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PubMed1976

Inheritance of nocardiophage phi EC in matings of nocardial lysogens.

Lysogens of Nocardia erythropolis were mated with nonlysogenic strains to study the inheritance of the phi EC prophage. Crosses between lysogenic strains of the Mat-Ce mating type and nonlysogenic Mat-cE strains produced Mat-cE lysogens at a recovery rate of 17%, whereas recombination frequencies between chromosomal traits were about 2.3 x 10(-5). Crosses of lysogenic Mat-cE mating types with nonlysogenic Mat-Ce produced Mat-Ce lysogens at a recovery rate of 19%, whereas recombinants for chromosomal traits were recovered at only 1.8 x 10(-5). Crosses of homologous mating types, lysogenic Mat-Ce with nonlysogenic Mat-Ce or lysogenic Mat-cE with nonlysogenic Mat-cE, failed to transfer the prophage. It was concluded that the phi EC prophage exists as a plasmid and can be transferred at high frequencies with patterns of transfer controlled like typical nocardial fertility. Evidence that the prophage may also exist as an integrated element was observed from recombination analyses.

Bacteriophages↗
PubMed1995

Identification and functional analysis of the transfer region of plasmid pMEA300 of the methylotrophic actinomycete Amycolatopsis methanolica.

Amycolatopsis methanolica contains a 13.3-kb plasmid (pMEA300) that is present either as an integrated element or as an autonomously replicating plasmid. Conjugational transfer of pMEA300 results in pock formation, zones of growth inhibition that become apparent when plasmid-carrying donor cells develop in a confluent lawn of plasmid-lacking recipient cells. A 6.2-kb pMEA300 DNA region specifying the functions of conjugation and pock formation was sequenced, revealing 10 open reading frames. This is the first sequence of the transfer region of a plasmid from a nonstreptomycete actinomycete. No clear similarities were found between the deduced sequences of the 10 putative Tra proteins of pMEA300 and those of Streptomyces plasmids. All Tra proteins of pMEA300 thus may represent unfamiliar types. A detailed mutational analysis showed that at least four individual proteins, TraG (9,488 Da), TraH (12,586 Da), TraI (40,468 Da), and TraJ (81,109 Da), are required for efficient transfer of pMEA300. Their disruption resulted in a clear reduction in the conjugational transfer frequencies, ranging from (5.2 x 10(1))-fold (TraG) to (2.3 x 10(6))-fold (TraJ), and in reduced pock sizes. At least two putative proteins, TraA (10,698 Da) and TraB (31,442 Da), were shown to be responsible for pock formation specifically. Specific binding of the pMEA300-encoded KorA protein to the traA-korA intragenic region was observed.

Actinobacteria↗
PubMed2002

Characterization of genes involved in modulation of conjugal transfer of the Bacteroides conjugative transposon CTnDOT.

In previous studies we identified an 18-kb region of the Bacteroides conjugative transposon CTnDOT that was sufficient for mobilization of coresident plasmids and unlinked integrated elements, as well as self-transfer from Bacteroides to Escherichia coli. When this 18-kb region was cloned on a plasmid (pLYL72), the plasmid transferred itself constitutively in the absence of a coresident conjugative transposon. However, when this plasmid was present in a Bacteroides strain containing a coresident conjugative transposon, conjugal transfer was repressed in the absence of tetracycline and enhanced in the presence of tetracycline. These results suggested that a negative and a positive regulator of conjugal transfer were encoded outside the transfer region of the CTnDOT element. In this work, a minimal and inducible transfer system was constructed and used in transfer and Western blot analyses to identify the differentially regulated genes from CTnDOT responsible for the enhancement and repression of pLYL72 conjugal transfer. Both of these regulatory functions have been localized to a region of the CTnDOT element that is essential for CTn excision. In the presence of tetracycline, the regulatory protein RteC activates the expression of a putative topoisomerase gene, exc, which in turn results in an increase in transfer protein expression and a concomitant 100- to 1,000-fold increase in the frequency of pLYL72 transfer. Our results also suggest that since exc alone cannot result in enhancement of transfer, other factors encoded upstream of exc are also required. Conversely, in the absence of tetracycline, a gene located near the 3' end of exc is responsible for the repression of transfer protein expression and also results in a 100- to 1,000-fold decrease in the frequency of pLYL72 transfer.

