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Biomedical subjects

U Koch

Publications and source records attributed to U Koch.

At least 19 recordsLinked to original sources
PubMed2003

[Surgical treatment of rhinophyma with the ultrasonic scalpel (Ultracision Harmonic Scalpel)].

BACKGROUND: There are multiple surgical approaches to the treatment of rhinophyma. Because of the exceptional vascularity of the nose, traditional surgical approaches to the management of rhinophyma are fraught with persistent intraoperative hemorrhage. Hemorrhage that is controlled with electrocautery or laser by a combination of excision of rhinophymatous tissue and simultaneous hemostasis invariably damages cartilage by thermal injury. The UltraCision Harmonic Scalpel achieved a tissue dissection with a simultaneous hemostasis and only minimal thermal tissue injury. To this date, in Europe no studies have been published on the use of the Ultracision Harmonic Scalpel in the surgical treatment of rhinophyma. PATIENTS AND TREATMENT: 6 patients had surgical treatment of rhinophyma with the UltraCision Harmonic Scalpel. The objective of the study was therefore to analyse the handling indication, the efficiency of intra- and postoperative hemostasis, the wound healing, the postoperative pain and the histologic results of tissue resections. RESULTS: Because of the effective intraoperative hemostasis supplementary hemostasis was not required in any examined patient. The efficient hemostasis and the tactile experience of the UltraCision Harmonic Scalpel enabled an accurate sculpting of the nose. Postoperative pain sensation was minimal. Wound healing was uneventful in all cases. Postoperative reepithelialization occurred within 28 days. Delayed complications like scarring did not occur within a median follow - up of 13 month. Histopathological evaluation was possible in all cases. CONCLUSION: The UltraCision Harmonic Scalpel offers a surgical treatment of rhinophyma with efficacious intra- and postoperative hemostasis. The combination of simultaneous tissue dissection and hemostasis enables a good overall view and control of the surgical site. Based on its mechanical function, the UltraCision Harmonic Scalpel has only a little thermal effect on neighbouring tissues and a good tactile experience that enables a controlled tissue resection. The UltraCision Harmonic Scalpel combines the advantages of tissue dissection and simultaneous hemostasis with the controlled handling of the traditional scalpel in rhinophyma surgery.

Aged↗
PubMed2003

[Conditions and strategies for the development of guidelines for the rehabilitation of patients with psychiatric and psychosomatic disorders].

In comparison to other countries, the German health care system can be characterized by an exceptionally extended system of inpatient psychotherapeutic treatment. About 20,000 beds are available in three different, partly mutually competitive medical settings: psychosomatic/psychotherapeutic hospital treatment, psychiatric hospital treatment and psychosomatic rehabilitation. The article first describes the latest developments and issues concerning the demarcation of tasks in these three therapeutic inpatient settings. The implementation of guidelines may contribute to a common understanding and function as a rational corrective with regard to the treatment appropriate for each individual case. Previous efforts to develop guidelines for the treatment of patients with psychiatric disorders are described. A special focus is put on the question of whether existing guidelines already fulfil the specific requirements for the rehabilitative treatment of these patients. The analysis reveals substantial deficits concerning the development of guidelines for the inpatient psychotherapeutic treatment in general as well as for the specific setting of psychosomatic/psychotherapeutic rehabilitation. Given this situation, the authors propose a strategy with 5 stages to the development of guidelines for this target group.

Combined Modality Therapy↗
PubMed2003

[The development of a case group concept for patients with mental diseases].

In the year 2000 the German legislative decided to implement a case-dependent reimbursement system in an acute inpatient setting beginning in 2003. The German-Diagnoses Related Group System (G-DRGs) will adopt the refined version of the Australian-Diagnoses Related Group System (AR-DRG, version 4.1). Based on empirical data and expertś panels the acute psychiatric hospitals have been exempted from the adoption of the case-based payment system. With regard to national and international experiences in the development of patient classification systems in psychiatry and medical rehabilitation this article illustrates the development of a case group concept for patients with mental disorders.

