Neuro Endocrinology Letters

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Isolation and partial characterization of catechol 1,2-dioxygenase of phenol degrading yeast Candida tropicalis
  • Article

December 2009


76 Reads

Lenka Vilimkova



Zuzana Koubkova




Candida tropicalis yeast is a microorganism that possesses high tolerance for phenol and shows strong phenol degrading activity. This yeast is capable of utilizing phenol as the sole carbon and energy source. While the enzyme participating on the first step of phenol biodegradation, NADPH-dependent phenol hydroxylase, has already been characterized, information on the enzyme participating in the second step of its degradation, catechol 1,2-dioxygenase, is scarce. The development of the procedure suitable for catechol 1,2-dioxygenase isolation and partial characterization of this enzyme are the aims of this study. Combination of chromatography on DEAE-Sepharose and gel-permeation chromatography on Sephadex G-100 was used for isolation of cytosolic catechol 1,2-dioxygenase from C. tropicalis yeast. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel chromatography on Sephadex G-100 were used to evaluate the molecular mass of the enzyme. The enzyme activity was followed by HPLC (catechol consumption and/or cis,cis-muconic acid formation). Using the isolation procedure consisting of chromatography and re-chromatography on a column of DEAE-Sepharose and gel filtration on Sephadex G-100, catechol 1,2-dioxygenase was purified from C. tropicalis cytosol to homogeneity. Catechol 1,2-dioxygenase was found to be a homodimer with a subunit molecular mass of 30000 +/- 5000. The enzyme oxidized catechol producing cis,cis-muconic acid. The optimal temperature and pH were 30 degrees C and 7.7, respectively. The data are the first report showing the isolation of eukaryotic catechol 1,2-dioxygenase from C. tropicalis to homogeneity and its partial characterization.

Hyper-betalipoproteinemia LDL 1,2: A newly identified nonatherogenic hypercholesterolemia in a group of hypercholesterolemic subjects

January 2011


136 Reads

The identification of a non-atherogenic and an atherogenic lipoprotein profile, non-athero phenotype A vs. athero phenotype B, in a group of hypercholesterolemic subjects reveals newly discovered non-atherogenic hypercholesterolemia. Individuals with this type of hypercholesterolemia, or hyper-betalipoproteinemia LDL1,2, are probably not at increased risk to develop a premature atherothrombosis or a sudden cardiovascular event. Examined individuals with hyper-betalipoproteinemia LDL1,2 were divided into two subgroups: individuals under 40 years of age, and older individuals between 46 and 71 years of age. Subjects in the under 40 years of age group did not have any apparent clinical or laboratory-proven impairment of the cardiovascular system. The older subjects with hyper-betalipoproteinemia and a non-atherogenic lipoprotein profile had only mild signs of clinically irrelevant aortic valve sclerosis. A quantitative analysis of the lipoprotein spectrum in plasma in a group of hypercholesterolemic subjects was performed. An innovative electrophoresis method on polyacrylamide gel (PAG) was used for the analysis of plasma lipoproteins and for the identification of atherogenic vs. non-atherogenic lipoproteins in plasma. With regard to lipids, total cholesterol and triglycerides in plasma were analyzed with an enzymatic CHOD PAP method (Roche Diagnostics, FRG). A new parameter, the score for anti-atherogenic Risk (SAAR), was calculated as the ratio between non-atherogenic to atherogenic plasma lipoproteins in the examined subjects. There was a high concentration of LDL1, and LDL2 subfractions (p<0.0001), and an extremely low concentration of LDL3-7 (p<0.0001) in the non-atherogenic lipoprotein profile of hyper-betalipoproteinemia LDL1,2 compared to the control group. Higher concentrations (p<0.0001) of lipids and lipoproteins in the non-atherogenic hypercholesterolemia, compared to the control group, were also found. The hyper-betalipoproteinemia LDL1,2 was also characterized by high SAAR values. There was found a higher concentration of HDL large and HDL intermediate subfractions in hypercholesterolemic subjects. The advantages of this new diagnostic method include: (i) identification of the existence of a non-atherogenic hyper-betalipoproteinemia LDL1,2 in examined hypercholesterolemic subjects with untreated hypercholesterolemia (ii) introduction of a new risk measure, the score for anti-atherogenic risk (SAAR), for the estimation of atherogenic/anti-atherogenic risk. (iii) the presence of small dense LDL in plasma is decisive for the declaration of an atherogenic lipoprotein profile. It is valid for hyperlipidemia and for normolipidemia as well.

