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Biomedical subjects

P Benes

Publications and source records attributed to P Benes.

At least 37 records · Page 2Linked to original sources
PubMed1994

Radiotracer method in the study of environmental speciation and migration of contaminants.

Principles, advantages, and limitations of the use of radiotracer method for the analysis of speciation and migration of contaminants in the environment are briefly discussed. Several recent examples of use in the author's laboratory are given: development of the separation method for methylmercury and inorganic mercury in hair, analysis of the speciation of cadmium in soil solutions, study of the interaction of 137Cs and 58Co with suspended sediments in river water, and determination of input data for mathematical modeling of radiocesium migration in a small river.

Radioactive Pollutants↗
PubMed1990

TNF alpha primes polymorphonuclear leukocytes for an enhanced respiratory burst to a similar extent as bacterial lipopolysaccharide.

We examined whether preincubating polymorphonuclear leukocytes (PMN) with TNF alpha would result in an enhanced respiratory burst upon subsequent stimulation by various agents. Bacterial lipopolysaccharide (LPS), a known primer of PMN, was used as control. We found that both LPS (0.01 to 10.0 microgram/ml) and recombinant TNF alpha (0.001 to 1.0 microgram/ml) act as direct stimulants of PMN as measured by chemiluminescence. Sixty minutes of preincubation of PMN with 1 microgram/ml TNF alpha or 10 micrograms/ml LPS resulted in similar priming for the respiratory burst elicited by opsonized zymosan, phorbol myristate acetate, zymosan, zymosan-activated serum, aggregated immunoglobulin, and f-met-leu-phe (FMLP) depending on the method of measurement used, i.e., chemiluminescence, production of O2-, and H2O2. Priming with TNF alpha for an enhanced response to stimulation by FMLP could be abrogated by anti-TNF alpha antibody. Cell-surface receptor numbers and binding-affinity constants for FMLP remained stable under conditions leading to priming. We conclude that TNF alpha is able to prime PMN for an enhanced respiratory burst to a similar extent as with LPS. Because PMN cell-surface receptors for FMLP are unaltered by priming, the enhanced respiratory burst seems to be due to changes in intracellular metabolism.

Antibodies↗
PubMed1989

[Radius-femoral dysplasia. A new form of hereditary metaphyseal dysplasia].

Höhle and Braun described a new form of hereditary metaphyseal dysplasia. It is characterized by changes in distal metaphyses of femoral bones which are formed as Erlenmeyer flasks, further by club-shaped dysplasias of the metaphyses of the other long bones, absence of skeletal hyperostosis and by characteristic varus-deformations of radial bones. An extensive family history research showed that the oldest carriers of these anomalies came from a small town in northern Bohemia. Completely identical case reports were published describing the carriers of metaphyseal dysplasia characters whose origin was also traced to the same region. The authors aim at drawing attention to this new disease, finding more carriers of metaphyseal dysplasia characters and at giving an impulse to an extensive research into this extremely systemic rare bone disease.

Adult↗
PubMed1989

[The effect of Saponinum album Merck on changes in the hemolytic resistance of erythrocytes in relation to age in healthy persons].

The authors elaborated a method for the assessment of the haemolytic resistance of erythrocytes which tests them from the aspect of resistance of their membranes against the haemolytic action of Saponinum album Merck. The physicochemical principle of this method is quite different from the routine test of osmotic resistance of red cells. By the described method red cells of healthy male and female donors aged 4 to 77 years were evaluated. By means of linear regression a significant relationship (with a confidence of 0.999) was proved between parameter M (saponin concentration producing 50% haemolysis (and age). From the evaluation it is apparent that with advancing age in man the resistance of red cell membranes against saponin action declines. From this and from known findings on the mechanism of saponin haemolysis it may be concluded that red cells of all age groups cannot be considered equal as regards the quality of membranes and that these cells undergo certain changes in the course of the lifetime of the individual.

Adolescent↗
PubMed1989

Persistent skin ulcers, mutilations, and acro-osteolysis in hereditary sensory and autonomic neuropathy with phospholipid excretion. Report of a family.

We observed three children in a Turkish family who from early childhood had deformations of the feet and torpid ulcers with subfocal osteomyelitis and osteolysis, which subsequently led to amputations. The fingers showed ainhumlike constriction bands and spontaneous amputations. Neurologic studies revealed an almost complete sensory and autonomic loss affecting all modalities and a marked involvement of motor fibers. The clinical symptoms fulfill many of the hallmarks of hereditary sensory and autonomic neuropathy type II, including autosomal recessive inheritance, onset of symptoms in childhood, and mutilating acropathy. A high urinary excretion of sphingomyelin and lecithin suggests that the pathogenic mechanism may be a disorder of phospholipid metabolism.