Australia↗
PubMed2003

[Preliminary results for superficial parotidectomy using the ultrasonically activated scalpel (Ultracision Harmonic Scalpel)].

BACKGROUND: The high density of blood vessels in the parotid gland, the direct vicinity to the facial nerve and the narrow surgical situs require efficient intra- and postoperative hemostasis. The ultrasonic scalpel (US) accomplishes both tissue dissection and vessel coagulation simultaneously by an ultrasonically activated shear movement of 55 500 Hz. The combination of hemostasis and tissue dissection particularly qualifies US for use in surgery of the parotid gland. Until now, there have been no published studies about application of US in surgery of the parotid gland. METHOD: 20 patients with benign parotid tumors treated with a conventional technique of superficial parotidectomy and 20 patients with a superficial parotidectomy using the ultrasonically activated scalpel were examined in regard to intra- and postoperative hemostasis, wound healing and postoperative pain. Also, the quality of the histopathological specimen obtained by US was evaluated. RESULTS: In 85 % (17/20) of superficial parotidectomy efficient intraoperative hemostasis did not require electrocoagulation. In 15 % (3/20) of parotid tumors additional bipolar electrocoagulation were required because of venous bleeding from vessels exceeding 2.0 mm in diameter. Postoperative bleeding did not occur at all. Wound healing was uneventful in all cases. Surgery-related postoperative pain was not intensified. Time of operation was shortened. Histopathological evaluation, especially in the margin area, was not impaired. CONCLUSION: The US offers tissue dissection with effective intra- and postoperative hemostasis. The combination of simultaneous tissue dissection and hemostasis enables a good overall view and control of the surgical site. In addition, based on the mechanical function the US has only a minimal thermal effect on neighboring tissues and enables controlled tumor resection without damaging the facial nerve.

Adult↗
PubMed2003

[New aspects of the mechanics of the auditory tube].

The aim of the present article is to describe the mechanical components of the auditory tube and the role of these components in auditory tube function. Particular attention will be given to those aspects which have not been sufficiently dealt with in the past, such as the role of the isthmus region, the function of the lateral mucosal folds, the significance of the of the surfactant proteins and the pathophysiology of the patulous auditory tube. Special attention is given to the tensor veli palatini muscle and its physiology. Because of its isometric contraction, the function of this muscle depends on so-called hypomochlia changing the direction of its force. In the context of this article, the three hypomochlia involved are the pterygoid hamulus, Ostmann's fatty tissue and the medial pterygoid muscle. The so-called "Eppendorf-maneuver" is depicted for the first time.

Biomechanical Phenomena↗
PubMed2002

Conceptional considerations for a German influenza pandemic preparedness plan.

A pandemic appearance of influenza A virus must be expected at any time. The limitations of health preserving and life-saving resources, which will inevitably be reached in the event of a pandemic, will be accompanied by ethical and possibly social conflicts, which can be lessened or resolved only through precautionary planning, clearly specified competencies and transparent decisions within a social consensus. In case of a shortage of vaccines and virostatic agents, decisions will have to be made with regard to the segment of the population that absolutely must be vaccinated. It is currently estimated that a (monovalent) vaccine developed for a new pandemic strain would only suffice for the single vaccination of approximately half of the German population after a year; only 10-14 million vaccine dosages would be available to provide basic immunization and single boosters to personnel required to maintain basic medical care and essential infrastructure after half a year. In the event of local influenza outbreaks, antiviral chemotherapeutic agents could be used to close the gap until a vaccine can become effective. Even if suitable influenza vaccines and virostatic agents are not sufficiently available at the start of a pandemic, it is still possible to at least prevent an outbreak of two of the most feared secondary infections that accompany influenza: pneumococcal pneumonia or meningitis and illnesses resulting from Haemophilus influenzae. Agreement still needs to be reached with manufacturers for guaranteeing the necessary vaccine production or ensuring that they have a sufficient stock to meet the minimum demand for antiviral agents and agents for symptomatic treatment.