Fig. 2. The diurnal changes of 5-HIAA (ng/mg protein) in the SCN, PA and ME of hypothalamus in control rats and after morning (11 a.m.) and evening (11 p.m.) administration of DM(n=6-10). X-axis-time (hr). ¨-the points repeating the control values at given hours. 
Disturbances of diurnal rhythms of biogenic amines contents in hypothalamic nuclei as an evidence of neurotropic effects of enterotropic carcinogen 1,2-dimethylhydrazine
  • Article
  • Full-text available

September 2001


57 Reads

Our data on the contents of norepinephrine (NE), dopamine (DA) and the metabolite of serotonin 5-hydroxyindoleacetic acid (5-HIAA) measured in the suprachiasmatic nuclei (SCN), preoptic area (PA) and median eminence (ME) of hypothalamus of rats after single subcutaneous injection of 1,2-dimethylhydrazine (DMH) as well as the effect of this carcinogen on formation of reactive oxygen species (ROS) in the PA are presented in this paper. Diurnal changes of DA in all studied brain structures and of NE in the PA have been observed in the control group. Their morning levels were higher than evening ones. Rhythms of 5-HIAA in the SCN and diurnal changes of ROS formation have been shown to have contrary changes in control. Both the morning (11 a.m.) and evening (11 p.m.) subcutaneous administration of DMH at the dose of 21 mg/kg of body weight resulted in changes of all rhythms observed in control. In some cases a phase shift was found, in others the rhythms of neurotransmitters and ROS formation disappeared entirely. The data obtained confirm the idea of dopaminergic and serotoninergic systems taking part in mechanisms of a response of the hypothalamic nuclei to non-photic stimuli. It is suggested that the effect of DMH on the content and diurnal rhythms of neurotransmitters in the hypothalamic structures under study is due to its affecting activities of the enzymes of biogenic amines synthesis, synaptic transmission, melatonin synthesis and secretion rhythms. The change in ROS formation that is caused by administration of DMH is likely to be due to a disturbance of diurnal rhythms of neurotransmitters that are one of the sources of formation of free radicals in the brain.

Fig. 1. The examples of spontaneously active pineal cells: A—multicellular activity; B—"slow" type cell in intact rat (regular spikes); C—"fast" type cell in colon tumor-bearing rat (regular spikes); D—"slow" type patterns in colon tumor-bearing rat cell. 
Fig. 2. Spontaneously active pineal cells frequency comparison in intact and colon tumor-bearing rats. 
Fig. 3. The ratio of different cell types in intact and colon tumor-bearing rats
Fig. 4. The group of 4 interacting pineal cells in colon tumor- 
Daytime pineal gland activation in rats with colon tumors induced by 1,2-dimethylhydrazine

February 2000


69 Reads

OBJECTIVES: Intact rats and rats with 1,2-dimethylhydrazine induced tumors of large intestine were used in experiments. Previously, blood melatonin concentration in these tumor-bearing rats was shown to increase at night, but not in the daytime. METHODS: The extracellular microelectrode registration of rat daytime pineal gland activity was performed. RESULTS: The existence of different types of pinealocytes in the pineal gland was confirmed. Tumor-bearing rats, in comparison to intact, demonstrated higher spike frequency due to cells switching from regular to pattern (4-6 times gain) activity and appearance of "fast" cells (>5Hz frequency). CONSLUSIONS: The literature about pinealocytes points to the correlation between electrical and secretory processes in pinealocytes; thus we suppose the groups of interacting cells, detected in tumor-bearing rats, to reflect cascade cells activation while pineal gland secretion increases. The results indicate, that in the daytime pinealocytes are secreting substances (not melatonin) in dependence with hormonal background.

Effect of β-1.3/1.6-D-glucan derived from oyster mushroom Pleurotus ostreatus on biomedical, haematological, biochemical, and immunological indices in rainbow trout (Oncorhynchus mykiss)

December 2012


172 Reads

Objectives: Effect of long-term oral administration of three different concentrations (0.5, 1.0, and 2.0%) of micronized β-1.3/1.6-D-glucan derived from oyster mushroom (Pleurotus ostreatus, Hiratake) on biometrical, haematological, biochemical, and immunological indices of half-year-old rainbow trout (Oncorhynchus mykiss) was assessed in the study. Design: Rainbow trout were feed commercial feed pellets containing β-1.3/1.6-D-glucan in the concentrations of 0.5, 1.0, and 2.0% for 85 days. Biometrical indices consisted in total and standard length, body and liver weight, from which derived somatic parameters such as Fulton´s condition factor and hepatosomatic index were calculated. Haematological parameters were evaluated according to unified methods for haematological examination in fish. Plasma biochemical profile was analysed using biochemical analyser Konelab 20i and Easy Lyte Analyzer. A phagocyte cells metabolic activity (induced chemiluminescence of phagocytes) was determined as an immunological parameter by a microplate luminometric method on Immunotech LM-01T. Results: No clinical signs of behavioral, respiratory, or neurologic distress were observed in rainbow trout. Fish showed normal feeding behavior. As for biometric parameters, no significant changes in total and standard length, body weight, liver weight, as well as in condition factor and hepatosomatic index of experimental and control fish were found. In the course of the study, weight gains in rainbow trout were similar and continuous. Shifts in PCV (p<0.05), haemoglobin (p<0.05), and MCHC (p<0.01) were found within haematological indices. Plasma concentration of glucose, lactate, total protein, cholesterol, calcium, natrium, potassium (all p<0.05), albumins and chlorides (both p<0.01), as well as catalytic activities of ALT and AST (both p<0.05) were changed in the course of the study. A phagocyte cells metabolic activity (luminol-induced chemiluminescence) in rainbow trout was not altered by oyster mushroom β-1.3/1.6-D-glucan administration. Conclusion: After long-term oral administration of three concentrations of micronized β-1.3/1.6-D-glucan derived from oyster mushroom (Pleurotus ostreatus, Hiratake) shifts in haematological and biochemical profiling were found in half-year-old rainbow trout (O. mykiss) in environmental conditions of a commercial rainbow trout fishery. Biometrical indices were not found significantly altered. No specific effect of β-glucan on immune system response of rainbow trout was found in the study. The use of β-glucan in prosperous, clinically healthy aquaculture is still an issue, nevertheless, its use in breedings endangered by stress stimuli, infectious diseases or adverse environmental factors is indisputable.

