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Biomedical subjects

D Wendler

Publications and source records attributed to D Wendler.

At least 19 recordsLinked to original sources
PubMed2004

The standard of care debate: the Declaration of Helsinki versus the international consensus opinion.

The World Medical Association's revised Declaration of Helsinki endorses the view that all trial participants in every country are entitled to the worldwide best standard of care. In this paper the authors show that this requirement has been rejected by every national and international committee that has examined this issue. They argue that the consensus view now holds that it is ethically permissible, in some circumstances, to provide research participants less than the worldwide best care. Finally, the authors show that there is also consensus regarding the broad conditions under which this is acceptable.

Clinical Trials as Topic↗
PubMed2001

Core safeguards for clinical research with adults who are unable to consent.

The National Bioethics Advisory Commission has proposed new safeguards for clinical research with adults who are unable to consent. Three other major U.S. groups have also proposed additional safeguards for this population, and existing Canadian and European guidelines already include such safeguards. While these six guidelines agree on some safeguards, they disagree on others. To allow important research to proceed while protecting adults who are unable to consent, it will be crucial to resolve these differences. This paper uses a side-by-side comparison of these six guidelines to highlight their major points of consensus, analyze their significant differences, and distill six core safeguards.

Adult↗
PubMed2001

The consent process for cadaveric organ procurement: how does it work? How can it be improved?

CONTEXT: Understanding the consent process that organ procurement organizations (OPOs) use is crucial to improving the process and thereby reducing the number of individuals who die each year for want of an organ transplant. However, no data exist on OPOs' current consent practices. OBJECTIVE: To assess whose wishes OPOs follow when procuring solid organs from deceased individuals and whether advance directives and computerized registries might improve the consent process for solid organ procurement. DESIGN, SETTING, AND PARTICIPANTS: Telephone survey conducted from June to August 1999 of all 61 active OPOs. MAIN OUTCOME MEASURES: Responses to the 49-question survey addressing consent practices in specific scenarios of deceased and next of kin wishes. RESULTS: Widespread divergence exists in OPOs' consent practices for cadaveric solid organ procurement. Regarding overall consent practices, 19 (31%) OPOs reported that they follow the deceased's wishes, 19 (31%) follow the next of kin's wishes, 13 (21%) procure organs if neither party objects, 8 (13%) procure organs if either party consents or neither objects, and 2 (3%) do not follow any of these 4 overall practices. These differences appear to be traceable to implicit ethical disagreements about whose wishes should be followed. A total of 29 (48%) OPOs reported having an official policy to address whether they follow the family's or deceased's wishes. Regarding factors that influence OPOs' choice of consent practice, 29 (48%) respondents ranked impact on the deceased's family as the most important factor, 13 (21%) ranked state law as most important, and 7 (11%) ranked the priority of the deceased's wishes as most important. Durable power of attorney appeared to have substantial weight in OPOs' decisions; for example, in the scenario in which the deceased supported organ donation and the next of kin opposed it, 34 (56%) OPOs reported they were likely to procure organs based on the consent of the holder of the deceased's durable power of attorney, whereas only 7 (11%) reported they were likely to procure organs based on a document of gift (a living will, donor card, or driver's license). CONCLUSIONS: Expanding the legal scope of living wills to cover individuals' organ donation preferences would likely have little impact on procurement rates. In contrast, expanding the legal scope of durable powers of attorney for health care may have a significant impact. A national discussion should take place addressing the underlying ethical issues that appear to account for much of the divergence among OPOs' consent practices for cadaveric solid organ procurement.

Advance Directives↗
PubMed2001

Suspended solids from industrial and municipal origins.

The origins of suspended solids are the effluents of municipal and industrial wastewater treatment plants and storm sewage treatment. This paper deals with the sources of industrial and municipal wastewater treatment and the single treatment of side streams. An overview of the common treatment processes is given and the main sinks for suspended solids are named and described. The food industry is based on the processing of organic matter (fruits, etc.). During the single processing steps three main fractions occur, inorganic material (e.g., from the washing step), organic residues (e.g., the peel), and suspended solids (SS) in the wastewater. Today higher rates of recycling (water and raw materials) can be found in all kinds of industrial processes. The principle is that avoidance should take precedence over utilization which should take precedence over disposal. Numerous possibilities of production-integrated measures exist, e.g., conveyance of production circuits, product recovery, and stepped cleaning. Despite and/or due to these efforts, huge amounts of residues occur. They are the main sink for suspended solids. Only seldom is landfilling used to treat these residues. Usually utilization as animal nourishment or biological (aerobic or anaerobic) or thermal (incineration) treatment methods are used. Huge capacities for a codigestion of agroindustrial residues (substrates) and wastewater sludge can be found in municipal digesters. As most of the food processing factories are indirect dischargers, the largest amount of the SS fraction in the wastewater is led to municipal wastewater treatment plants. Rarely, a connection between the SS concentrations in the influent and those in the effluent can be observed in conventional wastewater treatment. As a polishing step, filtration methods gain more and more importance with regard to suspended solids removal.

