Biomedical subjects

M Schütz

Publications and source records attributed to M Schütz.

At least 19 recordsLinked to original sources

PubMed2006

Myocardial perfusion in patients with typical chest pain and normal angiogram.

BACKGROUND: Approximately 10-30% of patients with typical chest pain present normal epicardial coronaries. In a proportion of these patients, angina is attributed to microvascular dysfunction. Previous studies investigating whether angina is the result of abnormal resting or stress perfusion are controversial but limited by varying inclusion criteria. Therefore, we investigated whether microvascular dysfunction in these patients is associated with perfusion abnormalities at rest or at stress. PATIENTS AND METHODS: In 58 patients (39 female, 19 male, mean age 58+/-10 years) with angina and normal angiogram as well as 10 control patients with atypical chest pain and normal coronaries (six female, four male, mean age 53+/-11 years) myocardial blood flow (MBF) was measured at rest and under dipyridamole using 13N-ammonia PET. Resting MBF and coronary flow reserve (CFR) as the ratio of hyperaemic to resting MBF were corrected for rate-pressure-product (RPP): normalized resting MBF (MBFn)=MBFx10,000/RPP and CFRn=CFRxRPP/10,000. RESULTS: Sixteen/58 patients had a normal CFRn (=2.5; group I; CFRn: 3.1+/-0.88); the same as the controls (CFRn: 3.3+/-0.74). Forty-two/58 patients presented a reduced CFRn (group II; CFRn: 1.78+/-0.57). Group II had both a higher MBFn (group II: 1.30+/-0.33 vs. Group I: 1.03+/-0.26; P<0.05 and vs. controls: 1.07+/-0.19; P<0.01) and a lower hyperaemic MBF (group II: 2.25+/-0.76 mL g-1 min-1 vs. Group I: 3.07+/-0.78 mL g-1 min-1; P<0.001 and vs. controls: 3.41+/-0.94 mL g-1 min-1; P<0.0001). CONCLUSION: Impaired CFRn in patients with typical angina and normal angiogram is owing to both an increased resting and reduced hyperaemic MBF. Therefore, PET represents a prerequisite for further studies to optimize treatment in individuals with anginal pain and normal coronary angiogram.

Adult↗

PubMed2005

Stabilisation of periprosthetic fractures with angular stable internal fixation: a report of 13 cases.

INTRODUCTION: Periprosthetic fractures of the femur present a challenging surgical problem. The aim of this study was to retrospectively evaluate the outcome of periprosthetic fractures stabilised with an angular stable, less invasive stabilisation system (LISS). PATIENTS AND METHODS: Thirteen patients (ten total hip-, two total knee-, one total hip- and knee-arthroplasty) with periprosthetic fractures were treated with the LISS internal fixator (in ten cases minimal invasive). Six patients had previous operations due to periprosthetic fractures. The average follow-up period was 20 months, follow-up rate 85%. RESULTS: All fractures showed radiographic fracture healing without implant loosening. Except one patient, all patients had returned to their pre-operative activity level. No early post-operative complications were seen. There was one implant failure after 4 months and two cases of malunion. CONCLUSION: The cases showed the internal fixator to be effective for the stabilisation of periprosthetic fractures, even in cases of poor bone quality with good functional outcomes. The internal fixator, with the option of minimal invasive application, is the preferred method of osteosynthesis in periprosthetic fractures.

Accidental Falls↗

PubMed2005

Dexamethasone stimulation of retinoic Acid-induced sodium iodide symporter expression and cytotoxicity of 131-I in breast cancer cells.

