ATAC-Seq Analysis of Accessible Chromatin: From Experimental Steps to Data Analysis

Accessible chromatin often represents gene regulatory elements, including promoters and enhancers, essential for gene expression. Assay for Transposase Accessible Chromatin sequencing (ATAC-seq) is one of the most popular techniques to investigate chromatin accessibility across the genome. Here we describe, step by step, a series of optimized experimental methods and bioinformatics pipelines for ATAC-seq analysis. As an example, we present an analysis of murine spermatogenic cells: a method to isolate germ cells, a reaction step using Tn5 transposase to insert sequencing adapters into accessible DNA, a library preparation method for high-throughput sequencing, and bioinformatics analysis of sequencing data. Overall, we introduce a framework of ATAC-seq analysis that can be applied to any cell population to identify cell-type-specific gene regulatory elements and their cis-regulatory networks.

A rapidly evolved domain, the SCML2 DNA-binding repeats, contributes to chromatin binding of mouse SCML2†

Genes involved in sexual reproduction diverge rapidly as a result of reproductive fitness. Here, we identify a novel protein domain in the germline-specific Polycomb protein SCML2 that is required for the establishment of unique gene expression programs after the mitosis-to-meiosis transition in spermatogenesis. We term this novel domain, which is comprised of rapidly evolved, DNA-binding repeat units of 28 amino acids, the SCML2 DNA-binding (SDB) repeats. These repeats are acquired in a specific subgroup of the rodent lineage, having been subjected to positive selection in the course of evolution. Mouse SCML2 has two DNA-binding domains: one is the SDB repeats and the other is an RNA-binding region, which is conserved in human SCML2. For the recruitment of SCML2 to target loci, the SDB repeats cooperate with the other functional domains of SCML2 to bind chromatin. The cooperative action of these domains enables SCML2 to sense DNA hypomethylation in an in vivo chromatin environment, thereby enabling SCML2 to bind to hypomethylated chromatin. We propose that the rapid evolution of SCML2 is due to reproductive adaptation, which has promoted species-specific gene expression programs in spermatogenesis.

Fecal DNA Analysis for Identifying Species and Sex of Sympatric Carnivores: A Noninvasive Method for Conservation on the Tsushima Islands, Japan

Fecal analysis is a useful tool for the investigation of food habits and species identity in mammals. However, it is generally difficult to identify the species based on the morphological features and contents of feces deposited by mammals of similar body size. Therefore we developed noninvasive DNA analysis methods using fecal samples for identification of the species and sex of four small sympatric carnivores living on the Tsushima Islands of Japan: the leopard cat (Felis bengalensis), Japanese marten (Martes melampus), Siberian weasel (Mustela sibirica), and feral cat (Felis catus). Based on DNA sequence data from previous phylogenetic studies, we designed species-specific primers for polymerase chain reaction (PCR) amplification of the partial mitochondrial cytochrome b gene (112-347 bp) to identify the species and primers for the partial SRY gene (135 bp) to determine the sex. Due to the adjustment of PCR conditions, those specific DNA fragments were successfully amplified and then applied for species and sex identification. Nucleotide sequences obtained from the PCR products corresponded with cytochrome b sequences of the carnivore species expected. The protocol developed could be a valuable tool in the management and conservation of the four carnivore species occurring on the Tsushima Islands.

Changes in physical state of ovarian membranes during pseudopregnancy in the rat

The role of the physical state of ovarian membranes was studied in immature rats after PMSG- and hCG-induced pseudopregnancy. Parallel changes in LH/hCG receptors, progesterone secretion and rigidity of membrane lipids were observed during pseudopregnancy. Possible structure-functional properties of the LH/hCG receptor were analyzed by the thermal perturbation technique. Thermal stability of the receptor was higher 5 days after hCG ovulatory injection to rats compared to days 11 or 18 and to control rats. Pseudopregnancy modified the quenching of protein fluorescence. The Stern-Volmer constants for controls and for rats on days 5, 11 and 18 of pseudopregnancy were found to be 2.4 and 4.6, 5.1 and 4.4, respectively, indicating that accessibility of fluorophores for the quencher was increased.

