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Biomedical subjects

D Andersen

Publications and source records attributed to D Andersen.

At least 19 recordsLinked to original sources
PubMed1999

Guidelines for good scientific practice.

The Danish Committee on Scientific Dishonesty (DCSD) has existed for five years. As a preventive measure two sets of guidelines for the presentation of experimental reports and data documentation have been issued. Experiences from 24 cases of suspected scientific dishonesty have proven a need for further guidelines covering a wider range of scientific practice. Three key areas susceptible to conflicts between researchers and often resulting in subsequent accusations of scientific misconduct have been localized. Guidelines have, therefore, been prepared for these three areas: 1) Agreements at the start of cooperative research projects. 2) Rights and duties in storing and using research data. 3) Authorship. It is hoped that they will be helpful in prevention of conflicts and deviations from good scientific practice, and that they will be useful in the education of young researchers. The Danish Committee on Scientific Dishonesty. The Ministry of Research and Information Technology, Copenhagen.

Denmark↗
PubMed1998

[Teratogenic effects of ACE-inhibitors and angiotensin II receptor antagonists].

Since the introduction of angiotensin converting enzyme-inhibitors (ACE-inhibitors) in the 1980's, more than 50 cases of foetotoxic effects ascribed to intrauterine exposure to inhibitors have been published. Among the most commonly reported effects are: Hypotension, renal dysplasia, anuria/oliguria, oligohydramios, intrauterine growth retardation, pulmonary hypoplasia, unclosed ductus arteriosus, incomplete ossification of the skull, intrauterine og neonatal death. Recent animal studies have confirmed that intrauterine or neonatal exposure to ACE-inhibitors or the AT1-receptor antagonist losartan can cause death and serious, irreversible organ damage. These effects are similar to the complications previously reported in humans. Animal studies suggest that the foetotoxic actions are most common after exposure during the last trimester. However, due to the severity of these complications, the use of ACE-inhibitors and AT1-receptor antagonists should be avoided throughout pregnancy and in women who are breast feeding.

Abnormalities, Drug-Induced↗
PubMed1998

Honest Danes.

Explore the source record for details and available documents.

Denmark↗
PubMed1997

Congestive heart failure in rats is associated with increased expression and targeting of aquaporin-2 water channel in collecting duct.

We tested whether severe congestive heart failure (CHF), a condition associated with excess free-water retention, is accompanied by altered regulation of the vasopressin-regulated water channel, aquaporin-2 (AQP2), in the renal collecting duct. CHF was induced by left coronary artery ligation. Compared with sham-operated animals, rats with CHF had severe heart failure with elevated left ventricular end-diastolic pressures (LVEDP): 26.9 +/- 3.4 vs. 4.1 +/- 0.3 mmHg, and reduced plasma sodium concentrations (142.2 +/- 1. 6 vs. 149.1 +/- 1.1 mEq/liter). Quantitative immunoblotting of total kidney membrane fractions revealed a significant increase in AQP2 expression in animals with CHF (267 +/- 53%, n = 12) relative to sham-operated controls (100 +/- 13%, n = 14). In contrast, immunoblotting demonstrated a lack of an increase in expression of AQP1 and AQP3 water channel expression, indicating that the effect on AQP2 was selective. Furthermore, postinfarction animals without LVEDP elevation or plasma Na reduction showed no increase in AQP2 expression (121 +/- 28% of sham levels, n = 6). Immunocytochemistry and immunoelectron microscopy demonstrated very abundant labeling of the apical plasma membrane and relatively little labeling of intracellular vesicles in collecting duct cells from rats with severe CHF, consistent with enhanced trafficking of AQP2 to the apical plasma membrane. The selective increase in AQP2 expression and enhanced plasma membrane targeting provide an explanation for the development of water retention and hyponatremia in severe CHF.

Animals↗
PubMed1997

Utility of a standard allergen series alone in the evaluation of allergic contact dermatitis: a retrospective study of 732 patients.

