Chemical cannibalistic cues make damselfly larvae hide rather than hunt.

Adopting cannibalism substantially affects individual fitness, and recognizing the presence of other cannibals provides additional benefits such as the opportunity to prepare for hunting or defense. This recognition can be facilitated by perceiving conspecific chemical cues. Their role in cannibalistic interactions is less studied than in interspecific predation and it is unclear whether these cues inform individuals of danger or of food availability. Interpretation of these cues is crucial to balance the costs and benefits of anti-predator and feeding strategies, which can directly influence individual fitness. In this study we aimed to test whether damselfly larvae shift towards bolder and more exploratory (cannibalistic) behavior, or become more careful to avoid potential cannibals (as prey) in response to such cues. We conducted behavioral and respiratory experiments with Ischnura elegans larvae to investigate their response to chemical cues from older and larger conspecific larvae. We found that I. elegans larvae decrease their activity and shift their respiratory-related behavior, indicating activation of anti-predator defense mechanisms in response to conspecific chemical cues. Our findings indicate that individuals exposed to conspecific chemical cues balance catching prey with staying safe.

Photosynthetic activity in both algae and cyanobacteria changes in response to cues of predation.

A plethora of adaptive responses to predation has been described in microscopic aquatic producers. Although the energetic costs of these responses are expected, with their consequences going far beyond an individual, their underlying molecular and metabolic mechanisms are not fully known. One, so far hardly considered, is if and how the photosynthetic efficiency of phytoplankton might change in response to the predation cues. Our main aim was to identify such responses in phytoplankton and to detect if they are taxon-specific. We exposed seven algae and seven cyanobacteria species to the chemical cues of an efficient consumer, Daphnia magna, which was fed either a green alga, Acutodesmus obliquus, or a cyanobacterium, Synechococcus elongatus (kairomone and alarm cues), or was not fed (kairomone alone). In most algal and cyanobacterial species studied, the quantum yield of photosystem II increased in response to predator fed cyanobacterium, whereas in most of these species the yield did not change in response to predator fed alga. Also, cyanobacteria tended not to respond to a non-feeding predator. The modal qualitative responses of the electron transport rate were similar to those of the quantum yield. To our best knowledge, the results presented here are the broadest scan of photosystem II responses in the predation context so far.

Uterine Development During Induced Puberty in Girls with Turner Syndrome.

Objective: Most girls and women with Turner syndrome (TS) require estrogen replacement therapy (ERT) to initiate or maintain pubertal development. Most likely, the most fundamental effect of ERT in hypogonadism is the promotion of uterine growth. The optimal ERT model is still being discussed. The present study aimed to assess uterine size in girls with TS in the prepubertal state during and after the induction of puberty and compare it to a healthy population. Methods: The analysis encompassed 40 TS girls. The prepubertal and postpubertal control groups contained 20 healthy girls each. All patients with TS were treated with 17-ß estradiol. Uterine imaging was performed with two-dimensional (2D) transabdominal ultrasound. The uterine volume (UV) and fundocervical antero-posterior ratio (FCR) were calculated in patients with TS before the pubertal induction, after 6-12 months of estrogen replacement therapy (ERT), after ≥ 36 months of ERT or ≥ 12 months after menarche. Results: The average age of TS patients at estrogen introduction and at the last control visit, when the uterus was considered mature, was 12.9 years and 16.1 years, respectively. The UV in patients with TS at the beginning of ERT was 1.55 ± 1.22 cm3 and was not significantly different from the UV in the prepubertal controls. The mature UV in patients with TS was 31.04 ± 11.78 cm3 and was significantly smaller than the UV of the postpubertal controls (45.68 ± 12.51 cm3, p<0.001). The FCR in girls with TS did not differ significantly from that in the prepubertal and postpubertal control groups, respectively. No prognostic factors could be established for the final UV. By the last control visit, thelarche had advanced in most patients to Tanner 4 and 5 (37.5% and 40%, respectively). Conclusions: Before the onset of ERT, patients with TS have a uterus similar in size to that in prepubertal healthy girls. Pubertal induction in patients with TS causes a significant increase in the UV that is detectable after 6-12 months of ERT. The mature uterus is smaller in patients with TS than in the age-matched healthy population.

Effects of Recombinant Human Growth Hormone Treatment, Depending on the Therapy Start in Different Nutritional Phases in Paediatric Patients with Prader-Willi Syndrome: A Polish Multicentre Study.

