 2 mm thickness), the bare arm and the arm covered with a standardized cotton sleeve (2 mm). The auscultatory sphygmomanometry was done blinded (non-sleeved, sleeved, standardized). RESULTS: Calculation of confidence intervals for the mean differences of the three settings (bare, clothing and standard sleeve) and equivalence testing demonstrated that a garment or cloth on the arm under the manometer cuffs did not significantly effect the blood pressure within the predefined interval of equivalence of +/- 4 mm Hg. Thus, measuring blood pressure with the cuff over the person's sleeve does not significantly effect the result. CONCLUSION: This study shows that measuring blood pressure in hypertensive persons with or without a cloth sleeve (maximally 2 mm thick) does not result in any statistically significant difference. This simplifies the blood pressure measurement that have to be taken frequently on hypertensive persons.

Olefin metathesis in supercritical carbon dioxide.

Liquid or supercritical carbon dioxide (scCO(2)) is a versatile reaction medium for ring-opening metathesis polymerization (ROMP) and ring-closing olefin metathesis (RCM) reactions using well-defined metal catalysts. The molybdenum alkylidene complex 1 and ruthenium carbenes 2 and 3 bearing PCy(3) or N-heterocyclic carbene ligands, respectively, can be used and are found to exhibit efficiency similar to that in chlorinated organic solvents. While compound 1 is readily soluble in scCO(2), complexes 2 and 3 behave like heterogeneous catalysts in this reaction medium. Importantly, however, the unique properties of scCO(2) provide significant advantages beyond simple solvent replacement. This pertains to highly convenient workup procedures both for polymeric and low molecular weight products, to catalyst immobilization, to reaction tuning by density control (RCM versus acyclic diene metathesis polymerization), and to applications of scCO(2) as a protective medium for basic amine functions. The latter phenomenon is explained by the reversible formation of the corresponding carbamic acid as evidenced by (1)H NMR data obtained in compressed CO(2). Together with its environmentally and toxicologically benign character, these unique physicochemical features sum up to a very attractive solvent profile of carbon dioxide for sustainable synthesis and production.

CD8(+) lymphocytes from simian immunodeficiency virus-infected rhesus macaques recognize 14 different epitopes bound by the major histocompatibility complex class I molecule mamu-A*01: implications for vaccine design and testing.

It is becoming increasingly clear that any human immunodeficiency virus (HIV) vaccine should induce a strong CD8(+) response. Additional desirable elements are multispecificity and a focus on conserved epitopes. The use of multiple conserved epitopes arranged in an artificial gene (or EpiGene) is a potential means to achieve these goals. To test this concept in a relevant disease model we sought to identify multiple simian immunodeficiency virus (SIV)-derived CD8(+) epitopes bound by a single nonhuman primate major histocompatibility complex (MHC) class I molecule. We had previously identified the peptide binding motif of Mamu-A*01(2), a common rhesus macaque MHC class I molecule that presents the immunodominant SIV gag-derived cytotoxic T lymphocyte (CTL) epitope Gag_CM9 (CTPYDINQM). Herein, we scanned SIV proteins for the presence of Mamu-A*01 motifs. The binding capacity of 221 motif-positive peptides was determined using purified Mamu-A*01 molecules. Thirty-seven peptides bound with apparent K(d) values of 500 nM or lower, with 21 peptides binding better than the Gag_CM9 peptide. Peripheral blood mononuclear cells from SIV-infected Mamu-A*01(+) macaques recognized 14 of these peptides in ELISPOT, CTL, or tetramer analyses. This study reveals an unprecedented complexity and diversity of anti-SIV CTL responses. Furthermore, it represents an important step toward the design of a multiepitope vaccine for SIV and HIV.

Indenylidene complexes of ruthenium: optimized synthesis, structure elucidation, and performance as catalysts for olefin metathesis--application to the synthesis of the ADE-ring system of nakadomarin A.

An optimized and large scale adaptable synthesis of the ruthenium phenylindenylidene complex 3 is described which employs commercially available diphenyl propargyl alcohol 5 as a stable and convenient carbene source. Previous ambiguities as to the actual structure of the complex have been ruled out by a full analysis of its NMR spectra. A series of applications to ring closing metathesis (RCM) reactions shows that complex 3 is as good as or even superior to the classical Grubbs carbene 1 in terms of yield, reaction rate, and tolerance towards polar functional groups. Complex 3 turns out to be the catalyst of choice for the synthesis of the enantiopure core segment 77 of the marine alkaloid nakadomarin A 60 comprising the ADE rings of this target. Together with a series of other examples, this particular application illustrates that catalyst 3 is particularly well suited for the cyclization of medium-sized rings by RCM. Other key steps en route to nakadomarin A are a highly selective intramolecular Michael addition setting the quaternary center at the juncture of the A and D rings and a Takai-Nozaki olefination of aldehyde 73 with CH2I2, Ti(OiPr)4 and activated zinc dust.

Tat-specific cytotoxic T lymphocytes select for SIV escape variants during resolution of primary viraemia.

Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections are characterized by early peaks of viraemia that decline as strong cellular immune responses develop. Although it has been shown that virus-specific CD8-positive cytotoxic T lymphocytes (CTLs) exert selective pressure during HIV and SIV infection, the data have been controversial. Here we show that Tat-specific CD8-positive T-lymphocyte responses select for new viral escape variants during the acute phase of infection. We sequenced the entire virus immediately after the acute phase, and found that amino-acid replacements accumulated primarily in Tat CTL epitopes. This implies that Tat-specific CTLs may be significantly involved in controlling wild-type virus replication, and suggests that responses against viral proteins that are expressed early during the viral life cycle might be attractive targets for HIV vaccine development.