CONTEXT: The sodium iodide symporter (NIS) mediates the active iodide uptake in the thyroid gland as well as lactating breast tissue. Recently induction of functional NIS expression was reported in the estrogen receptor-positive human breast cancer cell line MCF-7 by all-trans retinoic acid (atRA) treatment in vitro and in vivo, which might offer the potential to treat breast cancer with radioiodine. OBJECTIVE: In the current study, we examined the effect of dexamethasone (Dex) on atRA-induced NIS expression and therapeutic efficacy of 131-I in MCF-7 cells. DESIGN: For this purpose, NIS mRNA and protein expression levels in MCF-7 cells were examined by Northern and Western blot analysis after incubation with Dex (10(-9) to 10(-7) m) in the presence of atRA (10(-6) m) as well as immunostaining using a mouse monoclonal human NIS-specific antibody. In addition, NIS functional activity was measured by iodide uptake and efflux assay, and in vitro cytotoxicity of 131-I was examined by in vitro clonogenic assay. RESULTS: After incubation with Dex in the presence of atRA, NIS mRNA levels in MCF-7 cells were stimulated up to 11-fold in a concentration-dependent manner, whereas NIS protein levels increased up to 16-fold and iodide accumulation was stimulated up to 3- to 4-fold. Furthermore, iodide efflux was modestly decreased after stimulation with Dex in the presence of atRA. Furthermore, in the in vitro clonogenic assay, selective cytotoxicity of 131-I was significantly increased from approximately 17% in MCF-7 cells treated with atRA alone to 80% in MCF-7 cells treated with Dex in the presence of atRA. CONCLUSION: Treatment with Dex in the presence of atRA significantly increases functional NIS expression levels in addition to inhibiting iodide efflux, resulting in an enhanced selective killing effect of 131-I in MCF-7 breast cancer cells.

Blotting, Northern↗

PubMed2005

Local-MP2 electron correlation method for nonconducting crystals.

Rigorous methods for the post-HF (HF-Hartree-Fock) determination of correlation corrections for crystalline solids are currently being developed following different strategies. The CRYSTAL program developed in Torino and Daresbury provides accurate HF solutions for periodic systems in a basis set of Gaussian type functions; for insulators, the occupied HF manifold can be represented as an antisymmetrized product of well localized Wannier functions. This makes possible the extension to nonconducting crystals of local correlation linear scaling On techniques as successfully and efficiently implemented in Stuttgart's MOLPRO program. These methods exploit the fact that dynamic electron correlation effects between remote parts of a molecule (manifesting as dispersive interactions in intermolecular perturbation theory) decay as an inverse sixth power of the distance R between these fragments, that is, much more quickly than the Coulomb interactions that are treated already at the HF level. Translational symmetry then permits the crystalline problem to be reduced to one concerning a cluster around the reference zero cell. A periodic local correlation program (CRYSCOR) has been prepared along these lines, limited for the moment to the solution of second-order Moller-Plesset equations. Exploitation of point group symmetry is shown to be more important and useful than in the molecular case. The computational strategy adopted and preliminary results concerning five semiconductors with tetrahedral structure (C, Si, SiC, BN, and BeS) are presented and discussed.

Journal Article↗

PubMed2005

Density-functional theory-symmetry-adapted intermolecular perturbation theory with density fitting: a new efficient method to study intermolecular interaction energies.

The previously developed DFT-SAPT approach, which combines symmetry-adapted intermolecular perturbation theory (SAPT) with a density-functional theory (DFT) representation of the monomers, has been implemented by using density fitting of two-electron objects. This approach, termed DF-DFT-SAPT, scales with the fifth power of the molecular size and with the third power upon increase of the basis set size for a given dimer, thus drastically reducing the cost of the conventional DFT-SAPT method. The accuracy of the density fitting approximation has been tested for the ethyne dimer. It has been found that the errors in the interaction energies due to density fitting are below 10(-3) kcal/mol with suitable auxiliary basis sets and thus one or two orders of magnitude smaller than the errors due to the use of a limited atomic orbital basis set. An investigation of three prominent structures of the benzene dimer, namely, the T shaped, parallel displaced, and sandwich geometries, employing basis sets of up to augmented quadruple-zeta quality shows that DF-DFT-SAPT outperforms second-order Moller-Plesset theory (MP2) and gives total interaction energies which are close to the best estimates inferred from combining the results of MP2 and coupled-cluster theory with single, double, and perturbative triple excitations.