Recombinant human growth hormone (rhGH) treatment is an established management in patients with Prader-Willi syndrome (PWS), with growth promotion and improvement in body composition and possibly the metabolic state. We compared anthropometric characteristics, insulin-like growth factor 1 (IGF1) levels, metabolic parameters and the bone age/chronological age index (BA/CA) in 147 children with PWS, divided according to age of rhGH start into four groups, corresponding to nutritional phases in PWS. We analysed four time points: baseline, rhGH1 (1.21 ± 0.81 years), rhGH2 (3.77 ± 2.17 years) and rhGH3 (6.50 ± 2.92 years). There were no major differences regarding height SDS between the groups, with a higher growth velocity (GV) (p = 0.00) and lower body mass index (BMI) SDS (p < 0.05) between the first and older groups during almost the whole follow-up. IGF1 SDS values were lower in group 1 vs. other groups at rhGH1 and vs. groups 2 and 3 at rhGH2 (p < 0.05). Glucose metabolism parameters were favourable in groups 1 and 2, and the lipid profile was comparable in all groups. BA/CA was similar between the older groups. rhGH therapy was most effective in the youngest patients, before the nutritional phase of increased appetite. We did not observe worsening of metabolic parameters or BA/CA advancement in older patients during a comparable time of rhGH therapy.

Correlation of Genotype and Perinatal Period, Time of Diagnosis and Anthropometric Data before Commencement of Recombinant Human Growth Hormone Treatment in Polish Patients with Prader-Willi Syndrome.

Genotype-phenotype correlation in patients with Prader-Willi syndrome (PWS) has still not been fully described. We retrospectively analysed data of 147 patients and compared groups according to genetic diagnosis: paternal deletion of chromosome 15q11-q13 (DEL 15, n = 81), maternal uniparental disomy (UPD 15, n = 10), excluded DEL 15 (UPD 15 or imprinting centre defect, UPD/ID, n = 30). Group DEL 15 had an earlier genetic diagnosis and recombinant human growth hormone (rhGH) start (p = 0.00), with a higher insulin-like growth factor 1 (IGF1) level compared to group UPD/ID (p = 0.04). Among perinatal characteristics, there was only a tendency towards lower birth weight SDS in group UPD 15 (p = 0.06). We also compared data at rhGH start in relation to genetic diagnosis age-group 1: age ≤9 months, group 2: >9 months ≤ 2 years, group 3: > 2 years. Group 1 had the earliest rhGH start (p = 0.00), with lower body mass index (BMI) SDS (p = 0.00) and a tendency towards a higher IGF1 level compared to group 3 (p = 0.05). Genetic background in children with PWS is related to time of diagnosis and rhGH start, with a difference in IGF1 level before the therapy, but it seems to have little impact on perinatal data. Early genetic diagnosis leads to early rhGH treatment with favourable lower BMI SDS.

SEMA3A and IGSF10 Are Novel Contributors to Combined Pituitary Hormone Deficiency (CPHD).

Background: The mutation frequencies of pituitary transcription factors genes in patients with combined pituitary hormone deficiencies (CPHD) vary substantially between populations. However, apart from PROP1 the mutation rate of other genes is low and for almost half of the patients with CPHD the routine sequencing of known genes is unsuccessful in the identification of genetic causes. Methods: A cohort of 66 sporadic and nine familial CPHD cases (80 patients in total) were subjected to initial testing of the genes PROP1, POU1F1, LHX3, LHX4, and HESX1 using a targeted gene panel and MLPA. In patients who tested negative, a whole exome sequencing approach was employed. Results: In nine of the familial cases and 32 of the sporadic patients mutations in the PROP1 gene were found (the common pathogenic variants included c.301_302delAG and c.150delA). Mutations were also found in genes so far not related directly to CPHD. A unique homozygous and clinically relevant variant was identified in the SEMA3A gene, which may contribute to neural development and his phenotypic spectrum including short stature and isolated hypogonadotropic hypogonadism (IHH). Another pathogenic variant p.A1672T was found in the IGSF10 gene reported to be responsible for delayed puberty and neuronal migration during embryogenesis. Several suspected novel but predicted benign variants were also identified for the CHD7, WDR11 and FGF17 genes. Conclusion: Although PROP1 defects account for a majority of CPHD patients, identification of rare, less frequent variants constitutes a big challenge. Multiple genetic factors responsible for CPHD are still awaiting discovery and therefore the usage of efficient genomic tools (i.e., whole exome sequencing) will further broaden our knowledge regarding pituitary development and function.