Bacterial Outer Membrane Proteins↗
PubMed2005

Regulation of excision genes of the Bacteroides conjugative transposon CTnDOT.

The first step in the transfer of the Bacteroides conjugative transposon CTnDOT is excision of the integrated element from the chromosome to form a circular transfer intermediate. Excision occurs only after the bacteria are exposed to tetracycline. Previously, four excision genes were identified. One was the integrase gene intDOT, which appeared to be expressed constitutively. Three other genes essential for excision (orf2c, orf2d, and exc) were found located in a cluster 13 kbp downstream of intDOT. By using uidA fusions and real-time reverse transcriptase PCR, we demonstrate here that the excision genes orf2c, orf2d, and exc are part of an operon that also contains open reading frame orf3, previously shown not to be essential for excision. We also show that operon expression is regulated at the transcriptional level in response to tetracycline. The transcript start site for the operon has been localized. Three CTnDOT regulatory genes are thought to be involved in tetracycline regulation of excision, rteA, rteB, and rteC. By placing rteC under the control of a heterologous promoter, we found that RteC alone was sufficient for induction of the orf2c operon. If, however, the rteC gene was under the control of its own promoter, it was not able to induce orf2c operon expression unless rteA and rteB were present. Thus, RteA and RteB participate in excision by stimulating transcription of rteC. Using electrophoretic mobility shift analysis, we found that a purified His(6)-tagged form of RteC bound DNA upstream of the -33 region of the promoter. Changing the sequence in the region between bp -50 and -70 reduced the expression of the orf2c operon in vivo. Taken together, our results support the hypothesis that RteC acts as a DNA-binding protein that binds upstream of the orf2c promoter and is responsible for tetracycline-regulated transcriptional regulation of the orf2c operon.

Bacterial Proteins↗
PubMed1993

Signals that produce 3' termini in CYC1 mRNA of the yeast Saccharomyces cerevisiae.

The cyc1-512 mutant was previously shown to contain a 38-bp deletion, 8 nucleotides upstream from the major wild-type poly(A) site, in the CYC1 gene, which encodes iso-1-cytochrome c of the yeast Saccharomyces cerevisiae. This 38-bp deletion caused a 90% reduction in the CYC1 transcripts, which were heterogeneous in size, aberrantly long, and presumably labile (K. S. Zaret and F. Sherman, Cell 28:563-573, 1982). Site-directed mutagenesis in and adjacent to the 38-bp region was used to identify signals involved in the formation and positioning of CYC1 mRNA 3' ends. In addition, combinations of various putative 3' end-forming signals were introduced by in vitro mutagenesis into the 3' region of the cyc1-512 mutant. The combined results from both studies suggest that 3' end formation in yeast cells involves signals having the following three distinct but integrated elements acting in concert: (i) the upstream element, including sequences TATATA, TAG ... TATGTA, and TTTTTATA, which function by enhancing the efficiency of downstream elements; (ii) downstream elements, such as TTAAGAAC and AAGAA, which position the poly(A) site; and (iii) the actual site of polyadenylation, which often occurs after cytidine residues that are 3' to the so-called downstream element. While the upstream element is required for efficient 3' end formation, alterations of the downstream element and poly(A) sites generally do not affect the efficiency of 3' end formation but appear to alter the positions of poly(A) sites. In addition, we have better defined the upstream elements by examining various derivatives of TATATA and TAG ... TATGTA, and we have examined the spatial requirements of the three elements by systematically introducing or deleting upstream and downstream elements and cytidine poly(A) sites.

Alleles↗
PubMed1996

3pK, a novel mitogen-activated protein (MAP) kinase-activated protein kinase, is targeted by three MAP kinase pathways.