Antiviral Agents↗
PubMed2002

[The "Ultracision Harmonic Scalpel" ultrasound activated scalpel. Initial results in surgery of the tongue and soft palate].

The ultrasonically activated scalpel (UAS) performs tissue dissection and coagulation simultaneously by an ultra-high-frequency movement of the blade. In the present prospective study, results of UAS in the surgery of the tongue and the soft palate are analysed. 25 patients with carcinoma of the tongue and 11 patients with carcinoma of the soft palate were examined in regard to intra- and postoperative hemostasis, wound healing and postoperative pain. Also, the quality of the histo-pathological specimen obtained by UAS was evaluated. In 68% (17/25) of partial tongue resections, and in 82% (9/11) of soft palate resections efficient intraoperative hemostasis did not require electrocoagulation or suture ligature. In 32% (8/25) of tongue malignancies, all with extension to the tongue base, and in 18% (2/11) of soft palate resections additional ligation was required because of arterial bleeding from vessels exceeding 1.0 mm in diameter. Wound healing was uneventful in all cases. The histopathological evaluation, especially in the margin area, was not impaired. The UAS offers a tissue dissection with efficacious intra- and postoperative hemostasis. Arterial bleeding from vessels exceeding 1.0 mm in diameter should be sutured additionally. The combination of simultaneous tissue dissection and hemostasis enables a good overall view and control of the surgical situs. In addition, based on the mechanical function the UAS has only little thermical effect on neighbouring tissues and enables a controlled tumor resection without damaging vital structures.

Adult↗
PubMed2002

[Treatment recommendations in psychosomatic rehabilitation -- empirical analyses based on the pension insurers' standardized discharge report].

BACKGROUND: The recommendations for aftercare listed in discharge reports represent a core component of communication between inpatient psychosomatic rehabilitation and ambulatory follow-up care. The standardized discharge report used by the pension insurance institutes makes use of a generic category system for systematization and simplification of recommendations for aftercare. Neither the practice of making recommendations for aftercare as observed by therapists and physicians responsible for treatment in the inpatient setting nor the appropriateness and differentiation of the category system has previously been systematically examined. A randomized sample of discharge reports was analyzed for this purpose. METHODS: A sample of 500 discharge reports from an inpatient-oriented psychosomatic rehabilitation setting were analyzed regarding the categories of recommended aftercare measures and their relationship with socio-demographic variables, clinical diagnosis and sociomedical variables. RESULTS: Outpatient psychotherapy represents the most frequently recommended aftercare treatment, being suggested in nearly 70% of the patients. Further substantial percentages were found in recommendations for areas including occupational rehabilitation, somatic-medical recommendations, and recommendations for health behaviour and self-help groups. In approximately one quarter of the patients, recommendations for aftercare were given that were coded under the category of "other suggestions". In younger and socio-medically burdened patients, recommendations for the fields of occupational rehabilitation and psychotherapy were more frequently given. In patients with a somatic illness or a somatoform disorder as the primary diagnosis, recommendations within the field of outpatient psychotherapy were found less frequently, while recommendations in the somatic-medical area were more commonly found. DISCUSSION: The results give some support for the clinical validity of the form of recommendations given for aftercare measures in an inpatient psychosomatic rehabilitation setting. At the same time, the analyses indicate excessive as well as insufficient differentiation in the generic category system for follow-up treatment recommendations, which could lead to a loss of valuable information at the interface between inpatient and outpatient treatments.

Adult↗
PubMed2002

Hepatitis C virus proteins as targets for drug development: the role of bioinformatics and modelling.

Hepatitis C virus (HCV), a member of the Flaviviridae family, has been recognised to be responsible for both parenterally transmitted and sporadic non-A and non-B hepatitis affecting 1-3% of the world population. HCV is a positive stranded RNA virus encoding a single polyprotein which contains at least ten unique structural and non-structural proteins. Amongst these the structural protein E2 has been of special interest for vaccine development and the serine protease NS3, which is responsible for cleavage of the polyprotein, for the development of small molecule inhibitors. We will focus on the contribution of computational techniques and the use of structural information for the design and discovery of novel therapeutic agents for these targets. Both drug discovery and vaccine design efforts will be discussed taking into account also the problem of emerging resistance.

