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Biomedical subjects

M Herrmann

Publications and source records attributed to M Herrmann.

At least 37 records · Page 2Linked to original sources
PubMed2005

[The infected implant: bacteriology].

Periprosthetic infection is a significant complication in joint replacement surgery and develops in 0.5%-2% cases. Staphylococcus aureus and commensal microorganisms of the skin, especially coagulase-negative staphylococci, as well as a broad spectrum of other potential pathogens typically already colonize the surface of the foreign body at the time of implantation. Specific mechanisms such as bacterial adhesion to host factors absorbed in the material, biofilm formation, and a metabolic adaptation of adherent microorganisms play a paticulary important role in the pathogenesis and course of the disease. Microbiological diagnosis requires to some extent complex culture procedures of puncture specimens or tissue removed during surgery; this can be supplemented by modern molecular testing. Antimicrobial treatment must be conceived as a synopsis of clinical picture, confirmed pathogen, and the intended surgical procedure on an individual basis and is routinely administered as combination therapy for several weeks, sometimes also as sequential therapy. Validated preventive measures in joint replacement surgery include mandatory perioperative antibiotic prophylaxis and other additional measures.

Anti-Bacterial Agents↗
PubMed2004

First laser-controlled antihydrogen production.

Lasers are used for the first time to control the production of antihydrogen (H ). Sequential, resonant charge exchange collisions are involved in a method that is very different than the only other method used so far-producing slow H during positron cooling of antiprotons in a nested Penning trap. Two attractive features are that the laser frequencies determine the H binding energy, and that the production of extremely cold H should be possible in principle-likely close to what is needed for confinement in a trap, as needed for precise laser spectroscopy.

Journal Article↗
PubMed2004

[S2 guideline for infectious endocarditis].

Microbe-induced (infectious) endocarditis is an endovascular infection, caused mainly by bacteria, of cardiovascular structures. The major predilection site are the native heart valves, but involvement of implanted intracardiac foreign material is increasingly being seen. The mortality rate of infectious endocarditis depends on clinical factors and the causal agent, but also on the time of the establishment of the diagnosis and the initiation of appropriate treatment. In Germany, the current mortality rate ranges up to 18%. Between January 2003 and July 2004, with the aim of improving patient care and thus the outcome of this condition, a guideline commission worked out recommendations for the diagnosis, treatment and management of the disease for the use of general practitioners and hospital physicians, in particular microbiologists, infectiologists, cardiologists and cardiac surgeons. The basis for this guideline was the systematic search through the literature of the European guideline. On the 16th and 28th of June 2004, the entire guideline was formerly approved in a nominal group process.

Anti-Bacterial Agents↗
PubMed2004

[IKOP-Infection control in the operating theatreConsensus on the theme "Barrier measures during operations and invasive procedures"].

Postoperative surgical site infections remain frequent despite intensive control programs. With rising numbers of operations and invasive procedures in the outpatient setting and in immunocompromised patients, the prevention of wound infections presents a rapidly growing challenge to the medical community. Barrier measures including drapes and surgical gowns to prevent wound contamination, have clearly reduced the rate of wound infections. The optimal material characteristics for operating gowns and drapes are well defined, but there is still a long running controversy on the use of single-use versus reusable materials. We review the efficacy and ecological impacts of these different approaches. Currently no superiority of any of these approaches with regard to either efficacy or ecological impact can be found. The European Union has recently published a series of mandatory standards to specify material characteristics of barrier materials used in operating theatres (EN 13795). Their scope include production standards of these materials as well as specific processes in auditing their characteristics. The implementation of these norms will clearly present a challenge to European hospitals but will lead to better material characteristics in the end.

Europe↗
PubMed2004

[Autonomic innervation of the female pelvis. Anatomic basis].

The pelvic plexus with its sympathetic (hypogastric nerves, sacral sympathetic trunk) and parasympathetic (pelvic splanchnic nerves) sources provides and distributes the autonomic nervous supply for the pelvic organs. This homogeneous autonomic nerve plate is located within and deeply to the peritoneal fold (recto-uterine in the female pelvis) lying medially to the internal iliac vessels. Autonomic nerve fibres emerge from the pelvic plexus and travel to the anterolateral aspect of the rectum and the inferolateral and posterolateral aspects of the bladder and female genital tract. In addition, pelvic organs are innervated by nerves accompanying the vessels and the ureter which penetrate the pelvic plexus. Knowledge of the topography of the pelvic plexus indicates the most common sites for iatrogenic lesions and should help us in avoiding postoperative autonomic dysfunction.