Phenotypic plasticity of senescence in Daphnia under predation impact: no ageing acceleration when the perceived risk decreases with age.

Recognising the nature of the predation risk, and responding to it accurately, is crucial to fitness. Yet, even the most accurate adaptive responses to predation risk usually entail costs, both immediate and lifelong. Rooting in life-history theory, we hypothesize that an animal can perceive the nuances of prey size and age selectivity by the predator and modulate its life history accordingly. We test the prediction that-contrary to the faster or earlier senescence under predation risk that increases with prey size and age-under predation risk that decreases with prey size and age either no senescence acceleration or even its deceleration is to be observed. We use two species of indeterminate growers, small crustaceans of the genus Daphnia, Daphnia Pulex and Daphnia magna, as the model prey, and their respective gape-limited invertebrate predators, a dipteran, midge larva Chaoborus flavicans, and a notostracan, tadpole shrimp Triops cancriformis. We analyse age-specific survival, mortality and fertility rates, and find no senescence acceleration, as predicted. With this study, we complete the picture of the expected non-consumptive phenotypic effects of perceived predation pressure of different age-dependence patterns.

When males outlive females: Sex-specific effects of temperature on lifespan in a cyclic parthenogen.

Lifespans of males and females frequently differ as a consequence of different life history strategies adopted to maximize fitness. It is well visible in cyclic parthenogens, such as water fleas of the genus Daphnia, where males appear in the population usually only for periods when receptive females are available. Moreover, even within one sex, different life history strategies and mechanisms regulating lifespan may exist. Previous studies suggested that Daphnia males may regulate their lifespan by staying in colder waters than females. We hypothesize that such behavioral mechanism should be associated with stronger reaction to low temperature-that is greater lifespan extension in males than in females. In this study, we monitored survivorship of Daphnia magna females and males of three clonal lines cultured at 16 or 20°C. The results did not provide a species-level corroboration of our hypothesis; instead, they revealed very strong intraspecific differences in the responses of male and female lifespan to temperature change. They further suggest the existence of parallel life history strategies, hypothesis whose tests would bring new insights into the ecology of males in cyclic parthenogens.

The Usefulness of Magnetic Resonance Imaging of the Cardiovascular System in the Diagnostic Work-Up of Patients With Turner Syndrome.

Cardiovascular defects occur in 50% of patients with Turner syndrome (TS). The aim of the study was to estimate the usefulness of cardiac magnetic resonance imaging (CMR) and magnetic resonance angiography (angio-MR) as diagnostics in children and adolescents with TS. Forty-one females with TS, aged 13.9 ± 2.2 years, were studied. CMR was performed in 39 patients and angio-MR in 36. Echocardiography was performed in all patients. The most frequent anomalies diagnosed on CMR and angio-MR were as follows: elongation of the ascending aorta (AA) and aortic arch, present in 16 patients (45.7%), a bicuspid aortic valve (BAV), present in 16 patients (41.0%), and partial anomalous pulmonary venous return (PAPVR), present in six patients (17.1%). Aortic dilatation (Z-score > 2) was mostly seen at the sinotubular junction (STJ) (15 patients; 42.8%), the AA (15 patients; 42.8%), the thoracoabdominal aorta at the level of a diaphragm (15 patients; 42.8%), and the transverse segment (14 patients; 40.0%). An aortic size index (ASI) above 2.0 cm/m2 was present in six patients (17.1%) and above 2.5 cm/m2 in three patients (8.6%). The left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) were diminished (Z-score < -2) in 10 (25.6%), 9 (23.1%), and 8 patients (20.5%), respectively. A webbed neck was correlated with the presence of vascular anomalies (p = 0.006). The age and body mass index (BMI) were correlated with the diameter of the aorta. Patients with BAV had a greater aortic diameter at the ascending aorta (AA) segment (p = 0.026) than other patients. ASI was correlated with aortic diameter and descending aortic diameter (AD/DD) ratio (p = 0.002; r = 0.49). There was a significant correlation between the right ventricular (p = 0.002, r = 0.46) and aortic diameters at the STJ segment (p = 0.0047, r = 0.48), as measured by echocardiography and CMR. Magnetic resonance can identify cardiovascular anomalies, dilatation of the aorta, pericardial fluid, and functional impairment of the ventricles not detected by echocardiography. BMI, age, BAV, and elongation of the AA influence aortic dilatation. The ASI and AD/DD ratio are important markers of aortic dilatation. The performed diagnostics did not indicate a negative influence of GH treatment on the cardiovascular system.

