Fusion of inertial and magnetic sensors for 3D position and orientation estimation.

This paper presents a new method for 3D position and orientation estimation based on the magnetic field generated by a single coil and the fusion of low power magnetometers and inertial sensors. The fixed spatial relationship between the sensors is exploited to solve the ambiguity problem that occurs when only a single coil is employed. In this context a new positioning algorithm is developed and verified by simulations. Using a single coil instead of three coils as common in conventional magnetic field based systems brings a benefit both regarding power consumption and construction size. Moreover, as the proposed system requires no line of sight between source and sensors, it is ideally suited for portable, location-independent applications such as the mobile assessment of a persons' head to torso posture and movement e.g. for the purpose of examining causes for chronic pain in the cervical spine area under conditions of daily life.

[Gender specific differences in the frequency of admission to intensive care units, duration of stay and the application of intensive medical care measures in men and women aged 75 years and above in an Austrian region]. / Geschlechtsspezifische Unterschiede bezüglich Aufnahmeraten auf Intensivstationen, Aufenthaltsdauer und durchgeführten intensivmedizinischen Massnahmen bei Personen im Alter ab 75 Jahren in einer Osterreichischen Region.

OBJECTIVE: It was the aim of this study to evaluate the frequency of admission to intensive care units, duration of stay and application of intensive care treatments in patients aged 75 years and above and to analyse possible gender specific differences. METHODS: Analysis of hospital in-patient data of all hospitals of a southern Austrian region (federal state of Carinthia). RESULTS: In the year 2003, 4.7% of the men and 3.2% of the women aged 75 years and above were treated in intensive care units (p<0.001). This gender specific difference was independent of the reason for the intensive care admission. The mean duration of stay in intensive care units was longer for 75-79 year old men compared to women (6.38 vs. 4.91 days, p<0.01). Typical intensive care treatments like mechanical ventilation, artificial airways and vasoactive medication were applied more often to men than to women. CONCLUSION: In the aged there are marked gender specific differences in the application of intensive care treatments, especially in the end-of-life state in Austria. The reasons for these differences should be subject of future research.

A non-midline spheno-orbital encephalocele in a newborn.

Basal encephaloceles in western countries occur in 1 of every 35 000-40 000 live births; with an incidence of less than 10% they are the least common of all encephaloceles. Certain subtypes such as transsphenoidal variants may be as rare as 1 in 700 000 live births. These rare encephaloceles are classified into five anatomic types: spheno-ethmodial, transsphenoidal, spheno-orbital, transethmoidal, and spheno-maxillary. Here we present an exceedingly rare variant of a non-midline basal encephalocele of the spheno-orbital type, which was treated by resection of the encephalocele, which contained dysplastic central nervous system tissue, on day four post partum. The patient had no neurological deficits and a six year follow-up showed a normal intellect and a good cosmetic result.

Predictive value of neurodevelopmental assessment versus evaluation of general movements for motor outcome in preterm infants with birth weights <1500 g.

PURPOSE: The aim of this study was to make a comparison of predictive values of neurodevelopmental assessment and evaluation of videotaped spontaneous movements of premature infants for motor outcome. METHODS: We performed a prospective longitudinal study of 103 VLBW infants, 96 (455-1490 g, 24-35 weeks gestational age) including (a) a neurodevelopmental assessment based on criteria by Amiel-Tison/Grenier at 40 weeks postconceptional age, 3 and 20 months corrected age; (b) an evaluation of general movements with fidgety character, based on criteria by Prechtl, at 3 months; and (c) a standardized testing using the Griffiths Developmental Motor Scale at 20 months. We calculated sensitivity, specificity and predictive values for each method. RESULTS: For predicting motor outcome, the assessment of general movements (GM) had a positive predictive value of 89% and negative predictive value of 84%; neurodevelopmental assessment (NA) at 40 weeks had a positive predictive value of 33% and negative predictive value of 88%, respectively, with similar results for neurodevelopmental assessment at age 3 months. CONCLUSIONS: Normal motor outcome of VLBW infants may be accurately predicted by clinical neurodevelopmental assessment, but for adverse outcomes, evaluation of general movements (fidgety movements) is superior. GM assessment has a high predictive value, especially for CP, but it needs to be complemented by NA for non-CP outcomes. It is a simple, repeatable and non-intrusive technique, and may be a valuable method for the early detection of central nervous system impairment in VLBW infants in routine follow-up.

