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At least 289 records · Page 16Linked to original sources
PubMed2002

Epithalon decelerates aging and suppresses development of breast adenocarcinomas in transgenic her-2/neu mice.

Female transgenic FVB/N mice carrying the breast cancer gene HER-2/neu received epithalon (Ala-Glu-Asp-Gly) in a dose of 1 mg subcutaneously 5 times a week to from the 2nd month of life to death. Epithalon prolonged the average and maximum lifetimes of mice by 13.5 (p<0.05) and 13.9%, respectively. The peptide prolonged the average lifetime of animals without neoplasms (by 34.2%, p<0.05). Epithalon decelerated the development of age-related disturbances in reproductive activity and suppressed the formation of neoplasms. The peptide decreased the incidence of breast adenocarcinomas, lungs metastases (by 1.6 times, p<0.05), and multiple tumors (by 2 times). Epithalon 3.7-fold increased the number of mice without breast tumors (p<0.05), while the number of animals with 6 or more breast tumors decreased by 3 times (p<0.05). Epithalon prolonged the lifetime of mice with breast tumors by 1.4 times (p<0.05). These results indicate that Epithalon possesses geroprotective activity and inhibits breast carcinogenesis in transgenic mice, which is probably related to suppression of HER-2/neu expression.

Adenocarcinoma↗
PubMed2003

Fetal heart rate decelerations during ECT-induced seizures: is it important?

Electroconvulsive therapy (ECT) is sometimes indicated during pregnancy and may offer advantages over pharmacotherapy for the patient and the fetus (1,2). However, very little data is available on the impact of epileptic or ECT-induced seizures on the fetus. We report a case of brief fetal heart rate decelerations in a fetus associated with maternal ECT-induced convulsions.

Adult↗
PubMedDate not supplied

Atypical variable decelerations and intrauterine growth restriction.

Variable decelerations of the fetal heart rate are the most common changes noted during continuous fetal monitoring. In general, they are presumed to represent a normal response to fetal baroceptor stimulation. When atypical features are present, other considerations are warranted.

Adult↗
PubMed1999

[Horizontal deceleration trauma with diffuse decollement bleeding--a casuistry].

Treatment of severe haemorrhage caused by multiple trauma is a serious challenge to preclinical as well as clinical management. This is a case report of a motorcycle accident in which a patient sustained total amputation of both legs. Following adequate preclinical care, vital indication led to the patient's immediate surgical treatment. After initially successful haemodynamic stabilisation, the patient developed a horizontal deceleration trauma which resulted in an extended decollement of the muscles of the back and buttock. During the further clinical course, soft tissue bleeding occurred that affected the whole torso. Due to its extent, the bleeding could not be treated surgically, nor did it allow of haemodynamic stabilisation despite continuous massive transfusion. Retrospectively, the impressing amputation injury was treated successfully. In spite of all available surgical and intensive care efforts, however, the slowly demasking monstrous decollement with diffuse tissue bleeding proved to be an injury pattern leading to the patient's death.

Accidents, Traffic↗
PubMed1991

Sonographic verification of a nuchal cord following a vibratory acoustic stimulation-induced severe variable fetal heart rate deceleration with expedient abdominal delivery.

A case is presented in which external vibratory acoustic stimulation performed following a nonreactive nonstress test produced a severe variable deceleration of the fetal heart rate. A clinically suspected nuchal cord was confirmed by ultrasound. This rapid precise antepartum diagnosis of cord compression prevented untimely delay and led to immediate abdominal delivery of a nonacidotic, yet hypoxic, infant. This report suggests care be taken when fetal vibratory acoustic stimulation is applied in cases of oligohydramnios and a known existing nuchal cord.

Acoustic Stimulation↗
PubMed2004

Deflection and deceleration of hydrogen Rydberg molecules in inhomogeneous electric fields.

Hydrogen molecules are excited in a molecular beam to Rydberg states around n=17-18 and are exposed to the inhomogeneous electric field of an electric dipole. The large dipole moment produced in the selected Stark eigenstates leads to strong forces on the H2 molecules in the inhomogeneous electric field. The trajectories of the molecules are monitored using ion-imaging and time of flight measurements. With the dipole rods mounted parallel to the beam direction, the high-field-seeking and low-field-seeking Stark states are deflected towards and away from the dipole, respectively. The magnitude of the deflection is measured as a function of the parabolic quantum number k and of the duration of the applied field. It is also shown that a large deflection is observed when populating the (17d2)1 state at zero field and switching the dipole field on after a delay. With the dipole mounted perpendicular to the beam direction, the molecules are either accelerated or decelerated as they move towards the dipole. The Rydberg states are found to survive for over 100 micros after the dipole field is switched off before being ionized at the detector and the time of flight is measured. A greater percentage change in kinetic energy is achieved by initial seeding of the beam in helium or neon followed by inhomogeneous field deceleration/acceleration. Molecular dynamics trajectory simulations are presented highlighting the extent to which the trajectories can be predicted based on the known Stark map. The spectroscopy of the populated states is discussed in detail and it is established that the N+=2, J=1, MJ=0 states populated here have a special stability with respect to decay by predissociation.