Recently we have identified a mitogen-activated protein kinase (MAPK)-activated protein kinase, named 3pK (G. Sithanandam, F. Latif, U. Smola, R. A. Bernal, F.-M. Duh, H. Li, I. Kuzmin, V. Wixler, L. Geil, S. Shresta, P. A. Lloyd, S. Bader, Y. Sekido, K. D. Tartof, V. I. Kashuba, E. R. Zabarovsky, M. Dean, G. Klein, B. Zbar, M. I. Lerman, J. D. Minna, U. R. Rapp, and A. Allikmets, Mol. Cell. Biol. 16:868-876, 1996). In vitro characterization of the kinase revealed that 3pK is activated by ERK. It was further shown that 3pK is phosphorylated in vivo after stimulation of cells with serum. However, the in vivo relevance of this observation in terms of involvement of the Raf/MEK/ERK cascade has not been established. Here we show that 3pK is activated in vivo by the growth inducers serum and tetradecanoyl phorbol acetate in promyelocytic HL60 cells and transiently transfected embryonic kidney 293 cells. Activation of 3pK was Raf dependent and was mediated by the Raf/MEK/ERK kinase cascade. 3pK was also shown to be activated after stress stimulation of cells. In vitro studies with recombinant proteins demonstrate that in addition to ERK, members of other subgroups of the MAPK family, namely, p38RK and Jun-N-terminal kinases/stress-activated protein kinases, were also able to phosphorylate and activate 3pK. Cotransfection experiments as well as the use of a specific inhibitor of p38RK showed that these in vitro upstream activators also function in vivo, identifying 3pK as the first kinase to be activated through all three MAPK cascades. Thus, 3pK is a novel convergence point of different MAPK pathways and could function as an integrative element of signaling in both mitogen and stress responses.

Calcium-Calmodulin-Dependent Protein Kinases↗
PubMed1987

Individual mouse VL30 elements transferred to rat cells by viral pseudotypes retain their responsiveness to activators of protein kinase C.

By exploiting the retroviral characteristics of mouse VL30 elements, we transferred individual copies of VL30 to Rat-1 cells by infection. Analysis of clonal isolates containing single VL30 elements integrated into the Rat-1 genome indicates that responsiveness to activators of protein kinase C is an inherent property of at least some of the VL30 sequences.

Animals↗
PubMed1989

Lysozyme and mucins in gastric adenomas.

A method for the simultaneous demonstration of lysozyme and mucins in 39 cases of gastric adenomas differentiated two intermediate cell types. The first was similar to a columnar cell comprising a single cell population which covered extensive areas of the adenomas. This cell type often showed supranuclear lysozyme reactivity and apical neutral mucins, sialomucins, and sulphomucins in variable amounts. The second cell type was found in 11 adenomas, located mainly in the fundal area. It seemed to be a transitional form between the goblet cell and the Paneth cell. This cell type was scattered among columnar cells, occasional Paneth-like cells, and small goblet cells. These two types of intermediate cells may be regarded as abnormally differentiated integral elements of gastric adenomas. They may be associated with the neck stem cells in the cytogenesis of gastric adenomas.

Adenoma↗
PubMed1988

Electrophysiology of mammalian tectal neurons in vitro. I. Transient ionic conductances.

1. The electrophysiologic properties and ionic conductances of neurons located in the stratum griseum medium (SGM) of the guinea pig superior colliculus (SC) were studied by intracellular techniques in an in vitro mesencephalic slice preparation. 2. Cells were stained with Lucifer yellow and demonstrated a uniform appearance. They had an ovoid soma with dendrites directed toward the dorsal surface. These dendrites crossed the stratum opticum, and their fine ramifications reached the stratum zonale. 3. SGM cells had a mean resting potential of 59.4 +/- 5.1 (SE) mV (n = 30), a mean slope input resistance of 26.6 +/- 10 M omega (n = 30), and a mean time constant of 4.13 +/- 1.3 ms (n = 27). 4. Direct depolarization of SC neurons produced tonic repetitive firing. These Na+-dependent action potentials showed spike-frequency adaptation. After addition of tetrodotoxin (TTX) and replacement of Ca2+ by Ba2+, slow, high-threshold spikes were also generated. The trains of Ba2+ spikes did not show adaptation. 5. In about half of the cells direct hyperpolarization elicited a slow return of the membrane potential to base line at the termination of the pulse (probably due to activation of an A-type conductance) and no anomalous rectification. The remaining cells did not have an A-type conductance but demonstrated anomolous rectification which was reversibly abolished by Cs+ but unaffected by Ba2+. 6. Some cells could be anti- and/or orthodromically activated by a stimulating electrode placed at the intercollicular commissure. These, and action potentials elicited by direct activation, had a shoulder on their falling phase. The shoulder disappeared after removal of external Ca2+ or addition of Cd2+ to the bath. 7. During repetitive firing in those cells that demonstrated an A-type conductance, the shoulder became progressively more accentuated during the train of spikes, due to inactivation of this A-type conductance. This resulted in an increase in spike duration. 8. The electrophysiological properties of these cells and their morphological characteristics suggest that they may serve as the element integrating visual and nonvisual information at the superior colliculus.