Molecular Detection and Incidence of Y Chromosomal Material in Patients with Turner Syndrome.

The presence of a Y chromosome in patients with Turner syndrome (TS) is a risk factor for the development of gonadal tumor and/or virilization. With conventional cytogenetic analysis, some cells containing a Y chromosome can be missed. The aim of this study was to determine the presence and incidence of Y chromosome-derived material in TS patients using PCR and the markers SRY, DYZ1, DYZ3, DYS132, ZFY, and TSPY. Fifty-five TS patients (aged 5.5-26.75 years) were analyzed. A total of 17/55 (30.9%) were Y-positive, but only 7/17 had a Y chromosome in their karyotype and underwent gonadectomy. In 2 of these patients (28.6%), histopathologic examination revealed gonadoblastoma and dysgerminoma, respectively. In 8 patients in the studied group (8/55; 14.5%), the TSPY gene was detected, and the SRY gene (or a fragment) was identified in 9(3)/55 patients. No coding region mutations were observed in these SRY-positive patients. In conclusion, we have shown a high prevalence of Y chromosomal material in TS. Y markers were also observed in patients who had no Y chromosome in their karyotype, and PCR is very precise in detecting the presence of genetic material from the Y chromosome. Further follow-up of these Y-positive TS patients is mandatory.

Pituitary Microsomal Autoantibodies in Patients with Childhood-Onset Combined Pituitary Hormone Deficiency: an Antigen Identification Attempt.

The role of autoimmunization in the pathogenesis of pituitary disorders is poorly understood. The presence of pituitary autoantibodies (APA) has been detected in various pituitary disorders. Their role, however, remains elusive. Childhood-onset combined pituitary hormone deficiency (CPHD) may be caused by environmental or genetic factors. In some of patients, causes of the disease remain unclear and contributions of autoimmune processes have been postulated. The aim of this study was to identify the microsomes-derived pituitary antigens (MPA) as potential immunogenic autoantigens in patients with hypopituitarism, therefore 62 CPHD patients, 100 healthy controls and five autoimmune polyglandular syndrome type II (APS II) patients were included in the study. The clinical evaluation included hormonal tests and magnetic resonance imaging of the pituitary. The sources of MPA were pituitary glands taken from autopsies. Isolated MPA were then separated on SDS-PAGE gel and incubated with sera obtained from patients and controls. Microsomal APA were detected using Western blot and radioimmunological method. In all CPHD and APS II patients and in 9 % individuals from control group marked immunoreactivity was detected against MPA. Antibodies showed high affinity to 67, 60, 50 and 36 kDa MPAs. Since the identified autoantigens were of unknown nature, an in silico exploration of UniProt database was applied and indicated their possible relationship with chaperones, golgins and already known autoantigens like GAD67. Reactivity against MPA indicates that these proteins certainly play a role in the processes undergoing within pituitary of CPHD patients. The identification and further detailed studies on their role in the pathogenesis of CPHD should be continued.

How perceived predation risk shapes patterns of aging in water fleas.

Predation is an important selection pressure which shapes aging patterns in natural populations, and it is also a significant factor in the life history decisions of individuals. Exposure to the perceived threat of size-dependent fish predation has been shown to trigger adaptive responses in animal life history including an increase in early reproductive output. In water fleas, this response to perceived predation risk appears to have a cost, as a lifespan in an environment free of predation cues is 20% longer. The aim of this study is to establish the biodemographic basis of phenotypic differences in the water flea lifespan which are induced by the cues of fish predation. We examined mortality by fitting the Gompertz-Makeham model of mortality to large cohorts of two cladoceran species, Daphnia longispina and Diaphanosoma brachyurum. Our findings indicate that perceived exposure to the threat of fish predation (induced through chemical cues) only accelerated the rate of aging in Diaphanosoma, and not in Daphnia where the treatment led to an earlier onset of aging. The second of these two phenotypic responses is consistent with the genetically based differences between Daphnia from habitats that differ with respect to predation risk. In contrast, the response of Diaphanosoma demonstrates that the cue of extrinsic mortality-in this case, fish predation-is a key factor in shaping these cladoceran life histories in the wild, and is one of the few interventions which has been shown to induce a plastic change in the rate of aging.

