One- and two-photon absorption spectra of organoboron complexes: vibronic and environmental effects

We synthesized a series of four parent aza-β-ketoiminate organoboron complexes and performed spectroscopic studies using both experimental and computational techniques. We studied how benzannulation influences the vibronic structure of the UV/Vis absorption bands with a focus on the bright lowest-energy π → π* electronic excitation. Theoretical simulations, accounting for inhomogeneous broadening effects using different embedding schemes, allowed gaining in-depth insights into the observed differences in band shapes induced by structural modifications. We observed huge variations in the distributions of vibronic transitions depending on the position of benzannulation. By and large, the harmonic approximation combined with the adiabatic hessian model delivers qualitatively correct band shapes for the one-photon absorption spectra, except in one case. We also assessed the importance of non-Condon effects (accounted for by the linear term in Herzberg-Teller expansion of the dipole moment) for S0 → S1 band shapes. It turned out that non-Condon contributions have no effect on the band shape in one-photon absorption spectra. In contrast, these effects significantly change the Franck-Condon band shapes of the two-photon absorption spectra. For one of the studied organoboron complexes we also performed a preliminary exploration of mechanical anharmonicity, resulting in an increase of the intensity of the 0-0 transition, which improves the agreement with the experimental data compared to the harmonic model.

Photoswitchable Molecular Units with Tunable Nonlinear Optical Activity: A Theoretical Investigation

The first-, second-, and third-order molecular nonlinear optical properties, including two-photon absorption of a series of derivatives, involving two dithienylethene (DTE) groups connected by several molecular linkers (bis(ethylene-1,2-dithiolato)Ni- (NiBDT), naphthalene, quasilinear oligothiophene chains), are investigated by employing density functional theory (DFT). These properties can be efficiently controlled by DTE switches, in connection with light of appropriate frequency. NiBDT, as a linker, is associated with a greater contrast, in comparison to naphthalene, between the first and second hyperpolarizabilities of the "open-open" and the "closed-closed" isomers. This is explained by invoking the low-lying excited states of NiBDT. It is shown that the second hyperpolarizability can be used as an index, which follows the structural changes induced by photochromism. Assuming a Förster type transfer mechanism, the intramolecular excited-state energy transfer (EET) mechanism is studied. Two important parameters related to this are computed: the electronic coupling (VDA) between the donor and acceptor fragments as well as the overlap between the absorption and emission spectra of the donor and acceptor groups. NiBDT as a linker is associated with a low electronic coupling, VDA, value. We found that VDA is affected by molecular geometry. Our results predict that the linker strongly influences the communication between the open-closed DTE groups. The sensitivity of the molecular nonlinear optical properties could assist with identification of molecular isomers.

Decoding the infrared spectra changes upon formation of molecular complexes: the case of halogen bonding in pyridine⋯perfluorohaloarene complexes

A recently developed computational scheme is employed to interpret changes in the infrared spectra of halogen-bonded systems in terms of intermolecular interaction energy components (electrostatic, exchange, induction, dispersion) taking pyridine⋯perfluorohaloarene complexes as examples. For all complexes, we find a strong linear correlation between the different terms of the interaction-induced changes of the IR band associated with an intermolecular halogen bond stretching mode and the corresponding terms of the interaction energy, which implies that the interaction components play similar roles in both properties. This is not true for other vibrational modes localized in one of the monomers studied here, for which the corresponding interaction-induced changes in IR bands may present a completely different decomposition than the interaction energy.

The NeuroSAFE frozen section technique during radical prostatectomy - Implementation and optimization of technical aspects in a routine pathology workflow

BACKGROUND AND AIMS

In prostate cancer patients, application of the NeuroSAFE frozen section technique during radical prostatectomy has been shown to increase the rate of nerve sparing surgery and to improve functional outcome for the patients. The aim of this study is to report on technical and organizational optimization opportunities of the procedure.

MATERIAL AND METHODS

All patients submitted to bilateral intraoperative frozen section from January 2018 until December 2020 (n = 452) were retrospectively analyzed and parameters such as turnaround time, staff situation in the laboratory and histologic properties of the tumors were assessed.

RESULTS

The median turnaround time per case was 40.3 ( ± 10.5) min. In 2020 the average time needed from accessioning to diagnosis was 38.1 min. Multivariate linear regression suggested that the number of technical assistants/cryotomes (46.1 min vs. 39.13 min; p < 0.001), the place of microscopic examination (43.0 min vs. 38.7 min; p < 0.001) and the presence of a positive margin (38.0 vs. 44.0 min; p < 0.001) were significant influential factors. The turnaround time was independent of the uropathological expertize of the consultant (39.84 min vs. 40.7 min; p = 0.09), the tumor grade (42.3 vs 39.8 min; p = 0.493) and the presence of extraprostatic extension (44.0 vs 39.8 min; p = 0.099).

CONCLUSION

The implementation of simple optimization measures in the workflow as well as structured training of all pathology staff involved in the examination leads to a significant increase in the efficiency of the examination while maintaining the same level of resources. The results could thus be a contribution to the broader application of the procedure.