Autonomic Pathways↗
PubMed2004

[The infected implant. Part 1: bacteriology].

Periprosthetic infection is a significant complication in joint replacement surgery and develops in 0.5-2% of cases. Staphylococcus aureus and commensal microorganisms of the skin, especially coagulase-negative staphylococci, as well as a broad spectrum of other potential pathogens typically already colonize the surface of the foreign body at the time of implantation. Specific mechanisms such as bacterial adhesion to host factors absorbed in the material, biofilm formation, and a metabolic adaptation of adherent microorganisms play a particularly important role in the pathogenesis and course of the disease. Microbiological diagnosis requires to some extent complex culture procedures of puncture specimens or tissue removed during surgery; this can be supplemented by modern molecular testing. Antimicrobial treatment must be conceived as a synopsis of clinical picture, confirmed pathogen, and the intended surgical procedure on an individual basis and is routinely administered as combination therapy for several weeks, sometimes also as sequential therapy. Validated preventive measures in joint replacement surgery include mandatory perioperative antibiotic prophylaxis and other additional measures.

Anti-Bacterial Agents↗
PubMed2004

[Severe, non-infectious mitral valve endocarditis after mitral valve reconstruction in a 32-year old female with primary antiphospholipid syndrome].

BACKGROUND: A 32-year old female with primary antiphospholipid syndrome presented 8 months after mitral valve reconstruction with progressive exertional dyspnea and echocardiographically demonstrable critical mitral stenosis and regurgitation. Tachycardia, weight loss, sleep disturbances and increasing nervosity led to the diagnosis of concomitant hyperthyroidism. After the patient stopped the oral anticoagulation by herself, a 'catastrophic antiphospholipid syndrome' with multiple microthromboembolic events in several organs developed rapidly within a few weeks. Severe respiratory failure was observed 14 days after admission at our hospital because of a pulmonary edema. TREATMENT: Removal of the annuloplasty ring and alloplastic mitral valve replacement with a 25 mm bilifleat valve. Postoperatively, the patient was placed on oral anticoagulation. Several pre- and postoperative plasmaphereses lowered the level of antiphospholipid antibodies. The patient additionally underwent radioiodtherapy 5 months postoperatively. RESULTS: While hemodynamics and diuresis remained sufficient, ventilatory support with tracheostomy was necessary for 16 postoperative days to achieve stable respiration. Thirty months later, the patient is well and without further cardiac and neurological dysfunction. CONCLUSION: Secondary cardiac valve operations on patients with primary antiphospholipid syndrome may be successfully performed within a multidisciplinary approach. Oral anticoagulation remains the treatment of choice to prevent further thromboembolic events.

Adult↗
PubMed2004

Can serum NT-proBNP detect changes of functional capacity in patients with chronic heart failure?

Recently, in a cross-sectional study, a correlation of moderate degree was documented between serum BNP (brain natriuretic peptide) and exercise capacity in patients with chronic heart failure (CHF). However, it remains unknown if BNP, which increases in response to high myocardial wall stress, is sufficiently sensitive for changes in exercise capacity during clinical follow-up. To elucidate this, 42 CHF patients were recruited and randomized into a training (T; 58 +/- 10 years; n = 14 NYHA II; n = 5 NYHA III) and a control group (CO; 54 +/- 9, n = 17 NYHA II; n = 6 NYHA III). T carried out 12 weeks of endurance training on a cycle ergometer (4 sessions per week, 45 min duration). Venous blood sampling and cycle ergometry with simultaneous gas exchange measurements were carried out prior to and after the experimental phase. Due to its superior stability during laboratory procedures, NTproBNP was determined instead of BNP. Both proteins are secreted in equimolar amounts and share an identical diagnostic meaning. In both groups, NT-proBNP decreased slightly (T: from 1092 +/- 980 to 805 +/- 724 pg x ml(-1); CO: from 1075 +/- 1068 to 857 +/- 1138 pg x ml(-1); T vs CO: p = 0.65). Anaerobic threshold (AT) as a measure of exercise capacity went up in T (from 0.96 +/- 0.17 to 1.10 +/- 0.22 l x min(-1)) but remained almost constant in CO (pre: 1.02 +/- 0.27; post: 1.00 +/- 0.27 l x min(-1); T vs CO: p < 0.001). The correlation between changes in NT-proBNP and changes in AT remained insignificant (r = 0.02, p = 0.89)-even if only T was considered (r = 0.09, p = 0.72). Improved exercise capacity in CHF patients due to 3 months of endurance training is not reflected in the course of NT-proBNP. These findings are inconsistent with a sufficient sensitivity of this parameter to detect changes in exercise capacity during clinical follow-up. Changes in NT-proBNP beyond its spontaneous variability are more likely to be detected following therapeutical interventions which aim more clearly at the myocardium. In determining alterations of functional capacity ergometric testing cannot be replaced by serial determinations of NT-proBNP.

