Surgical therapy of chronic lung allograft dysfunction

Lung transplantation has become a standardized and widely accepted treatment modality for selected end-stage lung diseases. Many factors influ- ence the long-term survival of patients after lung transplantation. One of the most important is clearly the development of chronic lung allograft dysfunction (CLAD). This review summarizes current knowledge of the histopathology of CLAD and its clinical characteristics. It also describes lung re-transplantation as the only causal therapy, its possible complications, and outcomes in standard and high-urgency patients awaiting a suitable organ with extracorporeal membrane oxygenation support. Fundoplication is an important surgical modality potentially leading to an improvement of the patients' condition. The indications and outcomes of this surgical procedure are discussed in a separate chapter. In addition, several nonsurgical treatment options aimed at slowing the progression of CLAD are outlined, as well as ongoing research focused on extending the life of these patients.

Multiple organ resection for large paraganglioma a case report

Paragangliomas represent a group of neuroendocrine tumours which occur in various localizations. Most of them produce catecholamines, and in advanced cases present with typical symptoms and signs such as palpitations, headache and hypertension. The only curative treatment is radical resection. About one-quarter of paragangliomas are malignant, defined by the presence of distant metastases. There are multiple treatment options for unresectable metastatic tumours. They include radionuclid therapy, chemotherapy, and radiotherapy, although none of them are curative. Cytoreductive surgery can also be considered, especially when the goal is to decrease symptoms related to advanced disease. We present a rare case of a large paraganglioma of the left retroperitoneum. Despite radical surgery, early recurrence of the disease was observed.

Analysis of the molecular heterogeneity of poly(lactic acid)/poly(butylene succinate-co-adipate) blends by hyphenating size exclusion chromatography with nuclear magnetic resonance and infrared spectroscopy

The compositional and stereochemical heterogeneity of copolymers are key molecular metrics, and their knowledge is of pivotal importance for evidence based material development. Yet, while it is state of the art to determine these parameters for many petroleum based polymers, little insight exists in that regard for bio-based materials. Towards this end, size exclusion chromatography (SEC) was hyphenated with nuclear magnetic resonance spectroscopy (NMR) in an offline manner and a blend of poly(lactic acid) (PLA) and poly(butylene succinate-co-adipate) (PBSA) investigated. Thus, the microstructural heterogeneity could be shown with regard to tacticity of the PLA and regioregularity of the PBSA component. The results show, that the highest molar mass fraction differs in stereochemical composition from the others. It may be assumed that this is the result of misinsertions with regard to stereochemistry occurring during the catalytic polymerization of the lactide. While the content of both constituent polymers along the molar mass axis could be well studied using a univariate analysis of the infrared (IR) spectra, this method failed to profile the adipate and succinate content individually. For this purpose, SEC was coupled to IR spectroscopy in online mode and the spectra were evaluated by a multivariate protocol. Thus, the content of each monomer along the molar mass distribution could be mapped with high chromatographic resolution.

Degeneration alters the biomechanical properties and structural composition of lateral human menisci

OBJECTIVE

Because the literature relating to the influence of degeneration on the viscoelasticity and tissue composition of human lateral menisci remains contradictory or completely lacking, the aim of this study was to fill these gaps by comprehensively characterising the biomechanical properties of menisci with regard to the degree of degeneration.

DESIGN

Meniscal tissue from 24 patients undergoing a total knee replacement was collected and the degeneration of each region classified according to Pauli et al. For biomechanical characterisation, compression and tensile tests were performed. Additionally, the water content was determined and infrared (IR) spectroscopy was applied to detect changes in the structural composition, particularly of the proteoglycan and collagen content.

RESULTS

With an increasing degree of degeneration, a significant decrease of the equilibrium modulus was detected, while simultaneously the water content and the hydraulic permeability significantly increased. However, the tensile modulus displayed a tendency to decrease with increasing degeneration, which might be due to the significantly decreasing amount of collagen content identified by the IR measurements.

CONCLUSION

The findings of the current study may contribute to the understanding of meniscus degeneration, showing that degenerative processes appear to mainly worsen viscoelastic properties of the inner circumference by disrupting the collagen integrity.

Preoperative surgical risk stratification in osteosarcoma based on the proximity to the major vessels

Aims

The aim of this study was to determine the risk of local recurrence and survival in patients with osteosarcoma based on the proximity of the tumour to the major vessels.

