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Biomedical subjects

B Rasmussen

Publications and source records attributed to B Rasmussen.

At least 19 recordsLinked to original sources

Left ventricular dysfunction in normotensive Type 1 diabetic patients: the impact of autonomic neuropathy.

AIMS: The pathophysiological mechanisms responsible for increased cardiovascular mortality in diabetic autonomic neuropathy (AN) are largely unknown. The aim was to determine the relative role of AN in the pathogenesis of cardiac diastolic dysfunction and left ventricular hypertrophy in Type 1 diabetes. METHODS: Ten Type 1 diabetic patients with AN, defined by cardiovascular tests (AN+) and 10 age- and sex-matched patients without neuropathy (AN-) as well as 10 healthy subjects (C) participated in the study. Left ventricular diastolic function was assessed by Doppler echocardiography, whilst systolic function was evaluated by cine magnetic resonance (MR) imaging. RESULTS: Doppler echocardiography showed a significant decrease in E/A ratio, i.e. the ratio between peak Early transmitral filling velocity during early diastole (E-wave) and peak transmitral Atrial filling velocity during late diastole (A-wave), in AN+ compared with C (P < 0.01) [0.95 +/- 0.08 (mean +/- sem) (AN+); 1.19 +/- 0.09 (AN-); 1.33 +/- 0.10 (C)]. The E-wave deceleration time was significantly shorter in AN+ compared with AN- and C (P < 0.02) [178 +/- 7 ms (AN+); 203 +/- 9 ms (AN-); 205 +/- 9 ms (C)]. Cine MR imaging showed a significantly greater left ventricular mass index in AN+ compared with C [103 +/- 4 g/m(2) (AN+) vs. 98 +/- 7 (AN-) and 92 +/- 4 g/m(2) (C), P < 0.05]. CONCLUSION: Autonomic neuropathy is associated with left ventricular hypertrophy and diastolic dysfunction in Type 1 diabetic patients.

Autonomic Nervous System Diseases↗

Low-cost on-the-job peer training of nurses improved immunization coverage in Indonesia.

In Indonesia responsibility for immunizations is placed on local government health centres and on the nurses who provide the immunizations at each centre. An on-the-job peer training programme for these nurses, which was designed to improve the immunization performance of poorly performing health centres in terms of coverage and practice in Maluku province, was evaluated. Experienced immunization nurses were sent to health centres where nurses were inexperienced or performing poorly; the experienced nurses spent 1-2 weeks providing on-the-job training for the less experienced ones. An evaluation of the 13 centres that participated in the programme and the 95 that did not found that the programme increased both immunization coverage and the quality of practice. Coverage of diphtheria/pertussis/tetanus (DPT), polio, and measles vaccinations rose by about 39% in all 13 participating centres when compared with non-participating centres, and by about 54% in the 11 centres that had a functioning transportation system during the year after training. These results reflect increases in the actual number of doses given and improvements in the accuracy of reports. Potential threats to the study's validity were examined and found not to be significant. The out-of-pocket cost of the training programme was about US$ 53 per trainee or about US$ 0.05 per additional vaccine reported to have been given. The marginal cost per additional fully immunized child was estimated to be US$ 0.50.

Cost-Benefit Analysis↗

Physical estimation of triplet phases from two new proteins.

Three-beam interference experiments have been performed with crystals of two glycosidases: guinea-fowl hexagonal lysozyme, MW 14.3 kDa, and C. thermocellum endoglucanase CelA, MW 40 kDa. In both cases triplet phases could be estimated. Experimental parameters and details of the procedure are presented along with some examples of the results. The average differences between the estimated phases and those calculated from the crystallographic refinements were 17.9 and 15.9 degrees, respectively. A brief discussion of alternative methods for physical phase acquisition is given, including possible strategies for the measurement and application of experimental phases in macromolecular crystallography.

Animals↗

[Cases of measles in Denmark are caused by reintroduction of virus from abroad].