A new computational tool for interpreting infrared spectra of molecular complexes

The popularity of the Infrared (IR) spectroscopy is due to its high interpretive power. This study presents a new computational tool for analyzing the IR spectra of molecular complexes in...

Main results of the first Brazilian Registry of Heart Failure (BREATHE)

Background

Heart failure represents a common cause of hospitalization associated with poor short-term clinical outcomes. Little is known about the long-term prognosis of these patients in Latin America.

Methods

The rationale and design of the study were previously published (1). Briefly, BREATHE was the first nation-wide prospective observational study that included patients hospitalized due to acute heart failure in Brazil. In-hospital management as well as 12-month clinical outcomes were assessed. Patients were included during two time periods: from February 2011 to December 2012 (BREATHE I) and from June 2016 to July 2018 (BREATHE Extension). Adherence to evidence-based therapies was also evaluated.

Results

A total of 3,013 patients were included in 71 centers in Brazil. The median follow-up was 346 days. The BREATHE population included 39.3% of women, had a mean age of 65.2 (± 15.6) with a mean ejection fraction of 39.7% (± 17.5). Among the comorbidities, systemic arterial hypertension was the most common, present in almost 75% of the sample. At hospital admission, 83.8% of patients had clear signs of pulmonary congestion and the main cause of decompensation was poor adherence to heart failure medications, representing 27.8% of cases. Among patients with reduced ejection fraction, the concomitant use of renin-angiotensin-aldosterone inhibitors, beta-blocker and spironolactone at hospital discharge was 44.5% and decreased to 35.2% after 3 months (p&lt;0.01). Mortality rate at 12 months was 28.9 for every 100 patient years with 26.2% readmission at 90 days and 46.4% at 365 days. The most common etiology of heart failure was ischemic disease (Figure 1) but the worst prognosis was associated with Chagas disease (Figure 2) including an analysis of a composite outcome encompassing death, myocardial infarction, stroke or cardiac arrest after discharge.

Conclusions

In this large national prospective registry of patients hospitalized with acute heart failure, mortality and readmission were higher than what have been reported globally. Poor adherence to evidence-based therapies was a common both at hospital discharge and 1-year of follow-up.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Brazilian Society of Cardiology

Spinal subarachnoid haematoma after neuraxial anaesthesia in a patient with polycythaemia vera

Polycythaemia vera is a common haematological proliferative disorder. It is characterised by uncontrolled red cell production with ensuing peri-operative vaso-occlusive and haemorrhagic complications. Spinal haematoma after neuraxial anaesthesia is rare; most cases are associated with technical difficulties or bleeding disorders. Current consensus opinion suggests that neuraxial anaesthesia in patients with polycythaemia vera is safe due to a lower risk of thrombotic events and hypoxaemia compared with general anaesthesia. We report a case of a spinal subarachnoid haematoma after uneventful neuraxial anaesthesia in a patient with optimised polycythaemia vera. Despite an emergent laminectomy, the patient developed permanent motor deficits. This report highlights that although neuraxial anaesthesia is recommended by many authors, patients with polycythaemia vera can paradoxically have an increased haemorrhagic risk from platelet dysfunction and acquired von Willebrand disease. Clinicians proceeding with surgery under neuraxial anaesthesia should appreciate these risks even in patients with normal or apparently elevated thrombotic states. This case also demonstrates that traditional coagulation tests may need to be complemented by pre-operative platelet function tests and screening for von Willebrand disease. Finally, the importance of the patient participation in the choice of the anaesthesia technique cannot be understated, with specific attention paid to this frequently unrecognised risk.

Iatrogenic transthyretin cardiac amyloidosis after sequential liver transplantation

Introduction

Sequential liver transplantation (SLT) uses livers excised from patients with hereditary transthyretin-related amyloidosis during liver transplantation as grafts to other patients with severe hepatic pathologies and a reserved prognosis. We intended to investigate the development of cardiac manifestations consistent with iatrogenic transthyretin amyloidosis (iATTR).

Methods

We retrospectively analyzed the medical records of 72 consecutive patients submitted to SLT between 2007 and 2010, who received livers with V30M mutation.

Results

Our sample had 79% male patients and a mean age at transplantation of 55±6 years. Median follow-up time was 80 months, were 44% of the patients died. One-year mortality rate after SLT was 7%. Clinical manifestations of iATTR occurred in 29% of individuals, on average 6 years after SLT, and amyloid was seen in 76% of those who underwent a biopsy. Left ventricular hypertrophy (LVH) was identified in 42 (58%) patients at baseline. Considering 39 patients that had an echocardiography at baseline and during follow-up, 22 (61%) presented de novo LVH or basal LVH worsening during follow-up, with a significant increase of wall thickness (11±1 to 13±3 mm; p&lt;0.001). They had similar age at presentation (55±5 vs 58±5, p=0.249) and incidence of hypertension (52% vs 64%, p=0.365) but higher incidence of chronic kidney disease (CKD; 68% vs 29%, p=0.023). Mortality during follow-up was higher in patients with de novo LVH or worsening LVH but not significantly, probably due to the sample size (23% vs 7%, p=0.221, log rank test p=0.262). Considering the global sample, significant conduction changes were rarely seen (1 patient); however, there was a trend towards an increase in PR interval and atrial fibrillation was reported in 8% of cases.