Computational Biology↗
PubMed2002

Influenza pandemic: preparedness planning in Germany.

The following conceptual framework formed the basis for a common decision made by the health ministers of Germany's 16 federal states to set up an influenza pandemic preparedness plan. The worst case scenario was used, on the basis of the data from the pandemic of 'Spanish flu', in 1918-20. The priority groups for vaccination were assessed, as well as the potentially available antiviral treatments. National policies could be highly improved by a common European view.

Disease Outbreaks↗
PubMed2001

Role of charged residues in the catalytic mechanism of hepatitis C virus NS3 protease: electrostatic precollision guidance and transition-state stabilization.

Maturational cleavage of the hepatitis C virus polyprotein involves the viral chymotrypsin-like serine protease NS3. The substrate binding site of this enzyme is unusually flat and featureless. We here show that NS3 has a highly asymmetric charge distribution that is characterized by strong positive potentials in the vicinity of its active site and in the S5/S6 region. Using electrostatic potential calculations, we identified determinants of this positive potential, and the role of six different residues was explored by site-directed mutagenesis. Mutation of residues in the vicinity of the active site led to changes in k(cat) values of a peptide substrate indicating that basic amino acids play a role in the stabilization of the transition state. Charge neutralization in the S5/S6 region increased the K(m) values of peptide substrates in a manner that depended on the presence of negatively charged residues in the P5 and P6 positions. K(i) values of hexapeptide acids spanning P6-P1 (product inhibitors) were affected by charge neutralization in both the active site region and the S5/S6 region. Pre-steady-state kinetic data showed that the electrostatic surface potential is used by this enzyme to enhance collision rates between peptidic ligands and the active site. Calculations of the interaction energies of protease-substrate or protease-inhibitor complexes showed that electrostatic interaction energies oppose the formation of a tightly bound complex due to an unfavorable change in the desolvation energy. We propose that desolvation costs are minimized by avoiding the formation of individual ion pair interactions through the use of clusters of positively charged residues in the generation of local electrostatic potentials.

Amino Acid Sequence↗
PubMed2001

Subversion of the T/B lineage decision in the thymus by lunatic fringe-mediated inhibition of Notch-1.

Notch-1 signaling is essential for lymphoid progenitors to undergo T cell commitment, but the mechanism has not been defined. Here we show that thymocytes ectopically expressing Lunatic Fringe, a modifier of Notch-1 signaling, induce lymphoid progenitors to develop into B cells in the thymus. This cell fate switch resulted from Lunatic Fringe-mediated inhibition of Notch-1 function, as revealed by experiments utilizing lymphoid progenitors in which Notch-1 activity was genetically manipulated. These data identify Lunatic Fringe as a potent regulator of Notch-1 during the T/B lineage decision and show that an important function of Notch-1 in T cell commitment is to suppress B cell development in the thymus.

Animals↗
PubMed2001

Measurement of homonuclear three-bond J(H(N)Halpha) coupling constants in unlabeled peptides complexed with labeled proteins: application to a decapeptide inhibitor bound to the proteinase domain of the NS3 protein of hepatitis C virus (HCV).

A new isotope-filtered experiment has been designed to measure homonuclear three-bond J(H(N)Halpha) coupling constants of unlabeled peptides complexed with labeled proteins. The new experiment is based on the 3D HNHA pulse scheme, and belongs to the 'quantitative J-correlation' type. It has been applied to a decapeptide inhibitor bound to the proteinase domain of the NS3 protein of human hepatitis C virus (HCV).

Algorithms↗
PubMed2001

[Multiperspective estimates on the probability of patient return to work following orthopaedic rehabilitation: findings and predictive relevance].