Measles vaccination was implemented in the child vaccination programme in Denmark in 1987 and produced a rapid decline in the incidence. Few cases were recorded annually until 1999. The measles virus isolated in Denmark during 1997-1998 was compared by partial sequencing of the haemagglutinin-coding region with Danish strains from the prevaccination era collected in 1965-1983, as well as with representatives of globally circulating strains of today. The dissimilarity of the prevaccination era strains identified in Denmark in 1997-1998 along with the similarity of these five strains with globally circulating strains at present, substantiate the conclusion that there is no persistent circulation of the measles virus in Denmark.

Child↗

Consumer issues in navigating health care services for type I diabetes.

Despite increasing interest in consumer awareness and participation in health care service delivery, there has been little exploration of consumer views in relation to services for people with type I diabetes. The purpose of this qualitative exploratory study was to identify strategies people with type I diabetes used to access health services and the barriers they perceived in accessing the services they needed. Data gathered in semi-structured interviews revealed that consumers experience significant barriers when navigating the health care system. Three dominant themes were identified. They relate to access to specialist medical skill, to the transition from teenager to young adult and to pre-pregnancy and obstetric care. Directions for change in service delivery and policy development are discussed.

Adaptation, Psychological↗

Selective inhibition of IgG-mediated phagocytosis in gelsolin-deficient murine neutrophils.

Phagocytosis and the microbicidal functions of neutrophils require dynamic changes of the actin cytoskeleton. We have investigated the role of gelsolin, a calcium-dependent actin severing and capping protein, in peripheral blood neutrophils from gelsolin-null (Gsn-) mice. The phagocytosis of complement opsonized yeast was only minimally affected. In contrast, phagocytosis of IgG-opsonized yeast was reduced close to background level in Gsn- neutrophils. Thus, gelsolin is essential for efficient IgG- but not complement-mediated phagocytosis. Furthermore, attachment of IgG-opsonized yeast to Gsn- neutrophils was reduced ( approximately 50%) but not to the same extent as ingestion ( approximately 73%). This was not due to reduced surface expression of the Fcgamma-receptor or its lateral mobility. This suggests that attachment and ingestion of IgG-opsonized yeast by murine neutrophils are actin-dependent and gelsolin is important for both steps in phagocytosis. We also investigated granule exocytosis and several steps in phagosome processing, namely the formation of actin around the phagosome, translocation of granules, and activation of the NADPH-oxidase. All these functions were normal in Gsn- neutrophils. Thus, the role of gelsolin is specific for IgG-mediated phagocytosis. Our data suggest that gelsolin is part of the molecular machinery that distinguishes complement and IgG-mediated phagocytosis. The latter requires a more dynamic reorganization of the cytoskeleton.

Actins↗

[Circulatory support with the mechanical heart, "HeartMate"].

Treatment with the mechanical heart, HeartMate, has been introduced in Denmark. Short-term circulatory support can be obtained by intraaortic balloon counterpulsation, an external centrifugal pump and the total artificial heart. Long-term circulatory support can be established by treatment with the HeartMate. The principle of the mechanical heart is simple--a pump is implanted in parallel to the existing heart and connected to external, portable batteries. The patient quickly improves and is brought in an optimal state for transplantation. A few patients have been able to omit the subsequent heart transplantation. The patient's own heart improved during the treatment and the native heart functioned again after the system was explanted. The main complications during treatment are bleeding, infection, thromboembolic events and systemic failure. Permanent, fully implantable mechanical circulatory pumps are under development--which may herald the beginning of a whole new era for treatment of cardiac failure.

Assisted Circulation↗

[Economic aspects of implementation of the mechanical heart, "HeartMate"].

This economic evaluation was performed to assess the economic consequences for society and for the Danish health care sector of replacing the traditional treatment with Biomedicus assist device with The Mechanical Heart, HeartMate, as a bridge to transplantation for patients with severe cardiac failure. A cost-effectiveness analysis showed that the use of HeartMate is more cost-effective than the use of Biomedicus assist device. Using HeartMate one life-year gained costs DKK 225,000. Using Biomedicus one life-year gained costs DKK 270,000. The use of HeartMate results in an additional expenditure of DKK 615,000 per patient. By this additional expenditure the patients gain 3.6 extra life-years on average. The marginal expenditure by replacing the Biomedicus treatment with HeartMate is DKK 170,000 per extra life-year gained.