Multivariate analyses of prognostic factors in acute myeloid leukemia: relevance of cytogenetic abnormalities and CD34 expression.

Identification of additional prognostic factors besides karyotype is important for the improvement of the risk adapted treatment strategies in acute myeloid leukemia (AML). The aim of this study was to investigate whether other factors besides karyotype could be used as a prognostic tool in newly diagnosed AML. Biological and disease related established and potential prognostic factors were retrospectively analysed in 124 consecutive AML patients treated between 1993 and 2002 at the University hospital Rostock (Germany). One hundred patients received a potential curative intensive chemotherapy (81%), of whom 28 received an allogeneic HSCT at some point of their treatment course, 17 patients (14%) received palliative therapies and 7 patients (5%) received supportive care only. In patients that received potential curative therapies LDH >or=2000 U/l, WBC >50 GPT/l, CD34 surface expression on the AML blasts, secondary AML, unfavorable karyotype and no allogeneic HSCT at some point of treatment course were associated with unfavorable prognosis. However, in the multivariate risk factor analyses only unfavorable karyotype (p=0.012), CD34 positivity of AML blasts (p=0.046), no allogeneic HSCT (p=0.008) and first diagnosis after 1997 (p=0.025) were independent unfavourable prognostic factors. In conclusion, karyotype and CD34 expression are independent prognostic markers in newly diagnosed AML. Furthermore, receiving an allogeneic HSCT at some point of the treatment course seems to be of benefit for AML patients.

[Malaria in the emergency room. Results of the emergency treatment of 137 patients with symptomatic malaria]. / Malaria in der Notaufnahme. Ergebnisse der Notfallbehandlung bei 137 Patienten mit symptomatischer Malaria.

OBJECTIVE: To assess characteristics and outcome of emergency patients with acute malaria. PATIENTS AND METHODS: We retrospectively assessed the clinical and laboratory parameters of 137 consecutive patients (87 males, 50 females; median age 37 years, range 17 - 67 years) presenting with acute malaria to our tertiary care center between 1992 and 2002. RESULTS: Falciparum malaria was diagnosed in 116/137 and tertian malaria in 19/137 patients; a single patient was infected with both parasites while in another case the type of parasite remained unclear. Infections were acquired in Africa (121), Asia , and in the Americas . One traveler visited multiple continents. Only 36 % (50/137) of patients had used malaria chemoprophylaxis. 128/137 patients were treated as in-patients; 22 of these had to be treated on an intensive care unit. According to the criteria of the German Society of Tropical Medicine, 44/137 (32 %; 95 % confidence interval (CI): 25 - 40 %) patients suffered from complicated malaria. The overall mortality rate was 2/137 (1.5 %; 95 % CI: 0,4 - 5.2 %); the mortality rate of complicated malaria tropica was 2/44 (4,5 %; 95 % CI 1,3 - 15 %). Patients with complicated malaria were significantly older than those with uncomplicated malaria. Median length of hospital stay was 4 days in uncomplicated and 9 days in complicated cases. Based on costs of EUR 2500 per case, an attack rate of > 3 % in East African travelers and a cost of EUR 55 for a chemoprophylaxis with mefloquine, chemoprophylaxis is cost-effective. CONCLUSION: In our retrospective analysis, complicated malaria tropica was associated with older age. Although malaria causes considerable morbidity, the overall mortality from severe malaria is low. Reinforcement of chemoprophylaxis especially in travelers to Africa could reduce malaria cases and is cost-effective.

Tolerance for ATP-insensitive K(ATP) channels in transgenic mice.