The clinical role of serum concentrations of selected cytokines: IL-1ß, TNF-α and IL-6 in diagnosis of autoimmune thyroid disease (AITD) in children.

Chronic autoimmune thyroiditis (cAIT) leads to hypothyroidism due to T cell-mediated cytotoxicity in most cases. By contrast, Graves' disease (GD) with thyrotropin receptor stimulatory autoantibodies cause hyperthyroidism. Cytokines play a crucial role in modulating immune response in both disorders. The aim of study was to evaluate the concentrations of cytokines: IL-1ß, TNF-α and IL-6 in these two opposite clinical and hormonal thyroid diseases. The study group consisted of 64 children, 44 newly diagnosed, untreated children with cAIT (n = 22; with hypothyroidism) and GD (n = 22; hyperthyroidism), and the control group of 20 healthy children. Cytokine concentrations were evaluated using the ELISA technique. The studied groups of children did not differ significantly in concentrations of IL-6 (p = 0.48) and TNF-α (p = 0.067). In children with hypothyroidism, we found significantly higher concentrations of IL-1ß (median 2.16 pg/ml, IQR 0.87) compared to hyperthyroidism (median 1.39 pg/l, IQR 1.27) (p < 0.01) and the control group (median 1.88 pg/ml, IQR 1.04) (p < 0.05). The results of ROC curve analysis demonstrated the usefulness of IL-1ß (AUC = 0.77, p = 0.003) and TNF-α (AUC = 0.691, p = 0.034) as diagnostic parameters in cAIT which enable discrimination of children with autoimmune thyroid disease from healthy individuals. Concentrations of these markers are increased in autoimmune hypothyroidism. We found no significant sex differences in the tested parameters. In conclusion, IL-1ß and TNF-α may be considered as markers of hypothyroidism, and could efficiently discriminate between healthy and autoimmune hypothyroid children. Significantly higher concentrations of IL-1ß in children with hypothyroidism may be used to distinguish children with cAIT from GD patients.

Influence of silybin on biophysical properties of phospholipid bilayers.

AIM: Silybin (silibinin) is major biologically active flavonolignan extracted from milk thistle (Sylibum marianum). Its biological activities include hepato-protection, anticancer properties, and antioxidant- and membrane-stabilizing functions. Although membranes are postulated to be one of the cellular targets for silybin, little is known about its interaction with phospholipid bilayers. METHODS: In the present work, the interactions of silybin with phosphatidylcholine bilayers were studied in detail using fluorescence spectroscopy, microcalorimetry and electron spin resonance techniques. RESULTS: The results showed that silybin interacted with the surface of lipid bilayers. It affected the generalized polarization of the fluorescent probe Prodan, while not influencing the more deeply located Laurdan. Silybin lowered the main phospholipid phase transition temperature as judged by microcalorimetry, and caused the immobilization of spin probe Tempo-palmitate located on the surface of membranes. The mobility of spin probes 5- and 16-doxyl stearic acid was not affected by silybin. Silybin-induced quenching of 1,6-diphenyl-1,3,5-hexatriene fluorescence indicated that some flavonoid molecules partitioned into the hydrophobic region of membranes, which did not change significantly the biophysical properties of the deeper membrane regions. CONCLUSION: Such a behavior of silybin in membranes is in accordance with its postulated biological functions and neglectable side effects of therapies using silybin.

[Estimation of growth hormone secretion during sleep as a screening test in the diagnosis of GH deficiency]. / Ocena wydzielania hormonu wzrostu po zasnieciu jako badanie przesiewowe w diagnostyce somatotropinowej niedoczynnosci przysadki.