Cost-Benefit Analysis↗

Filamentous microfossils in a 3,235-million-year-old volcanogenic massive sulphide deposit.

The record of Archaean microfossils is sparse. Of the few bona fide fossil assemblages, most are from shallow-water settings, and they are typically associated with laminated, stromatolitic sedimentary rocks. Microfossils from deep-sea hydrothermal systems have not been reported in Precambrian rocks (> 544 million years old), although thermophilic microbes are ubiquitous in modern sea-floor hydrothermal settings, and apparently have the most ancient lineages. Here, I report the discovery of pyritic filaments, the probable fossil remains of thread-like microorganisms, in a 3,235-million-year-old deep-sea volcanogenic massive sulphide deposit from the Pilbara Craton of Australia. From their mode of occurrence, the micro-organisms were probably thermophilic chemotropic prokaryotes, which inhabited sub-sea-floor hydrothermal environments. They represent the first fossil evidence for microbial life in a Precambrian submarine thermal spring system, and extend the known range of submarine hydrothermal biota by more than 2,700 million years. Such environments may have hosted the first living systems on Earth, consistent with proposals for a thermophilic origin of life.

Archaea↗

Supporting decision makers in land use planning around chemical sites. Case study: expansion of an oil refinery.

An approach for supporting decisions on land use around chemical sites - along with a software decision support system (DSS) - based on multi-criteria decision analysis (MCDA; and particularly on the establishment of the set of efficient solutions and letting the final selection depend on local procedures and value tradeoffs) is being illustrated through a case study where five alternative expansions of a refinery are considered along with the existing situation. Alternative land use plans are based on combinations of alternative uses of specific land cells coupled with alternative expansion options. Criteria for evaluating alternative land use plans are the potential loss of life (PLL), the noise levels and the economic benefit resulting for each specific land use plan.

Accidents, Occupational↗

An analytical approach to the implementation of genetically modified crops.

Public scepticism towards genetically modified (GM) crops is increasing. To address this, the risks and benefits of GM crops must be examined across scientific disciplines, and be discussed with the authorities, the agricultural industry and the consumers. In a feasibility study we have systematically analysed the challenges of the development and marketing of GM crops in Europe. A life-cycle inventory was used together with established technology foresight techniques in an interdisciplinary and empirical framework. The approach taken in this study established a dialogue between stakeholders and provided a framework for discussions about the future direction of GM crops.

Agriculture↗

SHRIMP uranium-lead dating of diagenetic xenotime in siliciclastic sedimentary rocks

Diagenetic xenotime is common in siliciclastic sedimentary rocks, where it starts to form on detrital zircon shortly after sediment deposition. It is possible to estimate the age of sedimentary rocks by in situ uranium-lead analysis of that xenotime. Two Proterozoic sandstone units from northwestern Australia, previously constrained to the age interval of 1790 to 750 million years ago, have diagenetic xenotime ages of 1704 +/- 7 and 1704 +/- 14 million years ago. This method has potential for dating sedimentary sequences of all ages but should be especially valuable for refining the Precambrian time scale.

Journal Article↗

Ergonomic criteria in large-scale engineering design--I. Management by documentation only? Formal organization vs. designers' perceptions.

In engineering design projects ergonomics criteria may be supplied to project members along with other design requirements. A formal organization for human factors (HF) is set up where responsibilities pertaining to HF are specified. It is then assumed that the project functions according to this, and that the ergonomics criteria are known among project members. We have investigated the management of human factors in two large-scale offshore development projects. Our study shows that neither organization of HF nor ergonomics criteria were well known among project members. To be effective, the criteria have to be supported by one or more HF specialists who engage themselves actively in design.

Adult↗

Ergonomic criteria in large-scale engineering design--II. Evaluating and applying requirements in the real world of design.

