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Biomedical subjects

E van Leeuwen

Publications and source records attributed to E van Leeuwen.

At least 19 recordsLinked to original sources
PubMed2006

Reproduction and fertility in human immunodeficiency virus type-1 infection.

Human immunodeficiency virus type-1 (HIV-1) affects mostly men and women in their reproductive years. For those who have access to highly active antiretroviral therapy (HAART), the course of HIV-1 infection has shifted from a lethal to a chronic disease. As a result of this, many patients with HIV-1 consider having offspring, as do other patients of reproductive age with chronic illnesses. This article summarizes the current knowledge on the presence of HIV in the male and female genital tract, the effects of HIV-1 infection and HAART on male and female fertility and the results of various assisted reproduction techniques (ART) in HIV-1-infected men and women who wish to have offspring.

Anti-HIV Agents↗
PubMed2006

Impact of triphenyltin acetate in microcosms simulating floodplain lakes. I. Influence of sediment quality.

Floodplain lakes in the Rhine-Meuse delta of the Netherlands vary considerably in levels of sediment-bound toxicants. Microcosm experiments were done to compare the ecological impact of the fungicide triphenyltin acetate (TPT) between test systems with clean or polluted sediments (10 microcosms each). Differences in sediment quality affected the structure of the aquatic communities that developed in the microcosms. Initially, a faster growth of the macrophyte Elodea nuttallii was observed on the polluted sediments, which contained not only toxicants but also higher organic matter and nutrient levels. Dynamics of TPT concentrations in the overlying water were very similar between the two types of test system. Higher levels of TPT, however, were found in the sediment compartment of the clean sediment systems containing a smaller macrophyte biomass. TPT was very persistent in the sediments. In both test systems representatives of several taxonomic groups showed clear responses to a single application of TPT, although benthic Nematoda were not affected. Although a few differences in the intensity and/or duration of TPT-related population responses were observed between the two types of test system, the background pollutants in the polluted sediment hardly affected the overall sensitivity of the aquatic community to the additional chemical stressor TPT.

Animals↗
PubMed2005

[Decision-making regarding life-sustaining medical treatment in a pediatric intensive-care unit].

The complexity of the decision-making process regarding life-sustaining medical treatment was illustrated by the single case of a 12-year-old boy with severe meningococcal septicaemia. When his clinical condition deteriorated, necessitating haemodialysis and multiple amputations of the extremities, questions about the futility of treatment and the future quality of life puzzled the attending physician. In consultation with the treatment team and the parents, it was decided to continue medical treatment in this patient since there was too little prognostic certainty concerning bodily functions and morbidity and the expected future quality of life. After 60 days, the patient was discharged. Half-a-year later he was following an intensive rehabilitation programme and the possibility of renal transplantation was contemplated. Because of the consequences for the child and his family, a decision to continue life-sustaining medical treatment should be justified as thoroughly as one to withdraw or withhold treatment.

Child↗
PubMed2005

[Intra uterine insemination with processed sperm for HIV serodiscordant couples in whom the man is HIV positive].

The desire to have children is more and more common in HIV serodiscordant couples. The Academic Medical Centre Amsterdam has developed a new treatment protocol for couples in whom the man is HIV positive. Semen is processed to obtain HIV-1 free spermatozoa. These spermatozoa are used for IUI treatment. Thus far, 20 serodiscordant couples underwent 76 IUI cycles. An insemination was performed in 50 cycles (66%). The insemination was cancelled in 26 cycles, because of too many follicles (risk for multiple pregnancy), weekend (no possibilities for virological testing), not enough spermatazoa after preparation, a positive HIV-1 RNA test and other reasons. 10 out of 20 women became pregnant (50%), 8 women were on-going pregnant. The clinical and ongoing pregnancy rate per started cycle was 13% and 11% respectively. 7 babies have thus far been born and none of the mothers or babies seroconverted within this study period. Larger numbers of patients are necessary to support the safety of this program.

Adult↗
PubMed2005

Physicians' evaluations of patients' decisions to refuse oncological treatment.

