50 research outputs found

    Evaluation of pregnancy and delivery in 13 women who underwent resection of a sacrococcygeal teratoma during early childhood

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    Sacrococcygeal teratoma resection often brings changes in pelvic anatomy and physiology with possible consequences for defecation, micturition and sexual function. It is unknown, whether these changes have any gynecological and obstetric sequelae. Until now four pregnancies after sacrococcygeal teratoma resection have been described and cesarean section has been suggested to be the method of choice for delivery. We evaluated the pregnancy course and mode of delivery in women previously treated for a sacrococcygeal teratoma. The records of all patients who underwent sacrococcygeal teratoma resection after 1970 in one of the six pediatric surgical centers in the Netherlands were reviewed retrospectively. Women aged 18 years and older were eligible for participation. Patient characteristics, details about the performed operation and tumor histology were retrieved from the records. Consenting participants completed a questionnaire addressing fertility, pregnancy and delivery details. Eighty-nine women were eligible for participation; 20 could not be traced. Informed consent was received from 41, of whom 38 returned the completed questionnaire (92.7%). Thirteen of these 38 women conceived, all but one spontaneously. In total 20 infants were born, 17 by vaginal delivery and 3 by cesarean section, in one necessitated by previous intra-abdominal surgery as a consequence of sacrococcygeal teratoma resection. Conversion to a cesarean section was never necessary. None of the 25 women without offspring reported involuntary childlessness. There are no indications that resection of a sacrococcygeal teratoma in female patients is associated with reduced fertility: spontaneous pregnancy is possible and vaginal delivery is safe for mother and child, irrespective of the sacrococcygeal teratoma classification or tumor histolog

    The influence of injector design on the decay of pre-ignition turbulence in a spherical explosion chamber

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    This paper reports on an experimental study to characterize the turbulent flow field inside a 20 l Siwek chamber during the preignition period. An acrylonitrile-butadiene-styrene model of the chamber was constructed with optical quality windows enabling laser Doppler anemometry (LDA) to be used for turbulence measurements. Alumina (Al 2 O 3 ) particles were used as the seed dust for measuring the gas-phase turbulence. Three specific dust dispersion systems have been investigated: (1) the deflector plate (also referred to as the rebound nozzle); (2) the perforated annular nozzle; and (3) the circular "Dahoe" nozzle. It is assumed that changing the method of dust dispersion alters the turbulence characteristics. The flow field is non-stationary, i.e., the mean (or predominant fluid flow) and superimposed velocity fluctuations upon the mean decrease with time. Furthermore, there are variations from injection to injection. A procedure has been developed to analyze this non-stationary signal to extract the mean and fluctuating components of velocity, thereby paving the way for decay "laws" to be determined for a particular nozzle configuration

    Evaluation of pregnancy and delivery in 13 women who underwent resection of a sacrococcygeal teratoma during early childhood

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    Background: Sacrococcygeal teratoma resection often brings changes in pelvic anatomy and physiology with possible consequences for defecation, micturition and sexual function. It is unknown, whether these changes have any gynecological and obstetric sequelae. Until now four pregnancies after sacrococcygeal teratoma resection have been described and cesarean section has been suggested to be the method of choice for delivery. We evaluated the pregnancy course and mode of delivery in women previously treated for a sacrococcygeal teratoma. Methods: The records of all patients who underwent sacrococcygeal teratoma resection after 1970 in one of the six pediatric surgical centers in the Netherlands were reviewed retrospectively. Women aged 18 years and older were eligible for participation. Patient characteristics, details about the performed operation and tumor histology were retrieved from the records. Consenting participants completed a questionnaire addressing fertility, pregnancy and delivery details. Results: Eighty-nine women were eligible for participation; 20 could not be traced. Informed consent was received from 41, of whom 38 returned the completed questionnaire (92.7%). Thirteen of these 38 women conceived, all but one spontaneously. In total 20 infants were born, 17 by vaginal delivery and 3 by cesarean section, in one necessitated by previous intra-abdominal surgery as a consequence of sacrococcygeal teratoma resection. Conversion to a cesarean section was never necessary. None of the 25 women without offspring reported involuntary childlessness. Conclusions: There are no indications that resection of a sacrococcygeal teratoma in female patients is associated with reduced fertility: spontaneous pregnancy is possible and vaginal delivery is safe for mother and child, irrespective of the sacrococcygeal teratoma classification or tumor histology

    A comprehensive overview of radioguided surgery using gamma detection probe technology

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    The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology

    Quality measurement in neonatal surgical disorders : Development of clinical indicators

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    Objective This study aims to develop a set of quality indicators for the measurement of the quality of surgical care for neonates with surgical disorders. Methods An expert panel of the Netherlands Association of Pediatric Surgeons developed internal (clinical) indicators for neonatal surgery. This included the selection of appropriate care processes, a review of the scientific literature, consensus meetings to establish national guidelines, selection of clinical indicators with independent external evaluation, the setup of a national database, and a pilot study in one of the hospitals to evaluate the defined quality indicators in clinical practice. Results Seven neonatal surgical care processes were selected. Clinical guidelines to evaluate the care processes were established in six of seven disorders and were based on consensus agreement, which was reached in 81 to 97% of in total 220 relevant items. The expert panel selected a set of 24 indicators to estimate the quality of neonatal surgical care, of which 12 were outcome indicators and 12 process indicators. Conclusion The development of quality indicators is an important step toward monitoring and, if necessary, improving the quality of neonatal surgical care. Internal or clinical indicators guarantee that the results are only disclosed to the participating center itself and are therefore no threat to individual doctors

    Development and validation of an enzyme-linked immunosorbent assay for the quantification of trastuzumab in human serum and plasma

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    Trastuzumab, a humanized monoclonal antibody, is used for the treatment of breast cancer patients who overexpress the HER2 receptor. To optimize therapy, pharmacokinetic studies are necessary. The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for trastuzumab to support these pharmacokinetic studies. For this immunoassay, we raised anti-idiotype antibodies in rabbits. After purification of the rabbit material, the anti-idiotype antibodies are used as capturing antibodies on the ELISA plate. After trastuzumab has bound to the catcher antibody, a sandwich ELISA procedure is followed whereby biotinylated anti-idiotype antibodies can bind to trastuzumab. Detection is performed by streptavidin-polyHRP (poly-horseradish peroxidase) conjugate and (3,5,3',5')-tetramethylbenzidine (TMB) substrate. The reaction is stopped using sulfuric acid, and the absorbance is measured at 450 nm. The calibration range of the assay is 0.039 to 5 ng/ml in well. Because samples are analyzed in multiple dilutions, the validated range corresponds to 1.6 to 1600 ng/ml in undiluted serum. Samples above the upper limit of quantification (ULOQ) can be diluted before transfer to the assay plates. Validation results demonstrate that trastuzumab can be accurately and precisely quantified in human serum and plasma. The assay is now used to support pharmacokinetic studies with trastuzumab in human serum and plasm

    Limitations of Nerve Fiber Density as a Prognostic Marker in Predicting Oncological Outcomes in Hepatocellular Carcinoma

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    It has been shown that the presence and density of nerve fibers (NFs; NFD) in the tumor microenvironment (TME) may play an important prognostic role in predicting long-term oncological outcomes in various malignancies. However, the role of NFD in the prognosis of hepatocellular carcinoma (HCC) is yet to be explored. To this end, we aimed to investigate the impact of NFs on oncological outcomes in a large European single-center cohort of HCC patients. In total, 153 HCC patients who underwent partial hepatectomy in a curative-intent setting between 2010 and 2021 at our university hospital were included in this study. Group comparisons between patients with and without NFs were conducted and the association of recurrence-free survival (RFS) and overall survival (OS) with the presence of NFs and other clinico-pathological variables were determined by univariate and multivariable Cox regression models. Patients with NFs in the TME presented with a median OS of 66 months (95% CI: 30-102) compared to 42 months (95% CI: 20-63) for patients without NFs (p = 0.804 log-rank). Further, RFS was 26 months (95% CI: 12-40) for patients with NFs compared to 18 months (95% CI: 9-27) for patients without NFs (p = 0.666 log-rank). In a subgroup analysis, patients with NFD ≤ 5 showed a median OS of 54 months (95% CI: 11-97) compared to 48 months (95% CI: 0-106) for the group of patients with NFD > 5 (p = 0.787 log-rank). Correspondingly, the RFS was 26 months (95% CI: 10-42) in patients with NFD ≤ 5 and 29 months (95% CI: 14-44) for the subcohort with NFD > 5 (p = 0.421 log-rank). Further, group comparisons showed no clinico-pathological differences between patients with NFs (n = 76) and without NFs (n = 77) and NFs were not associated with OS (p = 0.806) and RFS (p = 0.322) in our Cox regression models. In contrast to observations in various malignancies, NFs in the TME and NFD are not associated with long-term oncological outcomes in HCC patients undergoing surgery
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