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PubMed1994

Characterization of cis-regulating elements and trans-activating factors of the rat cardiac troponin T gene.

To study the transcriptional regulation of the rat cardiac troponin T (cTnT) gene, chimeric genes composed of the upstream region (-757 to +193 base pairs (bp) relative to the transcription initiation site) of the cTnT gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were constructed and transfected into primary cultures of neonatal cardiomyocytes and cardiac fibroblasts. Deletion analysis showed that a 41-bp fragment (-249 to -209 bp) containing the MEF-2-like motif is an essential element for minimal cardiac-specific expression of the rat cTnT gene. The proximal promoter (-208 to -1 bp) contains two consensus CArG boxes, one M-CAT motif, one AP2 site, and one TATA box. The construct (cTNT-208) composed of the CAT reporter gene driven by this proximal promoter did not show cardiac muscle-specific expression. Ligation of consensus MEF-2-like sequence into the upstream of this chimera only partially increased its ability to express in cardiomyocytes. These results suggest that the spacing among MEF-2-like motif and proximal promoter and/or the flanking sequences of the MEF-2-like motif are important in determining cardiac muscle-specific expression. By footprint analysis with a DNA fragment (-303 to +6 bp), we identified three novel regions (called A, B, and C) protected by protein extract from rat hearts, in addition to the known motifs such as MEF-2, M-CAT, and CArG. Gel retardation with the probe (-235 to -141 bp), containing the MEF-2-like motif, one of the CArG boxes, and the C region, or the 41-bp probe (-249 to -209 bp), containing the MEF-2-like motif, revealed different DNA-protein complexes formed by heart, skeletal muscle, and liver extracts. By using DNA affinity purification, DNA-binding proteins with apparent molecular masses of 22-26 kDa were identified from rat heart extract but not from skeletal and liver extracts, suggesting the involvement of cardiac-specific proteins in regulating the cTnT gene expression.

Animals↗

PubMed1996

Three novel plasmid R6K proteins act in concert to distort DNA within the alpha and beta origins of DNA replication.

Three novel R6K genes which are responsible for expression of DNA distortion polypeptides (DDP) were identified. The DDPs act in vivo in concert to induce similar stepwise DNA helix distortions within two long inverted repeats (alpha LIR and beta LIR), which are essential elements for the two distally located R6K alpha and beta DNA replication origins. DDP1 and DDP2 are encoded by two tandem genes located at the 5' end of alpha LIR, whereas a gene coding for DDP3 is located at the 3' end of beta LIR. DDP1 and DDP2 are required for primary DNA distortion within alpha LIR or beta LIR, while DDP3 is essential for generation of secondary DNA distortion in these LIR sequences. Creation of DNA distortion within alpha LIR depends on its specific interaction with DDP1 and on the presence of the R6K primase DNA-binding site. The possible relevance of these findings to R6K replication is discussed.

Amino Acid Sequence↗

PubMed2003

Calcineurin initiates skeletal muscle differentiation by activating MEF2 and MyoD.

Skeletal muscle differentiation is characterized by withdrawal from the cell cycle, expression of muscle specific genes, fusion into multinucleated cells, and assembly of the contractile apparatus. Although many of the key regulatory elements have been identified, the factors that initiate the differentiation process are not well understood. The calcium-dependent phosphatase calcineurin plays an important regulatory role early in myogenesis, but the downstream effectors of calcineurin in differentiation are not known. Here, we show that calcium and calcineurin regulate expression of the myogenin gene at the level of transcription. The myogenin promoter contains two essential elements; an E-box and an A/T rich element that bind MRF and MEF2 transcription factors, respectively. Both of these elements are responsive to calcium and calcineurin. In differentiating myoblasts, MyoD is the major MRF protein that binds to the myogenin promoter E-box. Calcineurin activates MyoD indirectly by decreasing the expression of the Id inhibitory proteins, probably by down-regulating Egr-1 expression, an upstream activator of Id transcription. These results demonstrate that calcineurin regulates skeletal muscle differentiation by activating MEF2 and MyoD transcription factors leading to the induction of myogenin expression.

Animals↗

PubMed1996

Conducting a comprehensive school health program.