Table 3 . Effect of Forbush Decrease (FD) in cosmic ray intensity on mortality from myocardial infarction (MI) in Minnesota* 
Cross-spectrally coherent ~10.5- and 21-year biological and physical cycles, magnetic storms and myocardial infarctions*

February 2000


414 Reads

Magnetic storms trigger myocardial infarctions with mechanisms relating to heart rate variability. Solar cycle-to-solar cycle differences and solar cycle stage dependence shown herein may resolve prior controversy and serve to advocate coordinated worldwide systematically aligned biological and physical monitoring. * This paper was originally invited by the historian-geophysicist Wilfried SCHRöDER of Bremen, Germany, for his biographical "Encounters," and is to serve as an update on the project on the BIOsphere and the Cosmos (BIOCOS) and its offspring ICEHRV (Dr. Kuniaki Otsuka's International Chronome Ecologic Study of Heart Rate Variability). It is intended for distribution at a NATO conference on space weather hazards, organized by Dr. Ioannis Daglis, June 18-29, 2000.

The diagnostic utility of S-100B protein and TPA in patients with ischemic stroke

November 2007


45 Reads

The aim of the study is to asses blood plasma concentrations of S-100B protein and Tissue Polypeptide Antigen (TPA) in patients with confirmed ischemic stroke and to correlate these concentrations with stroke severity. S-100B protein and TPA blood plasma concentrations were determined in 47 patients with acute ischemic infarction and in the control population. S-100B protein was assessed on the 1th day, TPA on the 1th, 7th and 14th day. The clinical status was documented using Scandinavian Stroke Scale. The functional deficit after the stroke was scored by Barthel Index. The analysis of the entire examined group in relation to the control population showed elevated concentrations of S-100B protein (0.47 ng/ml vs. 0.19 g/ml). The highest concentrations were in the severe stroke group (0.89 ng/ml). The assessment of TPA blood plasma concentrations showed higher ones in the examined group of patients: 225.7 U/l on the 1st day; 96.1 U/l on the 7th day; 125.64 U/l on the 14th day after the stroke in relation to the control population. The analysis of obtained results showed significant increase of S-100B protein blood plasma concentrations in patients with severe stroke and TPA in patients with mild stroke. S-100 protein blood plasma concentration assessed on the 1st day after the ischemic stroke is the parameter presenting the highest diagnostic utility and its value above 0.6 ng/ml was obtained only in patients with severe stroke.

Involvement of the cocaine-amphetamine regulated transcript peptide (CART 55-102) in the modulation of rat immune cell activity

July 2008


74 Reads

Cocaine-amphetamine regulated transcript peptides (CART) belong to a neuropeptide family expressed in the central nervous system, especially in the hypothalamus, and also in peripheral tissues. The physiological functions of CART include modulation of pituitary hormone release, regulation of body weight, and the control of feeding behavior and metabolic activity. The reciprocal relationships between CART and immune system function have to be established. Therefore, in the present study we aimed to investigate the influence of CART, administered intracerebroventricularly (icv), on selected immune parameters and pituitary-adrenal axis hormone secretion in the rat. In rats submitted to icv infusion of CART or artificial cerebrospinal fluid (aCSF, control) selected immune parameters: splenocyte proliferation (spontaneous and mitogen-stimulated) and peritoneal leukocyte (PTL) activity (spontaneous and phorbol myristate acetate (PMA)-stimulated) were examined 60 and 120 min after treatment. The direct effect of CART on splenocytes in culture in vitro was also examined. Concentration of adrenocorticotrophic hormone (ACTH) and corticosterone was also measured in serum of control and CART infused rats. Splenocytes isolated 60 min after CART infusion exhibited a decreased, albeit non-significant, ability to proliferate spontaneously and were unable to answering to the mitogenic stimulation. This effect was not seen 120 min after CART treatment, which restored splenocyte proliferation decreased by aCSF infusion. CART addition in vitro did not influence proliferation of splenocytes from control rats. Spontaneous activity of peritoneal leukocytes was not modified by CART infusion. PMA-stimulated PTL activity was significantly decreased in aCSF-infused rats 120 min after treatment and CART infusion antagonized this effect. Non-significant increase in serum cortisol after 60 min followed by a significant decrease after 120 min with no change in ACTH concentration was found. The immunomodulatory activity of icv-infused CART appears to consist in the creation of a short-lasting immunosuppressive internal milieu, followed by the immunostimulatory one. This first effect was most probably due to the activation of the HPA axis and/or other immunosuppressive peptides, but not through the direct action of CART on immune cells. Thus, CART appears to be short-lasting and indirect modulator of immunity.

