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Biomedical subjects

J Konecki

Publications and source records attributed to J Konecki.

At least 19 recordsLinked to original sources

Bios data analyzer.

The Bios Data Analyzer (BDA) is a set of computer programs (CD-ROM, in Sabelli et al., Bios. A Study of Creation, 2005) for new time series analyses that detects and measures creative phenomena, namely diversification, novelty, complexes, nonrandom complexity. We define a process as creative when its time series displays these properties. They are found in heartbeat interval series, the exemplar of bios .just as turbulence is the exemplar of chaos, in many other empirical series (galactic distributions, meteorological, economic and physiological series), in biotic series generated mathematically by the bipolar feedback, and in stochastic noise, but not in chaotic attractors. Differencing, consecutive recurrence and partial autocorrelation indicate nonrandom causation, thereby distinguishing chaos and bios from random and random walk. Embedding plots distinguish causal creative processes (e.g. bios) that include both simple and complex components of variation from stochastic processes (e.g. Brownian noise) that include only complex components, and from chaotic processes that decay from order to randomness as the number of dimensions is increased. Varying bin and dimensionality show that entropy measures symmetry and variety, and that complexity is associated with asymmetry. Trigonometric transformations measure coexisting opposites in time series and demonstrate bipolar, partial, and uncorrelated opposites in empirical processes and bios, supporting the hypothesis that bios is generated by bipolar feedback, a concept which is at variance with standard concepts of polar and complementary opposites.

Creativity↗

[Chronic hepatic encephalopathy--clinical features and diagnosis].

Neuropsychiatric abnormalities affecting patients with chronic liver disease are termed chronic hepatic encephalopathy. The spectrum of hepatic encephalopathy varies from mild intellectual impairment to deep coma. The diagnosis is based on clinical findings, and psychometric and electroencephalographic testing.

Chronic Disease↗

[Neurological picture and selected diagnostic indices of vitamin b12 malabsorption syndrome].

Funicular myelosis is considered to be the main neurological syndrome in vitamin B12 deficiency. However, many authors tend to think that sensory neuropathy is the most common neurological manifestation of vitamin B12 deficiency. The aim of this paper was to assess neurological condition of patients with vitamin B12 malabsorption. The absorption of vitamin B-12 was assessed by Schilling's test. Patients with abnormal results of this test underwent neurological and medical examinations as well as series of accessory investigations. 16 cases of deficient vitamin B12 absorption accompanied by neurological symptoms were presented. The results of the investigation showed that the most common clinical manifestation of vitamin B12 deficiency was sensory neuropathy. In over 93% of described cases pathologic changes in gastric mucous membrane were found.

Adult↗

TU wave area-derived measures of repolarization dispersion in the long QT syndrome.

The purpose of this study was to evaluate area-derived parameters of repolarization dispersion in LQTS patients and their unaffected family members and to use this analysis to challenge the concept of dispersion of repolarization in surface ECG. The area under the curve between the J point and the next P wave was measured automatically in 12 leads of the digital ECG in 34 LQTS patients and 22 unaffected family members. The area-derived measures of repolarization included total repolarization area, T wave amplitude, time to accumulate the first (tA50) and the median (tA25-75) 50% of the total area, and the time to accumulate 97% of the total repolarization area (tA97). In comparison with unaffected family members, LQTS patients had significantly higher dispersion of tA50 (tA50-SD = 34 +/- 18 ms vs 11 +/- 6 ms, respectively, P < .001) and tA25-75 (t[A25-75]-SD = 44 +/- 19 ms vs 24 +/- 15 ms, respectively, P < .001), whereas no significant difference was observed in the dispersion of total repolarization area, T wave amplitude, and time to accumulate total repolarization area (tA97-SD = 44 +/- 20 ms vs 53 +/- 19 ms, respectively, ns). It is concluded the analysis of area-derived parameters of repolarization showed that LQTS patients have increased interlead variability of the repolarization morphology (tA50-SD and t[A25-75]-SD), whereas they do not have increased dispersion of the total repolarization duration (tA97-SD). This observation indicates that an increase in traditional measures of dispersion (QT dispersion) may represent a heterogeneity of repolarization shape, whereas the true dispersion of the total duration of repolarization, which is related to electrocardiographic lead projection, is similar in patients and healthy subjects.

Electrocardiography↗

ECG features of microvolt T-wave alternans in coronary artery disease and long QT syndrome patients.

UNLABELLED: T-wave alternans (TWA) is a marker of myocardial electrical instability. We compared ECG features of microvolt TWA in coronary artery disease (CAD) and long QT syndrome (LQTS) patients. METHOD: The study populations consisted of 43 CAD and 39 LQTS patients. TWA was detected in resting Holter recordings using the new correlation method (CM). After preprocessing to adjust for RR variability and respiratory modulation, CM was used to quantify TWA amplitude (A(CM)), duration (N(CM)), and magnitude (MAG(CM); defined as the product of A(CM) and N(CM)). RESULTS: TWA was detected in 19 (44%) CAD and 17 (44%) LQTS patients. TWA was associated with longer RR intervals (P = 0.006) and had larger magnitudes (P = 0.067) in LQTS than CAD patients. The TWA was identified as transient (nonstationary) in 15 of 19 (79%) TWA-positive CAD patients, and in 8 of 17 (47%) TWA-positive LQTS patients (P = 0.047). CONCLUSIONS: The frequency of TWA detected with CM is similar in LQTS and CAD patients. TWA is larger in LQTS than in CAD patients, whereas TWA is more frequently transient (nonstationary) in LAD than LQTS patients. In LQTS patients, but not in CAD patients, a longer RR is associated with TWA, indicating different electrophysiologic mechanisms in the two pathologies.