Conclusions

In our sample, probable iATTR was often seen within a decade after SLT. Further investigation of LVH needs to be made in these patients, as it can represent amyloid cardiomyopathy, but other contributing factors such as hypertension, CKD and age need to be taken into consideration. In our sample, development of a possible infiltrative pattern was relatively more common and conduction disorders were rarer than one would extrapolate from hereditary early onset ATTR V30M patients. Further studies may help us clarify if indeed these patients behave like late onset ATTR V30M. Our data suggests that these patients should probably undergo periodic cardiac imaging during follow-up.

Funding Acknowledgement

Type of funding source: None

GNAQ and GNA11 mutant nonuveal melanoma: a subtype distinct from both cutaneous and uveal melanoma

BACKGROUND

GNAQ and GNA11 mutant nonuveal melanoma represent a poorly characterized rare subgroup of melanoma with a gene mutation profile similar to uveal melanoma.

OBJECTIVES

To characterize these tumours in terms of clinical behaviour and genetic characteristics.

METHODS

Patients with nonuveal GNAQ/11 mutated melanoma were identified from the prospective multicentre tumour tissue registry ADOREG, Tissue Registry in Melanoma (TRIM) and additional cooperating skin cancer centres. Extensive data on patient, tumour and treatment characteristics were collected retrospectively. Targeted sequencing was used to determine tumour mutational burden. Immunohistochemistry staining was performed for programmed death-ligand 1 and BRCA1-associated protein (BAP)1. Existing whole-exome cutaneous and uveal melanoma data were analysed for mutation type and burden.

RESULTS

We identified 18 patients with metastatic GNAQ/11 mutant nonuveal melanoma. Tumours had a lower tumour mutational burden and fewer ultraviolet signature mutations than cutaneous melanomas. In addition to GNAQ and GNA11 mutations (nine each), six splicing factor 3b subunit 1 (SF3B1), three eukaryotic translation initiation factor 1A X-linked (EIF1AX) and four BAP1 mutations were detected. In contrast to uveal melanoma, GNAQ/11 mutant nonuveal melanomas frequently metastasized lymphatically and concurrent EIF1AX, SF3B1 and BAP1 mutations showed no apparent association with patient prognosis. Objective response to immunotherapy was poor with only one partial response observed in 10 treated patients (10%).

CONCLUSIONS

Our findings suggest that GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is both clinically and genetically distinct from cutaneous and uveal melanoma. As they respond poorly to available treatment regimens, novel effective therapeutic approaches for affected patients are urgently needed. What is already known about this topic? The rare occurrence of GNAQ/11 mutations in nonuveal melanoma has been documented. GNAQ/11 mutant nonuveal melanomas also harbour genetic alterations in EIF1AX, SF3B1 and BAP1 that are of prognostic relevance in uveal melanoma. What does this study add? GNAQ/11 mutant nonuveal melanomas show metastatic spread reminiscent of cutaneous melanoma, but not uveal melanoma. GNAQ/11 mutant nonuveal melanomas have a low tumour mutational burden that is higher than uveal melanoma, but lower than cutaneous melanoma. What is the translational message? Primary GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is clinically and genetically distinct from both cutaneous and uveal melanoma. As metastatic GNAQ/11 mutant nonuveal melanomas respond poorly to available systemic therapies, including immune checkpoint inhibition, novel therapeutic approaches for these tumours are urgently needed. Linked Comment: Rafei-Shamsabadi. Br J Dermatol 2020; 183:806-807.

[Ectopic thyroid tissue in the adrenal gland : A case report and review of the literature]

We present a case of ectopic thyroid tissue in the adrenal gland and discuss the findings with regard to the literature. Ectopic thyroid tissue below the diaphragm is rare and the mechanism of development is poorly understood. From a differential diagnostic point of view, it is important to exclude metastatic spread from a thyroid primary.

Partitioning of interaction-induced nonlinear optical properties of molecular complexes. II. Halogen-bonded systems

Following our study on hydrogen-bonded (HB) complexes [Phys. Chem. Chem. Phys., 2018, 20, 19841], the physical nature of interaction-induced (non)linear optical properties of another important class of molecular complexes, namely halogen-bonded (XB) systems, was analyzed in this study. The excess electronic and nuclear relaxation (hyper)polarizabilities of nine representative XB complexes covering a wide range of halogen-bond strengths were computed. The partitioning of the excess properties into individual interaction-energy components (electrostatic, exchange, induction, dispersion) was performed by using the variational-perturbational energy decomposition scheme at the MP2/aug-cc-pVTZ level of theory and further supported by calculations with the SCS-MP2 method. In the case of the electronic interaction-induced properties, the physical composition of Δαel and Δγel was found to be very similar for the two types of bonding, despite the different nature of the binding. For Δβel, the XB complexes exhibit a more systematic interplay of interaction-energy contributions compared to the HB systems studied in the previous work. Our analysis revealed that the patterns of interaction-energy contributions to the interaction-induced nuclear-relaxation contributions to the linear polarizability and the first hyperpolarizability are very similar. For both properties the exchange repulsion term is canceled out by the electrostatic and delocalization terms. The physical composition of these contributions is analogous to those observed for the HB complexes.