Journal Article↗

PubMed2005

[New osteosynthesis techniques for the treatment of distal femoral fractures].

The treatment of distal femoral fractures was for a long-time associated with high complication rates. Although implants and surgical techniques were improved, plate osteosynthesis and intramedullary nailing suffered from considerable rates of infection, non-union und malalignment. Attention to the soft tissue envelope by "biological" osteosynthesis and minimally invasive approaches resulted in decreased complication rates. Out of this movement grew the concept of minimal invasive plating with an internal fixator -- the LISS-DF (Less Invasive Stabilization System -- Distal Femur) -- and the retrograde nailing concept. This article should give a review about these two new techniques for the treatment of distal femoral fractures. Indications, the clinical use and the aftercare will be discussed.

Bone Plates↗

PubMed2005

[Combined simulation training: a new concept and workshop is useful for crisis management in gastrointestinal endoscopy].

INTRODUCTION: Crisis management as well as realistic emergency situations can be trained in the new developed simulation workshop "Gastrointestinal Endoscopy and Crisis Resource Management" by combining a full-scale simulator and the Erlanger Endoscopy Trainer. The aim of the current study was to evaluate the efficiency of the newly developed simulation workshop. METHODS: Endoscopists with more than 12 months experience can train their endoscopic skills and crisis resource management with the help of different simulators. In addition, two different scenarios (GI bleeding with significant blood loss and sedation overdoses) embedded in a realistic surrounding (emergency room) have to be managed by the participants. Vital parameters, endoscopic skills, as well as personal interactions were recorded and graded. RESULTS: 100 participants took part in the newly developed workshop (between June and December 2003). The participants showed a significantly better endoscopic performance and a significantly better crisis management after the standardized training program. CONCLUSIONS: Simulation training plays an essential role in aviation and minimizes the risk for human errors. In the current study it is clearly shown that simulation training is also useful in gastrointestinal endoscopy. The newly developed workshop may thus be of crucial importance to improve personal crisis management. Simulation also leads to an improvement of endoscopic and emergency skills. Accordingly, simulation training should be recommended or offered as an education option in gastrointestinal endoscopy.

Computer-Assisted Instruction↗

PubMed2005

Angle stable locking reduces interfragmentary movements and promotes healing after unreamed nailing. Study of a displaced osteotomy model in sheep tibiae.

BACKGROUND: Large interfragmentary movements may delay bone-healing. The hypothesis of the present study was that a reduction of interfragmentary movements, especially of torsional rotation and bending angles, would support the healing process and lead to improved healing following unreamed tibial nailing. The objective of this study was to investigate healing of an unstable tibial osteotomy site following stabilization with unreamed nailing with a modified tibial device that had angle stable holes for the locking bolts. We compared those findings with healing after stabilization of such sites with standard unreamed tibial nailing. The duration of the study period was nine weeks. METHODS: The site of a standardized displaced osteotomy (3-mm gap) in twelve ovine tibiae was stabilized with unreamed tibial nailing: six animals were treated with a modified nail that had angle stable holes for the locking bolts, and six were treated with standard unreamed tibial nailing. In vivo gait analysis with optical measurements of interfragmentary movements and simultaneous measurements of ground reaction parameters were performed three days after the operation and once weekly afterward. After the animals were killed at nine weeks, the treated and contralateral tibiae were explanted, the implants were removed, and radiographs were made and evaluated for bridged cortices. Each pair of tibiae was also mechanically tested until torsional failure, after which the whole callus region was subjected to histological and histomorphometric analysis. RESULTS: Throughout the examination period, the interfragmentary movements in all directions were significantly smaller in the group treated with the angle stable tibial nail than they were in the group treated with standard unreamed tibial nailing. The limbs treated with the angle stable tibial nails returned to almost full weight-bearing during the period of the investigation, whereas those treated with standard nailing did not. Histomorphometric analysis, radiographic data, and mechanical testing showed superior bone-healing following treatment with the angle stable tibial nail. CONCLUSIONS: Use of an angle stable tibial nail may help to reduce interfragmentary movements in vivo and thus lead to superior bone-healing compared with that following standard unreamed tibial nailing.