Adult↗

Expression of adhesion molecule CD44 in metastatic brain tumors.

Expression of CD44 (m.w. 80-95 kD) in 48 metastatic brain tumors was examined using monoclonal antibody on paraffin sections. The CD44 expression was found in 48% of studied tumors. The most constant expression of CD44 was observed in metastases from thyroid, skin and breast cancer. The brain metastases were characterized by quite heterogenous distribution of CD44 glycoprotein--the most pronounced expression was seen in individual neoplastic cells embedded in abundant stroma and in the vicinity of preserved neural tissue. Such a topographical distribution of CD44 supports its role in interactions of cancer cells with extracellular matrix components of the tumor stroma as well as of neural tissue.

Adenocarcinoma↗

Electrocardiographic findings in patients with diphenhydramine overdose.

QT interval prolongation and torsades de pointes ventricular tachycardia have been reported after therapeutic doses and overdosage of second generation antihistamines, such terfenadine and astemizol. Diphenhydramine (DPHM), a first generation H1 antagonist, is the most frequently used antihistaminic drug. Despite its widespread use, there are no data about cardiac action and electrocardiographic consequences of DPHM overdose. The 12-lead electrocardiograms of 126 patients (mean age 26 +/- 11 years) who had DPHM overdose were evaluated. The ingestion of large doses of DPHM (in majority of cases the dose was >500 mg) was primarily suicidal. Repolarization duration, dispersion, and morphology were evaluated in DPHM overdose patients and compared with those of healthy subjects. Mean heart rate of DPHM overdose patients was 103 +/- 25 beats/min. The QTc duration was significantly longer (453 +/- 43 vs 416 +/- 35 ms, respectively, p <0.001) and mean T-wave amplitude significantly lower (0.20 +/- 0.10 vs 0.33 +/- 0.15 mV, respectively, p <0.001) in DPHM-overdose patients than in control subjects. Dispersion of repolarization was significantly lower in DPHM-overdose patients than in control subjects (42 +/- 25 vs 52 +/- 21 ms, respectively; p = 0.003). None of the DPHM-overdose patients experienced torsades de pointes. In conclusion, DPHM overdose is associated with a significant increase in heart rate and a significant but moderate QTc prolongation. None of the studied patients, including those who had apparent QTc prolongation, experienced torsades de pointes ventricular tachycardia.

Adult↗

Brain protein synthesis in rats with portacaval shunts.

Effects of portacaval shunts on the brain protein synthesis were studied in rats 7, 10 and 13 weeks after the surgery. We evaluated the incorporation of [3H]-glycine with the usage of liquid scintillation. In comparison to the controls, the labelled amino acid was incorporated less effectively in all the examined brain regions throughout the experimental period. The lowest values were observed 10 weeks after the portacaval shunt and the drop was most distinct in the cerebellum (47%). The least profound changes occurred within 7 weeks after the surgery and the results were statistically significant only in the frontal cortex and the brain stem. Thirteen weeks after the shunting the incorporation of [3H]-glycine was moderately decreased (the drop ranged between 12% and 18%) but all the differences were statistically significant. It seems that the inhibition of the brain protein synthesis may contribute to the pathogenesis of the portal-systemic encephalopathy.

Animals↗

Free amino acids in cytosol of rat brain after intraventricular administration of 5,6-dihydroxytryptamine and 6-hydroxydopamine.

Levels of 24 free amino acids were estimated in the brain after administration of 5,6-dihydroxytryptamine and 6-hydroxydopamine into the lateral brain ventricles of male Wistar rats. These neurotransmitters caused serotoninectomy and sympathectomy in the diencephalon, striatum, brain stem and medulla, thalamus and hypothalamus, cerebral cortex and cerebellum. The most abundant amino acids in these brain structures were: glutamic acid, serine, aspartic acid, cystine, gamma-aminobutyric acid, glycine, tryptophan and alanine. We detected and quantified changes in the levels of these and other amino acids in the investigated regions of the rat central nervous system, under the influence of these two neurotransmitters.

5,6-Dihydroxytryptamine↗

Free amino acids in the cytosol of human atrium and ventricle of the heart, as analyzed by gas-liquid chromatography.

Size and composition of the amino acid pool in the cell cytosol of atrial and ventricular heart muscle of 6-8 week old human embryos was evaluated by gas-liquid chromatography. It was found that the free amino acid pool in the ventricular heart muscle is about 50% higher than in the atrium. Arginine constituted the most abundant amino acid in the ventricular and atrial heart muscle as well. Glutamic acid and alanine were the next most common amino acids and represented 10-18% and 7-10% of the amino acid pools, respectively. After appropriate biotransformation, these amino acids may not only be important substrates for the energy cycles of the heart, but may also play a critical role as stimulators of mitosis and regulators of the synthesis of nucleic acids and proteins.

Amino Acids↗

Free amino acids in bee hive product (propolis) as identified and quantified by gas-liquid chromatography.

Propolis is a natural resinous product collected by honey bees and containing, among other biochemical constituents, a variety of free amino acids. Acid extraction and quantification of these amino acids by gas-liquid chromatography reveals that their total concentration in this honey bee product is over 40% w/w, and that arginine and proline constitutes over 50% of the crude acid extract. As propolis was shown to stimulate mammalian tissue regeneration, we suggest that the physiological significance of arginine in the propolis product lies in its ability to stimulate mitosis and to enhance protein biosynthesis, and that the biochemical importance of proline in it, stems from its capability to promote build-up of collagen and elastin, two essential components in the matrix of connective tissues.

Amino Acids↗