[Predictive biomarkers in bladder cancer]

BACKGROUND

In the last few years, significant progress has been achieved in the therapeutic options for advanced urothelial bladder cancer.

OBJECTIVES

The aim of this work was to give an overview of the status and future perspective of the therapeutic options in this setting. Its focus is on the discussion of tissue-based therapy-predictive markers, which are evaluated through (molecular) pathology and thereby strengthening the role of pathology itself.

MATERIALS AND METHODS

Current (clinical study) data, the literature, and our own expertise were considered and summarized in the areas of therapy prediction of platinum-based chemotherapy, immunotherapy, and other therapeutic approaches.

RESULTS AND CONCLUSIONS

Molecular subtypes exhibit a predictive value both in platinum-based chemotherapy as well as in immunotherapy. However, further work is required to elucidate the predictive role of molecular subtypes in both settings. Changes in the DNA damage repair enzyme (DDR) genes, ERCC2, and ERBB2 as well as differences in the expression of EMMPRIN, survivin, and HMGA2 show promising results as further markers of chemotherapy efficacy. In the prediction of immunotherapy success, this mainly relates to the evaluation of the tumor mutation burden (TMB), tumor neoantigen burden (TNB), APOBEC signatures (MSig1; 3A/3B), and CD8-positive T‑effector cell signature. When using the fibroblast growth factor receptor (FGFR) inhibitor erdafitinib, which has not yet been approved in Germany, the evaluation of specific FGFR mutations and/or gene fusions by a companion diagnostic test is mandatory in the USA.

[Status of the availability and use of next generation sequencing (NGS) in bladder cancer-a questionnaire within the uropathology working group]

BACKGROUND

Technical advancement and availability of high-throughput analysis has advanced molecular subtyping of most cancers. Thus, new possibilities for precision oncology have emerged.

AIM

Therefore, we aimed to collect data regarding availability and use of next generation sequencing (NGS) for urothelial cancer within the uropathology working group of the German Society of Pathology.

METHODS

We collected data by questionnaires and additionally asked for sequencing results of bladder cancers in the participating institutions.

RESULTS

A total of 13 university-affiliated institutes of pathology took part in the survey. All university institutes offer NGS-based molecular panel diagnostics and provide panels covering between 15 and 170 genes. Altogether, only 20 bladder cancers were sequenced in routine diagnostics and for 10 cancers potential targeted treatment options were available.

DISCUSSION

So far, despite availability of NGS diagnostics at university institutes of pathology, only few bladder cancer samples have been sequenced. Based on current data from the molecular subtyping of bladder cancers, we recommend a step-by-step protocol with basic immunohistochemistry analysis and subsequent subtype-dependent analyses, e.g., alterations of the fibroblast growth factor receptors (FGFR) or comprehensive gene panel analyses.

Urachal cancer-current concepts of a rare cancer

Urachal cancer is a rare but aggressive disease. In addition to the non-glandular tumors, non-cystic urachal adenocarcinomas are nowadays distinguished from the primary cystic variant. (Immunohistochemical) markers are only of minor differential diagnostic value and, therefore, the diagnosis is primarily established in a multidisciplinary approach. The non-cystic variant accounts for the majority of cases (83%), is more common in men (63%), shows a median age at diagnosis of 51 years and has a 5-year survival rate of about 50%. In organ-confined disease, usually a partial cystectomy of the tumor in the bladder dome, including the median umbilical ligament and umbilicus, is performed. In advanced stages, systemic therapy is needed while 5‑fuorouracil (5-FU) containing regimes have been shown to be more effective. Due to the rarity of the tumor, targeted therapy approaches based on a biological rationale are becoming increasingly relevant. As molecular data are still sparse, we compiled and analyzed the largest urachal cancer cohort to date. In 31% of the cases, MAPK-/PI3K signaling pathway alterations were detected (especially in K-/NRAS) with implications for anti-EGFR therapy approaches. Further potentially therapeutic alterations were detected in FGFR1, MET, PDGFRA, and erbB2/HER2. Additionally, PD-L1 tumor cell expression (clone: 22C3) was demonstrated in 16% of cases, therefore making anti-PD-1/PD-L1 immuno-oncological approaches worth considering despite the absence of mismatch repair deficiency (MMR-d) and/or high microsatellite instability (MSI-h). Finally, urachal adenocarcinomas seem to be a distinct entity on the molecular level with closer resemblance to colorectal adenocarcinomas than to urothelial carcinomas.