Table 1 Thyroid function and other biochemical data from parents and proband. 
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The prognostic value of fine-needle aspiration biopsy of the thyroid gland - Analysis of results of 1078 patients

October 2012


110 Reads

Objective: We aimed to evaluate the prognostic value of thyroid fine needle aspiration biopsy (FNAB) in the diagnosis of pathologic lesions. Methods: Data from 1 078 consecutive patients (female : male ratio, 9:1) who underwent thyroidectomy were retrospectively analyzed. All patients had preoperative thyroid FNAB. Unilateral and bilateral FNAB were performed in 872 and 206 patients, respectively, resulting in 1 284 cytologic aspirates, which were compared to postoperative histology. Risk factors for malignancy (age, sex, single nodule, or nodule in multinodular goiter) were evaluated. Results: 203 (15.81%) aspirates were non-diagnostic. 768 (59.81%) were benign; 112 (8.72%) were atypical; 170 (13.24%) were follicular neoplasms, 5 (0.4%) had suspicion of malignancy; and 26 (2.02%) were malignant tumors on FNAB. The calculated risk of malignancy in each group was: 1.97%, 1.84%, 7.15%, 12.35%, 60%, and 100%. There were 2.02% false negative and 0.15% false positive results. Diagnostic discrepancies occurred in the follicular neoplasm group, of 86 biopsies (0.15%). Conclusion: FNAB is the primary method of preoperative diagnostics of thyroid tumors, as it allows many patients to avoid thyroidectomy. In addition, it helps the operating surgeon to decide the extent of surgical resection.

Ultrasonographic assesement of fetal nuchal translucency (NT) at 11th and 14th week of gestation - Polish multicentre study

April 2007


21 Reads

THE AIMS OF THE STUDY WERE: To evaluate range and median values of NT in a large, unselected Polish population; to determine the value of the 95th percentile and the median values for NT for given weeks of late 1st trimester pregnancy and to determine the level of chromosomal aberration risk corresponding to the values of the 95th percentile in the examined groups; to examine the possible correlation between CRL, NT width as well as the mother's age with the risk of the most frequent chromosomal aberrations. We have retrospective analyzed 7,866 pregnant women. All fetuses of this women had NT measurement performed, as well as CRL and assessed of the most frequent chromosomal abnormalities. The group of pregnant women was divided into 2 subgroups: until and above 35 years old. All population group was divided into 3 subgroups depending on gestational age (11, 12 and above 13th weeks of gestation). The median of NT in all population group was 1.5 mm and 95th percentile was 2.4 mm, whilst in group with low risk median of NT and 95th percentile were the same and in group with high risk of chromosomal abnormalities respectively 1.5 mm and 2.5 mm. There were strong correlations between maternal age and the risk of most frequent chromosomal abnormalities from NT. The obtained results of median values and the 95th percentiles of NT in the examined group and the age groups under 35 and 35 plus are similar to these quoted by FMF. The risk levels of trisomy of 21st chromosome were similar to the reference values used by FMF. With gestational age, NT value increases in a non-linear way, therefore it is incorrect to use the term "a normal value" for NT, therefore, only the risk level calculated with the dedicated software using NT and CRL measurements with maternal age should be stated.

Fig. 7. Arch n. 2440: a patient who underwent surgery but not chemotherapy, treated with adjuvant DBM). The patient underwent mastectomy in 1997 due to "Infiltrating ductal G2". October 27, 2009 - Lymph node histological test "Infiltation due to ductal cancer, metastatic" December 11, 2009 - PET scan: "... High metabolic activity lesions at axillary lymph nodal and bone level (dorsolumbar rachis, right acromion, some ribs bilaterally, right and left iliac regions, right pubic symphysis, left intertrocanteric region). Doubts with respect to right lung." December 29, 2009 - start of DBM treatment June 3, 2010 - PET scan "disappearance of the tracing focal hyper accumulation in the right nodal axillary region and some uptake skeletal areas (III front right costal arch, IV back right arch, left iliac ala, right sacroiliac synchondrosis and left intertrochanteric region) uptake gradient reduction at a vertebral level, uptake gradient reduction in the right subareolar region" 
The Di Bella Method (DBM) improved survival, objective response and performance status in a retrospective observational clinical study on 122 cases of breast cancer