OBJECTIVE: To gain insight into the standards of rationality that physicians use when evaluating patients' treatment refusals. DESIGN OF THE STUDY: Qualitative design with in depth interviews. PARTICIPANTS: The study sample included 30 patients with cancer and 16 physicians (oncologists and general practitioners). All patients had refused a recommended oncological treatment. RESULTS: Patients base their treatment refusals mainly on personal values and/or experience. Physicians mainly emphasise the medical perspective when evaluating patients' treatment refusals. From a medical perspective, a patient's treatment refusal based on personal values and experience is generally evaluated as irrational and difficult to accept, especially when it concerns a curative treatment. Physicians have a different attitude towards non-curative treatments and have less difficulty accepting a patient's refusal of these treatments. Thus, an important factor in the physician's evaluation of a treatment refusal is whether the treatment refused is curative or non-curative. CONCLUSION: Physicians mainly use goal oriented and patients mainly value oriented rationality, but in the case of non-curative treatment refusal, physicians give more emphasis to value oriented rationality. A consensus between the value oriented approaches of patient and physician may then emerge, leading to the patient's decision being understood and accepted by the physician. The physician's acceptance is crucial to his or her attitude towards the patient. It contributes to the patient's feeling free to decide, and being understood and respected, and thus to a better physician-patient relationship.

Anxiety↗
PubMed2004

Semen parameters of a semen donor before and after infection with human immunodeficiency virus type 1: case report.

Semen samples from a donor who seroconverted for human immunodeficiency virus type 1 (HIV-1) during the period that he was donating at our clinic were stored before and after infection. Semen analysis was done on all of these samples before cryopreservation. Retrospectively, both qualitative and quantitative HIV-1 testing was performed on the cryopreserved semen samples to determine the time of primary HIV-1 infection. After HIV-1 infection, semen volume, sperm motility and the percentage of spermatozoa with normal morphology were reduced compared with the same parameters before HIV-1 infection. HIV-1 RNA was intermittently detectable in semen. HIV-1 infection led to a reduction in semen volume, sperm motility and normal sperm morphology in this donor. However, the clinical significance of these findings is unclear. A longitudinal cohort study on the effects of HIV-1 infection on semen quality is necessary to confirm these findings.

Adult↗
PubMed2004

Craniopagus: the Suriname-Amsterdam conjunction.

OBJECTS: A case of a Suriname female occipito-parietal to occipito-parieto-temporal craniopagus twins is described. The girls were transferred to the VU University Medical Center (VUmc) in Amsterdam, the Netherlands, for further diagnostics and to analyze whether surgical separation was feasible and ethically justifiable. The multifactorial aspects of different treatment options are discussed. METHODS: The twins underwent multiple investigations by a multidisciplinary team. Advanced imaging techniques with 3D-CT scan, MRI and MRA scans, image fusion techniques and, most importantly, cerebral angiography with balloon occlusion tests were performed. CONCLUSIONS: Because of a shared venous ring, with preferential drainage to the left child, and which endovascular balloon occlusion showed could not be separated, surgical separation of the twins with a fair chance of survival without additional neurological damage and with prospects of a good quality of life was regarded as impossible. In accordance with the parents' wishes, the twins were not separated and offered optimal integral conservative treatment.

Cerebral Cortex↗
PubMed2003

Improvement of foot pedals used during surgery based on new ergonomic guidelines.

BACKGROUND: This study aims to create new ergonomic guidelines for the design of foot pedals used during surgery. METHODS: Observations in the operating room, a questionnaire among 45 laparoscopic surgeons/residents, an ergonomic literature study, and clog measurements were used to assess the problems occurring during use and to compile new guidelines for foot pedals. Based on these guidelines a new foot pedal was designed and a prototype was manufactured. RESULTS: During the surgical procedure 91% of the subjects occasionally loses contact with the foot pedal, which 56% experience as very annoying. All subjects think that the current foot pedals obstruct their freedom of movement; 75% occasionally hit the wrong switch and 53% experience physical discomfort in their legs and/or feet. Therefore, 93% of the subjects would like to control the diathermy in a different way. The new prototype of a foot pedal was evaluated in a pilot test and proved to be ergonomically better than the currently used foot pedals. CONCLUSION: The new guidelines for foot pedals result in an ergonomic improvement in their design.