STIP1 Tissue Expression Is Associated with Survival in Chemotherapy-Treated Bladder Cancer Patients

To optimize treatment decisions in advanced bladder cancer (BC), we aimed to assess the therapy predictive value of STIP1 with regard to cisplatin therapy. Cisplatin-based chemotherapy represents the standard first-line systemic treatment of advanced bladder cancer. Since novel immunooncologic agents are already available for cisplatin-resistant or ineligible patients, biological markers are needed for the prediction of cisplatin resistance. STIP1 expression was analyzed in paraffin-embedded bladder cancer tissue samples of 98 patients who underwent adjuvant or salvage cisplatin-based chemotherapy by using immunohistochemistry. Furthermore, pre-chemotherapy serum STIP1 concentrations were determined in 48 BC patients by ELISA. Results were correlated with the clinicopathological and follow-up data. Stronger STIP1 nuclear staining was associated with worse OS in both the whole patient group (p = 0.034) and the subgroup of patients who received at least 2 cycles of chemotherapy (p = 0.043). These correlations remained significant also in the multivariable analyses (p = 0.035 and p = 0.040). Stronger STIP1 cytoplasmatic immunostaining correlated with shorter PFS both in the whole cohort (p = 0.045) and in the subgroup of patients who received at least 2 cycles of chemotherapy (p = 0.026). Elevated STIP1 serum levels were associated with older patient's age, but we found no correlation between STIP1 serum levels and patients' outcome. Our results suggest that tissue STIP1 analysis might be used for the prediction of cisplatin-resistance in BC. In contrast, pretreatment STIP1 serum levels showed no predictive value for chemotherapy response and survival.

[Predictive biomarkers in oncologic uropathology]

BACKGROUND

Tumors of the genitourinary system are common. In recent years, our understanding of their molecular background and therefore the number of potential predictive biomarkers has massively increased.

OBJECTIVES

The aim of the current work is to give an overview of recent (molecular) developments and predictive biomarkers in urologic oncology and to give a perspective of what might become relevant in the future of the field.

MATERIAL AND METHODS

We considered the recent literature and study data and combined it with our own expertise in tumors of the urinary system, kidneys, and prostate.

RESULTS AND CONCLUSIONS

The molecular subtypes of muscle-invasive urothelial bladder cancer (MIBC) hold a predictive and prognostic significance and correlate with clinicopathological features. Immune therapy with checkpoint inhibitors (CPI) has a major role in urothelial carcinoma (UC), but also in renal cell carcinoma and a subgroup of prostate cancers. The first-line use in UC is restricted to PD-L1-"positive" cases (≥IC2/3, CPS ≥ 10). Further predictive markers are currently under evaluation, while the predictive significance of tumor mutational burden (TMB) is under debate. In addition to a subgroup of renal cell carcinomas, a subgroup of prostate carcinomas with alterations in the DNA repair system might benefit from a customized therapy approach (PARP inhibitors, platin-containing chemotherapy). The multitude of potentially therapy-relevant molecular alterations and related predictive biomarkers calls for the implementation of sophisticated molecular analyses in daily routine. This will lead to an even more rapid dynamic in the field of genitourinary pathology.

High-soluble CGA levels are associated with poor survival in bladder cancer

Recently, a neuroendocrine-like molecular subtype has been discovered in muscle-invasive urothelial bladder cancer (BC). Chromogranin A (CGA) is a widely used tissue and serum marker in neuroendocrine tumors. Our aim was to evaluate serum CGA (sCGA) concentrations and their associations with clinical and follow-up data in BC and renal cell carcinoma (RCC). sCGA concentrations were analyzed in the following cohorts: (1) BC training set (n = 188), (2) BC validation set (n = 125), (3) RCC patients (n = 77), (4) healthy controls (n = 97). CGA immunohistochemistry and RT-qPCR analyses were performed in 20 selected FFPE and 29 frozen BC tissue samples. Acquired data were correlated with clinicopathological parameters including comorbidities with known effect on sCGA as well as with patients' follow-up data. sCGA levels were significantly higher in BC but not in RCC patients compared to healthy controls. High sCGA levels were independently associated with poor overall and disease-specific survival both in the BC training (P < 0.001, P = 0.002) and validation set (P = 0.009, P = 0.017). sCGA levels were inversely correlated with glomerulus filtrating rate (GFR) and linearly correlated with creatinine clearance and urea concentrations. These correlations were not related to the prognostic value of sCGA. Tissue CGA levels were low to absent independently of sCGA concentrations. Our results demonstrate elevated levels and an independent prognostic value for sCGA in BC but not in RCC. Despite the significant correlation between sCGA and GFR, the prognostic relevance of sCGA seems not related to impaired renal function or other comorbidities.