Ergonomic standards to be used in engineering design are at present being developed throughout the world. However, not much is known about how ergonomic criteria function in an organizational setting. This study investigates how engineering designers in two large-scale engineering projects evaluate ergonomic criteria that are part of the design requirements in the projects. The designers state a clear preference for specific criteria. We also show how all design criteria are subject to organizational constraints, and that specific formulations are not a guarantee for the implementation of ergonomic criteria. Emphasising a few specific criteria might have an educational impact on the designers. The active involvement of an HF specialist is also critical to ensure a positive outcome for ergonomic criteria in the design negotiation process.

Adult↗

Joining group psychotherapy: developmental considerations.

This article examines the experience of new members joining an ongoing psychotherapy group. The group's stage of development and the new member's personality development are suggested to be important variables in this significant event. The experience of joining is found to share some things in common with the beginning phase of group for the group as a whole, but also noted are some unique elements. The process of joining is viewed as a highly anxious event for the new member, with antecedents in the individual's life experience. The new member is compromised by not knowing the group members, nor their shared history, norms, and dynamics. Concurrently, the group may experience a range of fears, wishes, and anxieties about the new member. Developmental considerations for the new member and the stage of group help to inform intervention strategies.

Adaptation, Psychological↗

Complete structure of the 11-subunit bovine mitochondrial cytochrome bc1 complex.

Mitochondrial cytochrome bc1 complex performs two functions: It is a respiratory multienzyme complex and it recognizes a mitochondrial targeting presequence. Refined crystal structures of the 11-subunit bc1 complex from bovine heart reveal full views of this bifunctional enzyme. The "Rieske" iron-sulfur protein subunit shows significant conformational changes in different crystal forms, suggesting a new electron transport mechanism of the enzyme. The mitochondrial targeting presequence of the "Rieske" protein (subunit 9) is lodged between the two "core" subunits at the matrix side of the complex. These "core" subunits are related to the matrix processing peptidase, and the structure unveils how mitochondrial targeting presequences are recognized.

Amino Acid Sequence↗

The 1.8 A crystal structure of the dimeric peroxisomal 3-ketoacyl-CoA thiolase of Saccharomyces cerevisiae: implications for substrate binding and reaction mechanism.

The dimeric, peroxisomal 3-ketoacyl-CoA thiolase catalyses the conversion of 3-ketoacyl-CoA into acyl-CoA, which is shorter by two carbon atoms. This reaction is the last step of the beta-oxidation pathway. The crystal structure of unliganded peroxisomal thiolase of the yeast Saccharomyces cerevisiae has been refined at 1.8 A resolution. An unusual feature of this structure is the presence of two helices, completely buried in the dimer and sandwiched between two beta-sheets. The analysis of the structure shows that the sequences of these helices are not hydrophobic, but generate two amphipathic helices. The helix in the N-terminal domain exposes the polar side-chains to a cavity at the dimer interface, filled with structured water molecules. The central helix in the C-terminal domain exposes its polar residues to an interior polar pocket. The refined structure has also been used to predict the mode of binding of the substrate molecule acetoacetyl-CoA, as well as the reaction mechanism. From previous studies it is known that Cys125, His375 and Cys403 are important catalytic residues. In the proposed model the acetoacetyl group fits near the two catalytic cysteine residues, such that the oxygen atoms point towards the protein interior. The distance between SG(Cys125) and C3(acetoacetyl-CoA) is 3.7 A. The O2 atom of the docked acetoacetyl group makes a hydrogen bond to N(Gly405), which would favour the formation of the covalent bond between SG(Cys125) and C3(acetoacetyl-CoA) of the intermediate complex of the two-step reaction. The CoA moiety is proposed to bind in a groove on the surface of the protein molecule. Most of the interactions of the CoA molecule are with atoms of the loop domain. The three phosphate groups of the CoA moiety are predicted to interact with side-chains of lysine and arginine residues, which are conserved in the dimeric thiolases.

Acetyl-CoA C-Acyltransferase↗