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Biomedical subjects

K Krüger

Publications and source records attributed to K Krüger.

At least 19 recordsLinked to original sources

Effects of monomethyltin and dimethyltin compounds on heterologously expressed neuronal ion channels (Xenopus oocytes) and synaptic transmission (hippocampal slices).

The aim of this study was to investigate the effects of monomethyltin trichloride (MMT) and dimethyltin dichloride (DMT) on various neuronal ion channels heterologously expressed in Xenopus oocytes and on synaptic transmission in hippocampal slices of young (14-21 days old) and adult (2-4 months old) rats. The Xenopus oocyte expression system was chosen to allow direct assessment of the effects of MMT and DMT both on glutamate receptors sensitive to AMPA and NMDA and on various voltage-operated potassium and sodium channels. Hippocampal slices were used to analyze the effects of MMT and DMT on synaptic potentials generated by the important excitatory Schaffer collateral-CA1 synapse. In general, MMT and DMT were found to have no effect either on voltage-operated sodium and potassium channels or on the metabotropic glutamate receptor but they did differentially affect the functions of ionotropic glutamate receptors and glutamatergic synaptic transmission. MMT (100 microM) significantly reduced NMDA-mediated ion currents by up to 32%, but had no effect on ion currents through AMPA receptors. In slices of adult rats, MMT had no effect on the amplitudes of evoked fEPSPs and brought about a 35% reduction in the LTP amplitudes. In contrast, in slices of young rats MMT evoked a reversible 30% increase in the amplitudes of fEPSPs but had no effect on LTP induction. DMT (100 microM) reduced ion currents through NMDA-receptor ion channels by up to 29% and those through AMPA-receptor ion channels by up to 7%. In hippocampal slices 100 microM DMT reduced the amplitudes of fEPSPs (adults: 50%; young rats: 70%) and LTP (adults: 40%; young rats: 55%). Neither of the organotins affected the paired-pulse facilitation at this synapse, indicating that the organotins exert their effects at the postsynaptic site. The action of MMT and DMT may contribute to the organotin-induced impairment of behavior patterns in connection with learning and memory.

Animals↗

[NSAIDs and COX-2-inhibitors: current status].

NSAIDs (non steroidal anti-inflammatory drugs) are a crucial component for the therapy of pain induced by inflammatory and degenerative joint diseases. Nevertheless their known therapeutic efficacy is contrasted by significant side effects. The recently developed selective COX-2-inhibitors appear to have a better gastrointestinal safety profile, especially relevant to patients with an increased risk for gastrointestinal ulcers and bleeding. However, this effect may similarly be reached by the combination of NSAIDs with proton pump inhibitors. Recent data relate to an elevated myocardial infarction rate in patients using COX-2-inhibitors. This risk may also occur in conventional NSAIDs. Therefore an individual risk calculation is necessary before COX-2-inhibitors or NSAIDs are used. Treatment should be performed with the lowest dosage for the shortest time possible. Combination therapy with salicylic acid seems to abolish the protective effect of COX-2-inhibitors in the GI-tract. Definite risk factors for the treatment with NSAIDs and COX-2-inhibitors have to be defined in further studies providing the best treatment schedule for an individual patient.

Aged↗

[Multislice CT in diagnostic work-up of polytrauma].

BACKGROUND: In severely injured patients, diagnostic procedures should be as brief as possible. With the use of spiral CT technology, the time required for diagnosis is minimized. QUESTION: Do severely injured patients benefit when primary diagnostic examinations are completed in less than 30 min? How much time is required for primary emergency department (ED) care and how much in the CT scanner? MATERIAL AND METHODS: Between 31 July 2001 and 31 December 2003, severely injured patients with ISS scores over 16 underwent total body spiral CT scans (Siemens Somatom Volume Zoom Multislice CT) after initial ultrasonography. One hundred patients (M:F=25:75) with an average age of 42 years (range: 3-81 years) were evaluated retrospectively. The average ISS score was 32.8+/-12 points (range: 17-75 points). RESULTS: The average time in the ED, prior to CT, was 33+/-14 min. The CT scans lasted 16+/-5 min and the total diagnostic time was 48+/-14 min. Fifty percent of patients were taken immediately to the operating room. The mortality rate in hospital was 13%. The average hospital stay was 30 days, with an average ICU stay of 10 days. CONCLUSION: The shorter the time spent in the ED, the shorter the stays in ICU and in total hospitalization were, regardless of injury severity. With structured management and shortening of diagnostic time with spiral CT, the time in the ED was decreased from 85 to 48 min.

Adolescent↗

[Ultrasound guided implantation of chest port systems via the lateral subclavian vein].