To examine the role of sarcolemmal K(ATP) channels in cardiac function, we generated transgenic mice expressing GFP-tagged Kir6.2 subunits with reduced ATP sensitivity under control of the cardiac alpha-myosin heavy chain promoter. Four founder mice were isolated, and both founders and progeny were all apparently normal and fertile. Electrocardiograms from conscious animals also appeared normal, although mean 24-hour heart rate was approximately 10% lower in transgenic animals compared with littermate controls. In excised membrane patches, K(ATP) channels were very insensitive to inhibitory ATP: mean K(1/2) ([ATP] causing half-maximal inhibition) was 2.7 mmol/L in high-expressing line 4 myocytes, compared with 51 micromol/L in littermate control myocytes. Counterintuitively, K(ATP) channel density was approximately 4-fold lower in transgenic membrane patches than in control. This reduction of total K(ATP) conductance was confirmed in whole-cell voltage-clamp conditions, in which K(ATP) was activated by metabolic inhibition. K(ATP) conductance was not obvious after break-in of either control or transgenic myocytes, and there was no action potential shortening in transgenic myocytes. In marked contrast to the effects of expression of similar transgenes in pancreatic beta-cells, these experiments demonstrate a profound tolerance for reduced ATP sensitivity of cardiac K(ATP) channels and highlight differential effects of channel activity in the electrical activity of the 2 tissues.

Mitochondria are the main ATP source for a cytosolic pool controlling the activity of ATP-sensitive K(+) channels in mouse cardiac myocytes.

OBJECTIVE: The aim was to identify the major ATP source controlling the activity of sarcolemmal K(ATP) channels in ventricular cardiomyocytes. METHODS: K(ATP)-channel current (I(KATP)) was measured with the patch-clamp technique in either the whole-cell (glycogenolysis blocked by 10 mmol/l EGTA), cell-attached, or inside-out configuration. RESULTS: In the absence of any substrate, I(KATP) (amplitude 31+/-4 nA; n=5) appeared spontaneously 520+/-160 s (n=6) after whole-cell access. This latency was shortened by exposure to anoxia (117+/-33 s, n=32) and even more by uncoupling (1-10 micromol/l FCCP; 25+/-3 s; n=13) while the amplitude was unchanged. During metabolic inhibition the latency was remarkably prolonged when the F1F0-ATPase was blocked by oligomycin, suggesting that under those conditions the F1F0-ATPase is the major ATP consumer. Glucose (5.5-20.0 mmol/l) in the bath solution did not affect the amplitude of I(KATP) but prolonged its latency compared to respective substrate-free conditions. However, I(KATP) was blocked immediately by mitochondrial substrates. FCCP also induced large I(KATP) in cell-attached measurements in either the absence or presence of glucose and oligomycin. CONCLUSIONS: The activity of K(ATP) channels in cardiomyocytes of mice is controlled by a cytosolic [ATP] pool for which oxidative phosphorylation is the predominant ATP source.

Dibenzylamine--a novel blocker of the voltage-dependent K+ current in myocardial mouse cells.

Ventricular myocytes of the mouse ventricle were voltage clamped with a patch-clamp technique in the whole-cell configuration. At depolarizing voltage pulses, these myocytes develop a large voltage-dependent K+ outward current. Application of the drug dibenzylamine (DBA) to the bath solution blocked the voltage-dependent K+ current. The concentration/response relationship for the peak current at +40 mV indicates a 1:1 binding of the drug to the receptor with a concentration of half maximum effect of 43.1 micromol/l. The block did not require activation of the channels by depolarizing pulses. At concentrations causing partial block (25 micromol/l), the block was independent of voltage. At the same concentration, DBA completely blocked the slow component of the recovery from inactivation (-80 mV) whereas steady-state inactivation was not altered. It is concluded that DBA is a novel blocker of the voltage-dependent K+ current in mouse cardiac myocytes which preferentially affects the current component generating the slow recovery from inactivation.

High-dose etoposide phosphate and G-CSF mobilizes peripheral blood stem cells in patients that previously failed to mobilize.

