649 research outputs found
Ethical dilemmas and decision-making in the healthcare for transgender minors
Transgender care, especially regarding the care of children and adolescents, is a relatively new field, in which developments are rapid, in which there is still relatively little empirical data available on long-term outcomes of providing or refraining from early medical treatment, and which is a subject of polarized debate. This thesis describes the themes that lead to controversies surrounding the use of early medical treatment for transgender children and adolescents. For each theme, it describes how the considerations, ideas and newly obtained scientific data, when applicable, have changed and developed over the recent years. It shows that care for transgender children and adolescents inherently involves ethical dilemmas, even if more clinical research data will be provided to underpin the evidence-base. Evidence alone will likely not be able to provide answers to all raised uncertainties concerning adolescent gender-affirming medical care. Ethical dilemmas will therefore probably remain part of this sensitive field of care. Besides illumination of some of these ethical dilemmas, this thesis gives suggestions for future studies and proposes ways of dealing with them in clinical practice. LUMC / Geneeskund
Ionic partition and transport in multi-ionic channels: A Molecular Dynamics Simulation study of the OmpF bacterial porin
We performed all-atom molecular dynamics simulations studying the partition
of ions and the ionic current through the bacterial porin OmpF and two selected
mutants. The study is motivated by new interesting experimental findings
concerning their selectivity and conductance behaviour at neutral pH. The
mutations considered here are designed to study the effect of removal of
negative charges present in the constriction zone of the wild type OmpF channel
(which contains on one side a cluster with three positive residues and on the
other side two negatively charged residues). Our results show that these
mutations induce an exclusion of cations from the constriction zone of the
channel, substantially reducing the flow of cations. In fact, the partition of
ions inside the mutant channels is strongly inhomogeneous, with regions
containing excess of cations and regions containing excess of anions.
Interestingly, the overall number of cations inside the channel is larger than
the number of anions in the two mutants, as in the OmpF wild type channel. We
found that the differences in ionic charge inside these channels are justified
by the differences in electric charge between the wild type OmpF and the
mutants, following an electroneutral balance
Trajectories of Adolescents Treated with Gonadotropin-Releasing Hormone Analogues for Gender Dysphoria
Gonadotropin-releasing hormone analogues (GnRHa) are recommended as initial treatment for adolescents diagnosed with gender dysphoria, providing time to follow gender identity development and consider further treatment wishes without distress caused by unwant
The development and characterisation of porphyrin isothiocyanate–monoclonal antibody conjugates for photoimmunotherapy
A promising approach to increase the specificity of photosensitisers used in photodynamic therapy has been through conjugation to monoclonal antibodies (MAb) directed against tumour-associated antigens. Many of the conjugations performed to date have relied on the activated ester method, which can lead to impure conjugate preparations and antibody crosslinking. Here, we report the development of photosensitiser–MAb conjugates utilising two porphyrin isothiocyanates. The presence of a single reactive isothiocyanate allowed facile conjugation to MAb FSP 77 and 17.1A directed against internalising antigens, and MAb 35A7 that binds to a non-internalising antigen. The photosensitiser–MAb conjugates substituted with 1–3 mol of photosensitiser were characterised in vitro. No appreciable loss of immunoreactivity was observed and binding specificity was comparable to that of the unconjugated MAb. Substitution with photosensitiser had a minimal effect on antibody biodistribution in vivo for the majority of the conjugates, although a decreased serum half-life was observed using a cationic photosensitiser at the higher loading ratios. Tumour-to-normal tissue ratios as high as 33.5 were observed using MAb 35A7 conjugates. The internalising conjugate showed a higher level of phototoxicity as compared with the non-internalising reagent, using a cell line engineered to express both target antigens. These data demonstrate the applicability of the isothiocyanate group for the development of high-quality conjugates, and the use of internalising MAb to significantly increase the photodynamic efficiency of conjugates during photoimmunotherapy
Hydroxypyridinone and 5-Aminolaevulinic Acid Conjugates for Photodynamic Therapy