February 2012


1,649 Reads

Objectives: To increase the efficacy and reduce the toxicity of cancer therapy. Method: The DBM with MLT (melatonin), Retinoids, vitamins E, D3, and C has a differentiating, cytostatic, antiangiogenic, immunomodulating, factorially synergic effect, at the same time reinforcing those functions that Physiology considers essential for life. With Somatostatin and/or its analogues, the DBM has an antiproliferative effect, negatively regulating the most powerful mitogenic molecule (GH), receptorially co-expressed and interactive with Prolactin, inhibited by Cabergoline and/or Bromocriptin. The negative regulation of GH extends directly to the GH-dependent growth factors. In breast cancer, the DBM entails the use of estrogen inhibitors and minimal apoptotic, non-cytotoxic and non-mutagenic doses of Cyclophosphamide or Oncocarbide, the tolerability of which is enhanced by MLT and the vitamins in the DBM. Results: Complete and stable cure of 4 cases, and rapid regression of the tumour in another 5 cases with just the DBM (first-line therapy), without surgical intervention. No disease recurrence with the use of the DBM as adjuvant therapy. Five-year survival of 50%, of stage IV cases, considerably higher than the data reported in the literature. A more or less generalised improvement in the quality of life, without any significant and/or prolonged toxicity. Conclusions: The acknowledgement of the still underestimated scientific evidence, such as the multiple antitumoral mechanisms of action of MLT, the negative regulation of the interactive mitogens GH-GF (GH-dependent growth factors), Prolactin and estrogens, together with the differentiating and homeostatic action of retinoids and Vitamins E, D3, and C and MLT, made it possible to achieve these results. An essential aspect of the mechanism of action on the clinical response is the factorial synergy of the DBM components.

Isolation and partial characterization of the adduct formed by 13-hydroxyellipticine with deoxyguanosine in DNA

November 2008


18 Reads

Ellipticine is a potent antineoplastic agent exhibiting multiple mechanisms of its action. Recently, we have found that 13-hydroxyellipticine, formed from ellipticine as the predominant metabolite in human livers, is bound to deoxyguanosine in DNA, generating the major DNA adduct in vivo and in vitro. The development of the methods suitable for the preparation of this adduct in the amounts sufficient for identification of its structure and those for its isolation and partial characterization is the aim of this study. High performance liquid chromatography (HPLC) was employed for separation of 13-hydroxyellipticine-mediated deoxyguanosine adduct. The 32P-postlabeling technique was utilized to detect this adduct in DNA. The formation of the 13-hydroxyellipticine-derived deoxyguanosine adduct in DNA in vitro was increased under the alkaline pH of the incubations and by the formation of the sulfate and acetate conjugates of 13-hydroxyellipticine generated by reactions with 3'-phosphoadenosine-5'-phosphosulfate (PAPS) or acetyl-coenzyme A (acetyl-CoA) catalyzed by human sulfotransferases (SULTs) 1A1 and 1A2 and N,O-acetyltransferases (NATs) 1 and 2. The HPLC method suitable for separation the 13-hydroxyellipticine-derived deoxyguanosine adduct from other reactants, deoxyguanosine and 13-hydroxyellipticine, was developed. The structure of this adduct is proposed to correspond to the product formed from ellipticine-13-ylium with the exocyclic 2-NH2 group of guanine in DNA. The data are the first report on HPLC isolation of the deoxyguanosine adduct formed by 13-hydroxyellipticine in DNA and its partial characterization.

The association between TaqI A polymorphism of ANKK1 (DRD2) gene and ADHD in the Czech boys aged between 6 and 13 years

February 2010


322 Reads

The purpose of this study was the correlation of the combined type of ADHD in children and Taq IA polymorphism DRD2 gene. We hypothesized a positive correlation of DRD2 polymorphisms in the combined type of ADHD patients without co-morbidity. Our research sample included 586 unrelated boys of the Czech origin aged between 6 and 13 years. The ADHD group consisted of 269 boys and the control group consisted of 317 boys. PCR detection of the DRD2 polymorphism was carried out by using primers, described by Grandy (Grandy et al. 1989). The comparison of genotype frequencies showed statistically highly significant difference between the studied groups (p<0.0001). A statistically significant difference was also found when the allelic frequencies between the two groups were compared (p<0.0001), with the A1 allele having a 4.359 fold higher risk of ADHD (Risk Ratio=4.359, 95% CI of RR=3.5753 to 5.3144, Odds Ratio= 7.7824; 95% CI of OR=10.315 to 13.6719). Our results presented a highly positive correlation between the combined type of ADHD without co-morbidity and ANKK l (DRD2) polymorphism .

A follow-up of 130 patients with acromegaly in a single centre

January 2007


59 Reads

Acromegaly is a rare disease with increased mortality rate. The aim was to present our centre experience in the diagnosis and treatment of a series of patients suffering from acromegaly. 130 patients (55 men, 75 women) aged 19-84 years presenting with clinical and hormonal features of acromegaly, attending Department of Endocrinology and Out-patient Clinic between 1990 and 2004 were studied. They were analyzed their GH and IGF-1 levels, CT and MRI scans, and they were administered medical therapy, neurosurgery and radiotherapy. We have observed 106 macro-, 16 microadenomas and 1 case of ectopic GHRH. 115 patients were operated, as cured were recognized 74 of them. Pituitary irradiation was applied to 11 patients, in 4 of them it did not cure the disease. Medical therapy was efficacious in 12% patients treated with bromocriptine, 73% with long-acting lanreotide and 58% with long-acting octreotide. In 7 patients other malignant neoplasm were detected. 11 patients died during the follow-up. There is possible underdiagnosis of acromegaly in our region, especially in males. We have observed better diagnostic opportunities in recent years when MRI was available. It was accompanied by better outcome of surgical and pharmacological treatment and better control of the complications of the disease.