Ten consecutive patients in our unit who had failed to mobilize a sufficient stem cell yield after either an initial or several mobilization regimens received high-dose etoposide phosphate (1500-2000 mg/m2) followed by granulocyte colony-stimulating factor (G-CSF; 10 micrograms/kg per day) to stimulate mobilization. Eight of the ten patients were apheresed. A median of 2.1 x 10(6) CD34+/kg (range 0-5.2) was collected. The number of CD34+ cells/microliter peripheral blood (pB) was significantly increased compared to the first-line mobilization [median 13.0 (range 2.68-29) versus median 4.76 (range 1.36-12); P < 0.05]. Besides hematotoxicity and four cases of infection (WHO grade 3), no major side effects were seen. The median duration of neutropenia was short (5 days, range 0-10), which is important in heavily pretreated patients. These results indicate that high-dose etoposide phosphate with G-CSF is safe, well tolerated, and may be effective in peripheral blood stem cell (PBSC) mobilization in patients who had previously failed to mobilize.

Transcriptional augmentation: modulation of gene expression by scaffold/matrix-attached regions (S/MAR elements).

For a long time S/MARs could only be characterized by the assays in vitro that led to their detection. Only recently a number of biological activities emerged that are common to most or all S/MARs that are detected by the classic procedures. This review focuses on the phenomenon of transcriptional augmentation that is found for genomically anchored or episomal genes and on a group of partially overlapping activities that are suited to maintain an episomal status. Further, it is attempted to correlate properties of the S/MAR-scaffold interaction with prominent or prototype protein binding partners.

Fatal connections: when DNA ends meet on the nuclear matrix.

A damaged nucleus has long been regarded simply as a "bag of broken chromosomes," with the DNA free ends moving around and forming connections with randomly encountered partners. Recent evidence shows this picture to be fundamentally wrong. Chromosomes occupy specific nuclear domains within which only limited movement is possible. In a human diploid nucleus, 6.6 x 10(9) base pairs (bp) of DNA are compartmentalized into chromosomes in a way that allows stringent control of replication, differential gene expression, recombination and repair. Most of the chromatin is further organized into looped domains by the dynamic binding of tethered bases to a network of intranuclear proteins, the so-called nuclear scaffold or matrix. Thus, DNA movement is severely curtailed, which limits the number of sites where interchanges can occur. This intricate organizational arrangement may render the genome vulnerable to processes that interfere with DNA repair. Both lower and higher eukaryotic cells perform homologous recombination (HR) and illegitimate recombination (IR) as part of their survival strategies. The repair processes comprising IR must be understood in the context of DNA structural organization, which is fundamentally different in prokaryotic and eukaryotic genomes. In this paper we first review important cellular processes including recombination, DNA repair, and apoptosis, and describe the central elements involved. Then we review the different DNA targets of recombination, and present recent evidence implicating the nuclear matrix in processes which can induce either repair, translocation, deletion, or apoptosis. J. Cell. Biochem. Suppl. 35:3-22, 2000.

Anoxia generates rapid and massive opening of KATP channels in ventricular cardiac myocytes.

OBJECTIVE: The aim was to improve the measurement of both the time course and amplitude of anoxia-induced KATP-channel current (IKATP) in isolated heart cells to specify the role of these channels in the time course of K+ accumulation in the ischemic myocardium. METHODS: Ionic currents in isolated ventricular heart cells of the mouse were measured with a patch clamp technique under normoxic conditions (atmospheric pO2), during wash-out of oxygen, and under anoxic conditions (pO2 < 0.2 mmHg). During the measurement, the actual pO2 in the close proximity of the cell was determined with an optical technique by exciting Pd-meso-tetra(4-carboxyphenyl)porphin with light flashes of 508-570 nm and evaluating the quenching kinetics of the emitted phosphorescence signal at 630-700 nm. These quenching kinetics steeply depend on pO2 and can be evaluated best at pO2 values near 0 mmHg. RESULTS: Out of 28 cells, 23 cells started to develop IKATP at pO2 values between 0 and 0.4 mmHg, i.e. in the range of the level of half maximum activity of the cytochrome oxidase. The remaining five cells developed IKATP between 0.4 and 1.8 mmHg. With respect to the time course, 18 out of 27 cells started to develop IKATP within the first minute after pO2 had decreased to values below 0.2 mmHg. The amplitude of IKATP induced by anoxia and various metabolic inhibitors was large, 29 +/- 12 and 48 +/- 21 nA (+40 mV), respectively. The anoxia-induced IKATP was significantly smaller than IKATP induced by metabolic inhibitors. During the pulses of 50 ms duration to +40 mV, the amplitude of IKATP decayed and, after clamping back to -80 mV, IKATP generated large tail currents. This suggests a notable change in the concentration gradient of K+ ions in the time range of tens of milliseconds. CONCLUSIONS: The results in isolated myocytes indicate that KATP channels open sufficiently rapidly after starting anoxia and generate sufficiently large conductance at maintained anoxia to explain both the time course and magnitude of the ischemic K+ accumulation if an appropriate counter-ion flux is available.

