Double aneuploidy mosaicism with Down-Klinefelter's syndrome.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
S Nikolic
Publications and source records attributed to S Nikolic.
Complexity of molecules
Several currently used measures of the complexity of molecules, such as, for example, those by Bertz and Randic or those based on the number of spanning trees, are briefly reviewed. We also proposed as complexity measures the sum of vertex-weights and the sum of edge-weights and their variants related to partition of vertex-weights and edge-weights into classes by their numerical values. The vertex-weights considered are the squares of the vertex-degrees, and the edge-weights are products of vertex-degrees making up the edges. Comparison is made between considered complexity measures for selected molecular graphs. All considered indices increase with increasing size and cyclicity and most with increasing branching. However, they differ regarding the influence of symmetry.
Journal Article↗
QSPR modeling: graph connectivity indices versus line graph connectivity indices
Five QSPR models of alkanes were reinvestigated. Properties considered were molecular surface-dependent properties (boiling points and gas chromatographic retention indices) and molecular volume-dependent properties (molar volumes and molar refractions). The vertex- and edge-connectivity indices were used as structural parameters. In each studied case we computed connectivity indices of alkane trees and alkane line graphs and searched for the optimum exponent. Models based on indices with an optimum exponent and on the standard value of the exponent were compared. Thus, for each property we generated six QSPR models (four for alkane trees and two for the corresponding line graphs). In all studied cases QSPR models based on connectivity indices with optimum exponents have better statistical characteristics than the models based on connectivity indices with the standard value of the exponent. The comparison between models based on vertex- and edge-connectivity indices gave in two cases (molar volumes and molar refractions) better models based on edge-connectivity indices and in three cases (boiling points for octanes and nonanes and gas chromatographic retention indices) better models based on vertex-connectivity indices. Thus, it appears that the edge-connectivity index is more appropriate to be used in the structure-molecular volume properties modeling and the vertex-connectivity index in the structure-molecular surface properties modeling. The use of line graphs did not improve the predictive power of the connectivity indices. Only in one case (boiling points of nonanes) a better model was obtained with the use of line graphs.
Journal Article↗
Significant increase of aortic root volume and commissural area occurs prior to aortic valve opening.
BACKGROUND AND AIM OF THE STUDY: The increased use of autologous, homologous or heterologous aortic root demands a detailed knowledge of its anatomy and function. The advent of 3-D digital sonomicrometry offered the opportunity to acquire precise information on the root and leaflet movements during the cardiac cycle. METHODS: Under cardiopulmonary bypass, sonomicrometry crystals were implanted in the aortic root and valve of eight sheep. Crystals were sutured at each commissure (n = 3), the top of the sinotubular junction (n = 3), lowest point of the annulus (n = 3), and leaflet tip (n = 3). 3-D coordinates of each crystal were recorded, together with left ventricular and aortic root pressures and ECG. When the animal had returned to a stable hemodynamic condition, the maximum and minimum distances between two crystals, and areas between three crystals, were calculated. Changes in root volume and leaflet position were time-related to the pressure changes. RESULTS: The most significant change between maximum and minimum distance between crystals during the cardiac cycle occurred at the commissural level. Similarly, the triangle defined by the three commissural crystals showed the greatest change in area (47%). The root volume increased by an average of 22%; about 40% of this increase occurred during the isovolumic phase. The aortic leaflets began to open before ejection. CONCLUSION: We postulate that aortic valve opening is initiated by the outward pull of the commissures. These findings should impact on aortic root surgery.
Animals↗
Mechanism of sustained mechanical alternans. Effect of variations in ventricular billing volume.
This study investigations the phenomenon of sustained mechanical alternans (SMA) through the use of quantitative criteria. Discrete analysis is used to demonstrate that the hemodynamic variables during SMA are governed by a simple mathematical relation. The analysis shows that the value of the slope created by the two alternating beats on the stroke volume (SV)-end-diastolic volume (EDV) plane is gamma = (mu - 1) (1 + beta)/(mu - beta), where mu = SVs/SVw, and SVs and SVw denote the strong and weak beats, respectively, in the presence of one contractile state, and the beats associated with the higher and lower contractile states, respectively, in the presence of two alternating contractile states; beta = FVs/FVw, where FVs and FVw are the filling volumes after SVs and SVw, respectively. This equation is valid, whether SMA is exhibited in the presence of one or two contractile states and irrespective of the SV-EDV functional relation. Assuming constant afterload, a criterion based on this slope (gamma) is described to determine if SMA is caused by variations in EDV and FV. The slope of the SV-EDV curve in the presence of one contractile state (denoted as gamma) was determined directly (34 runs in eight dogs) by preventing FV in a beat, after a steady state, using a remote-controlled mitral valve. The slope gamma = 0.892 +/- 0.078 was found to agree with data in the literature. In 10 other dogs, mitral flow and aortic flow were measured in 55 series of SMA. In 51 series, gamma was greater than 1. Because the experimental slope in the presence of one contractile state, gamma, is smaller than or equal to 1, the possibility that one contractile state is involved in this series is rejected. On the other hand, when two contractile states are involved, the slope that the two successive beats create on the SV-EDV plane, gamma, is determined by connecting the two SV-EDV relations. This slope tends to be greater than 1. Thus, in these 51 series, SMA cannot be explained as a result of the Frank-Starling mechanism and variations in FV but as a result of two alternating contractile states. In the other four series, the value of gamma can be compatible either with the presence of one contractile state or with two alternating contractile states. This quantitative analysis enables the classification of the various types of SMA into subcategories with well-defined features. The quantitative analysis presented here shows that the common genesis of SMA is an alternating contractile state.