Equipment Design↗
PubMed2001

Dutch law and ethics concerning the experimental treatment of early psychosis.

Moral and social attitudes towards medical treatment and research rapidly changed during the last four decades of the Twentieth Century. In the Netherlands these changes are reflected in three laws adopted in the 1990s. The Law on Medical Treatment Agreement (Wet Geneeskundige BehandelOvereenkomst, WGBO, 1992) reflects the respect for autonomy and the protection of patient's rights. The Law on Special Admission to Psychiatric Hospitals (Bijzondere Opneming Psychiatrische Ziekenhuizen, BOPZ, 1994) reflects the idea that psychiatric subjects should be entitled to execute their civil rights as long as no danger exists to themselves or others, while the Law on Medical Research (Wet Medisch Onderzoek, WMO 1999), reflects the present moral opinions on bio-medical research. From these laws objections can be derived against the development of treatment and experiments on early psychosis. It will be argued here that these laws can also be taken to stimulate this kind of research. The difference between the two options is related to preconceived moral opinions towards psychosis and schizophrenia.

Commitment of Persons with Psychiatric Disorders↗
PubMed2000

Medical students' cases as an empirical basis for teaching clinical ethics.

PURPOSE: To identify ethical issues that interns encounter in their clinical education and thus build a more empirical basis for the required contents of the clinical ethics curriculum. METHOD: The authors analyzed a total of 522 required case reports on ethical dilemmas experienced by interns from September 1995 to May 1999 at the medical school of Vrije Universiteit in Amsterdam. They identified four regularly described and numerous less frequently described topics. RESULTS: The interns addressed a wide range of ethical themes. In 45% of the cases, they mentioned disclosure or non-disclosure of information and informed consent; in 37%, medical decisions at the end of life; in 16%, medical failures; and in 9%, problems transferring patients from one caregiver to another. The interns also identified 27 themes linked to their unique position as interns and 19 themes related to specific types of patients. CONCLUSION: Based on self-reported experiences, the authors conclude that clinical ethics teachers should reflect on a multitude of dilemmas. Special expertise is required with respect to end-of-life decisions, truth telling, medical failures, and transferring patients from one caregiver to another. The clinical ethics curriculum should encourage students to voice their opinions and deal with values, responsibilities, and the uncertainty and failings of medical interventions.

Decision Making↗
PubMed2000

Personal values and cancer treatment refusal.

This pilot study explores the reasons patients have for refusing chemotherapy, and the ways oncologists respond to them. Our hypothesis, generated from interviews with patients and oncologists, is that an ethical approach that views a refusal as an autonomous choice, in which patients are informed about the pros and cons of treatment and have to decide by weighing them, is not sufficient. A different ethical approach is needed to deal with the various evaluations that play a role in treatment refusal. If patients forgo further treatment, while curative or palliative methods are available, there is no perspective from which to integrate the weighing of pros and cons of treatment and the preferences and values of individual cancer patients. A discrepancy thus results as regards what "good reasons" are, evoking misunderstandings or even breaking off communication. Suggestions are given for follow up research.

Academic Medical Centers↗
PubMed2000

A longitudinal study of informational interventions to save energy in an office building.

Informational interventions were employed to promote two behaviors relevant for efficient heating of individual offices in a large office building. In two successive winter seasons, interventions were applied during 4-week periods. Short-term effects were assessed weekly, and long-term effects were assessed 1 year after each of the two intervention periods. Improvements were observed in each intervention period, with partial behavior maintenance 1 year later. The changes observed in the individual offices across conditions are suggestive of the program's capacity to correct relapses in earlier proenvironmental behavior.

Behavior Therapy↗