Ca2+ fluxes and channel regulation in rods of the albino rat.

By use of microelectrodes, changes in the receptor current and the Ca2+ concentration were measured in the rod layer of the rat retina after stimulation by flashes or steady light. Thereby light induced Ca2+ sources, and sinks along a rod were determined in dependence of time. Thus, the Ca2+ fluxes across the plasma membrane of a mammalian rod could be studied in detail. By light stimulation, Ca2+ sources are evoked along the outer segment only. Immediately after a saturating flash, a maximum of Ca2+ efflux is observed which decays exponentially with tau = 0.3 s at 37 degrees C (4.2 s at 23 degrees C). During regeneration of the dark current, the outer segment acts as a Ca2+ sink, indicating a restoration of the Ca(2+)-depleted outer segment. These findings agree with earlier reports on amphibian rods. Further experiments showed that the peak Ca2+ efflux and tau are temperature dependent. The peak amplitude also depends on the external Ca2+ concentration. In contrast to the reports on amphibian rods, only a part of the Ca2+ ions extruded from the outer segment is directly restored. Surprisingly, during steady light the Ca2+ efflux approaches a permanent residual value. Therefore, in course of a photoresponse, Ca2+ must be liberated irreversibly from internal Ca2+ stores. There is certain evidence that the inner segment acts as a Ca2+ store. Our results show that the Ca2+ fraction of the ions carrying the dark current is proportional to the extracellular Ca2+ concentration. This indicates that the Ca2+ permeability of the plasma membrane of the rod outer segment is independent of the Ca2+ concentration.

Mechanical induction of beta 1-integrin-mediated calcium signaling in a hepatocyte cell line.

Mechanical stress influences growth, differentiation, and gene expression in a variety of cell types. It is believed that via extracellular matrix the mechanical stimulus is transmitted to integrin receptors which thus play a key role in transducing signals into the cell interior. Here we demonstrate that incubation of suspended hepatocytes with specific antibodies to beta 1-integrin subunits followed by a short-term mechanical stimulation is sufficient to induce a rise in intracellular Ca2+. The results indicate that mechanical loading of individual integrin subunits activates Ca(2+)-specific signal pathways.

Local increase of beta 1-integrin expression in cocultures of immortalized hepatocytes and sinusoidal endothelial cells.

The expression and spatial arrangement of beta 1-integrins was determined on two immortalized liver cell lines held in coculture, namely the epithelial cell line mHepR1 and a sinusoidal endothelial cell line. On mHepR1 cells the distribution of beta 1-integrins was restricted to the basolateral plasma membrane domains, a staining pattern that is typical of polarized epithelial cells. On the endothelial cell line the beta 1-integrins were distributed all over the cell surface. In coculture the endothelial cells tended to cover over the epithelial cells. Epithelial cells located in their vicinity exhibited an increased staining of beta 1-integrins at basolateral plasma membrane domains, which was most prominent with regard to the alpha 2-subunit. When mHepR1 cells were cultivated on various types of extracellular matrix also synthesized by the endothelial cells only collagen IV was found to increase the intensity of beta 1-integrin expression at the cell surface. The results indicate that beta 1-integrin expression in epithelial cell colonies can locally be modulated by interactions with non-parenchymal cells. In addition, the data suggest that mHepR1 cells may be a favorable system for analyzing basic functions of beta 1-integrins in polarized epithelial cells.