PURPOSE: Retrospective analysis of the success and complication rates of chest port implantation via the lateral subclavian vein. MATERIALS AND METHODS: Between January 2003 and June 2004, the lateral subclavian vein in 271 patients (186 women, 85 men, mean age 53.2 years) was punctured guided by ultrasound. This access was used to insert a port system, and the catheter tip was placed at the cavoatrial junction. The port reservoir was implanted in a subcutaneous infraclavicular pocket and fixed to the fascia of the pectoralis muscle. Indications for port implantation were chemotherapy (n = 239), total parenteral nutrition (n = 2) and intravenous medication (n = 30). The patient follow-up was mainly performed either by the oncology division of the department of gynecology or by the department of internal medicine. RESULTS: A chest port catheter system was successfully implanted in all patients. The catheter remained in place for a mean duration of 269.4 days (SD 192.3 days). No complications occurred during implantation. In the post-interventional period, 6 catheter dysfunctions were found (thrombotic 0.09 per 1000 catheter days; mechanic 0.05 per 1000 catheter days). While one local infection occurred in the early post-interventional period, 3 local and 15 systemic infections were independent of the port catheter placement (0.39 per 1000 catheter days). The rate of port catheter ex-plantation due to dysfunction or infection was 0.07 per 1000 catheter days. CONCLUSION: Ultrasound-guided puncture of the lateral subclavian vein is a safe procedure for the insertion of central venous port catheter systems and had a very low complication rate in our study. For further evaluation of our port placement technique, prospective studies compared to placement through the internal jugular vein are necessary.

Catheterization, Central Venous↗

[Success and complication rate of CT-guided marking of pulmonary nodules with coil wires for video-assisted thoracoscopic surgery (VATS)].

PURPOSE: To assess the success and complication rate of the CT-guided marking of pulmonary nodules for video-assisted thoracoscopic surgery (VATS). MATERIALS AND METHODS: Pulmonary nodules (mean diameter 9 +/- 5 mm, mean pleural distance 7 +/- 5 mm) were marked with a coil wire in 30 patients (20 males, mean age 57.6 +/- 15.5 years, 22 patients with a history of malignancy). The intended coil-nodule distance was < or = 10 mm. RESULTS: 81 % of nodules were not visible by thoracoscopy. The technical success rate of CT-guided marking was 86.7 %. The projected nodule-coil distance was achieved in 90 % of cases. The procedure had to be changed from thoracoscopy to thoracotomy in 4 patients due to coil wire marking problems: 2 x coil displacement, 1 x coil-nodule distance > 10 mm, unfavorable direction of wire. Histology was determined in all patients (70 % malignant, 30 % benign). Complications requiring therapy were not observed. CONCLUSIONS: The CT-guided marking of pulmonary nodules is a precondition for VATS if the nodule does not involve the visceral pleura in the majority of cases. The success rate is high with a low complication rate.

Adult↗

Response of the polyphagous whitefly Bemisia tabaci B-biotype (Hemiptera: Aleyrodidae) to crop diversification - influence of multiple sensory stimuli on activity and fecundity.

A fundamental question concerning crop diversification is which mechanisms determine pest population size in polycultures compared to monocultures. It has been proposed that polyphagous insects experience a difficulty in decision-making when selecting food and oviposition sites in the presence of different host plants. This hypothesis was tested in the extremely polyphagous whitefly Bemisia tabaci (Gennadius) B-biotype, where behaviour (movement) and fecundity of females were compared in choice and no-choice experiments in the laboratory. Two parallel tests, one on different crops, including cucumber, bean and tomato, and one on different tomato cultivars, were conducted using both a mixture of crops and of tomato cultivars, as opposed to the same crop or cultivar respectively. Bemisia tabaci showed a distinct behavioural preference for cucumber when exposed to different crops simultaneously suggesting that B. tabaci has no difficulty in choosing a host plant, i.e. in making a decision, when one of the plants offered in the choice test is a high-ranking host plant. Conversely, when only low-ranking hosts of similar, but not identical, signatures were present, female whiteflies appeared to have difficulty in making a decision, resulting in increased movement and reduced fecundity. This is consistent with both the hypothesis that polyphagous insects have a problem selecting a host plant when given multiple choices and with the hierarchy threshold model, under which egg loads are lessened between periods of searching for better host plants. The study illustrates how insect behaviour can be affected by inter-cropping not only with different crops, but also with different cultivars of the same crop, thus potentially providing a simple and efficient way of reducing whitefly population build-up.

Animals↗

Health behavior in psychiatric in-patients compared with a German general population sample.