Adult↗
PubMed1987

A macrophage-suppressing 40-kD protein in a case of pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare disease of unknown etiology. Macrophage dysfunctions are claimed to be involved in the pathogenesis. We investigated phagocytosis and oxidative metabolism of alveolar macrophages in a case of pulmonary alveolar proteinosis. These cells phagocytize normally and phagocytizable stimulants cause a normal oxidative burst. In response to the membrane signals phorbolmyristate acetate and aggregated immunoglobulin, however, no stimulated turnover of the oxidative metabolism can be observed. A 40-kD protein found in the lavage fluid mediates this macrophage-inhibiting effect. This phenomenon may contribute to the frequent opportunistic infections seen in PAP patients. It can be concluded from our data that the high frequency of infections with opportunistic species in these patients can be reduced by therapeutic bronchoalveolar lavage. By this procedure the abnormal macrophage-suppressing protein can be washed out of the lung at an early stage of the disease.

Adult↗
PubMed1987

Impaired function of numerically augmented Fc-receptors on granulocytes in a HLA B8+ patient with palmoplantar pustulosis.

We examined granulocytes or polymorphonuclear leukocytes (PMN) in an HLA B8+ patient with palmoplantar pustulosis (PPP). Controls included another patient with PPP, however, lacking this antigen and a healthy, HLA B8+ person. Chemiluminescence (CL) served to monitor the respiratory burst in PMN comparing as stimuli zymosan, opsonized zymosan, phorbol myristate acetate, as well as aggregated immunoglobulin (aggIg), the latter as Fc-receptor (FcR) stimulus. FcR density on PMN was determined using 125I-IgG and expressed in the form of Scatchard plots. The effects of serum on the aggIg-induced CL were also measured. We found both control individuals to respond to stimulation by aggIg as a function of a dose-dependent increase of CL. By contrast, the HLA B8+ patient with PPP failed to respond to aggIg; only the highest concentration of aggIg induced marginal CL. Conversely, stimulation by the other agents was similar in all three individuals. The patient with the functional FcR defect expressed 2.5 times more FcR/PMN than the controls. No difference emerged in comparing autologous serum with a reference normal serum on the aggIg-induced CL, ruling out saturation by serum factors alone to be a cause for the defect. In remission, the functional FcR was absent. Our results suggest a defect of signal transduction in PMN from numerically enhanced FcR to the cytosol in the patient with PPP.

Adult↗
PubMed1986

Augmented glucose-6-phosphate dehydrogenase activity and normal penetration and metabolism of dehydroepiandrosterone in mononuclear leukocytes in psoriasis.

The aim of the study was to determine a biochemical basis for the augmented oxidative metabolism found in mononuclear leukocytes (MNL) of patients with active psoriasis. Dehydroepiandrosterone (DHEA) is known to inhibit glucose-6-phosphate dehydrogenase (G-6-PDH). We determined the activity of G-6-PDH as well as the penetration and metabolism of DHEA - diminished plasma concentrations of which have been found in psoriatics previously - in 16 patients with active psoriasis and 16 controls. MNL in patients with psoriasis possessed 52% more (p less than 0.05) G-6-PDH activity, based on cell number, and 34% more (p less than 0.05) activity, based on soluble protein. No difference in DHEA penetration and metabolism in MNL was found between psoriatics and controls, in contrast with previous findings of reduced penetration and increased reduction in erythrocytes of psoriatics. We conclude that the enhanced G-6-PDH activity in MNL of patients with active psoriasis is not due to altered DHEA penetration or metabolism.

Adult↗
PubMed1986

[Suppression of phagocyte function by seminal plasma: possible predisposition for AIDS].

A pathogenic retrovirus (HTLV-III) has recently been isolated in the seminal plasma (SP) of patients with AIDS. In order to test whether SP may influence non-specific immunity we compared the influence of SP on the phagocytic release of lysozyme, chemotaxis and chemiluminescence. SP inhibited the release of lysozyme from granulocytes in a log-linear fashion; incubation with undiluted SP resulted in about 50% inhibition. Chemotaxis of granulocytes remained stable under the influence of SP. Chemiluminescence of both granulocytes and monocytes was completely blocked by undiluted SP; 1000-fold dilutions still caused an inhibition of about 20%. The separation of SP by column chromatography yielded fractions with a molecular weight of 10(4) to 2 X 10(4), 10(5) to 4 X 10(5) and greater than 10(6) inhibiting chemiluminescence. A cell-free chemiluminescent system showed the reduction of chemiluminescence to be based to a large extent on quenching of the photons generated. Our results indicate that SP possesses potent properties that suppress non-specific immunity, possibly an important predisposing factor to AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1985

[Plasma androgen levels in female acne patients].

In 30 female patients suffering from acne vulgaris and 32 female controls, we determined the plasma levels of androstenedione, testosterone and dihydrotestosterone. The average rates of all three androgens were significantly increased in acne. But only the dihydrotestosterone rate showed a clear separation from the individual values of the two collectives. These findings suggest increased synthesis of dihydrotestosterone within the skin of patients with acne vulgaris.