Effect of guarana on exercise in normal and epinephrine-induced glycogenolytic mice

The tonic action of water Guarana extract, (Paullinia cupana MART.), was investigated in normal, exercised, and epinephrine-induced glycogenolytic mice. A water extract of Guarana (GW) (500 mg/kg) increased the blood glucose level (p < 0.001) and decreased the liver glycogen contents of mice 60 min after oral maltose administration (p < 0.05). GW also significantly suppressed exercise-induced hypoglycemia (60 min: p < 0.05). However, GW did not affect the blood glucose in epinephrine-induced glycogenolytic and exercise mice. These findings indicate that the suppressive mechanism of hypoglycemia might be due to the promotion of glycogen resolution.

[Relation between fatty acid composition, vitamin e and malondialdehyde levels, and activity of antioxidant enzymes in the blood]

The aim of our study was to determine the composition of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) in erythrocytes and to investigate their relation to the concentration of vitamin E (Vit E) in the plasma, level of malondialdehyde (MDA) in the serum and activities of antioxidant enzymes (AE) in erythrocytes. We examined 128 healthy volunteers (57 men and 71 women) at the ages ranging between 20 and 72. Fatty acids were assessed by gas chromatography, vitamin E by the HPLC method, MDA by the spectrophotometric method, GSH-Px by the kinetic method, CU, Zn-SOD by the Randox test. We have detected the following order in the proportion of fatty acids: SFA > PUFA > MUFA. The increase in PUFA and MUFA was in direct correlation with the concentration of MDA and AE activity, however in reverse correlation with Vit E. A reverse correlation was observed in the increase in SFA. We have found an increase in lipoperoxidation due to the increase in PUFA in erythrocytes in the group of healthy people. This state is concommited by an increase in the activity of antioxidant protection for the maintenance of the balance state. The authors assume that a decrease in Vit E can be caused by its increased "consumption" as the most effective antioxidant in lipid environment. (Tab. 2, Fig. 1, Ref. 27.)

[Relation between levels of vitamins C, E, A and beta-carotene and activity of antioxidant enzymes in the blood]

Antioxidant protection is procured by many enzymatic and non-enzymatic factors which maintain the physiological level of reactive forms of oxygen. The aim of this study was to determine the levels and relationship between concentrations of the selected non-enzymatic antioxidants in healthy people (vitamin C--Vit C, vitamin E--Vit E, beta-carotene-beta-Car and vitamin A--Vit A) in the serum, antioxidant enzymes, CuZn-superoxide dismutase--SOD, catalase CAT, glutathione peroxidase--GPx) in erythrocytes and malondialdehyde (MDA) in the serum. We have examined 128 volunteers (57 men and 71 women) at the age ranging between 20 and 72. The average levels of vitamins and beta-Carotene were detected near the lower level of normal values or below it, whilst the highest interindividual differences were detected in Vit C and Vit E. The level of Vit E indirectly correlated with SOD, GPx, MDA, but directly with CAT. On the contrary, the levels of Vit A directly correlated with SOD, GPx, MDA and indirectly with CAT. The levels of Vit C and beta-Carotene had no relation with the activities of antioxidant enzymes and the level of MDA. The direct correlation was between the levels of Vit C and Vit E, and Vit C and beta-Carotene.

CONCLUSIONS

1. A decrease in average levels of Vit A, C, E and beta-Carotene in the blood of the investigated group of healthy persons indicates their lower antioxidant protection. 2. The relation between Vit E, MDA, activities of GPx and SOD indicates the presumed mutually supplementing effect of these antioxidants in liquidation of products of lipoperoxidations. (Tab. 2, Fig. 3, Ref. 17.)