Aged↗
PubMed2004

UV irradiation inhibits ABC transporters via generation of ADP-ribose by concerted action of poly(ADP-ribose) polymerase-1 and glycohydrolase.

ATP-binding cassette (ABC) transporters are involved in the transport of multiple substrates across cellular membranes, including metabolites, proteins, and drugs. Employing a functional fluorochrome export assay, we found that UVB irradiation strongly inhibits the activity of ABC transporters. Specific inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1) restored the function of ABC transporters in UVB-irradiated cells, and PARP-1-deficient cells did not undergo UVB-induced membrane transport inhibition. These data suggest that PARP-1 activation is necessary for ABC transporter functional downregulation. The hydrolysis of poly(ADP-ribose) by poly(ADP-ribose) glycohydrolase (PARG) was also required, since specific PARG inhibitors, which limit the production of ADP-ribose molecules, restored the function of ABC transporters. Furthermore, ADP-ribose molecules potently inhibited the activity of the ABC transporter P-glycoprotein. Hence, poly(ADP-ribose) metabolism appears to play a novel role in the regulation of ABC transporters.

ATP-Binding Cassette Transporters↗
PubMed2004

Experimental autoimmune encephalomyelitis (EAE): lesion visualization on a 3 Tesla clinical whole-body system after intraperitoneal contrast injection.

PURPOSE: To investigate the intravital visibility of CNS lesions in rats with experimental autoimmune encephalomyelitis (EAE), the animal correlate of multiple sclerosis, using a 3-Tesla (T) whole-body MR system. MATERIALS AND METHODS: Three healthy Dark Agouti (DA) rats and 16 DA rats with clinical signs of EAE were examined on a 3T whole body-system using a normal wrist coil. In total, 25 examinations were preformed using T2- and T1-weigthed images in transverse and sagittal orientation with a slice thickness of 2 mm or 1 mm (voxel size up to 0.2 x 0.2 x 1 mm). Sedation was achieved by intraperitoneal injection of ketamine and xylazine. In addition, T1-weighted images were obtained after the instillation of 1.0 ml of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) (0.5 mmol/ml) into the peritoneal cavity. RESULTS: T2- and T1-weighted images of the brain and spinal cord with high spatial and contrast resolution could be obtained in all animals. The anatomical details of the olfactory bulb glomeruli, cerebellum foliae, ventricles and corpus callosum were clearly visible. The EAE lesions presented as hyperintense areas in T2-weighted images and could be demonstrated in all clinically affected animals by MRI and histologically verified. In total, the 16 affected rats had 28 cerebral and 2 spinal cord lesions (range 1 to 4, median 2). Contrast enhancement was noted in 12 animals and ranked as severe in ten and moderate in two cases. No adverse effects were noted due to sedation or intraperitoneal contrast injection. CONCLUSIONS: The intravital demonstration of cerebral and spinal cord EAE lesions in rats is possible on a 3T whole-body MR scanner using a normal wrist coil. Intraperitoneal injection of ketamine/xylazine and contrast agent is an easy, safe and effective procedure in rats.

Adrenergic alpha-Agonists↗
PubMed2004

Dose-dependent biphasic induction and transcriptional activity of nuclear factor kappa B (NF-kappaB) in EA.hy.926 endothelial cells after low-dose X-irradiation.