Since the late 1980s, the eight-component model of the comprehensive school health program (CSHP), has been adopted widely in the United States and internationally. While it is acknowledged that the eight program elements should be delivered in a coordinated, interactive manner, numerous issues regarding how this integration best can be achieved, including who at the school level should have this responsibility and how the eight components relate conceptually and logistically, have not been addressed adequately. In essence, a CSHP transforms several solo performers into an orchestra. This article proposes the school health coordinator as an essential element in the eight-component model of the CSHP--the maestro, without whom there can be no symphony. The coordinator's principal responsibilities include administration, integration of personnel and programs, evaluation, and direct intervention. Three program elements--staff wellness, healthy environment, and community/family involvement--are subsumed within the coordinator's role, effectively reducing the number of program elements from eight to five. Potential benefits in addition to issues regarding feasibility of the SHC, are discussed and studies examining the effectiveness of the SHC model are recommended.

Administrative Personnel↗

PubMed2005

A meta-analysis of interventions to improve care for chronic illnesses.

OBJECTIVE: To use empirical data from previously published literature to address 2 research questions: (1) Do interventions that incorporate at least 1 element of the Chronic Care Model (CCM) result in improved outcomes for specific chronic illnesses? (2) Are any elements essential for improved outcomes? STUDY DESIGN: Meta-analysis. METHODS: Articles were identified from narrative literature reviews and quantitative meta-analyses, each of which covered multiple bibliographic databases from inception to March 2003. We supplemented this strategy by searching the MEDLINE database (1998-2003) and by consulting experts. We included randomized and nonrandomized controlled trials of interventions that contained 1 or more elements of the CCM for asthma, congestive heart failure (CHF), depression, and diabetes. We extracted data on clinical outcomes, quality of life, and processes of care. We then used random-effects modeling to compute pooled standardized effect sizes and risk ratios. RESULTS: Of 1345 abstracts screened, 112 studies contributed data to the meta-analysis: asthma, 27 studies; CHF, 21 studies; depression, 33 studies; and diabetes, 31 studies. Interventions with at least 1 CCM element had consistently beneficial effects on clinical outcomes and processes of care across all conditions studied. The effects on quality of life were mixed, with only the CHF and depression studies showing benefit. Publication bias was noted for the CHF studies and a subset of the asthma studies. CONCLUSIONS: Interventions that contain at least 1 CCM element improve clinical outcomes and processes of care--and to a lesser extent, quality of life--for patients with chronic illnesses.

Chronic Disease↗

PubMed1991

Regulation of myocardial contractility.

This symposium focuses on recent developments in the cellular and molecular basis of myocardial contractility. This topic is an essential element in modern exercise biology as both the acute and chronic responses to exercise are dependent on these mechanisms. The papers in this symposium reflect knowledge garnered from advances over the past decade in a variety of fields including: molecular biology, tissue culture (isolation of functional myocytes), organic chemistry (fluorescent Ca2+ indicators), and electrophysiology (patch clamp technology). In cardiac muscle, contractility is regulated essentially in two ways: the intracellular Ca2+ transient and the response of the myofilaments to that transient. This symposium addresses both of these mechanisms in some detail. The response of the myofilaments can be altered through both covalent modification (e.g., phosphorylation) of various contractile proteins and noncovalent (e.g., change in pH) mechanisms. The [Ca2+]i can increase from about 100 nM in diastole to the low microM range in systole. The peak [Ca2+]i observed in systole can vary several-fold owing to an orchestrated modulation of several different Ca2+ transport proteins on both the sarcolemma and sarcoplasmic reticulum. This modulation is quite distinct from that observed in skeletal muscles and underscores the physiological differences in these two types of striated muscle in varying contractile force. These proteins include: the L-type voltage-dependent Ca2+ channel and the Na+/Ca2+ exchanger in the sarcolemma, and the Ca2+ release channel and Ca2+ pump in the sarcoplasmic reticulum. Each of these proteins is subject to complex regulation by a variety of modulators, and aspects of this regulation are discussed in detail.

Action Potentials↗

PubMed2005

Distribution of elements in the millipede, Oxidus gracilis C. L. Koch (Polydesmida: Paradoxosomatidae) and the relation to environmental habitats.