Structural analysis of binding of a diamantoid substrate to cytochrome P450 2B4: Possible role of Arg 133 in modulation of function and activity of this enzyme

November 2008


30 Reads

Understanding the enzyme mechanism of P450 enzymes needs a detailed knowledge of substrate-enzyme interactions. Here, we examined the interaction of cytochrome P450 2B4 with a diamantanoid substrate. The interaction was followed using a photoactivable label, 3-azidiamantane. After photochemically driven reaction, the labeled enzyme was cleaved by trypsine and the labeled peptides separated by HPLC and identified with the help of radioactivity (for tritiated label) and mass spectrometry. The results were analysed on the basis of the known X-ray structures for mammalian cytochromes P450. Identification of labeled peptides has shown that the probe (binding as a substrate to the enzyme) was attached to fragments: 30-48 (the most likely positions of the label are Leu44, Gln45 and Asp47), 127-140 (with Arg133 labeled, as indicated by mass spectrometry), 359-373 and 434-443 (the exact position of the label unknown). The structural comparison indicates considerable differences in Arg133 interaction with heme propionates, connected with binding of the substrate. Labeling of this residue may thus reflect its involvement in modulation of cytochrome P450 activity. The results show existence of additional binding sites for substrate on cytochrome P450 2B4, located close to the surface of the enzyme.

An integrative approach to the study of human behavior. (Poster accepted for the International Conference of Psychology "Psychology After The Year 2000" at the University of Haifa, Israel, June 12-14, 2000)

February 2000


41 Reads

The human behavior is a fundamental phenomenon in contemporary sciences in the widest sense of the word. The wide range of world problems such as wars, criminality, social depravation, famine, different catastrophes as Tjernobyl up to the pandemic AIDS, etc. are transferable into one common denominator: the failure of man in his behavior. Adequate understanding of all behavioral mechanisms and their failures is condition sine qua non for the most important task-the prediction of actual behavior resulting from different bio-psycho-socio-cultural sources. The authors express presumption about the essential importance of three basic postulates (I-III) in every kind of behavioral research: (I) Human life is an indivisible continuum from its very beginning (especially vulnerable) over adulthood (inclusive reproduction) until death. The prenatal stages of life are integral and very sensitive periods of human ontogenesis. Every discontinuity in this development can lead to physical, mental and social disfunctions in both prenatal and postnatal life. (II) Motivation is a basic inner drive generating the actual human behavior. All its five components should be taken into consideration: 1. Qualitative (the kind of motivational state: alimentary, sexual, territorial, etc.) 2. Quantitative (the intensity of motivational state, "arousal"). 3. Inner structure of each motivational state (into partial motivational states with specific sensitivity to external stimulation). 4. Synthetic (causal and functional aspects of actual motivation). 5. Hierarchy of motivational states (self-preservation of the individual is probably on the top of such a hypothetical hierarchical structure). (III) Both previous postulates demand the integrative approach to the study of human behavior and refers to three basic sources of behavior: 1. Function of the CNS. 2. Function of the endocrine system. 3.Variability of external conditions (including all kinds of behavioral stimulation).

A new mutation in WFS1 gene (C.1522-1523delTA, Y508fsX421) may be responsible for early appearance of clinical features of Wolfram syndrome and suicidal behaviour

January 2007


28 Reads

Wolfram syndrome (WS) is an autosomal recessive disorder characterized by the association of juvenile-onset diabetes mellitus and optic atrophy. It is also known by the acronym DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness). We diagnosed Wolfram syndrome in 2 male siblings and determined a new mutation (c. 1522-1523delTA, Y508fsX421). Both affected siblings were homozygous, other family members were heterozygous. Dilated renal outflow tracts in the third decade, and neuropsychiatric disorders including bipolar disorder and neurosensorial deafness appear in the fourth decade in ordinary WS, whereas these features appeared in second decade in our patients. This mutation may be responsible for early appearance of dilated renal outflow tracts and multiple neurological abnormalities. Psychiatric disturbances such as suicide were reported at increased frequency in Wolfram patients and in heterozygous carriers. Suicidal behaviour occurred in our patients when they were yet 11 and 13 years old. Therefore, our findings may indicate that there may be a relationship between this WFS1 mutation and mood disorder such as suicidal behaviour. We determined a new mutation (c. 1522-1523delTA, Y508fsX421) in WS1 gene in 2 siblings with Wolfram syndrome. This mutation may be responsible for early appearance of clinical features of Wolfram syndrome, and there may be a relationship between this mutation and suicidal behaviour.