Analysis of Variance↗

PubMed2004

Locked internal fixator: sensitivity of screw/plate stability to the correct insertion angle of the screw.

OBJECTIVE: Internal fixators with angular stability have been developed to provide high stability without compression of the plate on to the bone. Angular and axial stability of a plate-screw construct can be achieved using a conically threaded screw head undersurface and a corresponding conically threaded plate hole. Furthermore, the insertion angle of the screw must correspond precisely to the axis of the screw hole. This is not always achieved in clinical practice and may result in screw loosening. The objective of this study was to examine the relationship between the stability of the locked screw-plate on the insertion angle of the screw. METHODS: Locking screws were inserted in an isolated (Point Contact Fixator, PC-Fix) or combined (Locking Compression Plate, LCP 4.5) locking hole with the use of an aiming device. The optimal insertion angle for these plates is perpendicular to the plate surface. The screws were inserted with an axis deviation of 0 degrees (optimal condition), 5 degrees , and 10 degrees respective to the optimal angle (variance +/- 1 degrees ). The samples were tested under shear or axial (push out) loading conditions until failure occurred. An Instron materials testing machine was used. RESULTS: Locking screws inserted in the isolated locking hole (PC-Fix) showed a significant decrease of failure load if inserted at 5 degrees and 10 degrees angle. Using an optimal insertion angle (0 degrees ), failure load was 1480 +/- 390 N, with 5 degrees axis deviation 780 +/- 160 N, P = 0.0001, and with 10 degrees axis deviation 550 +/- 110 N, P = 0.0001. Screws inserted in the combined locking hole (LCP) also showed a significant decrease of push-out force of 77% (4960 +/- 1000 N versus 1120 +/- 400 N) with 10 degrees axis deviation. Compared to optimal insertion angle (0 degrees ), bending load to failure did decrease up to 69% (1240 +/- 210 N vs. 390 +/- 100 N) with 10 degrees axis deviation. CONCLUSION: A locking head screw exhibits high stability with a moderate axis deviation in the angle of insertion of up to 5 degrees . However, there is a significant decrease in stability with increasing axis deviation (>5 degrees ). An aiming device is recommended to provide optimal fixation with angular stability.

Bone Screws↗

PubMed2003

[Mechanical borderline indications in the treatment of unreamed tibial nailing].

The extended usage of unreamed tibial nailing resulted in reports of an increased rate of complications, especially for the distal portion of the tibia. The goal was to gain a thorough understanding of the load-sharing mechanism between unreamed nail and bone in a fractured tibia, and to identify borderline indications due to biomechanical factors. In finite element analyses of a human tibia, horizontal defects were modeled using unreamed nailing for five different fracture locations, including proximal and distal borderline indications for this treatment method. The findings of this study show that with all muscle and joint contact forces included, nailing leads to considerable unloading of the interlocked bone segments. Unreamed nailing of the distal defect results in an extremely low axial and high shear strain between the fragments. Apart from biological reasons, clinical problems reported for distal fractures may be due to the less favorable mechanical conditions in unreamed nailing. From a biomechanical perspective, the treatment of distal tibial shaft fractures with unreamed nailing without additional fragment contact or without stabilizing the fibula should be carefully reconsidered.

Biomechanical Phenomena↗

PubMed2003

Stabilization of proximal tibial fractures with the LIS-System: early clinical experience in Berlin.