Journal Article↗
PubMed2000

Doppler-derived mitral deceleration time as an early predictor of left ventricular thrombus after first anterior acute myocardial infarction.

BACKGROUND: The relation between left ventricular (LV) diastolic function and LV thrombus has not yet been fully investigated. The aim of this study was to determine whether early assessment of Doppler-derived mitral deceleration time (DT), a measure of LV compliance and filling, may predict LV thrombus formation after acute myocardial infarction. METHODS AND RESULTS: Two-dimensional and Doppler echocardiographic examinations were performed in 98 consecutive patients (aged 57 +/- 12 years; 8 women) with first acute myocardial infarction. The patients were studied within 24 hours and at days 3, 7, 15, and 30 after arrival to the coronary care unit. Mitral flow velocities were obtained from the apical 4-chamber view with pulsed Doppler. LV thrombus was detected in 20 of 98 patients. Patients were divided into 2 groups according to LV thrombus formation: group 1 (n = 20) with thrombus and group 2 (n = 78) without thrombus. Mitral E-wave DT was significantly shorter in group 1 than group 2 (134 ms vs 175 ms; P <.001). Patients in group 1 had significantly larger LV end-diastolic and end-systolic volumes and a higher wall motion score index than patients in group 2 (133 +/- 39 mL vs 112 +/- 41 mL, P =.03; 83 +/- 34 mL vs 59 +/- 30 mL, P =.003; and 1.8 +/- 0.3 mL vs 1.5 +/- 0.3 mL, P =.007, respectively). The LV ejection fraction was significantly lower in group 1 than in group 2 (39% +/- 13% vs 48% +/- 12%; P =.004). In a multivariate regression analysis, mitral E-wave DT was identified as an independent variable related to development of LV thrombus (P =.04). CONCLUSIONS: Doppler-derived mitral DT is superior to conventional clinical and 2-dimensional echocardiographic assessment in estimating the risk of left ventricular thrombosis after myocardial infarction.

Aged↗
PubMed2002

Deceleration time of early filling in patients with left ventricular systolic dysfunction: functional and prognostic independent value.

BACKGROUND: Although diastolic function parameters have been mentioned as significant predictors of functional capacity and prognosis in patients with left ventricular (LV) systolic dysfunction, it has not been fully elucidated whether they keep an independent predictive value when multiple parameters from a wide variety of examinations are considered. METHODS: We prospectively studied 60 patients with New York Heart Association (NYHA) class II-IV chronic heart failure symptoms and LV ejection fraction <0.4. At the time of entry into the study, demographic data and functional class were obtained, and usual Doppler echocardiographic, radionuclide ventriculographic, cardiopulmonary exercise testing and hemodynamic variables were determined. Deceleration time of early filling (DT) and NYHA functional class were the only independent predictors of functional capacity as assessed by means of peak oxygen uptake (peak VO2). Mean follow-up was 21 +/- 6 months, and event-free survival was defined as the absence of cardiac death, urgent cardiac transplantation, or hospital admission requiring inotropic or mechanical support. RESULTS: Multivariate Cox analysis showed that DT (P =.008), peak VO2 (P =.01), and NYHA class (P =.02) were independent predictors of event-free survival at 1 year. Patients in the lowest tertile of DT (<130 ms) had a significantly lower event-free survival than patients in the intermediate (44% vs 80%, P =.03) and in the highest tertile (44% vs 83%, P =.02). Patients with both a DT <130 milliseconds and a peak VO2 <14 mL/kg/min had the highest rate of events at 1 year (83% vs 22% for the remaining patients, relative risk 3.75, P <.001). CONCLUSIONS: In patients with LV systolic dysfunction, DT is a powerful independent predictor of functional capacity and prognosis among a wide variety of variables. A shortened DT (<130 ms) identifies a subgroup of patients with a worse outcome, especially when combined with a reduced peak VO2 (<14 mL/kg/min).

Aged↗
PubMed2001

Generation of ultra-intense single-cycle laser pulses by using photon deceleration.