BACKGROUND: Because of many disadvantages of growth hormone (GH) stimulation tests the diagnosis of growth hormone deficiency (GHD) is still problematic for the clinician. THE AIM of the study was the estimation of diagnostic usefulness of the GH provocation tests and basal IGF-I concentration measurement in the diagnosis of GHD. MATERIAL AND METHODS: The study group consisted of 180 children with short stature diagnosed in the Department of Pediatric Endocrinology and Diabetes in the years 1998-2003. Pharmacological stimulation test with insulin, clonidine, glucagon and L-dopa were used. GH concentration in physiological test after the onset of sleep was also measured. In 60 patients IGF-I concentration was estimated. For statistical analysis Spearman test was used. RESULTS: The highest mean GH concentrations (19.18 microl U/ml) and GH peaks (26.39 microl U/ml) were observed in sleep test. IGF-I concentration was correlated with GH concentration levels in physiological test after onset of sleep (r=0.4; p<0.05). CONCLUSIONS: Sleep is the strongest stimulatory agent for GH secretion. The estimation of GH secretion after the onset of sleep can be used as a screening test in the diagnosis of GHD. Because of many diagnostic problems in estimation of pituitary function the auxologic parameters should be considered as the most important part in the diagnostic work-up of children with short stature due to GHD.

The effects of growth hormone treatment in patients with somatotropin deficiency during their developmental age.

INTRODUCTION: In Poland treatment with growth hormone of adolescent patients dates back to 1964. Till 1993 the therapy was conducted in an interrupted manner, depending on the periodic availability of the drug. The data form such forms of therapy suggested that the end height within 3rd centile was achieved only by a portion of treated patients. Since 1995 the growth hormone is used in continuous therapy, which allows to sum up the effects of the therapy, including the growth rate and end height. MATERIAL AND METHODS: A total of 117 children and adolescent of both sexes, aged 4.6 to 18.1 years, with diagnosed somatotropic or multihormonal pituitary insufficiency were included in the study. All of them were treated with growth hormone and had an analysis of growth rate and end height. RESULTS: In the first 6 months of growth hormone treatment the growth rate achieved 10.4 cm/year in boys and 10.0 in girls and showed no correlation with maturation status. In the second half of the year the growth rate declined slightly. During the remainder of the therapy the growth rate markedly declined, and this effect was most notable in girls. In 93% of patients after the end of therapy the final height was no different than the expected height. CONCLUSIONS: 1. The growth rate in first half a year of the treatment was 3 times higher than before the beginning of therapy. 2. In the second half of the first year the growth rate slightly declined. 3. In following years the growth rate declined notably. 4. The final achieved height in most of the patients does not differ from the prognosed height.

Modulation of MRP1 protein transport by plant, and synthetically modified flavonoids.

The influence of novel synthetic and plant origin flavonoids on activity of multidrug resistance-associated protein (MRP1) was investigated in human erythrocytes used as a cell model expressing MRP1 in plasma membrane. The fluorescent probe, BCPCF (2', 7'-bis-(3-carboxy-propyl)-5-(and-6)-carboxyfluorescein), was applied as a substrate for MRP1 multidrug resistance transporter. The effect of compounds belonging to different classes of natural flavonoids: flavone, flavonol, isoflavones and flavanolignan was compared with action of new synthetic derivatives of genistein. Most of the flavonoids showed strong or moderate ability to inhibit transport carried out by MRP1. Inhibitory properties of flavonoids were compared to the effects of indomethacin, probenecid and MK-571 known as MRP1 inhibitors. Studying the influence of new synthetic genistein derivatives on BCPCF transport we have found that the presence of hydrophobic groups substituting hydrogen of hydroxyl group at the position 4' in ring B of isoflavone is more important for inhibitory properties than hydrophobic substitution at the position 7 in ring A. In case of naturally occurring isoflavones the replacement of hydrogen at position 4' by hydrophobic ring structure seems also to be favourable for inhibition potency.

Metabolic O-demethylation does not alter the influence of isoflavones on the biophysical properties of membranes and MRP1-like protein transport activity.

Multidrug resistance transporter MRP1 could be effectively inhibited by some flavonoids. The influence of the two pairs of isoflavones: formononetin/daidzein and biochanin A/genistein on the efflux of fluorescent substrate of MRP1-like protein from erythrocytes and biophysical properties of lipid membranes has been compared. Compounds in each pair differ by the substituent in position 4' of B ring of isoflavone molecule. In the process of O-demethylation, CH(3) group (present in formonetin and biochanin A) is replaced by hydrogen (daidzein, genistein). Inhibition of MRP1-like protein transport activity by methylated and demethylated isoflavones was very similar. Their influence on lipid thermotropic properties and fluidity of lipid bilayer was not also significantly different.