The Proximal Tibia Less Invasive Stabilization System (LISS PLT) is an internal fixator for the treatment of proximal tibial fractures according to the principles of "Minimally invasive surgery". From July 1998 to August 2000 22 fractures were treated in our clinic with the new Proximal Tibia LISS and the prospective course of healing was documented. The period of follow-up was 12 months. The inclusion criteria were defined as proximal tibial shaft fractures and intraarticular proximal tibial fractures of all degrees of severity. A total of 15 proximal medial and lateral tibial plateau fractures (AO 41) and 7 metaphyseal fractures were treated (AO 42), seven of these fractures presented with open soft tissue damage. The average age of the patients treated was 42 years. With a follow-up rate of 91% (2 patients lost to follow-up), definite consolidation of the fracture was seen in 19/20 cases. In one patient, the fracture had only been partially bridged and secondary bone grafting was performed. Radiologically, there was one case of a varus malalignment of 6 degrees, in two further cases there were valgus malalignments of 5 degrees and 7 degrees at the time of surgery. The other cases all healed in correct alignment. In one case, the implant became loose on the distal shaft and was stabilized again using bicortical screws. In a case with type IIIB soft tissue damage, a soft tissue infection became manifest, but healed uneventfully after a revision operation with the implant in situ.

Adult↗

PubMed2003

[Palmar plating with the locking compression plate for dorsally displaced fractures of the distal radius--first clinical experiences].

Injuries and irritation of extensor tendons are common problems in the treatment of fractures of the distal radius when plating is used via a dorsal approach. By the development of locking compression plates the possibility of palmar plating for dorsally displaced fractures of the distal radius is available. In this study our first clinical experiences using the 3.5 mm radius locking compression plate (LCP) are reported. Between February 2002 and September 2002 24 patients with dorsally displaced fractures of the distal radius were treated using a palmar approach with the LCP and included in a prospective study. The mean age of the patients was 52 years (28-87 years). Six weeks and six months after surgery a clinical assessment was done, the range of motion of the injured wrist was measured, and an X-ray control of the injured joint was performed. The preliminary results demonstrate the option of early functional treatment using the locking compression plate. Most of the patients had a good to excellent range of motion of the injured wrist which resulted in an early return to former activity. There were few intra- and postoperative complications. No irritation of the median nerve, no infection was observed. In one case a screw which was placed intraarticularly was removed prematurely. The palmar locking compression plate has been proven as a safe and effective implant for the treatment of dorsally displaced fractures of the distal radius.

Adult↗

PubMed2003

Pharmacodynamics of FTY720, the first member of a new class of immune-modulating therapeutics in transplantation medicine.

FTY is a novel immunomodulator currently undergoing clinical investigation and has the potential of improving immunosuppressive therapy after organ transplantation. Previous experimental studies in animals have shown that FTY has a unique mechanism of action. We have studied the pharmacodynamic effects of FTY in stable renal allograft recipients taking part in a phase I clinical trial. As in various animal models including non-human primates, a single oral dose of FTY (0.25 - 3.5 mg) significantly reduced peripheral lymphocyte count by 30 - 70%. The peripheral lymphocyte count returned to baseline within 24 hours. Only in those patients treated with the highest dose of FTY (3.5 mg), did peripheral lymphopenia persist for more than 96 hours. FTY reduced all lymphocyte subsets, T cells more than B cells and CD4+ cells more than CD8+ cells. The reduction in CD3+CD62L+ cell counts was more pronounced, whereas CD3+CCR5+ cell counts were less affected in comparison to the total number of CD3+ lymphocytes. We found only slightly increased apoptosis rates (< 5%) in peripheral lymphocytes, and this change does not explain the marked reduction in lymphocyte count. In cultured human lymphocytes only suprapharmacological doses of 10 microM FTY induced apoptosis (20.6 +/- 2.8%) after a 4-h incubation. More important, clinically relevant doses of 0.1 microM FTY increased lymphocyte mobility 2-fold. No effect of FTY on anti-CD3mAb-stimulated lymphocyte proliferation was detected and there was no change in phagocytosis rates in whole-blood cultures incubated with FTY. Further studies are necessary to investigate the mechanism of action of FTY in detail.