Effect of local anesthetics on accessibility and thermal stability of the rat ovarian LH/hCG receptor

Perturbation of rat ovarian membranes induced by local anesthetics altered the accessibility and thermal stability of the LH/hCG receptor. Incubation of ovarian membranes with tetracaine and benzyl alcohol resulted in a dose-dependent loss of binding activity of the LH/hCG receptor. Possible structure-functional properties of the receptor in membranes treated with local anesthetics were analyzed by the thermal perturbation technique. The heat inactivation profile of the LH/hCG binding sites in 10 mM tetracaine and 20 mM benzyl alcohol treated membranes was shifted to lower temperatures of about 15 degrees C and 4 degrees C (T50 values), respectively. The thermal stability of the receptor decreased with an increasing concentration of the local anesthetics. Thermal destabilization of the LH/hCG receptor induced by the action of tetracaine was higher at pH 9.5 than at pH 5.5. Treatment of ovarian membranes with 5 mM tetracaine modified and with 20 mM benzyl alcohol failed to change the quenching of protein fluorescence, characteristic for control membranes. Incubation of ovarian membranes with tetracaine and benzyl alcohol increased the membrane lipid fluidity, as determined by fluorescence polarization of the 1,6-diphenyl-1,3,5-hexatriene probe (DPH).

Involvement of tryptophan in the structural alterations of the rat ovarian LH/hCG receptor

Treatment of the rat ovarian membrane-bound and Triton X-100 solubilized LH/hCG receptor with the tryptophan-specific reagents N-bromosuccinimide (NBS) and 2-hydroxy-5-nitrobenzyl bromide (HNB-Br) resulted in inactivation of the receptor to bind hCG. Fluorescence quenching studies indicated that oxidation of tryptophan residues by NBS decreased the accessibility of fluorophores for acrylamide. Preceding binding of hCG to receptor sites was found to protect fluorophores from NBS action. Modification of tryptophan residues was associated with alteration in the rigidity of ovarian membranes and with destabilization of the LH/hCG receptor structure. The results suggest that tryptophan residue is essential for hCG binding to the receptor.

Diethylpyrocarbonate, a histidine selective reagent, causes structural alteration of rat ovarian LH/hCG receptor

Treatment of rat ovarian membrane-bound and Triton X-100 solubilized LH/hCG receptor with a histidine-specific reagent diethylpyrocarbonate (DEPC) resulted in inactivation of the ability of the receptor to bind hCG. The partial reversibility of this inhibition by hydroxylamine demonstrated that histidine residues are involved in hCG-receptor binding. Fluorescence quenching experiments indicated that DEPC did not change the accessibility of fluorophores for acrylamide. Alterations of quenching rate generally suggest exposure of tryptophanyl residues. Modification of histidyl residues was connected with an alteration of the physical state of ovarian membranes. Membrane lipid rigidity was decreased after DEPC reaction. Thermal perturbation techniques were used to monitor structural changes in the receptor due to the action of DEPC on membranes. Heat inactivation of hCG-binding sites demonstrated that there was a significant destabilization of the LH/hCG receptor structure when the membranes were treated with DEPC. Thermal destabilization produced by 5 mmol/l DEPC caused a decrease in T50 values by about 12 degrees C. These results suggest that histidine residues are located at the binding sites of the receptor, and that they are also involved in alterations of membrane proteins, the structural integrity of which secondarily influences the accessibility of the LH/hCG receptor.

[Levels of Cu, Zn, Se and their relation to levels of ceruloplasmin and the activity of antioxidative enzymes]

BACKGROUND

Essential trace elements copper, zinc and selenium are important parts of antioxidant enzymes as superoxide dismutase, glutathione peroxidase as well as of transport protein with antioxidant properties-ceruloplasmin. Mentioned trace elements may affect antioxidant defence system.

AIM OF STUDY

The aim of our study was to estimate serum levels of copper, zinc, and selenium in a group of healthy subjects and to correlate them with erythrocyte activity of Cu,Zn-SOD, GSH-Px and serum levels of ceruloplasmin.

METHODS

We examined a group of 128 healthy volunteers (57 men and 71 women) aged 20 to 74 years. The analyses of trace elements we performed by atomic absorption spectrophotometry, Cu,Zn-SOD were detected by Randox test, GSH-Px by kinetic method and ceruloplasmin was measured immunoelectrophoretically.

RESULTS

We have not found any correlations between investigated trace elements, age and sex. Average serum levels were as follows: copper (17.26 +/- 2.71 mumol/L), zinc (15.30 +/- 1.92 mumol/L), and selenium (0.79 +/- 0.19 mumol/L). There was a weak linear correlation between serum levels of copper and ceruloplasmin.