Action Potentials↗
PubMed2002

Vectorial Transcellular Calcium Transport in Intestine: Integration of Current Models.

In spite of decades of research, the exact subcellular pathway for calcium transport in intestine has not been elucidated. In this mini-review, we present three models for vectorial movement of calcium across the cell: facilitated (cytoplasmic) diffusion, vesicular/lysosomal transport, and tunneling through the endoplasmic reticulum compartment. We conclude by offering one way to integrate elements of these three models.

Journal Article↗
PubMed1999

[Problems of study designs with randomization, blinding and placebos].

As randomised double-blind trials are not rarely demanded as a prerequisite for the scientific acceptance of complementary medicine, the author has analysed the soundness of this demand on the basis of the international literature. As a result there appeared a number of methodological, practical and ethical problems which question the theoretically deduced primal value of this study design relative to the needs of medical practice and of health insurance issues. The experimental instruments of randomisation, blinding and placebo deliberately exclude essential therapeutic factors which are integral elements of complementary medical concepts; therefore, it is suggested to supplement quantitatively and collectively oriented experimental research by non-experimental procedures, which adequately reflect the context- and practice-related individual reality.

Bioethics↗
PubMedDate not supplied

The hysterical personality disorder: a phenomenological approach.

The background of the present study is a general uncertainty as to what comprises the essence of hysterical (histrionic) personality disorder. Using phenomenological methodology, phenomena observable in the 'classic' hysterical personality are analysed, described, named, and classified according to the basic functions of human experience and behaviour. The resulting psychopathological picture of the hysterical personality facilitates a differential diagnosis that is often decidedly difficult. The phenomenon of dissociation of the mental processes is demonstrated for the various basic functions. A specific feature of the disorder is shown which generates a dissociation of contents of the personality along a conscious-preconscious-unconscious continuum. It is concluded that dissocation is, in the final analysis, the prerequisite for a compromised and partial acting out of prohibited non-integrated elements, e.g. aggression, as a coping strategy.

Adaptation, Psychological↗
PubMed1981

Mastering change: epidemiological and case studies in Senegal, West Africa.

While it has often been assumed that persons exposed to rapid social change incur a risk to their mental health, research results have been inconsistent. The authors found that 269 urban migrants in Senegal, West Africa, did not demonstrate worse mental health than did 300 rural nonmigrants. Case studies suggest that outcome is determined not by change per se but by social contingencies which modify the situations, as well as by personal assets which individuals bring with them. Critical factors include the persistence of familiar cultural forms within the new environment and skills such as literacy and the ability to creatively integrate elements of the old and new cultures.

Acculturation↗
PubMed1995

Dopamine agonists in Parkinson's disease.

The main pathologic hallmark of Parkinson's disease is a degeneration of the dopaminergic cells in the substantia nigra, pars compacta and--to a lesser extent--in the ventral tegmental area. Striatal dopamine concentrations are significantly reduced before clinical symptoms become apparent. Recent neuroanatomic and function studies have revealed that the nigrostriatal dopaminergic projection is only one of the neuronal elements integrated into extensive basal ganglia-thalamocortical circuits that are intimately involved in the regulation of motor activity. The possibilities for therapeutic intervention at the level of the different dopamine receptor subtypes and their effect on the regulation of motor behavior will be briefly reviewed. Dopamine precursors are considered to provide the best symptomatic treatment, whereas dopamine agonists, although less effective, might be important in slowing the progression of the disease. Our results with pergolide as monotherapy and in combination therapy in patients with Parkinson's disease also are discussed.