Apoptosis↗

PubMed2003

Less invasive stabilization system (LISS) in the treatment of distal femoral fractures.

The treatment of distal femoral fractures has been associated with a high rate of complications for a long time. Although implants and surgical techniques have improved, plate osteosynthesis and intramedullary nailing have been accompanied by a high occurrence of infection, non-union and malalignment. The treatment of soft tissue envelopes using "biological" osteosynthesis and minimally invasive approaches has resulted in a decrease in complication rates and ultimately led to the concept of the less invasive stabilization system (LISS). This is an extramedullary-applied, internal fixator shaped according to the implantation site anatomy, with minimal invasiveness. The purpose of this study was to present this new surgical technique and draw attention to its advantages and importance. Although this is not a scientific paper, we hope to provide enough evidence of the LISS usefulness. The main LISS components include multiple-fixed angle screws and an insertion handle for submuscular sliding of a fixator and placement of percutaneous, self-drilling, unicortical screws for fixation of the diaphyseal fracture fragments. The LISS has been designed to preserve periosteal perfusion and to facilitate a minimally invasive application. Since the first implantation of the LISS, only a few studies have been published on its use in treatment of distal femoral fractures. The rate of infection has been low, ranging from 0 to 4%. The rate of delayed union has been between 2.4 and 6.1%, but delayed unions do not necessarily lead to secondary bone grafting or repeat osteosynthesis as the LISS has a high and lasting stability. When the LISS is used, bone grafting is rarely necessary (0 to 1.6% in primary and 0 to 5% in secondary grafting). Also implant failure differs from the failure of plate osteosynthesis because, with the use of LISS, no screw loosening or secondary malalignment occurs. Implant failures (up to 7.4%) were recorded particularly at the time of LISS introduction in surgical practice and were attributed to the technique of implantation rather than to the implant itself. Good treatment outcomes have been reported. The average knee flexion has been 103 degrees and 107 degrees. In 72.5% of the patients, flexion has been more than 90 degrees and an extension lag of > or = 10 degrees has been found in only 7.5% of all cases. The average Neer score has ranged from 73.9 to 77.2 points. In conclusion, the LISS is a useful implant for treatment of distal femoral fractures, especially when bone quality is poor. Infection, delayed union and non-union rates are low, as shown by yet unpublished data from our clinic. Primary bone grafting, which is rarely necessary with this system, is carried out only when there is a great bone loss. Implant failure, such as screw loosening or secondary malalignment, is not seen.

Adult↗

PubMed2002

Functional relevance of soluble TNF-alpha, transmembrane TNF-alpha and TNF-signal transduction in gastrointestinal diseases with special reference to inflammatory bowel diseases.

As a result of extensive clinical and basic research, the pivotal role of tumour necrosis factor (TNF) in the pathogenesis of chronic inflammatory diseases such as inflammatory bowel disease (IBD) has now generally been acknowledged. This has led to promising clinically effective anti-TNF-strategies. Of note, there is more and more evidence that TNF seems to play a key role in other gastrointestinal diseases including Helicobacter pylori infection, pancreatitis, viral hepatitis and toxic liver damage, too. The action of TNF at the cellular level is mediated by two cell surface receptors, TNF-R1 (p60) and TNF-R2 (p80). The function of these receptors and the downstream intracellular signal transduction pathway have been extensively studied in vitro and it can be expected, that there are critically important steps in TNF-signal transduction that might be dysregulated in these disease states. Their elucidation could lead to a better understanding of the pathogenesis of these diseases, in particular IBD and potentially reveal new, more specific therapeutic targets. Objective of this review is to give an overview about the current knowledge on TNF signal transduction in relationship to selected examples of important gastrointestinal disorders with special focus on IBD. Finally, the implications for future research efforts will be discussed.

Antibodies, Monoclonal↗

PubMed2002

[Progression of the pension-application process in psychosomatic patients].