This article analyses various methods of predicting whether patients in orthopaedic rehabilitation will return to work. In this regard, items of patients, physicians in charge of rehabilitation and general practitioners have been collected and compared to working time lost due to illness. In total, 72 % of patients had successfully returned to work after one year. The patients whose reintegration could not be achieved could be identified best by asking if they believed that they would be in a position to work until the statutory retirement age (96 % identified) on the one hand and on the other hand by the physicians' estimate as to the degree the last gainful activity might be resumed (90 % identified). In this context, the criteria have to be laid down very restrictively in order to sufficiently filter out patients not likely to return to work. The patients likely to return to work are identified best by means of the following characteristics: lack of intention to retire early (96 % identified), planning to return to work directly after rehabilitation (88 % identified), and little working time lost due to illness prior to rehab (86 % identified). In general, a major percentage of patients not likely to return to work can be identified by these statements of patients and physicians. The statements of general practitioners are clearly less valuable for prediction and show only weak correlation with the respective statements of the physicians in charge of rehabilitation.

Adult↗
PubMed2001

[Living organ donation vs. cadaveric donation - study of liver transplanted children and their families].

There is only scarce information on the quality of life of child recipients of liver transplants and their families. Particularly children with a living related graft and their families never have been compared to children who received a cadaveric graft and their families. We investigated the following issues in our study: How do parents and children from participating families rate their strain, their quality of life and their relationships within their family? Do families with a living - related donor differ from those with a cadaveric donor? What do living donors and their partners think about the donation retrospectively? The study was conducted with 106 participants from 50 families (42 mothers, 40 fathers, and 24 children older than 6 years). In 20 of these families, a living transplantation had been performed. Participants were interviewed and asked to fill out several questionnaires. School-aged children with a liver transplant show good social integration among their peers and in school. The child's disease, however, has a great impact on the family. Family members show a reduction in social contact, and an increase in marital crises, and problematic relations amongst siblings. Families in which a cadaveric graft was performed, are less satisfied with life, and show more symptoms of exhaustion. Every family studied possessed or acquired - a high degree of internal or external coping resources. Living - related donors tried hard to obtain an understanding of the medical context. The partner, rather than the donor himself, feels anxious before the donation. The limited time available for the decision to donate is not perceived by the donors to be critical. Ten percent of living donors feel "a little" that their health is affected. The decision to donate is supported "strongly" or "very strongly" by the partners in 80 % of the cases. A possible strain on the child through the expectation of gratitude by the donor is stated by 20 %. All of the donors agree that if they were to be asked today, they would donate again, only one of the partners raised objections. In summary, as a retrospective pilot study, this study primarily generates hypotheses rather than testing them and helps to develop research tools for the field. Results suggest that a psychological support be made available both prior to and following the operation, not only for the children but also for their families, with particular attention to the partners of the living donors and the siblings of the affected children.

Adolescent↗
PubMed2001

Hepatitis C virus protease inhibitors: current progress and future challenges.

Hepatitis C is a predominantly chronic viral infection, affecting 1-3% of the world population. The causative agent, the hepatitis C virus (HCV), has a positive strand-RNA genome that is utilized, in infected cells, as an mRNA to drive the synthesis of a large polyprotein precursor. This precursor subsequently undergoes proteolytic maturation to generate all of the functional, both structural and nonstructural proteins necessary for viral replication and assembly. The proteolytic activity that is responsible for the generation of the mature viral polymerase as well as for most of the cleavages occurring in the nonstructural region of the polyprotein is expressed by the virus itself and is contained in its nonstructural protein 3 (NS3). Here, the N-terminal 180 amino acids form a chymotrypsin-like serine protease domain. Full activation of this protease is achieved only after complexation with another viral protein, the cofactor protein NS4A. Together, NS3 and NS4A form the active, heterodimeric serine protease that presently is the target of medicinal chemistry efforts aiming at the development of inhibitors with potential antiviral activity. We here review the recent progress in our understanding of the structure and function of the enzyme and in the development of selective and potent NS3 protease inhibitors.

Binding Sites↗