OBJECTIVE: To compare the health relevant behavior of psychiatric patients and the general population. METHOD: Health behavior of 363 psychiatric in-patients with ICD-10 diagnoses of schizophrenia, bipolar disorders, major depressive disorders and neurotic, and somatoform disorders was compared with health behavior of a representative sample of 7200 persons from German general population. RESULTS: Increased prevalence rates for smoking and illicit drug use were found for all diagnostic groups. Risk alcohol consumption was increased in patients with schizophrenia and depression. Smokers with schizophrenia had an excess cigarette consumption compared with general population. The number of unhealthy food habits was increased in all diagnostic groups, and the body mass index was found to be increased for patients with schizophrenia. Patients with depression were more physically active than general population. CONCLUSION: Poor health behavior is widespread in patients with all major psychiatric diagnoses. Interventions to reduce risk behavior and strengthen health preventive lifestyles are necessary.

Demography↗

[The efficacy of selective Cox-2-inhibitors in comparison with conventional NSAIDs].

The currently approved coxibs celecoxib and etoricoxib, have an equivalent effect in comparison with conventional NSAIDs. This has been established both in comparative studies and by several years of practical application. While celecoxib is approved only for the symptomatic treatment of arthrosis and rheumatoid arthritis, etoricoxib can also be employed in the treatment of acute attacks of gout.

Acute Disease↗

Phylogenetic analysis and species allocation of individual equids using microsatellite data.

The taxonomic status of all equid species is not completely unravelled. This is of practical relevance for conservation initiatives of endangered, fragmented equid populations, such as the Asiatic wild asses (in particular Equus hemionus onager and E. hemionus kulan). In this study, a marker panel consisting of 31 microsatellite loci was used to assess species demarcation and phylogeny, as well as allocation of individuals (n = 120) to specific populations of origin (n = 11). Phylogenetic analysis revealed coalescence times comparable with those previously published from fossil records and mtDNA data. Using Bayesian approaches, it was possible to distinguish between the studied equids, although individual assignment levels varied. The observed results support the maintenance of separate captive conservation herds for E. hemionus onager and E. hemionus kulan. The first molecular genetic results for E. hemionus luteus remained contradictory, as they unexpectedly indicated a closer genetic relationship between E. hemionus luteus and E. kiang holderi compared with the other hemiones.

Animals↗

Rapid alleviation of signs and symptoms of rheumatoid arthritis with intravenous or subcutaneous administration of adalimumab in combination with methotrexate.

OBJECTIVE: This randomized, placebo-controlled, double-blind, Phase 1 study assessed the magnitude, onset, and duration of response with intravenous (i.v.) and subcutaneous (s.c.) adalimumab (Humira, Abbott Laboratories) combined with methotrexate (MTX) in patients with active rheumatoid arthritis (RA) despite previous MTX therapy. METHODS: Fifty-four patients were randomized to two injections of i.v. or s.c. adalimumab (1 mg/kg) or placebo while continuing on MTX (mean dose, 15.7 mg/week). Dosing intervals were determined by the European League Against Rheumatism (EULAR) response criteria, and were allowed to range from 1 to 3 months. Efficacy was mainly assessed using the EULAR response criteria and the American College of Rheumatology (ACR) response criteria. RESULTS: Moderate EULAR response was achieved at least once within 29 days after the first injection in 83% and 61% of patients receiving i.v. and s.c. adalimumab respectively, compared with 44% for placebo [probability (p) < or = 0.05 for i.v. adalimumab versus placebo]. A 20% improvement in disease activity according to the ACR criteria (ACR20 response) was achieved by 72% and 67% of patients receiving i.v. and s.c. adalimumab respectively, compared with 28% for placebo (p < or = 0.01 and p < or = 0.05, respectively, versus placebo). By Day 15 after the first and second injections, statistically significant moderate EULAR and ACR20 response rates were achieved with either i.v. or s.c. adalimumab compared with placebo (p < or = 0.05). The mean times to second injection for i.v. adalimumab, s.c. adalimumab, and placebo were 42.2 days (range: 27-84 days), 38.3 days (range: 26-85 days), and 28.4 days (range: 26-32 days), respectively (minimum time allowed by the protocol between the first and second injections was 4 weeks). Adalimumab in combination with MTX was well tolerated, with no patients being withdrawn because of adverse events. CONCLUSION: Either i.v. or s.c. adalimumab added to MTX significantly improved the signs and symptoms of RA compared with MTX alone. Subcutaneously administered adalimumab appeared to provide a response that was as great, as rapid, and as enduring as that with i.v. adalimumab.

Adalimumab↗