[Urachal cancer - current concepts of a rare cancer (German version)]

Urachal cancer is a rare but aggressive disease. In addition to the non-glandular tumors, non-cystic urachal adenocarcinomas are nowadays distinguished from the primary cystic variant. (Immunohistochemical) markers are only of minor differential diagnostic value and, therefore, the diagnosis is primarily established in a multidisciplinary approach. The non-cystic variant accounts for the majority of cases (83%), is more common in men (63%), shows a median age at diagnosis of 51 years and has a 5-year survival rate of about 50%. In organ-confined disease, usually a partial cystectomy of the tumor in the bladder dome, including the median umbilical ligament and umbilicus, is performed. In advanced stages, systemic therapy is needed while 5‑fuorouracil (5-FU) containing regimes have been shown to be more effective. Due to the rarity of the tumor, targeted therapy approaches based on a biological rationale are becoming increasingly relevant. As molecular data are still sparse, we compiled and analyzed the largest urachal cancer cohort to date. In 31% of the cases, MAPK-/PI3K signaling pathway alterations were detected (especially in K-/NRAS) with implications for anti-EGFR therapy approaches. Further potentially therapeutic alterations were detected in FGFR1, MET, PDGFRA, and erbB2/HER2. Additionally, PD-L1 tumor cell expression (clone: 22C3) was demonstrated in 16% of cases, therefore making anti-PD-1/PD-L1 immuno-oncological approaches worth considering despite the absence of mismatch repair deficiency (MMR-d) and/or high microsatellite instability (MSI-h). Finally, urachal adenocarcinomas seem to be a distinct entity on the molecular level with closer resemblance to colorectal adenocarcinomas than to urothelial carcinomas.

[Klatskin tumor: long-term survival following surgery]

BACKGROUND

Perihilar cholangiocarcinoma (Klatskin tumor) is a rare tumor entity with an unfavorable prognosis despite optimal treatment.

OBJECTIVES

The aim of the study is to investigate beneficial histopathological features and recommendations for surgery in perihilar cholangiocarcinoma to improve patients' long term survival.

MATERIAL AND METHODS

192 patients suffering from perihilar cholangiocarcinoma underwent attempted tumor resection between 1998 and 2008 at our clinic. 50 patients survived more than 2 years. The follow-up ended in December 2013. The resection type, the UICC stage and histopathological features were compared between three groups (2-3-year, 3-5-year and > 5-year survival groups).

RESULTS

The overall 5‑year survival rate of the study groups was 32 %, and even 16 % survived more than 10 years after surgery. Patients with lymph node positive tumors (p = 0.0126) and distant metastasis (p = 0.0376) had the poorest survival rate. Perineural invasion had no significant impact on the overall survival, but patients surviving more than 5 years had the lowest incidence of perineural invasion with 18.75 %. Caudate lobectomy was significantly (p = 0.011) associated with a survival of more than 5 years in our study.

CONCLUSIONS

Complete tumor resection with additional caudate lobe resection is associated with long-term survival. Perineural invasion seems to be a negative prognostic factor for long-term survival.

Partitioning of interaction-induced nonlinear optical properties of molecular complexes. I. Hydrogen-bonded systems

Interaction-induced electronic and vibrational (hyper)polarizabilities were decomposed into different interaction types (electrostatic, exchange, induction and dispersion).

A Comprehensive Computational Study of the Interaction between Human Serum Albumin and Fullerenes

Human serum albumin (HSA) is the most abundant blood plasma protein, which transports fatty acids, hormones, and drugs. We consider nanoparticle-HSA interactions by investigating the binding of HSA with three fullerene analogs. Long MD simulations, quantum mechanical (fragment molecular orbital, energy decomposition analysis, atoms-in-molecules), and free energy methods elucidated the binding mechanism in these complexes. Such a systematic study is valuable due to the lack of comprehensive theoretical approaches to date. The main elements of the mechanism include the following: binding to IIA site results in allosteric modulation of the IIIA and heme binding sites with an increase in α-helical structure of IIIA. Fullerenes displayed high binding affinities for HSA; therefore, HSA can be used as a fullerene carrier, facilitating any toxic function the fullerene may exert. Complex formation is driven by hydrogen bonding, van der Waals, nonpolar, charge transfer, and dispersion energy contributions. Proper functionalization of C60 has enhanced its binding to HSA by more than an order of magnitude. This feature may be important for biological applications (e.g., photodynamic therapy of cancer). Satisfactory agreement with relevant experimental and theoretical data has been obtained.

Elucidation of the binding mechanism of renin using a wide array of computational techniques and biological assays

We investigate the binding mechanism in renin complexes, involving three drugs (remikiren, zankiren and enalkiren) and one lead compound, which was selected after screening the ZINC database. For this purpose, we used ab initio methods (the effective fragment potential, the variational perturbation theory, the energy decomposition analysis, the atoms-in-molecules), docking, molecular dynamics, and the MM-PBSA method. A biological assay for the lead compound has been performed to validate the theoretical findings. Importantly, binding free energy calculations for the three drug complexes are within 3 kcal/mol of the experimental values, thus further justifying our computational protocol, which has been validated through previous studies on 11 drug-protein systems. The main elements of the discovered mechanism are: (i) minor changes are induced to renin upon drug binding, (ii) the three drugs form an extensive network of hydrogen bonds with renin, whilst the lead compound presented diminished interactions, (iii) ligand binding in all complexes is driven by favorable van der Waals interactions and the nonpolar contribution to solvation, while the lead compound is associated with diminished van der Waals interactions compared to the drug-bound forms of renin, and (iv) the environment (H2O/Na(+)) has a small effect on the renin-remikiren interaction.