The concentrations of 55 elements in the millipede, Oxidus gracilis, soil and plant in the habitat were examined using inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). In all the millipedes, Ca concentration derived from calcium carbonate in the exoskeleton was the highest at average 94 microg/mg-weight. The other major elements were the following: Mg, K, Na, Zn, Fe, Al, Cu, Sr, Ba, Mn and Ti (>1 ng/mg-body weight), whereas Se, Mo, Ag, Cd, Co, Li and Ce etc. were in trace levels. Interestingly, the various 15 elements such as Ca, Na, Zn, Al, Ba, Ga, Ag, Cd, Co and Y in environmental habitats were well reflected in the body of the millipede. Although the heavy metal contents, in the order of Cu>Pb>Cd, were similar to those of other invertebrates, Cu in the millipede was remarkably high concentration. Zn was maintained in a range of 72-394 ng/mg-weight as essential element in the body and no difference was found in the sexes. The C1 chondrite normalization pattern for lanthanoid series elements in the millipede, soil and plant indicated that the environmental habitats were well protected from pollution. These characteristics of internal elements and metal accumulation in the millipede or relation to their habitats would be useful information for the environmental pollution studies.

Animals↗

PubMed2006

[Determination of trace elements in pumpkin by FAAS].

Conditions for simultaneous determination of multi-trace elements in pumpkin by FAAS were studied. K, Ca, Mg, Na, Zn, Cu, Mn, Fe, Co and Cr in different parts and different growth periods of pumpkin were determined, the relative standard deviation of the method is between 0.1% and 2.6%, and the recovery is between 96.7% and 106.5%. Analytical results were satisfactory. The results showed that some elements essential to human such as K, Ca, Mg, Zn, Cr and Mn in pumpkin are abundant, implying that the nutritive value of pumpkin is high.

Cucurbita↗

PubMed2006

Quantum telecommunication based on atomic cascade transitions.

A quantum repeater at telecommunications wavelengths with long-lived atomic memory is proposed, and its critical elements are experimentally demonstrated using a cold atomic ensemble. Via atomic cascade emission, an entangled pair of 1.53 microm and 780 nm photons is generated. The former is ideal for long-distance quantum communication, and the latter is naturally suited for mapping to a long-lived atomic memory. Together with our previous demonstration of photonic-to-atomic qubit conversion, both of the essential elements for the proposed telecommunications quantum repeater have now been realized.

Journal Article↗

PubMed1995

Proton activation analysis of stable isotopes for a molybdenum biokinetics study in humans.

Molybdenum is a trace element essential to life. Nevertheless, little information is available on its metabolism in humans. A methodology based on stable isotope administration that combines compartmental analysis, simultaneous use of two tracers, and proton nuclear activation (PNA) is presented. A four-compartment metabolic model was adopted. The compartments are stomach, small intestine, transfer compartment, and unquantified tissue pool. The employment of two different stable isotopes of the element under investigation as tracers was made possible by PNA. Optimization of the technique for molybdenum determination in plasma led to the choice of 95Mo and 96Mo as tracers. Their concentrations in plasma can be determined measuring the disintegration gamma lines of the corresponding technetium radioisotopes produced via (p,n) reaction. In the adopted experimental conditions, a minimum detectable concentration of 2 ng isotope/ml plasma was attained. A kinetics study was performed on two healthy volunteers. To both subjects one tracer was orally administered, and the other intravenously injected. Venous blood samples were withdrawn at different postinjection times and the concentrations for both isotopes determined. The model parameters describing molybdenum kinetics were obtained for the two individuals. Total absorbed fraction was found to be 0.84 +/- 0.03 and 0.86 +/- 0.07, respectively.

Activation Analysis↗

PubMed1984

Mutational dissection of the 21 bp repeat region of the SV40 early promoter reveals that it contains overlapping elements of the early-early and late-early promoters.

Using quantitative S1 nuclease analysis and recombinants which contain the SV40 early promoter region linked to the rabbit beta-globin gene coding sequence, we have studied the effect of deletion, inversion and point mutations, located within the 21 bp repeat region, on initiation of transcription from the early-early and late-early startsites in the absence of T-antigen. Our data establish unequivocally that the six GC-rich repeats present in the 21 bp repeat region are essential elements of both the early-early and late-early promoters and that they are not redundant, since mutations, which affect only the GC-rich repeat most proximal to the TATA box, decrease drastically the activity of the early-early promoter, but increase that of the late-early promoter. On the other hand, the four GC-rich repeats most proximal to the 72 bp repeat are common elements of the two overlapping early-early and late-early promoters. Our results, which confirm that the early-early promoter is stronger than the late-early one, also support our previous suggestion that they are in competition for the transcriptional machinery. The general organization of the SV40 early promoter region is discussed.