Mouslech Z, Valla V. Endocannabinoid system: An overview of its potential in current medical practice. Neuro Endocrinol Lett 30: 153-179
The endocannabinoid system (ECS) is a lipid signalling system, comprising of the endogenous cannabis-like ligands (endocannabinoids) anandamide (AEA) and 2-arachidonoylglycerol (2-AG), which derive from arachidonic acid. These bind to a family of G-protein-coupled receptors, called CB1 and CB2. The cannabinoid receptor 1 (CB1R) is distributed in brain areas associated with motor control, emotional responses, motivated behaviour and energy homeostasis. In the periphery, the same receptor is expressed in the adipose tissue, pancreas, liver, GI tract, skeletal muscles, heart and the reproduction system. The CB2R is mainly expressed in the immune system regulating its functions. Endocannabinoids are synthesized and released upon demand in a receptor-dependent way. They act as retrograde signalling messengers in GABAergic and glutamatergic synapses and as modulators of postsynaptic transmission, interacting with other neurotransmitters. Endocannabinoids are transported into cells by a specific uptake system and degraded by the enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). The ECS is involved in various pathophysiological conditions in central and peripheral tissues. It is implicated in the hormonal regulation of food intake, cardiovascular, gastrointestinal, immune, behavioral, antiproliferative and mammalian reproduction functions. Recent advances have correlated the ECS with drug addiction and alcoholism. The growing number of preclinical and clinical data on ECS modulators is bound to result in novel therapeutic approaches for a number of diseases currently treated inadequately. The ECS dysregulation has been correlated to obesity and metabolic syndrome pathogenesis. Rimonabant is the first CB1 blocker launched to treat cardiometabolic risk factors in obese and overweight patients. Phase III clinical trials showed the drug's ability to regulate intra-abdominal fat tissue levels, lipidemic, glycemic and inflammatory parameters. However, safety conerns have led to its withrawal. The role of endocannabinoids in mammalian reproduction is an emerging research area given their implication in fertilization, preimplantation embryo and spermatogenesis. The relevant preclinical data on endocannabinoid signalling open up new perspectives as a target to improve infertility and reproductive health in humans.

Growth-inhibitory action of melatonin and thiazolidinedione derivative CGP 52608 on murine 16/C breast cancer cells

July 2006


53 Reads

Melatonin may influence directly tumor cells through the specific binding sites. The best known melatonin binding sites are membrane receptors. Recently, the participation of nuclear signalling via estrogen as well as RZR/ROR receptors in oncostatic action of melatonin on the breast cancer has been widely discussed. The aim of present study was to investigate effects of melatonin, the selective ligand for nuclear RZR/ROR receptors - CGP 52608, and methotrexate on growth of murine 16/C breast cancer cells. The experiment was performed in vitro. The breast cancer cells were incubated for 2 days in the presence of melatonin, CGP 52608 (at concentrations of 10(-5)M, 10(-7)M, 10(-9)M, 10-(11)M ) and methotrexate (at concentrations of 0.25 and 0.125 microg/ml). The growth of cells was measured using the modified Mossman method. All examined compounds significantly inhibited the growth of cancer cells. The effects of MLT and CGP 52 608 were comparable with suppression caused by methotrexate. The significant differences of efficacy between two examined concentrations of methotrexate were not observed. The obtained data together with our previous results indicate that nuclear receptors RZR/ROR play an important, although not sufficiently recognized role in the oncostatic action of melatonin.

The Di Bella Method (DBM) in the treatment of prostate cancer: A preliminary retrospective study of 16 patients and a review of the literature
Objective: To evaluate the objective clinical response and the safety of the combined administration of somatostatin, melatonin, retinoids, vitamin D3, dopamine subtype 2 receptor (D2R) agonists and low doses of cyclophosphamide, associated with androgen ablation, in patients with a histological diagnosis of prostate adenocarcinoma (Pac). Materials and methods: The clinical data of 30 patients with non-invasive and metastatic prostate cancer, who attended our institution over a period of more than 5 years, were retrospectively reviewed. Results: 16 patients satisfied the evaluation criteria. Median age: 64 years. Disease stages: 8 patients (50%) were in Stage II. For advanced stages (Stage IV), secondary lesions were located in the bones and lymph nodes. Taken together, an overall objective response (OR) [Complete response (CR) + Partial Response (PR)] was achieved in 69% of the patients, with 88% of objective clinical benefit [CR+PR+SD]. For local Prostate Cancer group, an OR was achieved in 87.5% of patients (7 cases; 53-98; 95% CI), with CR in 62.5% (5 cases, 31-86; 95% CI). In metastatic disease, the OR was 50% (4 cases; 21-78; 95% CI), with a 20% of CR (2 cases; 7-59; 95% CI) and 75% of clinical benefit. Conclusions: This preliminary study shows that patients with early and advanced forms of prostate cancer, not previously treated by surgery and/or chemo-radiotherapy, can achieve a more than positive clinical benefit with the protocol foreseen by the Di Bella Method. Further clinical investigations are strongly recommended.