Photodynamic therapy (PDT) is a promising treatment strategy for malignant and nonmalignant lesions. 5-Aminolaevulinic acid (ALA) is used as a precursor of the photosensitizer, protoporphyrin IX (PpIX), in dermatology and urology. However, the effectiveness of ALA–PDT is limited by the relatively poor bioavailability of ALA and rapid conversion of PpIX to haem. The main goal of this study was to prepare and investigate a library of single conjugates designed to coadminister the bioactive agents ALA and hydroxypyridinone (HPO) iron chelators. A significant increase in intracellular PpIX levels was observed in all cell lines tested when compared to the administration of ALA alone. The higher PpIX levels observed using the conjugates correlated well with the observed phototoxicity following exposure of cells to light. Passive diffusion appears to be the main mechanism for the majority of ALA–HPOs investigated. This study demonstrates that ALA–HPOs significantly enhance phototherapeutic metabolite formation and phototoxicity
Transvaginal Ultrasonographic Cervical Measurement in Predicting Failed Labor Induction and Cesarean Delivery for Failure to Progress in Nulliparous Women
The aim of this study was to evaluate the value of transvaginal sonographic cervical measurement in predicting failed labor induction and cesarean delivery for failure to progress in nulliparous women. One hundred and sixty-one women scheduled for labor induction underwent transvaginal ultrasonography and digital cervical examinations. Logistic regression demonstrated that cervical length and gestational age at induction, but not the Bishop score, significantly and independently predicted failed labor induction. According to the receiver operating characteristic curves analysis, the best cut-off value of cervical length for predicting failed labor induction was 28 mm, with a sensitivity of 62% and a specificity of 60%. In terms of the likelihood of a cesarean delivery for failure to progress as the outcome variable, logistic regression indicated that maternal height and birth weight, but not cervical length or Bishop score, were significantly and independently associated with an increased risk of cesarean delivery for failure to progress. Transvaginal sonographic measurements of cervical length thus independently predicted failed labor induction in nulliparous women. However, the relatively poor predictive performance of this test undermines its clinical usefulness as a predictor of failed labor induction. Moreover, cervical length appears to have a poor predictive value for the likelihood of a cesarean delivery for failure to progress
Adenocarcinoma in Ileal Pouch after Proctocolectomy for Familial Adenomatous Polyposis: Report of A Case
Restorative proctocolectomy with ileal pouch-anal anastomosis is one of the surgical treatments of choice for patients with familial adenomatous polyposis. Although the risk of cancer developing in an ileal pouch is not yet clear, a few cases of adenocarcinoma arising in an ileal pouch have been reported. We report a case of adenocarcinoma in ileal pouch after proctocolectomy with ileal pouch-anal anastomosis. A 56-yr-old woman was diagnosed as having familial adenomatous polyposis. Total colectomy with ileorectal anastomosis was performed. Six years later, she underwent completion-proctectomy with ileal J pouch-anal anastomosis including anorectal mucosectomy for rectal cancer. After 7 yr, she presented with anal spotting. Endoscopic biopsies revealed adenocarcinoma at the ileal pouch. Resection of the ileal pouch and permanent ileostomy were performed. The risk of cancer in an ileal pouch and its prevention with regular surveillance must be emphasized
Preoperative CSF Melatonin Concentrations and the Occurrence of Delirium in Older Hip Fracture Patients:A Preliminary Study
BACKGROUND: Delirium is characterized by disturbances in circadian rhythm. Melatonin regulates our circadian rhythm. Our aim was to compare preoperative cerebrospinal fluid (CSF) melatonin levels in patients with and without postoperative delirium. METHODS: Prospective cohort study with hip fracture patients ≥ 65 years who were acutely admitted to the hospital for surgical treatment and received spinal anaesthesia. CSF was collected after cannulation, before administering anaesthetics. Melatonin was measured by radioimmunoassay (RIA). Data on delirium was obtained from medical and nursing records. Nurses screened every shift for delirium using the Delirium Observation Screening Scale (DOSS). If the DOSS was ≥3, a psychiatrist was consulted to diagnose possible delirium using the DSM-IV criteria. At admission, demographic data, medical history, and information on functional and cognitive status was obtained. RESULTS: Seventy-six patients met the inclusion criteria. Sixty patients were included in the analysis. Main reasons for exclusion were technical difficulties, insufficient CSF or exogenous melatonin use. Thirteen patients (21.7%) experienced delirium during hospitalisation. Baseline characteristics did not differ between patients with and without postoperative delirium. In patients with and without postoperative delirium melatonin levels were 12.88 pg/ml (SD 6.3) and 11.72 pg/ml (SD 4.5) respectively, p-value 0.47. No differences between patients with and without delirium were found in mean melatonin levels in analyses stratified for cognitive impairment or age. CONCLUSION: Preoperative CSF melatonin levels did not differ between patients with and without postoperative delirium. This suggests that, if disturbances in melatonin secretion occur, these might occur after surgery due to postoperative inflammation
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