BACKGROUND: Patch testing remains the standard for the diagnosis of allergic contact dermatitis. The validity and usefulness of a standard patch test allergen series has not been addressed adequately by previous studies. OBJECTIVE: We sought to examine the utility of the standard allergen series as a sole screening tool in the diagnosis of allergic contact dermatitis. METHODS: The charts of 732 patients referred for patch testing were reviewed for positive patch test results. The group of patients with positive reactions was stratified into two groups based on the clinical relevance of their reactions. These groups were subsequently analyzed to determine whether the reactions were to part of the standard series of allergens or to part of a supplementary group. RESULTS: Of patients tested, 50% had a positive patch test. Of those, 221 (30%) had reactions deemed clinically relevant. Only 23% of patients with positive patch tests reacted to an allergen(s) in the standard series exclusively. When adjusted for clinical relevance, only 15.7% of patients were completely evaluated with the standard series of 20 allergens. CONCLUSION: The standard allergen series of 20 allergens available in the United States is limited as a screening tool when used alone in the evaluation of patients with allergic contact dermatitis.

Allergens↗
PubMed1997

Cardiovascular actions of chronic intracerebroventricular administration of metformin in normotensive rats.

Acute intracerebroventricular administration of the antihyperglycaemic agent metformin (0.25-1 mg) elicits sympathoinhibitory responses in spontaneously hypertensive rats. However, cardiovascular actions of chronic intracerebroventricular metformin administration are unknown. To define the dose-response relationship during chronic intracerebroventricular metformin administration, mean arterial pressure, heart rate, and locomotor activity were measured continuously by radiotelemetry in 40 normotensive rats. After a 10 day control period, an intracerebroventricular cannula was implanted and connected to an osmotic minipump which delivered metformin in the following doses: 0 [saline]. 0.01, 0.1, 1, and 10 mg/day. LD50 was 1.5 mg/day. Metformin, 1 mg/day attenuated the nocturnal, physiological increase in mean arterial pressure (-7.3 +/- 1.6% versus before metformin), produced behavioural changes and tended to increase locomotor activity. Lower doses of intracerebroventricular metformin (0.1 and 0.01 mg/day) did not affect mean arterial pressure, heart rate or locomotor activity. In conclusion, chronic intracerebroventricular administration of high dose metformin (1.0 mg/day) attenuates the nocturnal, physiological increase in mean arterial pressure. These findings are compatible with a toxic, sympathoinhibitory action of high doses of metformin intracerebroventricularly.

Animals↗
PubMed1996

Bleeding ulcer.

A review is presented on theory and practice in the handling of gastroduodenal bleeding in the presurgical era with emphasis on the Meulengracht treatment. A description is thereafter given of the development of criteria for emergency surgery in the preendoscopic period with special mention of the circulatory evaluation using measurements of central venous pressure. A survey is given on the development in endoscopic diagnosis and treatment with a critical evaluation of the predictive value of clinical factors and endoscopic stigmata of haemorrhage. Finally the sparse knowledge on the haemostatic mechanisms of current endoscopic therapies is presented.

Blood Transfusion↗
PubMed1995

Rapidly progressive sclerosing cholangitis following surgical treatment of pancreatic pseudotumor.

Two patients with sclerosing cholangitis presented with a distal stricture of the common bile duct in association with pancreatic pseudotumors. Jaundice resolved following surgery to correct biliary obstruction, but diffuse cholangiographic abnormalities and clinical evidence of sclerosing cholangitis became evident 2 and 4 months later. Rapid progression of symptomatic disease necessitated liver transplantation in one patient, but the other had a complete response to methotrexate therapy. The rapid disease progression in these two patients may have been triggered by surgery that resulted in a generalized fibroproliferative response of the biliary tree, already affected with localized sclerosing cholangitis contiguous to a pancreatic pseudotumor. We suggest that localized sclerosing cholangitis associated with pancreatic pseudotumors may be a unique variant that can progress rapidly but respond dramatically to antiinflammatory therapy.