Agriculture↗
PubMed2000

Informed consent, exploitation and whether it is possible to conduct human subjects research without either one.

Clinical research with adults who are unable to provide informed consent has the potential to improve understanding and care of a number of devastating conditions. This research also has the potential to exploit some of society's most vulnerable members. Recently, a number of task forces and individual writers have proposed guidelines to ensure that such research is both possible and ethical. Yet, there is widespread disagreement over which safeguards should be adopted. In the present paper, I consider to what extent these disagreements can be resolved by appeal to a general account of the interests of subjects who are unable to consent and the conditions that must be satisfied for research enrollment to constitute exploitation of their inability to make their own decisions.

Adult↗
PubMed1998

[Primary paraurethral malignant mixed tumor (carcinosarcoma) of the vagina. A case report].

In total malignant mixed tumors (carcinosarcomas) represent a very rare gynecological neoplasm. In accordance with the embryological genesis primary localizations are with descending probability the uterus, the ovarians and finally the tubes. We report on a 55 year old female patient, with a paraurethral mass, which was primarily diagnosed in 1994. Histopathological evaluation of a transvaginal biopsy did not demonstrate evidence of malignancy at that time. After painful enlargement the paraurethral mass was resected surgically and histopathological evaluation revealed a primary paraurethral malignant mixed tumor (carcinosarcoma). Postoperatively, the patient underwent percutaneous (46.4 Gy) and intracavitary (2 x 6 Gy) radiation. Twelve months postoperatively there is no evidence of disease.

Brachytherapy↗
PubMed1996

Immunohistochemical assessment of steroid hormone receptors in tissues of the anal canal. Implications for anal incontinence?

BACKGROUND: A prerequisite for a hormonal influence on anal continence in women is the presence of hormone receptors in the tissues of the anal canal. Using immunohistochemical techniques, we demonstrated and localized estrogen and progesterone receptors (ER, PR) in tissue sections of the anal canal. METHODS: Thirty-five specimens of the anorectal region from 21 patients (14 women, seven men) were examined histologically for smooth muscle (present in specimens from ten females and in seven males), striated muscle (present in three females and five males), and perimuscular connective tissue (present in 12 females and seven males). Immunostaining for ER and PR was then performed by incubating with primary anti-ER and anti-PR antibody and visualization of specific antibody binding by the ABC technique with DAB as chromogen. RESULTS: Positive staining for ER and PR was seen exclusively over cell nuclei. Estrogen receptors were found in the smooth muscle cells of the internal sphincter of all females (10/10) and in four of the seven males. Staining for ER was detected in the perimuscular connective tissue of all females (12/12) and in four of the seven males. No specific staining for ER or PR was found in the nuclei of striated muscle cells of the external sphincter in males or females (n = 8). In females, about 50% of the ER-positive tissues were also found to be positive for PR. Amongst the male patients, only one exhibited staining for PR, and this was confined to the smooth muscle. CONCLUSIONS: Expression of ER is a constitutional feature of the connective tissue and smooth muscle cells of the anal continence organ. Estrogen receptors and PR are not detectable in the striated muscle fibers of the external anal sphincter in either sex. The presence of ER in the stroma and smooth muscles of the anal canal suggests that these tissues are targets for estrogen. This constitutes a theoretical basis for the beneficial effects of estrogen and progestin replacement on anal continence in postmenopausal women.

Anal Canal↗
PubMed1996

Deception in medical and behavioral research: is it ever acceptable?

Ethicists argue that deception is unacceptable, whereas researchers regard it as a necessary part of (certain kinds of) research. This impasse could be resolved by establishing the specific conditions under which deception in medical and behavioral research can be tolerated. An approach based on a consideration of the "Ethical Principles of Psychologists and Code of Conduct," one of the few writings on this topic, would satisfy the needs of both parties. It takes the form of a requirement that subjects be informed of the use of deception before enrolling in a deceptive study. This "second order consent" approach to acceptable deception represents our best chance for reconciling respect for subjects with the occasional scientific need for deceptive research.

Behavioral Research↗
PubMed1995

Tropheryma whippelii endocarditis confirmed by polymerase chain reaction.