CONCLUSION

There was no relationship between serum copper and zinc levels and Cu,Zn-SOD activity, and serum concentration of selenium and GSH-Px activity in the group of healthy subjects. A moderate linear correlation was estimated between serum values of copper and ceruloplasmin. (Tab. 2, Fig. 4, Ref. 29.)

Fluorescence quenching studies of the rat ovarian LH/hCG receptor

Fluorescence quenching method providing information about the structure and dynamics of proteins, ligand-protein and protein-lipid interactions was used in a study of the rat ovarian LH/hCG receptor. The efficiency of two different quenchers, acrylamide and iodide, was tested. Acrylamide was significantly more effective in quenching of intrinsic fluorescence of ovarian membranes than iodide and therefore it was used in all of the following experiments. Both acrylamide and iodide were not effective in quenching of membranes labelled with fluorescence probe 1,6-diphenyl-1,3,5-hexatriene (DPH). In the process of desensitization of ovarian LH/hCG receptors the administration to rats of hCG modified the quenching rate of protein fluorescence and intrinsic fluorescence spectral properties of membranes. Alteration in the quenching of intrinsic fluorescence of ovarian membranes was observed after chemical modification of LH/hCG receptors by 2-hydroxy-5-nitrobenzyl bromide (HNB-Br). The accessibility of tryptophan fluorophores was increased in HNB-Br-treated membranes. Delipidation of the LH/hCG receptor modified the quenching of protein fluorescence characteristic for control proteoliposomes. These results demonstrate that fluorescence quenching technique can be successfully applied in the study of the LH/hCG receptor.

Cloning of a marine cyanobacterial promoter for foreign gene expression using a promoter probe vector

A marine cyanobacterial promoter was cloned to allow efficient foreign gene expression. This was carried out using chloramphenicol acetyl transferase (CAT) as a marker protein. For rapid and simple measurement of CAT activity, a method based on a fluorescently labeled substrate was improved by utilizing HPLC equipped with a flow-through fluorescent spectrophotometer. This method was used in conjunction with a newly constructed promoter probe vector. Cyanobacterial transformants, harboring plasmid containing a cloned 2-kbp marine cyanobacterial genomic fragment, showed a 10-fold higher CAT activity, compared with that achieved using the kanamycin-resistant gene promoter. From the sequence analysis of the cloned fragment, a putative promoter region was found.

[Levels of erythrocyte glutathione and ceruloplasmin and transferrin in the serum and their role in antioxidant protection]

All organisms are protected from harmful reactive oxygen which is produced also under physiological conditions by a complex antioxidative system. Our work was aimed at the ascertainment of the level of reduced and oxidated glutathione in erythrocytes of healthy people, the concentrations of ceruloplasmin (GSH) and transferrin (GSSG) in the serum, as well as the investigation of the relationship to antioxidative enzymes ---Cu, Zn-superoxide dismutase (SOD), catalase (CAT) and Se-glutathione-peroxidase (GPx) in erythrocytes. We discovered a mutual direct linear correlation between the levels of GSH, GSSG, CPL and TRF, indirect linear relation between the concentrations of TRF, GSH, GSSG and activities of SOD and GPx, between the concentrations of CPL and GPx activities, and a direct linear relation between concentrations of GSH and TRF with CAT activity. The results indicate to a mutual dependence of investigated nonenzymatic antioxidative factors and antioxidative enzymes. (Tab2, Fig. 4, Ref.13.).

[Antioxidative enzyme activity in the blood of healthy persons]

BACKGROUND

Under physiological conditions the dynamic balance between the reactive oxygen production and detoxication is maintained.

OBJECTIVES

The study was aimed at the detection of the activity of antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) in erythrocytes and the level of malondialdehyde (MDA) in the serum of healthy subjects, their relation to age, body weight, sex, smoking, and the possible correlation between individual parameters.

METHODS

The authors have examined 128 healthy volunteers (57 men and 71 women) from 20 to 72 years of age. The results were statistically evaluated by means of the ANOVA programme.