A scheme to generate single-cycle laser pulses is presented based on photon deceleration in underdense plasmas. This robust and tunable process is ideally suited for lasers above critical power because it takes advantage of the relativistic self-focusing of these lasers and the nonlinear features of the plasma wake. The mechanism is demonstrated by particle-in-cell simulations in three and 2(1/2) dimensions, resulting in pulse shortening up to a factor of 4, thus making it feasible to generate few-femtosecond single-cycle pulses in the optical to IR domain with intensities I > 10(20) W/cm(2) by using present-day laser technology.

Lasers↗
PubMed1995

The Topology of Limb Deceleration in Prehension Tasks.

Whether a subject uses a constant tau-dot strategy to decelerate a reach to grasp an object is typically determined by performing a linear regression of tau onto real time to contact. This method has the disadvantage of requiring an assumption (on the part of the experimenter) concerning the endpoint targeted by the subject. In the present contribution, an alternative, topological method is proposed that makes use of a phase-plane representation of the movement. In two experiments, experimentally obtained movement trajectories were evaluated, using this new method, and the results were found to support the constant tau-dot strategy. At the same time, however, an alternative model, associated with dynamical systems theory, was demonstrated to fit the data even better. It is argued that the topology of the phase plane suggests a softening spring description for a large part of the decelerative phase, followed by a final adjustment. Deterioration of the functionality of the adjustment made in this latter phase was observed when visual information was not available during movement execution.

Journal Article↗
PubMedDate not supplied

Deceleration of age at menarche in Poland.

The purpose of this paper is to describe secular growth changes in age at menarche of girls in Poland during the past 40 years. For this purpose data obtained from four consecutive surveys conducted in 1955, 1966, 1978 and 1988 were analysed. Each cohort was selected from settlements: big cities, small towns (approximately 10,000 inhabitants) and villages. Data regarding schoolgirls aged 7-18 years were collected by the status quo method. It was found that after the continuous trend towards an earlier maturation of Polish girls from 1955 to 1978 a substantial slowing down, and even a reverse trend, was observed. The deceleration of the age at menarche is most marked among girls from small towns. The results seem to have been caused by the retardation of menarcheal age in social groups which in the previous examinations were the earliest maturers.

Adolescent↗
PubMed2001

Growth deceleration and bone metabolism in nutritional dwarfing rats.

Nutritional status as well as energy and protein intake are critical regulators of IGF-1 and IGFBP-3 and contribute to the modulation of bone remodeling and formation. The purpose of this study was to investigate on an experimental model with nutritional dwarfing (ND), whether the alterations on body growth velocity, energy metabolism and body composition could affect serum concentrations of IGF-1 and IGFBP-3 and bone (tibiae and mandible) histology and histomorphometry. Twenty-one male weanling Wistar rats (body weight = 38.20 +/- 0.94 g) were randomized to three groups: seven of them were killed at day = 0 (CO, n = 7); control (C, n = 7); and experimental 80 (E80, n = 7). During 4 weeks, C was fed ad libitum with a 1:1 carbohydrate to fat diet. E80 was being underfed with the same diet by 80% and the following parameters were measured: weight (Wt) for length (L) ratio z-score; oxygen consumption (VO2); body composition (BC) by EM-SCAN SA 3000. At t = 28, E80 and C were killed. Serum IGF-1 and IGFBP-3 and bone histology and histomorphometry were performed on C0, E80 and C. E80 showed Wt for L z-score between lean and adequate, a decrease in VO2 according to body proportions, a BC of a delayed puberty individual, IGF-1 and IGFBP-3 decreased by 56 and 53%, respectively. Tibiae's hematopoyetic and adipose bone marrow areas were combined, with sealing trabeculae on metaphyseal areas. This study suggests that there is a relationship among growth deceleration in ND rats and structural alterations on tibiae.

Animals↗
PubMed2026

Increased precipitation decelerates temporal succession of grassland soil microbial communities.

Global precipitation regimes have been shifted in recent decades, imposing significant consequences in water-limited grassland ecosystems. However, the effects of increased precipitation on the succession of soil microbial communities remain unclear, mainly due to the scarcity of long-term experiments with time-series data. Here, we examined temporal succession of grassland soil microbial communities in a long-term increased precipitation experiment. Both soil microbial taxonomic and functional structures were significantly altered by increased precipitation. Increased precipitation significantly decelerated the succession rates of soil microbial functional structure (i.e. time-decay relationships). Consistent with the increased microbial decomposition and heterotrophic respiration, the abundances of soil microbial carbon decomposition genes were markedly enhanced by increased precipitation. Furthermore, increased precipitation stimulated genes involved in nutrient cycling processes, potentially promoting plant growth. Collectively, the contributions of stochastic processes in shaping microbial communities were increased under increased precipitation, suggesting that microbial successional trajectories may shift toward multiple alternative states characterized by greater stochasticity under future altered precipitation regimes.