Aged↗
PubMed2004

Cardiopulmonary exercise testing and prognosis in chronic heart failure: a prognosticating algorithm for the individual patient.

The identification of individuals who are at high risk of chronic heart failure (HF) is a medical art of growing concern. Cardiopulmonary exercise stress testing (CPX) has become an important clinical tool to predict outcome. The value of peak oxygen consumption rests in the fact that it integrates elements of cardiac adaptations, and skeletal muscle, pulmonary, and endothelial dysfunctions more than other traditional prognostic indicators of chronic HF. Recently, exercise-related ventilatory abnormalities have gained attention, stimulating scientific debate and an innovative perspective. This review, through a critical examination of previous experiences, will focus on the prognostic application of CPX, defining a proficient outline of treatment for the individual patient.

Algorithms↗
PubMed2004

Retrospective analyses of clinical features and therapeutic outcomes in thymectomized patients with myasthenia gravis at Shinshu University.

OBJECTIVES: Thymectomy has become recognized as an integral element in the treatment of patients with myasthenia gravis (MG). Although the incidence of elderly-onset MG has recently been increasing, there is little data demonstrating the efficacy and complications of thymectomy in this population. To clarify this point, we divided the thymectomized patients with MG into young and elderly groups, and retrospectively examined their clinical features and therapeutic outcomes. PATIENTS AND METHODS: We reviewed 57 MG patients who had been admitted to our hospital between 1988 and 2002. The patients were classified into young (younger than 60) and elderly (60 or older) groups according to the age of onset, and the therapeutic outcomes of thymectomy were evaluated using myasthenic severity scales and the duration from operation to discharge. RESULTS: Myasthenic severity scales significantly improved after thymectomy in the elderly group both with (p<0.005) and without thymoma (p<0.05) compared with before. With regard to the duration from thymectomy to discharge, no significant difference could be found between the young and elderly groups, irrespective of associated thymoma. There were no serious complications during and after thymectomy in either the young or the elderly group. CONCLUSIONS: Despite various possible complications due to aging, thymectomy should be actively considered also in the treatment of elderly MG patients because it can reliably and safely improve myasthenic symptoms in combination with immunosuppressive agents, including corticosteroid.

Adult↗
PubMed2004

Developing inhibitors to selectively target two-component and phosphorelay signal transduction systems of pathogenic microorganisms.

Two-component signal transduction systems and their expanded variants known as phosphorelays are integral elements of the virulence and antimicrobial resistance responses of a wide range of pathogenic bacteria and fungi and also regulate essential functions. As a consequence, two-component systems and phosphorelays are recognized targets for the development of novel antimicrobial agents and a number of chemically synthesized inhibitors from different chemical classes have been identified by compound library screens. However, in the majority of cases these compounds do not appear to be selective for signal transduction pathways and exert their effect by multiple mechanisms of action. The key to designing molecules to selectively disrupt signal transduction may lie with the conserved features of response regulators and the structural analysis of complexes of signaling proteins.

Anti-Infective Agents↗
PubMed1991

Physical fitness effects on substance abuse risk factors and use patterns.

In this study, seventy-four adolescents in either a school, community or hospital based drug intervention program received and eight to nine week structured fitness activity class as an integrated element of their respective prevention or treatment program. Prepost assessments indicated significant gains in the field fitness tests of one mile run, 1 minute situp, 1 minute pushup, percent fat and flexibility for the total sample. Based upon prepost change on the one mile run time (less than 1:00) subjects were categorized as improvers (n = 38) and non-improvers (n = 36). Improvers demonstrated a significant increase in the self concept risk factor (Piers Harris Self Concept Scale) and a significant decrease in anxiety and depression risk factors (General Well-Being Scale) compared to the non-improvers. At posttest, the improvers self reported substance use patterns were significantly lower compared to the non-improvers for percentage of the sample who were multiple drug users and alcohol uses per week and were significantly higher for the percentage of the sample demonstrating total abstinence. These findings are suggestive of the usefulness of physical training as a supplemental intervention for adolescent substance abusers.

Adolescent↗