Acne Vulgaris↗
PubMed1984

Interaction between C1-INA, coagulation, fibrinolysis and kinin system in hereditary angioneurotic edema (HANE) and urticaria.

The C1-inactivator plays an important role not only in the initial phases of the complement system, but also in those of the coagulation, fibrinolysis and kinin systems. The present study was concerned with the reciprocal influence of decreased C1-inactivator levels in patients with hereditary angioneurotic edema (HANE, HAE). In 13 HANE-I patients there were significantly increased levels of the coagulation factors XII, XI, V, of plasminogen and of alpha 2-antiplasmin, while the factors IX and VII were decreased. Conversely, it emerged that in patients with markedly raised prephase factor levels, angioneurotic edema occurred in the presence of normal or only slightly decreased C1-inactivator levels. However, the ratio between factor XI and C1-INA activity was significantly higher than in normal and urticaria patients. Factor XII, HMWK, XI, VIII and V levels were significantly raised in 10 patients with frank chronic urticaria, while factor VII was lowered. Numerous other factors and inhibitors of the coagulation, fibrinolysis and kinin systems were, however, normal or showed no significant differences.

Angioedema↗
PubMed1983

Hereditary angioneurotic oedema and blood-coagulation: interaction between C1-esterase-inhibitor and the activation factors of the proteolytic enzyme systems.

C-1-inactivator (C-1-INA) does not only exert its important inhibitory functions in the complement system but also in the first step in the activation of the coagulation, fibrinolytic and kallikrein system. We therefore determined in nine patients with hereditary angioneurotic oedema (HANE) with obvious quantitative or functional defects of C-1-INA, and one further patient with Quincke-type oedema of different origin, the coagulation factors of the initial phase such as Hageman factor, plasma thromboplastin antecedent (PTA) and high molecular weight kininogen (HMWK). These factors were further correlated with the concentration as well as functional activity of C-1-INA. Nine of ten patients showed a significant, sometimes even excessive, increase in the levels of factor XII (mean +/- SD = 146% +/- 63), HMWK (mean +/- SD = 126% +/- 56) and PTA (mean +/- SD = 289% +/- 294), and a decrease of C1-esterase inhibitor (C-1-inactivator), which was measured with a immunologic method (mean +/- SD = 9.6 mg/dl +/- 6.6) for its concentration as well as being measured for its activity (mean +/- SD = 30.4% +/- 24.9).

Angioedema↗
PubMed1983

Influence of certain stimulation parameters on the character of the cortical self-sustained after-discharge.

The ECoG pattern of self-sustained after-discharges (SSADs) evoked by rhythmic electrical stimulation of the cerebral cortex is far from uniform. In acute experiments on male rats the authors studied the significance of the frequency, intensity and length of stimulation for the character of the resultant SSAD. In the first group (11 rats), a stimulation frequency of 8 Hz was used; the stimulation series, which lasted 10 and 20 s, always led to the formation of a SSAD composed of spike-and-wave rhythm right from the outset. Shortening the time of stimulation markedly reduced its effectiveness. In the second group (10 animals), stimulation with 50 Hz frequency often evoked a complex SSAD starting with desynchronization, which was followed by fast spike activity of increasing amplitude and only later by spike-and-wave rhythm or by polyspike-and-wave rhythm. Towards the end, serrated waves--i.e. graphoelements typical of SSADs evoked by electrical stimulation of limbic structures--often appeared in the SSAD. A higher stimulation intensity increased the incidence of this complex SSAD. In this group a minimum duration of stimulation was also essential (series of less than 2 s were not reliably effective). When this second type of SSAD ended, depression of ECoG activity was followed in 27% of the cases by a spontaneous recurrent seizure (RS). The ECoG character of these RS can be very variable. The two types of seizures evoked by slow and fast stimulation differ from each other not only in respect of their ECoG pattern (where the difference is probably due to more pronounced propagation to subcortical structures after faster stimulation), but also as regards the presumed mechanism of their onset.

Animals↗
PubMed1982

[Improvement in the longitudinal growth in Ullrich-Turner syndrome with oxandrolone. Function of urinary excretion of steroid hormones].

Urinary excretion of steroid hormone metabolites pregnandiol, pregnantriol, aetiocholanolone, dehydroepiandrosterone and androsterone of 20 patients with Turner's syndrome was measured by gas chromatography. In some of the patients urinary excretion did not reach the minimal value obtained in a control group. Sixteen of these patients were given an average daily dose of 0.1 mg oxandrolone/kg body-weight. Mean value for bone age, after an average treatment duration of 17.3 months (s = 9.7), increased by 12.6 months (s = 12.7). Growth rate was 5.9 cm (s = 1.9) per year. Androsterone and dehydroepiandrosterone excretion in patients in whom the chronological age/bone age ratio had worsened, was more than double that in patients in whom it had improved. Measurement of the urinary excretion of dehydroepiandrosterone and androsterone thus seems to be of prognostic value in the treatment of Turner's syndrome with androgens.

Adolescent↗