PURPOSE: Low-dose radiotherapy is known to exert an anti-inflammatory effect, but the underlying radiobiological mechanisms are still elusive. It was recently reported that transforming growth factor (TGF) beta1 essentially contributes to the reduced adhesion of peripheral blood mononuclear cells to endothelial cells at low-dose X-irradiation. As the transcription factor nuclear factor kappa B (NF-kappaB) is crucially involved in mediating an inflammatory response by inducing the expression of cytokines and adhesion molecules, NF-kappaB DNA binding and transcriptional activity as well as its impact on the expression of TGF-beta1 in EA.hy.926 endothelial cells were analysed subsequently to low-dose radiotherapy. MATERIALS AND METHODS: Human EA.hy.926 endothelial cells were grown to subconfluence. Twenty hours after X-irradiation with single doses ranging from 0.3 to 3 Gy, the cells were activated with tumour necrosis factor-alpha. Four hours later, the cells were harvested. NF-kappaB DNA-binding activity of nuclear extracts was analysed by electrophoretic mobility shift assay. The NF-kappaB subunits p50, p65/RelA, c-Rel and RelB of the NF-kappaB complexes were quantified by enzyme-linked immunoabsorbant assay. The transcriptional activity of NF-kappaB was measured using luciferase reporter gene assays in EA.hy.926 endothelial cells transiently transfected with the plasmid pB2xLuc. To correlate transcriptional activity to TGF-beta1 expression, NF-kappaB decoy oligonucleotides were used to inhibit NF-kappaB activity and TGF-beta1 secretion. RESULTS: After low-dose radiotherapy, an increased NF-kappaB DNA-binding activity was observed in stimulated EA.hy.926 endothelial cells with a relative maximum (threefold induction) at 0.5 Gy. The NF-kappaB activation then decreased after X-irradiation at 0.6-0.8 Gy and subsequently increased again at doses of 1 and 3 Gy. This biphasic induction profile of NF-kappaB was confirmed by the analysis of the NF-kappaB-specific transcriptional activity. The latter showed a relative maximum at 0.5 Gy, a relative minimum between 0.5 and 1.0 Gy, and an increase at 3 Gy. Transfection of EA.hy.926 endothelial cells with NF-kappaB decoy oligonucleotides before irradiation resulted in a 50% reduction of TGF-beta1 secretion at 0.5 Gy compared with control oligonucleotides or untreated cells. CONCLUSIONS: Low-dose radiotherapy induces a biphasic activation of NF-kappaB with a relative maximum at 0.5 Gy. The induction by NF-kappaB of TGF-beta1 in endothelial cells might contribute to the anti-inflammatory properties of low-dose ionizing irradiation.

Cell Nucleus↗
PubMed2004

Renal clearance and daily excretion of cortisol and adrenal androgens in patients with rheumatoid arthritis and systemic lupus erythematosus.

BACKGROUND: In rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), patients demonstrate low levels of adrenal hormones. OBJECTIVE: To investigate whether increased renal clearance and daily excretion contribute to this phenomenon. METHODS: Thirty patients with RA, 32 with SLE, and 54 healthy subjects (HS) participated. Serum and urinary levels of cortisol, cortisone, 17-hydroxyprogesterone (17OHP), androstenedione, dehydroepiandrosterone (DHEA), and DHEA sulphate (DHEAS) were measured. RESULTS: Clearance of DHEAS and DHEA was lower in patients than in HS, and clearance of androstenedione was somewhat higher in patients than in HS, but daily excretion of this latter hormone was low. Clearance of cortisol, cortisone, and 17OHP was similar between the groups. The total molar amount per hour of excreted DHEA, DHEAS, and androstenedione was lower in patients than HS (but similar for cortisol). Serum DHEAS levels correlated with urinary DHEAS levels in HS and patients, whereby HS excreted 5-10 times more of this hormone than excreted by patients. Low serum levels of adrenal androgens and cortisol in patients as compared with HS were confirmed, and proteinuria was not associated with changes of measured renal parameters. CONCLUSIONS: This study in patients with RA and SLE demonstrates that low serum levels of adrenal androgens and cortisol are not due to increased renal clearance and daily loss of these hormones. Decreased adrenal production or increased conversion or conjugation to downstream hormones are the most likely causes of inadequately low serum levels of adrenal hormones in RA and SLE.