Editorial - 16th Annual Congress on Atherosclerosis, December 6-8, 2012

November 2012


11 Reads

Dear Colleagues, in front of you is a supplement of Neuroendocrinology Letters containing the full text of selected papers to be presented at the opening of the XVI Congress of Atherosclerosis for 2012. The dominant role in atherosclerosis and its clinical complications as a leading cause of death is evident. During the past two decades, the clinical complications of atherosclerosis is not only the top killer in the developed countries but also in many developing countries. This Supplement represents a new and groundbreaking step in the development of the Czech Society for Atherosclerosis. When we started to set up our society in 1995, our intention was to unite all our Czech colleagues working in the field of risk factors for atherosclerosis - from the experimental approach in preventive cardiology, to clinical treatment and epidemiology of cardiovascular diseases. Our aim was quite modest and we expected to organize relatively small conferences to give a chance for all specialists to meet and discuss issues of common research. In recent years, our Congress has become a conclave that promotes interaction between these groups and provides an exchange of basic research in the prevention and treatment of atherosclerosis in the Czech Republic. Not only has the size of our annual congresses increased steadily from our first conference in Podebrady 1996, but also the quality of the data presented is to gradually increase. It is clear from the list of full-text papers to be presented this year - that the broad research field of atherosclerosis and its risk factors is expanding. We will consider new information on such topics as the ongoing fight against smoking, the treatment of risk factors for cardiovascular disease through diet, statins, and hormones and the clinical data technologically advanced treatment of heart failure. There is a tradition of our congresses that several documents on molecular genetics of cardiovascular disease are also included. Personally, I am glad that this addition also contains several articles focusing on gradually increasing importance of adipose tissue in obesity and the risk of premature atherosclerosis development. The new scientific information in this Supplement of Neuroendocrinology Letters is a further step in the development of our society.

SUMO1 enhances 17-β estradiol's effect on CRH promoter activation through estrogen receptors

May 2008


72 Reads

Human corticotrophin-releasing hormone (CRH) plays a pivotal role in the stress response. Its expression is under the control of various steroid hormones, such as estrogens. The transcriptional activity of the estrogen receptor (ER) may be modified by small-ubiquitin related modifier (SUMO1). In the present study, we aim to reveal the role of SUMO1 in the regulation of ER-mediated CRH promoter activation. CHO-K1 cells were transfected with human ER and SUMO1 expressing plasmids together with the CRH promoter reporter gene. CRH mRNA was detected in BE(2)C cells by real time PCR. We found that estradiol could elevate CRH promoter activity to a much higher level in cells co-transfected with ER and SUMO1 than that with ER alone, and that the enhancement was blocked by the ER inhibitor, ICI182,780. Furthermore, the endogenous CRH mRNA expression was also increased when the BE(2)C cell were transfected with ERalpha and SUMO1 in contrast to the transfection with ERalpha alone. Our results indicate that SUMO1 participates in the modulation of ER-mediated CRH mRNA expression which may be important for the regulation of the stress response.

Effect of estradiol 17-β on LH subunits and prolactin mRNAs expression in the pituitary of old female rats

February 2000


13 Reads

OBJECTIVES: The aim of the study was to examine susceptibility of the pituitary gland to estrogenic impulse in old, noncycling rats by measurement of steady state level of mRNAs encoding LH subunits a and b and mRNA for PRL. METHODS: 22-month-old rats were ovariectomized and after one week they were subcutaneously implanted with silastic tubing filled with oil or with estradiol 17-beta. Pituitary alpha, LHbeta and PRL mRNAs content and serum LH and PRL concentration was determined. RESULTS: The effect of E (2)treatment was manifested by the significant increase in the weight of the uterus and pituitary gland as well as by elevation of total pituitary RNA (109%, 60% and 78%, respectively; p<0.001). No significant changes (p>0.05) in serum LH concentration were observed, while levels of mRNAs encoding alpha and LH-beta subunits were lowered by 54% (p<0.05) and 96% (p<0.01), respectively, in the rats subjected to E(2) stimuli. No direct correlation between synthesis and release of LH in E(2) treated old rats was observed. The blood PRL concentration and the pituitary level of PRL mRNA increased up to 2,000% and 1,300%, respectively (p<0.001). Spontaneous pituitary adenoma was observed in about 30% of the rats, irrespective of treatment. CONCLUSIONS: These data show that in old rats estrogenic stimulus can effectively diminish both pituitary LH subunits mRNAs as well as stimulate pituitary PRL mRNA level indicating that the E(2)-dependent processes involved in the regulation of corresponding genes are still functional.

The presence of 17-?? estradiol in Mytilus edulis gonadal tissues: Evidence for estradiol isoforms

June 2003


219 Reads

In earlier studies, we demonstrate that 17-beta -estradiol and an estrogen cell surface receptor can be found on various human cells, i.e., vascular endothelial, monocytes, and granulocytes, where they are coupled to nitric oxide release. We further demonstrated this phenomenon in the marine mussel Mytilus edulis ganglionic tissues. In the present report we sought to determine if estrogen can be found in M. edulis reproductive tissues. We determined the presence of 17-beta -estradiol via high pressure liquid chromatography (HPLC) and radioimmunoassay (RIA) in the animals gonads. This substance was further identified via nanoelectro-spray ionization quadrupole time of flight mass spectrometry (Q-TOF-MS). 17-beta -estradiol was identified and quantified in Mytilus gonads. Interestingly, we also determined that estradiol isoforms also were present in this tissue. These data demonstrate that 17-beta-estradiol and an estradiol isoform is present in M. edulis gonadal tissues, suggesting that they have functions related to reproduction. This further suggests that estrogen's association with reproductive activities has a long evolutionary history and that this association began in invertebrates.

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