Animals↗
Effect of early diastolic loading on myocardial relaxation in the intact canine left ventricle.
Early transmitral flow (MiF) patterns depend strongly on the rate of fall of measured left ventricular pressure (Pm) determined by both the active decay of pressure (Pa) due to myocardial relaxation and the increase in pressure due to stretch of passive elements during filling (Pp). This study was designed to uncouple passive forces from deactivation in order to reveal the instantaneous rate and duration of myocardial relaxation. We assumed a parallel combination of passive and active elements: Pm(t,V) = Pa(t) + Pp(V), with no constraints on the form of Pa(t), where t is time and V is ventricular volume. Pp(V) was determined by a retrospective analysis of data obtained in 11 anesthetized dogs instrumented for volume clamping with a remote-controlled mitral valve, with left atrial and left ventricular micromanometers, and with an electromagnetic probe to measure MiF. The passive pressure-volume relation (both positive and negative portions) was determined by clamping at end-systolic volume or after various filling volumes, and fit to logarithmic functions. Pp(t) was then calculated from Pp(V) and V(t) (integral of MiF). Time to end relaxation (Ter) was defined as time when Pa = 0. During isovolumic relaxation, when dPp/dt = 0, dPm/dt is equal to the relaxation rate, dPa/dt. In completely isovolumic relaxations, asymptote P infinity = -7 +/- 6 mm Hg (thus, Pa is 7 mm Hg greater than Pm) and Ter = 40 +/- 15 msec, compared with 175 +/- 53 msec during normal filling. In high versus low inotropic state, Pa at the beginning of filling was greater (18.1 +/- 6.1 vs. 12.2 +/- 3.9 mm Hg), and Ter was shorter (170 +/- 42 vs. 228 +/- 43 msec). Active pressure Pa(t) during filling is not an exponential function, and at any time, it was always greater after filling than in nonfilling beats, which indicates an increase in the relaxation duration. We conclude that myocardial relaxation is modulated by filling, which slows its rate and increases its duration, and is therefore a function of both ventricular volume and time. Such a mechanism may have an important role in regulating the diastolic pressure-volume relation.
Animals↗
Teaching stress management techniques to a schizophrenic patient.
This paper describes a stress management training program used with a 26-year-old schizophrenic man attending an outpatient day care program. In a seven-session program the patient was taught to use various techniques in muscle relaxation and biofeedback to decrease anxiety and to cope with stress. The patient's improvement on 7 of the 20 items of the State-Trait Anxiety Inventory demonstrated the effectiveness of even a short-term stress management program.
Adult↗
[Adolescence. The problem of identity and development of the self].
This is a contribution to the description of the birth and development of the feeling of identity, such as organized by the genesis of the authentic self, which in sociology is called the value system of young people. My clinical experience suggests that this development, which is spread over two decades, goes through two phases: formation of basic identity; formation of sexual identity. They are integrated into the total self-identity at the end of adolescence. The basic identity organizes the intra-psychic structuration by the internalization of the super ego, after the oedipal phase. I use the term Ego-identity to define this phase of global functioning. The constitution of the authentic self is evidence of this integration.
Adolescent↗
Left ventricular filling dynamics and diastolic function.
Explore the source record for details and available documents.
Animals↗
[Fatal therapeutic event after an injection of chlorpromazine].
Accidental deaths after parenteral use of medicaments are usually very rare. The most common cause of death is allergic reaction. In literature, the most menacing medicaments are antibiotics. Taking into account that macroscopic and microscopic autopsy findings are uncharacteristic and poor clinical features and circumstances are more or less characteristic and objective, and that the establishing of cause and mode of death could be a problem for dissectors. Later, in forensic expertise, the questions about medical malpractice could arise. In this paper the authors report on the case of a male, aged 46, a chronic psychiatric patient with schizophrenia, treated by neuroleptics, who died about half an hour after intramuscular injection of chlorpromazine. On the basis of the autopsy, microscopical and toxicological findings, clinical features and circumstances, as well as exclusion of other possible violent and morbid causes of death, it was established that the unexpected and sudden death was caused by anaphylactic allergic reaction due to injected medicament--chlorpromazine.
Anaphylaxis↗