Patients and Methods

A total of 226 patients with high-grade non-metastatic osteosarcoma in the limbs were investigated. Median age at diagnosis was 15 years (4 to 67) with the ratio of male to female patients being 1.5:1. The most common site of the tumour was the femur (n = 103) followed by tibia (n = 66). The vascular proximity was categorized based on the preoperative MRI after neoadjuvant chemotherapy into four types: type 1 > 5 mm; type 2 ≤ 5 mm, > 0 mm; type 3 attached; type 4 surrounded.

Results

Limb salvage rate based on the proximity type was 92%, 88%, 51%, and 0% for types 1 to 4, respectively, and the overall survival at five years was 82%, 77%, 57%, and 67%, respectively (p < 0.001). Local recurrence rate in patients with limb-salvage surgery was 7%, 8%, and 22% for the types 1 to 3, respectively (p = 0.041), and local recurrence at the perivascular area was observed in 1% and 4% for type 2 and 3, respectively. The mean microscopic margin to the major vessels was 6.9 mm, 3.0 mm, and 1.4 mm for types 1 to 3, respectively. In type 3, local recurrence-free survival with limb salvage was significantly poorer compared with amputation (p = 0.025), while the latter offered no overall survival benefit. In this group of patients, factors such as good response to chemotherapy or limited vascular attachment to less than half circumference or longitudinal 10 mm reduced the risk of local recurrence.

Conclusion

The proximity of osteosarcoma to major blood vessels is a poor prognostic factor for local control and survival. Amputation offers better local control for tumours attached to the blood vessels but does not improve survival. Limb salvage surgery offers similar local control if the tumour attachment to blood vessels is limited. Cite this article: Bone Joint J 2019;101-B:1024–1031.

Thermally stable and efficient polymer solar cells based on a novel donor-acceptor copolymer

We report high photovoltaic performance of a novel donor-acceptor (D-A) conjugated polymer poly[2,6[4,8-bis(2-ethyl-hexyl)benzo[1,2-b;4,5-b']dithiophene-co-2,5-thiophene-co-4,7[5,6-bis-octyloxy-benzo[1,2,5]thiadiazole]-co-2,5-thiophene] (PBDTTBTZT) in bulk heterojunctions with [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM). A power conversion efficiency (PCE) of more than 7% is obtained for optimized charge-extracting electrodes. Upon application of thermal stress via annealing, a superior thermal stability is demonstrated as compared to poly[N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT).

Proton conductivity and phase transitions in 1,2,3-triazole

1,2,3-Triazole (TR) is a good proton conductor which is tidely related to formation of a hydrogen bond network along the N-HN trajectory and its self-dissociation into diH-1,2,3-triazolium and 1,2,3-triazolate. To gain a deeper understanding, the proton conductivity of TR is measured by impedance spectroscopy (IS) across its melting temperature and an additionally discovered solid-solid phase transition. The orthorhombic high temperature phase and the monoclinic low temperature modification are investigated by polarized optical microscopy, DSC- and WAXS measurements. Furthermore, the diffusion coefficients of TR are determined from IS data and measured by (1)H PFG NMR spectroscopy in the melt which allows for separate evaluation of contributions of proton hopping across the hydrogen bond network and the vehicle mechanism to the proton conductivity where the vehicles are defined as charged species generated by TR self-dissociation. Finally, the degree of dissociation of TR is calculated and the influence of the self-dissociation of TR on the proton conductivity is discussed in the context of the dielectric constant.

Abstract S3-06: Emergence of constitutively active estrogen receptor mutations in advanced estrogen receptor positive breast cancer

Introduction: The lack of estrogen receptor (ER) expression is the primary cause of de novo resistance of breast cancers to endocrine therapy. In contrast, in most cases of acquired endocrine resistance, ER is expressed and other mechanisms of resistance have been proposed, such as ER mutations. Pre-clinical studies demonstrated a small number of specific point mutations that can enhance ER function. However, the studies on clinical samples performed in the 1990's were limited by small sample size, lack of detailed clinical correlation and lacked the sensitivity of next-generation sequencing (NGS). Therefore, in this study we sought to comprehensively investigate the frequency and functional significance of ER mutations throughout the progression of breast cancer from primary disease to advanced metastatic disease using targeted NGS.

Methods: In this retrospective study, a total of 249 tumor specimens were analyzed. The specimens include 134 ER positive and, as controls, 115 estrogen receptor negative tumors. The estrogen receptor positive samples consist of 58 primary breast cancers and 76 metastatic sample. All tumors were sequenced with high coverage using NGS targeting the coding sequence of ER and an additional 181 cancer-related genes.