Adult↗
PubMed1995

[Scandinavian cooperation in scientific misconduct].

During recent years the scientific world has addressed the problem of scientific fraud, with a view to setting up a system to alert the scientific community in the event of more serious instances, such as occurred recently in the USA, but also to function in a preventive capacity with regard to fraud and accusations of fraud in research. The scientific communities in the Nordic countries have recently begun to cooperate in this field.

Humans↗
PubMed1993

Saturation by pulse oximetry: comparison of the results obtained by instruments of different brands.

We noticed that arterial oxygen saturation by pulse oximetry (SpO2) was generally lower when determined by the Ohmeda Biox 3700 pulse oximeter than when determined by the Nellcor N-100 pulse oximeter, and we investigated whether this finding was consistent and the reason for the discrepancy. We placed both oximeters simultaneously on 30 infants with indwelling arterial catheters and measured arterial partial pressure of oxygen (PaO2), percentage of fetal hemoglobin, and complete cooximetry, including arterial oxygen saturation (SaO2) with a Radiometer OSM-3 cooximeter, with and without correction for fetal hemoglobin levels, in four samples of blood from each infant during a 12-hour period for a total of 120 samples. The Nellcor SpO2 was consistently higher than the Ohmeda SpO2 by a mean (+/- SD) of 1.61% +/- 2.69% (p < 0.001). The Nellcor SpO2 correlated best with functional SaO2 (oxyhemoglobin (HbO2)/(HbO2 + reduced hemoglobin)) x 100); Ohmeda SpO2 correlated best with fractional SaO2 (HbO2/(HbO2 + reduced hemoglobin + carboxyhemoglobin + methemoglobin)) x 100), reflecting a fundamental difference in the calibration algorithms used in the two instruments. A desired PaO2 of 50 to 100 mm Hg, is maintained when the range of SpO2 is 90% to 96% for Ohmeda SpO2 and 92% to 98% for Nellcor SpO2 in the neonate, giving a positive predictive value in this study of 94% to 95%. We conclude that SpO2 determined by pulse oximeters of different brands is not interchangeable, and this may be of clinical importance in predicting PaO2 on the basis of SpO2.

Catheterization, Peripheral↗
PubMed1993

Scientific dishonesty and good scientific practice.

Scientific dishonesty has been the subject of much public interest in recent years. Although the problem has had a low profile in Denmark, there is no reason to believe that it is non-existent. Several preconditions known to be important prevail here as well as in other countries, such as pressure to publish and severe competition for research grants and senior academic positions. The Danish Medical Research Council (DMRC) decided to respond to this problem by preparing a report on scientific dishonesty with suggestions to the research institutions on rules for good scientific practice and procedures for investigation of suspected dishonesty. To this end, an investigatory system was suggested. The system should consist of two regional committees and one national committee. They should be headed by high court judges and experienced health sciences researchers as members. The committees will investigate cases reported to them and conclude on whether dishonesty has been established and on whether the scientific work should be retracted. Sanctions shall remain the task of the institutions. Preventive measures comprise open access to and a long storage period for scientific data.

Denmark↗
PubMed1993

Scientific dishonesty: a Danish proposal for evaluation and prevention.

The term scientific dishonesty covers the wide scope from consciously fraudulent actions to gross negligence and refers both to character trait and to actions. Scientific dishonesty may occur in any country, but reactions in Europe have been slow to emerge. On the basis of a thorough review, the Danish Medical Research Council therefore has made recommendations on how to handle and how to prevent scientific dishonesty. Suspected cases must be referred directly to a national committee chaired by a High Court judge. An ad hoc investigatory committee may be appointed in each case. If dishonesty is established, the institution then is asked to implement appropriate sanctions and to report on the actions taken to the national committee. Prevention of scientific dishonesty forms an essential part of good scientific practice and must have an impact on research training, requirements for data storage, guidelines for scientific publication, and criteria for evaluating grant proposals and promotions.

Denmark↗