RESULTS

The group of healthy people had a large dispersion of interindividual activities of antioxidant enzymes and MDA levels. Age and weight were reversely correlated to the CAT activity in erythrocytes. The CAT activity was significantly higher in women than in men, and the GPx activity was lower in smokers than in non-smokers. The rest of investigated parameters were not significantly influenced by sex of examined people and smoking. Mutual correlation between individual enzymes were highly significant.

CONCLUSIONS

A large dispersion of activities of the investigated enzymes and MDA levels in healthy individuals do not allow to make a standard use of these parameters in clinical practice. (Tab. 5, Fig. 2, Ref. 20.).

Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor

The role of the physical state of ovarian membranes was studied in the process of the early desensitization of the LH/hCG receptor. Thirty min after injection of a desensitizing dose of hCG to rats, the hCG-responsive adenylylcyclase activity was reduced, whereas hCG binding to ovarian membranes was still normal. Early desensitization decreased rigidity of membrane lipids, determined by fluorescence polarization of DPH. Possible structure-functional properties of the LH/hCG receptor were analyzed by thermal perturbation technique. Desensitization decreased thermal stability of the LH/hCG receptor in membranes and in proteoliposomes. Desensitization modified the quenching of protein fluorescence and intrinsic fluorescence spectral properties of membranes. The Stern-Volmer constants for control and desensitized membranes were found to be 4.3 and 5.5, respectively, indicating that desensitization elevated the accessibility of fluorophores for acrylamide. The changes of the physical properties of membranes resulting from desensitization was exhibited solely in the treatment with hCG in vivo, but not in vitro. The results suggest that the hCG-induced alteration of the physical state of luteal membranes may be a requirement for the induction of changes that lead to desensitization.

Effect of phospholipids on the reconstitution and thermal stability of delipidated rat ovarian luteinizing hormone/human chorionic gonadotropin receptors in proteoliposomes

The role of lipids and a possible structure-functional alteration of delipidated LH/hCG receptor reconstituted into proteoliposomes was analyzed by thermal perturbation techniques. Delipidated receptor lost to a great extent its binding activity and thermal stability. The LH/hCG receptor was almost fully reactivated by the reconstitution into proteoliposomes with phosphatidylcholine (PC) and sphingomyelin (SpM) and partly with phosphatidylethanolamine (PE) and phosphatidic acid (PA). The heat inactivation profile of delipidated LH/hCG binding sites was shifted to a lower temperature by about 4 degrees C (T50 values). Thermal inactivation of the receptor by delipidation was entirely inverted by treatment with soybean PC, dioleoyl PC and dipalmitoyl PC and partially with SpM. The presence of negatively charged phospholipids, phosphatidylserine (PS), phosphatidylglycerol (PGl) and PA, did not change the heat-inactivation profile of the LH/hCG receptor modified the differential scanning calorimetric profile and the quenching of protein fluorescence characteristic for control proteoliposomes. Delipidation increased membrane lipid rigidity. Reconstitution of delipidated proteoliposomes with soybean PC, dioleoyl PC, PGl, PS and PA decreased, and that of dipalmitoyl PC, lysoPC, SpM and cholesterol increased the degree of fluorescence polarization of DPH of proteoliposomes. The different action of phospholipids on the reconstitution, thermal inactivation of the receptor and membrane lipid fluidity in proteoliposomes suggests that lipid fluidity is not related to the stabilizing action of phospholipids on the LH/hCG receptor.

[Non-homogeneity of the average life span in Slovakia]

The life expectancy at birth of males in the Slovak Republic (SR) is one of the shortest in Europe. Exact explanation of this phenomenon is still unknown. The statistical significance of the relation between life expectancy and various factors (infant mortality rate, ethnical structure, educational level, religious belief, economic activity of inhabitants and environmental factors) was analysed by multifactorial methods in all 38 districts of Slovakia. A surprising paradox phenomenon was observed in the areas with the highest pollutant emissions, where the life expectancy was the longest. Infant mortality rate, ethnical structure and particularly the educational level of the districts were significantly correlated with life expectancy. The life expectancy was negatively influenced mostly by the proportion of elementary--educated males. We suppose the style of life presents the background of these relations, but there is a lack of statistically reliable data from the individual districts of SR for more profound analysis. It must be stressed that neither the statistically high significant correlation is evidence of the causal connection between observed parameters. (Tab. 1, Fig. 5, Ref. 16.)