Results: Recurring somatic mutations at codons 537 and 538 within the ligand-binding domain of the estrogen receptor were detected in ER positive metastatic tumors. Overall, the frequency of these mutations was 12% (95% CI 6%-21%) in metastatic patients compared with none in the primary cases. In total there were 9 recurring somatic mutations; Y537C (11%), Y537N (33%), Y537S (22%) and D538G (33%). In addition in a small number of paired primary and metastatic samples from the same patient, these mutations were found only in the metastatic specimens. In a subset of heavily pre-treated patients the frequency was 20% (5/25, 95% CI 7%-41%). ER activating mutations were not detected in any stage of ER negative disease. ER alterations were not mutually exclusive with any of the other commonly altered genes and of the most frequently altered genes, all but ER alterations displayed similar frequencies across primary and metastatic specimens. Functional studies in cell line models demonstrated that these ER mutations render ER constitutively active and confer resistance to hormone deprivation, tamoxifen and fulvestrant.

Conclusions: Herein, we reveal functional ER mutations as potential drivers of endocrine resistance during the progression of ER positive breast cancer. The absence of detectable mutations in the primary tumors suggests clonal evolution as the mechanism of resistance. Thus, these mutations have the potential to be an important genetic biomarker of endocrine resistance in ER positive metastatic breast cancer and could assist in clinical decision making as disease progresses. Our findings also underscore the value of repeated biopsies of metastatic lesions. Lastly, since the frequencies of these mutations are substantial when sensitive testing methods are used in the correct clinical context, pre-clinical and clinical studies to identify novel therapeutics that can overcome this resistance are warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S3-06.

Abstract P6-04-11: Quantitative Differences among Spectral Counts Based on LC-MS/MS Spectra Accurately Cluster Basal, Her2-Overexpressing and Luminal A Breast Carcinomas

Characterization of breast cancer subtypes at the protein-level is largely unexplored and is a powerful approach to identify novel biomarkers that may have diagnostic and prognostic utility. Shotgun proteomics analyzes mixtures at the peptide-level to generate MS/MS spectra that are then used to identify the peptides and proteins from which they were derived. We developed a method in our laboratory utilizing SDS-PAGE followed by in-gel digestion coupled with reversed-phase (RP) liquid chromatography-tandem mass spectrometry (RP-LC-MS/MS) for proteomic analysis of LCM-acquired cells. This method was then applied to a clinical sample set consisting of basal, Her2-overexpressing and luminal A frozen tumor tissues as determined by prior microarray studies. Three tumors per group were dissected in triplicate, for a total of 27 samples. Each dissection consisted of approximately 10,000 cells, corresponding to 3-5 μg protein. Following LCM, the thermoplastic membranes containing the captured cells were peeled from the cap, suspended in SDS loading buffer and gently heated for 10 minutes. The solubilized proteins were electrophoresed 2 cm into a 10-20% Tricine gel followed by in-gel trypsin digestion and peptide extraction. Replicate LC-MS/MS analysis of the tryptic peptides from each of the 27 samples was performed on a Thermo LTQ XL ion trap mass spectrometer. The resultant tandem mass spectra were searched against the human IPI database using the Myrimatch search algorithm and the results filtered using IDPicker. A spectral counting approach was applied to the data-dependent data to compare quantitative differences among the identified proteins. A total of 91,646 spectra were confidently identified, corresponding to 1671 protein groups across all biological and technical replicates. An average of 545, 543, and 610 protein groups were identified in the basal, ERBB2, and luminal A subtypes, respectively, from an equivalent of approximately 800 cells. Spectral count differences between datasets were analyzed using both a Quasi-likelihood Poisson regression model, developed in-house, and the Limma package in Bioconductor. Using a False Discovery Rate &lt; 0.05, a total of 90 proteins showed statistically significant differences in expression among the breast tumor subtypes. Hierarchical cluster analysis generated a heat map of the protein expression patterns. Novel proteins as well as proteins corresponding to genes previously shown by gene array studies to be specific to each tumor type, including NES, ERBB2 and LGALS3BP, were represented among the differentially expressed proteins. These results demonstrate the feasability of this method to identify differential expression of protein biomarkers among breast cancer subtypes. These biomarkers should yield new insights into the pathogenesis of breast cancer and could be rapidly adapted into clinical diagnostics to guide therapeutic decisions for individual patients. The possible role in breast cancer for the novel proteins identified is currently under investigation.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-04-11.