Endothelial Caveolin-1 regulates the radiation response of epithelial prostate tumors

The membrane protein caveolin-1 (Cav1) recently emerged as a novel oncogene involved in prostate cancer progression with opposed regulation in epithelial tumor cells and the tumor stroma. Here we examined the role of stromal Cav1 for growth and radiation response of MPR31-4 prostate cancer xenograft tumors using Cav1-deficient C57Bl/6 mice. Syngeneic MPR31-4 tumors grew faster when implanted into Cav1-deficient mice. Increased tumor growth on Cav1-deficient mice was linked to decreased integration of smooth muscle cells into the wall of newly formed blood vessels and thus with a less stabilized vessel phenotype compared with tumors from Cav1 wild-type animals. However, tumor growth delay of MPR31-4 tumors grown on Cav1 knockout mice to a single high-dose irradiation with 20 Gray was more pronounced compared with tumors grown on wild-type mice. Increased radiation-induced tumor growth delay in Cav1-deficient mice was associated with an increased endothelial cell apoptosis. In vitro studies using cultured endothelial cells (ECs) confirmed that the loss of Cav1 expression increases sensitivity of ECs to radiation-induced apoptosis and reduces their clonogenic survival after irradiation. Immunohistochemical analysis of human tissue specimen further revealed that although Cav1 expression is mostly reduced in the tumor stroma of advanced and metastatic prostate cancer, the vascular compartment still expresses high levels of Cav1. In conclusion, the radiation response of MPR31-4 prostate tumors is critically regulated by Cav1 expression in the tumor vasculature. Thus, Cav1 might be a promising therapeutic target for combinatorial therapies to counteract radiation resistance of prostate cancer at the level of the tumor vasculature.

Reliable but Timesaving: In Search of an Efficient Quantum-chemical Method for the Description of Functional Fullerenes

Fullerene and its derivatives are currently one of the most intensively investigated species in the area of nanomedicine and nanochemistry. Various unique properties of fullerenes are responsible for their wide range applications in industry, biology and medicine. A large pool of functionalized C60 and C70 fullerenes is investigated theoretically at different levels of quantum-mechanical theory. The semiempirial PM6 method, density functional theory with the B3LYP functional, and correlated ab initio MP2 method are employed to compute the optimized structures, and an array of properties for the considered species. In addition to the calculations for isolated molecules, the results of solution calculations are also reported at the DFT level, using the polarizable continuum model (PCM). Ionization potentials (IPs) and electron affinities (EAs) are computed by means of Koopmans' theorem as well as with the more accurate but computationally expensive ΔSCF method. Both procedures yield comparable values, while comparison of IPs and EAs computed with different quantum-mechanical methods shows surprisingly large differences. Harmonic vibrational frequencies are computed at the PM6 and B3LYP levels of theory and compared with each other. A possible application of the frequencies as 3D descriptors in the EVA (EigenVAlues) method is shown. All the computed data are made available, and may be used to replace experimental data in routine applications where large amounts of data are required, e.g. in structure-activity relationship studies of the toxicity of fullerene derivatives.

HER2 expression and markers of phosphoinositide-3-kinase pathway activation define a favorable subgroup of metastatic pulmonary adenocarcinomas

OBJECTIVES

Pulmonary adenocarcinomas (ADC) can be sub-grouped based on dominant oncogenic drivers. EGFR mutations define an entity of metastatic ADC with favorable prognosis and high susceptibility to EGFR tyrosine kinase inhibition. In contrast, the clinical impact of additional ERBB family members in ADC is less defined. To this end we prospectively studied HER2 expression, gene amplification, and mutation in relation to outcome of patients with advanced or metastatic ADC.

MATERIALS AND METHODS

Diagnostic tumor biopsies from 193 sequential patients with stage III/IV ADC were prospectively studied for HER2 expression by immunohistochemistry (IHC). Cases with IHC scores 2+ or 3+ were analyzed by HER2 chromogenic in situ hybridization (CISH), and sequencing of HER2 exons 20 and 23. Additional prospectively determined biomarkers included PTEN, cMET, pAKT, and pERK expression, KRAS, EGFR, BRAF and PIK3CA mutations, and ALK fluorescence ISH (FISH).

