Candidiasis, Bacterial Vaginosis, Trichomoniasis and Other Vaginal Conditions Affecting the Vulva

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Energy and charge control in mass spectrometry of synthetic polymers

Synthetic polymers are the products of humans’ attempts to imitate nature’s gigantic molecular chain architectures. The extended variety of building blocks and reaction mechanisms resulted in a plethora of different polymeric architectures. The biggest challenge for polymer chemists is to develop an understanding of the relation between the chemical structure of polymers and their physicochemical and mechanical properties. Mass spectrometry (MS) can provide detailed information about the elemental composition, monomer unit and end-group structure of polymeric systems. However, it also has its limitations. The analysis of high molar mass and/or disperse and/or structurally complicated synthetic polymers remains a big challenge. This thesis tries to address this challenge by controlling the charge state and energy of synthetic polymers during MS. Chapter 2 gives a general introduction to polymer analysis and MS. Besides this introduction, Chapter 2 presents some examples of current practical state-of-the-art MS, and liquid chromatography coupled to MS, methods for the analysis of synthetic polymers. Chapter 3 provides an example of the current performance of LC coupled to tandem MS (MS/MS) in the analysis of structurally complicated polymers, such as vegetable oil ethoxylates. Chapter 4 presents the method development to achieve an accurate and reproducible control of the applied excitation energy in a quadrupole ion trap. The method is checked by studying the required excitation energy for fragmentation of poly(ethylene glycol)s as a function of their size. This dependence is shown to be linear and in agreement with other MS instruments where the applied excitation energy can be controlled in a more accurate way. In Chapter 5, the methodology for accurate and reproducible control of the applied excitation energy is used to discriminate between different polymer classes. It is shown that discrimination is achieved by determining a “characteristic” parameter (i.e., the characteristic collision voltage (CCV)), which is related to the polymer’s structure and expresses the stability of the respective polymer ion upon excitation. The determination of the CCV is then used in the analysis of a mixture of a structurally complicated copolymer system and various, nominally isobaric, homopolymers, which cannot be discriminated by conventional MS and MS/MS methods. Chapters 6, 7 and 8 present the study of non-covalent complex ions of high molar mass synthetic polymers and molecules containing ammonium functionalities. These complex ions appear to have a preference for low charge states. Chapter 6 and 7 present the investigations of the parameters that influence the formation of these low charge state adducts ions. Chapter 8 presents the behavior of these non-covalent complex ions upon activation at both low and relatively high collision regimes. The amount and type of fragments ions is strongly influenced by the structure of the ammonium ion. The results show that MS/MS of these non-covalent complex ions can be used as a source of polymer structural informatio

Isolated distant lymph node metastases in ovarian cancer. Should a new substage be created?

Abstact: Objective: To evaluate the prognostic significance of isolated distant lymph node metastases in comparison to other metastatic sites and stage IIIC disease. Methods: The National Cancer Data Base was accessed and patients diagnosed between 2004 and 2014 with stage IV or IIIC epithelial ovarian cancer who met criteria for pathological staging were identified. Overall survival (OS) was calculated with Kaplan-Meier curves and compared with the log-rank test. A Cox model was constructed to control for confounders. Results: A total of 33,561 patients met the inclusion criteria; 582 (1.7%) had stage IV only due to distant lymph node metastases (stage IV-LN), 8130 (24.2%) had stage IV with other sites of distant metastases (stage IV-other) and 24,849 (75.4%) had stage IIIC disease. The median OS for patients with stage IV-LN was 42.41 months (95% CI: 37.59, 47.23) compared to 30.23 months (95% CI: 29.30, 31.16) for those with stage IV-other (p < .001) and 45.57 (95% CI: 44.86, 46.28) for those with stage IIIC disease (p = .54). On multivariate analysis, patients with stage IV-other had a worse survival (HR: 1.41, 95% CI: 1.27, 1.57) compared to those with stage IV-LN. There was no statistically significant difference in survival between patients with stage IV-LN and stage IIIC disease (HR: 1.00, CI: 0.90, 1.11, p = .99). Conclusions: Isolated distant LN metastases is associated with better survival compared to stage IV disease due to other metastatic sites and comparable to patients with stage IIIC disease. Keywords: Ovary, Cancer, Stage IV, Lymph nodes, Metastasi

Role of adjuvant chemotherapy in the management of stage IC ovarian granulosa cell tumors

Objective: The aim of the present study was to investigate the patterns of use and prognostic significance of adjuvant chemotherapy (CT) for patients with stage IC ovarian granulosa cell tumors (GCTs). Methods: We identified patients with stage IC GCTs diagnosed between 2004 and 2015 in the National Cancer Data Base (NCDB). Logistic regression was performed to identify variables independently associated with chemotherapy administration. Overall survival (OS) was evaluated for patients diagnosed between 2004 and 2014 following generation of Kaplan-Meier curves and compared with the log-rank test. A Cox model was constructed to control for known confounders. Results: A total of 492 patients with stage IC GCTs were identified, of which 166 (33.7%) received CT. Tumor size > = 10 cm (OR: 1.85, 95% CI: 1.21, 2.82) was independently associated with the administration of CT. There was no difference in OS between patients who did (n = 145) and did not (n = 282) receive CT, p = 0.52; 5-yr OS rates were 93.7% and 91.6% respectively. After controlling for patient age (<50 vs ≥50 years), tumor size and performance of lymphadenectomy (LND), the administration of CT was not associated with a survival benefit (HR: 1.07, 95% CI: 0.52, 2.21). Conclusions: Approximately one in three patients with stage IC GCTs received CT in the NCDB, however CT was not associated with a survival benefit. Keywords: Ovary, Tumor, Chemotherapy sex cord-stromal, Granulosa cel

Discrimination of polymers by using their characteristic collision energy in tandem mass spectrometry.

International audienceThe characteristic collision energy to obtain 50% fragmentation, expressed as the characteristic collision voltage (CCV), was used as a tool to discriminate different classes of polymers. The CCV value of different polymers was determined in a quadrupole ion trap mass spectrometer. Good linear correlation (0.980 polymethacrylates > polyesters > polysaccharides. This suggests that polysaccharides fragment most easily (low CCVs), while polyethers require the highest collision energy among the polymers studied. The effect of end group on the CCV was also studied, showing a minor influence in most cases. In addition, the applicability of CCV as discriminator was studied for a mixture of (1) polylactic acid (PLA), (2) poly(tetramethylene glycol) (PTMEG), and (3) PLA-block-PTMEG-block-PLA block copolymer. Differences between the CCV values of four nominally isobaric polymers (of which two were copolymers and two were homopolymers) were observed. These results demonstrate that the insertion of a "weak" link into a polymer chain significantly affects the energy required for fragmentation