Psychosomatic disorders have become increasingly important as a reason for premature retirement. To identify specific characteristics of pension applicants, we broke a random sample consisting of 1,109 patients admitted to Burg Hospital within the framework of psychosomatic rehabilitation programmes into three main groups: a) patients who had not applied for any kind of pension benefits and 'high-risk groups' of pension aspirants who b) had either already submitted an application or c) intended to do so. The comparison of the sociomedical data from the two groups showed that the high-risk group contained a markedly larger percentage of unemployed patients and patients who had been on sick leave for longer periods. The average age of the pension aspirants was higher. Moreover, this group contained a larger percentage of male patients than did the non-applicant group. An assessment of rehabilitation potential uncovered a distinctly depressed potential in the high-risk group. Moreover, the assessment of individual patient performance conducted at the end of each rehabilitation programme yielded significantly lower scores for the high-risk groups in comparison with the non-applicant group. On the basis of the decrease in symptoms, it is evident that only small therapeutic success can be achieved with these patients, who as a group display a significantly lower therapeutic motivation than their non-applicant counterparts. Furthermore, there was a higher incidence of recurrent depressive disorders and somatic pain disorders in the high-risk groups. The development of pension aspirations can be described as a process starting with a disorientation phase, proceeding to an ambivalence phase and culminating in a rigid terminal phase. Patients who have reached this stage are generally resistant to rehabilitation efforts. For this reason, early recognition of pension aspirations is of critical importance.

Adult↗

PubMed2001

Cytochromes c555 from the hyperthermophilic bacterium Aquifex aeolicus (VF5). 1. Characterization of two highly homologous, soluble and membranous, cytochromes c555.

Two distinct class I (monoheme) c-type cytochromes from the hyperthermophilic bacterium Aquifex aeolicus were studied by biochemical and biophysical methods (i.e., optical and EPR spectroscopy, electrochemistry). The sequences of these two heme proteins (encoded by the cycB1 and cycB2 genes) are close to identical (85% identity in the common part of the protein) apart from the presence of an N-terminal stretch of 62 amino acid residues present only in the cycB1 gene. A soluble cytochrome was purified and identified by N-terminal sequencing as the cycB2 gene product. It showed an alpha-peak at 555 nm, an E(m) value of +220 mV, and electron paramagnetic resonance parameters of gz = 2.89, gy = 2.287, and gx = 1.52. A firmly membrane-bound cytochrome characterized by nearly identical properties was detected and attributed to the cycB1 gene product. The very high degree of homology of its N-terminal part to cytochrome c553 from Heliobacterium gestii strongly suggests it to be anchored to the membrane via N-terminally attached lipid molecules. The two heme proteins were named cytochrome c555s (soluble) and cytochrome c555m (membranous). Electron paramagnetic resonance on partially ordered membrane multilayers suggests that the solvent-exposed heme domain of cytochrome c555m is flexible with respect to the membrane plane. Possible functional roles for both cytochromes are discussed.

Adaptation, Biological↗

PubMed2001

Quick reference guide to antiretrovirals.

Antiretroviral therapy continues to rapidly evolve and complex drug interactions are common. The quick reference guide is an attempt to summarize the following aspects of highly active antiretroviral treatment in concise tables: dosing of antiretroviral agents; drug-drug interactions between antiretroviral agents; antiretroviral resistance mutations and interactions of antiretroviral agents with TB-medications, oral contraceptives and methadone. Dosing and drug interaction data has been collected from manufacturers' dosing information, peer reviewed medical journals and scientific meetings. References are inserted directly in the tables referring to conferences or publication the information is derived from. In order to remain clinically relevant, regular updates to this publication are posted on the Medscape Web site at http://hiv.medscape.com/updates/quickguide - Please check regularly to ensure you are using the most recent edition. It is available as an HTML document; a PDF document; and for downloading to your Palm organizer.

Antiviral Agents↗