This report concerns a patient with cardiac manifestation of Whipple's disease. For the first time, the gene that encodes the 16s rRNA of Tropheryma whippelii was identified in a native aortic valve by means of a polymerase chain reaction technique. DNA amplification gives evidence of Tropheryma whippelii as a causative organism in infective endocarditis.

Actinobacteria↗
PubMed1992

A controlled study of maternal serum concentrations of lipoproteins in pregnancy-induced hypertension.

Seventeen women with pregnancy-induced hypertension (PIH) and 17 controls with uncomplicated pregnancy who were matched for maternal and gestational age were investigated for lipid concentrations in whole serum and lipoprotein fractions. The triglyceride level in the low-density lipoprotein fraction was higher in PIH patients than in controls (P < 0.03). The differences between values of other parameters did not attain the level of statistical significance, although the tendency of the results was consistent with findings reported in other studies. The differences observed were small and the data exhibited wide variation. Therefore, it appears unlikely that serum lipid and lipoprotein concentrations could gain major clinical importance as diagnostic parameters in PIH.

Cholesterol↗
PubMed1992

Menstrual cycle exhibits no effect on postprandial lipemia.

Menstrual cycle effects on postprandial lipemia were investigated in 13 healthy women. They were monitored (dietary intake, basal body temperature) for a period of one cycle. Statistically significant follicular-luteal differences were neither observed between fasting triglyceride serum levels nor between areas under triglyceride response curves after a standardized oral fat load.

Adult↗
PubMed1991

[Histochemical model investigations of the action mechanisms of lathyrogenic substances].

In histochemical model studies, aminoacetonitrile and 3-aminopropionitrile can form hydrolysis-stable azomethines (Schiff bases) with periodate-induced aldehyde groups of tissue slices. Both substances and triethylentetramine do not inhibit the histochemical monoaminoxidase activity, they even can act as substrates of this enzyme. These substances cause an inhibition of the histochemical aminopeptidase M activity, but this inhibition was recognized as a methodological error due to the formation of complexes between diazonium salts and aliphatic amines. The results indicate that the inhibition of the lysyl oxidase will not be the only mechanism of action of lathyrogenic substances.

Aminoacetonitrile↗
PubMed1991

Annulated gap junctions in the rat neural tube.

Annulated gap junctions have been studied electron microscopically in normal rat embryo neural tube on day 12 of gestation. Localization, size and content of annulated gap junctions were characterized. Like in other tissues annulated gap junctions are thought to be involved in a degradation cycle of gap junctions.

Animals↗
PubMed1990

[Incidence of human papillomavirus types 31, 33 and 35 in cervix intra-epithelial neoplasms].

206 patients with cervical intraepithelial neoplasia (CIN) were examined at the Department of Gynaecology and Obstetrics of the University of Tübingen for genital infections with human papilloma viruses (HPV) using DNA-hybridisation. 1. The HPV-type-groups 31/33/35 and 16/18 occurred with approx. the same frequency. 2. Significantly more potentially reversible changes (CIN I.-II.) were associated with HPV types 31, 33 and 35 than with HPV-types 16 and 18, which were found more often in CIN III. (P less than 0.02). 3. In 37.5% of the infections established by DNA-hybridisation, the morphological criterion "koilocytosis" was not detected. DNA-hybridisation is a powerful tool in the differentiation of CIN. The sensitivity of this method is greater than that of morphological HPV, diagnostics.

Adult↗
PubMed1990

Neuroepithelial cell contacts in 12 days old rat embryo: normal and annulated gap junctions.

Neuroepithelial cells in the neural tube of 12 days old rat embryos make contact with each other by extended junctional complexes between their lateral membranes near the luminal surface. In this stage gap junctions are not numerous. Besides these "normal" gap junctions, especially in the upper part of the neuroepithelial cells, annulated gap junctions occur. They seem to originate by an endocytotic process of normal gap junctions with participation of cytoskeletal elements. The content of these annulated gap junctions mainly consists of ribosome-like particles in a high density, but larger particles may also occur. Annulated gap junctions sometimes reveal an intimate contact with the smooth endoplasmic reticulum or with the perinuclear cistern. If present in the perinuclear region the annulated gap junctions show membrane irregularities and other signs which are thought to mark steps of breakdown. Life-cycle and possible functions of the annulated gap junctions during neurulation need further investigation.

Animals↗
PubMed1989

[The temporomandibular joint--structure and function during the course of development].

The temporomandibular joint is one of the most complicated articulations of our body. Its relative stability of function is in contrast to the apparent instability of some structures enclosed. The paper summarizes some thoughts about this joint and it should be stressed the especial difficulty in teaching the joint in the stomatological anatomy.

Humans↗