RESULTS AND CONCLUSION

HER2-IHC was feasible in 176 (91.2%) cases. Of 53 (30%) cases with IHC scores 2+/3+, 45 (85%) could be studied by CISH and 34 (64%) by sequencing. The lower number of HER2-mutational analyses resulted from exhaustion of tumor tissue and DNA following mutational analysis of KRAS, EGFR, BRAF and PIK3CA. HER2 amplification was detected in 4 cases (2.3%), while no mutation was found. HER2 expression correlated with expression of pAKT and cMET. Expression of HER2 and pAKT was associated with favorable overall survival in stage IV disease. HER2-expressing ADC more frequently harbored KRAS mutations, while HER2 expression was absent in all 4 cases with BRAF mutation. HER2-IHC was not predictive of HER2 gene amplification or mutation, which both were rare events in prospectively studied patients with advanced or metastatic ADC. Expression of HER2 and pAKT define a population of patients with stage IV ADC with a distinct disease course, who could benefit from specifically tailored pharmacotherapies.

Theoretical modelling of photoswitching of hyperpolarisabilities in ruthenium complexes

Static excited-state polarisabilities and hyperpolarisabilities of three Ru^II ammine complexes are computed at the density functional theory (DFT) and several correlated ab initio levels. Most accurate modelling of the low energy electronic absorption spectrum is obtained with the hybrid functionals B3LYP, B3P86 or M06 for the complex [Ru^II(NH₃)₅(MeQ⁺)]³⁺ (MeQ⁺=N-methyl-4,4′-bipyridinium, 3) in acetonitrile. The match with experimental data is less good for [Ru^II(NH₃)₅L]³⁺ (L=N-methylpyrazinium, 2; N-methyl-4-{E,E-4-(4-pyridyl)buta-1,3-dienyl}pyridinium, 4). These calculations confirm that the first dipole- allowed excited state (FDAES) has metal-to-ligand charge-transfer (MLCT) character. Both the solution and gas-phase results obtained for 3 by using B3LYP, B3P86 or M06 are very similar to those from restricted active-space SCF second-order perturbation theory (RASPT2) with a very large basis set and large active space. However, the time-dependent DFT λ_max predictions from the long-range corrected functionals CAM-B3LYP, LC-ωPBE and wB97XB and also the fully ab initio resolution of identity approximate coupled-cluster method (gas-phase only) are less accurate for all three complexes. The ground state (GS) two-state approximation first hyperpolarisability β_2SA for 3 from RASPT2 is very close to that derived experimentally via hyper-Rayleigh scattering, whereas the corresponding DFT-based values are considerably larger. The β responses calculated by using B3LYP, B3P86 or M06 increase markedly as the π-conjugation extends on moving along the series 2→4, for both the GS and FDAES species. All three functionals predict substantial FDAES β enhancements for each complex, increasing with the π-conjugation, up to about sevenfold for 4. Also, the computed second hyperpolarisabilities γ generally increase in the FDAES, but the results vary between the different functionals.

[Heterotopic sebaceous glands in the esophagus: case report with review of the literature]

Heterotopia of sebaceous glands is a very rare endoscopically indistinct benign finding in the esophagus. To date only 30 cases have been reported in the literature. The lesions exhibit a considerable variation in number and size. No malignant transformation has yet been reported. From the pathologists' point of view an inflammatory or neoplastic process has to be excluded as the cause of the non-distinctive endoscopic findings.

A new anastomotic leakage model in circular double stapled colorectal anastomosis after low anterior rectum resection in pigs

BACKGROUND

A high incidence of anastomotic leakage (37.5%) is reported after low anterior rectal resection (LAR) and circular double-stapled anastomosis without protective ileostoma. Since the pathomechanism of anastomosis leakage is still unclear, a suitable animal model would be most desirable.

METHODS

The objective was to assess the incidence of clinically apparent and inapparent leakage after LAR in pigs (n = 20). Endpoints were radiological, clinical, macroscopic, and histologic proof of anastomotic leakage on the 9th postoperative day. Integrity of anastomosis was assessed by double-contrast barium examination on 9th postoperative day. Animals were sacrificed and anastomoses were resected for histopathological investigation. In case of earlier clinical apparent anastomotic leakage, radiologic double-contrast barium was performed immediately.

RESULTS

LAR with a circular double-stapled anastomosis without protective ileostoma was performed in 20 pigs (m:f = 8:12). Length of resection was 10-20 cm, anastomosis was performed 7 cm ab ano. Five animals (25%) developed clinical apparent anastomotic leakage (no appetite, fever, inactivity, tachypnea, discomfort, pain) between the 6th (n = 1) and 9th (n = 4) postoperative day, proven by double-contrast barium radiographs. Additionally in 1 animal clinical inapparent anastomotic insufficiency was observed radiologically. Total rate of leakage was 30% (n = 6). These results were confirmed by leucocytosis, low potassium levels, in two cases high ALT and AST and local peritonitis in all cases.

CONCLUSION

Including one additional case of clinical inapparent leakage, total rate of anastomotic leakage was 30% (6/20). Thus we managed to establish a new experimental model of anastomotic leakage after low rectal resection comparable to the human situation.