Soil Microbiology↗
PubMedDate not supplied

Long-term enhanced expression of heat shock proteins and decelerated apoptosis in polymorphonuclear leukocytes from major burn patients.

Heat shock proteins (HSPs), as molecular chaperones, have been reported to protect cells against a variety of environmental stresses. The objective of this study was to clarify the serial changes in expression of HSPs, oxidative activity, and apoptosis in polymorphonuclear leukocytes (PMNLs) from burn patients. Eight patients with severe burns (mean burn index 24.0 +/- 6.1) were included. Blood samples were serially obtained at five time points: days 0 to 1, days 2 to 7, days 8 to 14, days 15 to 21, and days 22 to 28. We measured expressions of HSP27, HSP60, HSP70, and HSP90 in permeabilized PMNLs by flow cytometry with the use of a monoclonal antibody against each HSP. The oxidative activity and apoptosis in PMNLs were also measured by flow cytometry. During all five time periods, expressions of HSP27, HSP60, and HSP70 in PMNLs from burn patients were significantly greater than those in PMNLs from healthy volunteers. The expression of HSP90 in PMNLs of burn patients increased between days 2 and 21. Oxidative activity in their PMNLs was significantly enhanced between days 2 and 28, and PMNL apoptosis was markedly inhibited for as long as 4 weeks after thermal injury. In conclusion, major burn causes long-term, enhanced expression of HSPs in PMNLs along with increased oxidative activity and decelerated apoptosis. The enhanced expression of HSPs may regulate the oxidative stress response and life-span of PMNLs in burn patients.

Apoptosis↗
PubMed2003

Mechanism of growth reduction of the deceleration-phase ablative Rayleigh-Taylor instability.

The deceleration-phase (dp) ablative Rayleigh-Taylor instability (RTI) of igniting and nonigniting inertial fusion capsules is studied by high-resolution two-dimensional Lagrangian fluid simulations. It is found that growth reduction of the dp-RTI with respect to classical RTI results from the advection of perturbed fluid elements outside a thin unstable fluid layer. Within this layer, at fixed Lagrangian position, perturbations grow approximately classically.

Journal Article↗
PubMed2005

Accelerating, hyperaccelerating, and decelerating networks.

Many growing networks possess accelerating statistics where the number of links added with each new node is an increasing function of network size so the total number of links increases faster than linearly with network size. In particular, biological networks can display a quadratic growth in regulator number with genome size even while remaining sparsely connected. These features are mutually incompatible in standard treatments of network theory which typically require that every new network node possesses at least one connection. To model sparsely connected networks, we generalize existing approaches and add each new node with a probabilistic number of links to generate either accelerating, hyperaccelerating, or even decelerating network statistics in different regimes. Under preferential attachment for example, slowly accelerating networks display stationary scale-free statistics relatively independent of network size while more rapidly accelerating networks display a transition from scale-free to exponential statistics with network growth. Such transitions explain, for instance, the evolutionary record of single-celled organisms which display strict size and complexity limits.

Journal Article↗
PubMed2000

1s lamb shift in hydrogenlike uranium measured on cooled, decelerated ion beams.

The Lyman- alpha transitions of hydrogenlike uranium associated with electron capture were measured in collisions of stored bare U (92+) ions with gaseous targets at the storage ring ESR. By applying the deceleration technique, the experiment was performed at slow collision energies in order to reduce the uncertainties associated with Doppler corrections. From the measured centroid energies, a ground state Lamb shift of 468 eV+/-13 eV is deduced which gives the most precise test of quantum electrodynamics for a single electron system in the strong field regime. In particular, the technique applied paves the way towards the 1 eV precision regime.

Journal Article↗
PubMed2000

Ablative stabilization of the deceleration phase rayleigh-taylor instability

The growth rates of the deceleration-phase Rayleigh-Taylor instability for imploding inertial confinement fusion capsules are calculated and compared with the results of numerical simulations. It is found that the unstable spectrum and the growth rates are significantly reduced by the finite ablation flow at the shell's inner surface. For typical direct-drive capsules designed for the National Ignition Facility, the unstable spectrum exhibits a cutoff for l approximately 90.

Journal Article↗