17-alpha-Hydroxyprogesterone↗
PubMed2004

Hydrostatic pressure induced death of mammalian cells engages pathways related to apoptosis or necrosis.

We investigated the response to high hydrostatic pressure (HHP) of mammalian cells, since HHP is proposed to be suitable to inactivate mammalian cells in biopharmaceutics and patient's material. We observed that cells were not restricted in their viability by pressures up to 100 MPa. Mammalian cells die when treated with pressures of 200 MPa or more. But the effects of 200, 300 or 400 MPa do not follow the same pattem. At 200 MPa, cells die in a way that is related to apoptosis. Some apoptotic characteristics like phosphatidylserine (PS) exposure and morphological alterations appear very fast. Other features like a higher exposure of intracellular NPn ligands and pronounced degradation of DNA and lectin ligands are unique features of HHP induced apoptosis. Cells treated with 300 and 400 MPa die immediately following a unique necrotic pathway, since treated cells harbour high DNA and glycoprotein degrading activities.

Apoptosis↗
PubMed2004

High hydrostatic pressure inactivated human tumour cells preserve their immunogenicity.

High hydrostatic pressure (HHP) is an established method to inactivate biomolecules and microoganisms. It is routinely used for the sterilization of foodstuff. Recently, new applications as inactivation of microorganisms and tumour cells for bone transplants or for cancer vaccines have emerged. Characterization of the HHP-induced cellular responses are a prerequisite for its clinical use. To this end, we investigated the fate of human cells after HHP by cytofluorometry. We observed that the induction by HHP of cell death is time- and pressure-dependent. Surprisingly, an HHP-treatment of 100 MPa did not reduce viability at any time point. Pressures from 150 to 250 MPa-induced programmed cell death in most cells. However, survivors were observed in long term culture experiments under these conditions. Pressures above 300 MPa immediately induced cell death by necrosis and completely inactivated the cells. In contrast to inactivation by other necrosis inducing treatments like heat, freeze/thaw, or chemical agents, HHP avoids generation of Maillard products and disintegration and lysis of the cells. Instead HHP generates a gelatinised mixture of antigens captured in a distinct and robust particle and maintains their humoral immunogenicity. The high viscosity of the internal matrix of a pressurised cell is reflected by the slow penetration of the low molecular compound propidium iodide and limits the bleeding of antigen before uptake by antigen presenting cells. Taken together, HHP is an alternative method for the inactivation of mammalian cells in clinical settings.

Animals↗
PubMed2003

Antibiotic-associated diarrhea: therapeutic aspects and practical guidelines--an interdisciplinary approach to a common problem.

Antibiotic-associated diarrhea (AAD) is a common complication of antibiotic treatment, most often seen in non-hospitalised patients. In principle, such diarrhea can be triggered by any antibiotic. An interdisciplinary working group discussed the different aspects of AAD in view of its gastroenterological, microbiological, paediatric, general medical and pharmaceutical implications, also in consideration of the position of patients and health insurance funds. This paper implies therapeutic aspects and practical guidelines to raise awareness of these problems also in routine situations and to enable the persons and institutions involved on the various levels of the health-care system (patients, pharmacists, family doctors, specialists and hospitals) to handle the problem of AAD more easily in a standardised way as far as diagnostics, therapy and prevention are concerned.

Adult↗
PubMed2003

Antibiotic-associated diarrhea: incidence, risk factors of antibiotics and patients, pathophysiology and differential diagnosis--an interdisciplinary approach to a common problem.

Antibiotic-associated diarrhea (AAD) is a common complication of antibiotic treatment, most often seen in non-hospitalised patients. In principle, such diarrhea can be triggered by any antibiotic. An interdisciplinary working group discussed the different aspects of AAD in view of its gastroenterological, microbiological, paediatric, general medical and pharmaceutical implications, also in consideration of the position of patients and health insurance funds. The incidence, risk factors of antibiotics and patients, the pathophysiology of the various types of AAD and the differential diagnosis are reviewed.

Adolescent↗