Helminth survey of wildcats in Japan

Two Iriomote cats (Felis iriomotensis) and 2 Tsushima leopard cats (Felis bengalensis euptilura) killed probably by traffic accidents were submitted to the helminthological examination. In Iriomote cats, 8 species of parasites (Spirometra erinacei, Toxocara cati, Molineus springsmithi, Uncinaria maya, Capillaria aerophila, C. felis-cati, larvae of an unidentifiable lung worm and one species of Acanthocephala) were found. In Tsushima leopard cats, 10 species of parasites (Pharyngostomum cordatum, Spirometra erinacei, Toxocara cati, Molineus springsmithi, Arthrostoma hunanensis, Uncinaria felidis, Capillaria felis-cati, larvae of an unidentifiable lung worm, and two species of Acanthocephala) were detected.

Effects of partial delipidation of rat ovarian membranes on thermal stability of LH/hCG receptors

The role of lipids and of possible structure-functional properties of the LH/hCG receptor were analyzed by thermal perturbation techniques in its native membrane environment. A method for the reversible removal of lipids from membranes with a mild detergent Tween 20 was developed. The receptor was reactivated with phosphatidylcholine (PC) by its reconstitution into proteoliposomes. The heat inactivation profile of LH/hCG binding sites in delipidated membranes was shifted to a temperature lower by approx. 8 C degrees (T50 values). Thermal inactivation of the delipidated LH/hCG receptor was found to be a quick process. Occupation of receptor binding sites by the agonist before thermal perturbation induced stabilization of the receptor. Thermal inactivation of the receptor by delipidation was fully reversed by treatment with soybean PC, dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC), partly with phosphatidylethanolamine (PE) and sphingomyelin (SpM), but not with phosphatidylserine (PS), phosphatidylglycerol (PGl) or cholesterol. Delipidation modified the differential scanning calorimetric profile characteristic of control membranes. Delipidation of ovarian membranes also increased membrane lipid rigidity. The addition of PC, DOPC and PS to delipidated membranes decreased, that of DPPC and SpM increased, while PGl did not change the degree of fluorescence polarization of DPH, suggesting that membrane lipid fluidity was not involved in the stabilizing action of specific phospholipids against thermal inactivation of the ovarian LH/hCG receptor.

Early hCG-induced desensitization of rat ovarian LH/hCG receptors is associated with altered physical state of membranes

Injection of pseudopregnant rats with pharmacological doses of hCG produced desensitization of adenylylcyclase and steroidogenic systems in ovarian membranes and luteal cells. Membrane lipid rigidity, as determined by fluorescence polarization of DPH, decreased as early as 0.5 h after injection of hCG. Desensitization also modified the differential scanning calorimetric profile characteristic of control membranes. The accessibility of ovarian LH/hCG receptors was unchanged. The results indicate that the hCG-induced decrease of membrane lipid rigidity is preceded by the process of desensitization of the rat ovary.

Foreign gene expression in marine cyanobacteria under pseudo-continuous culture

Foreign gene expression in a marine cyanobacterium, Synechococcus NKBG 15041c, has been carried out in both batch and pseudo-continuous culture, using chloramphenicaol acetyltransferase (CAT) as a model peptide and the broad host range vector pKT230. CAT has been successfully expressed in marine cyanobacteria under kanamycin resistance gene promoter. Pseudo-continuous culture of these recombinant marine cyanobacteria has been done by varying the dilution rate. At a dilution rate between 0.01 to 0.02 h-1, highest productivity was achieved. Under these conditions, long-term pseudo-continuous culture of recombinant marine cyanobacteria was achieved for more than 600 h with CAT productivity 18-fold greater than that observed in batch culture.

Radiation damage to lymphocyte membrane. Changes of binding and fluorescent parameters of 1-anilino-8-naphthalene sulphonate

The changes of binding and fluorescent parameters of 1-anilino-8-naphthalene sulphonate (ANS) bound to lymphocyte membrane after irradiation in vitro were investigated. No significant dose dependence was found for either fluorescence or its polarization within the dose range of 0.1 to 0.7 Gy from a gamma-neutron field 252Cf source. Marked changes were however found for parameters of ANS binding to membrane after irradiation. The number of binding sites decreased by about 60% and the dissociation constant K decreased by about 70% as compared to control values. The quantum yield of fluorescence also decreased compared with control value. The experimental findings were interpreted as suggesting structural changes in the lipid environment of the lymphocyte membrane caused by irradiation.

Conjugative gene transfer in marine cyanobacteria: Synechococcus sp., Synechocystis sp. and Pseudanabaena sp

Versatility of gene transfer by transconjugation in marine cyanobacteria was demonstrated. In this study, seven different marine cyanobacteria were used as recipient cells. First, transconjugation was carried out using the mobilizable transposon (Tn5) carrying plasmid pSUP1021. Transconjugates were observed in all marine cyanobacteria tested. Second, the broad-host-range vector pKT0230 (IncQ) was tested for transconjugation. pKT230 has been successfully transferred in a marine cyanobacterium Synechococcus sp. NKBG15041C, and replicated as an autonomous replicon without alteration in the restriction enzyme pattern. A maximum transfer efficiency of 5.2 x 10(-4) transconjugants/recipient cell was observed, when mating was performed on agar plates containing low salinity (0.015 M NaCl) medium. This is the first study to demonstrate gene transfer in marine cyanobacteria via transconjugation.

"Clusters" of CJD in Slovakia: the first laboratory evidence of scrapie

Epidemic-like occurrence of Creutzfeldt-Jakob disease was observed in 1987 in Slovakia (Orava). Search for the cause of CJD focus indicated a coincidence of genetic and environmental risks in clustering patients. Since Spongiform Encephalopathies might be transmitted orally, (Bovine Spongiform Encephalopathy), the possibility of zoonotic source of CJD cases in Orava was also considered. A deficient knowledge about the occurrence of scrapie in Slovakia stimulated an examination of sheep with signs of CNS disorders in two flocks of Valasky breed in Orava. In one flock, neurohistopathological examination revealed in sheep brains lesions characteristic for scrapie. Frozen brain tissue of these animals were used for the detection of scrapie associated fibrils. They were found in 2 animals from the same flock. This is the first laboratory confirmation of scrapie in Czecho-Slovakia. The possible epidemiological and economical implications are emphasized.

Psychoanalytic psychotherapy in Japan: the issue of dependency pattern and the resolution of psychopathology

In this paper, I have tried to describe some of the characteristics of psychoanalytic psychotherapy in Japan in terms of dependency patterns in the psychotherapeutic relationship and the resolution of psychological problems. In the beginning of my paper I described problems concerning the professional network of psychiatry and psychotherapy in Japan and looked at the general attitude of the people toward this type of therapy. Then I briefly mentioned the attraction of traditional folk healing practices and outlined two of the academically acknowledged psychotherapies which originated in Japan. I have also presented characteristics of psychoanalytic psychotherapy practice in conjunction with those Japanese psychotherapies, discussing them in terms of the following issues: 1. General differences in psychoanalytic psychotherapy as contrasted to Naikan and Morita therapies and problems in psychoanalytic treatment that result from these differences. 2. Symptom resolution patterns in psychoanalytic treatment in Japanese patients and in relation to dream interpretation. 3. The cultural pattern of transference and how this relates to the Buddhistic figure of Kannon. 4. The Ajase Complex, a model of maternal transferential issues and an interpretation of objected-relations among the Japanese, namely the importance of forgiveness as a resolution of guilt and resentment. 5. The Amida Complex, a model of the cultural pattern of countertransference and the feeling of omnipotence and need for praise in the therapist. 6. Some complications and characteristics of a patient's perception of psychoanalytic interpretation. 7. The patient's perception of the psychoanalytic psychotherapist.