Base Composition↗

PubMed1998

Study of the age and sex dependence of trace elements in hair by correspondence analysis.

The aim of the study was to examine the potential of multidimensional analysis, and in particular of correspondence analysis (CA), in bringing to light the influence of sex and age on trace element (TE) concentrations in hair from an unselected French population. Sixteen elements (S, Hg, Se, Zn, Pb, Cd, Ni, Co, Mn, Fe, Cr, Mg, Al, Ca, Cu, Ag) were assayed by inductively coupled argon plasma (ICAP) emission spectroscopy in the scalp hair of 135 men and 346 women. In spite of the high background noise, CA was able to reveal the differing patterns in males and females. For instance, in this population, higher relative levels of the essential elements, Ca, Mg, Zn, and Cu, but also of Ag, characterized women's hair, whereas higher relative levels of the heavy metals, Fe and Pb, were associated with men's hair. Al and Ag were unexplainedly high in the hair of the youngest members of the population. The Cu and Co of youth seemed to give way to a predominance of Zn in maturity. The hair of individuals in their forties tended to be richest in Ca and Mg, but these elements decreased with advancing age. Heavy metals (Hg, Pb, Fe) accumulated with age, whereas Se, Mn, and Cr seemed independent of age. CA is manifestly a very useful tool for revealing underlying dimensions in complex dynamic systems and unsuspected relationships among variables. Clearly, the significance of the high Al and Ag contents in the hair of certain members of the population, especially of the very young, needs to be investigated from both physiological and toxicological aspects.

Adolescent↗

PubMed1998

Some considerations in the structure of the self and its pathology.

The author's intention is to contribute to the study of the structure of the self, both discussing the different processes of interiorisation and identification that play their parts in this development, and looking into the role played by the objects, and especially the superego. Interiorisation (the choice of this word is explained) is seen as a broad concept that covers incorporation, internalisation, introjection and introjective identification, and the dynamic of each of these mechanisms is discussed, along with its influence in the development of the structure of the self and of its constituent elements. Taking these concepts as a theoretical base, the author goes on to consider the field of 'pathology of defect' compared with the more classical pathology of conflict. Starting from the findings of different authors, especially Fairbairn and Kohut, he enlarges upon theoretical aspects of this 'pathology of defect' and its close relationship with Kohut's theories of narcissism, emphasising that, apart from other factors, an essential element in understanding this pathology is the development of the superego. Clinical material is presented to illustrate the theory.

Adult↗

PubMed1991

Determination of eight elements in six human cancer cell lines and two human normal cell lines by PIXE.

Gastric, hepatic, and pulmonary cancer cell lines, and the third passage of normal gastric and pulmonary cell lines were analyzed by proton induced X-ray emission (PIXE) method. The contents of element Sr, Ca, Fe, Zn, P, K, Cu, and As in the cell lines were determined. The Sr, Ca, Fe, Zn, and As contents in cancer cell lines were significantly lower than those in the normal cell lines (p less than 0.05), whereas there were no significant differences for the P, K, and Cu contents (p greater than 0.1). The results suggest that the need of some essential elements has been diminished in cancer cell proliferation.

Cell Line↗

PubMed1999

Does theory have value in clinical child psychology?

Examines the value and importance of theory in child psychology, particularly with respect to clinical practice. Although it is readily apparent that theory is not an essential element of treatment, the role of theory is to provide a coherent framework for clinical intervention. Theory provides a foundation for understanding the presenting pathology, the factors that affect it, the patient's and therapist's roles within the context of treatment, and the specific intervention strategies to be utilized. Therapeutic commonalities are considered as they may affect treatment outcome, but they are not viewed as the essential factors in efficacy. The value and meaning of eclecticism are also discussed.

Child↗

PubMed1995

Regulation of endothelial VCAM-1 expression in murine cardiac grafts. Expression of allograft endothelial VCAM-1 can be manipulated with antagonist of IFN-alpha or IL-4 and is not required for allograft rejection.

This report provides evidence to support the hypothesis that tumor necrosis factor-alpha (TNF-alpha) and IL-4 promote the expression of new endothelial surface molecules in rejecting murine heterotopic cardiac allografts. The microvascular endothelia of these cardiac allografts all develop strong reactivity with the monoclonal antibodies (mAbs) YN1.1/74 (anti-ICAM-1), M/K-2 (anti-VCAM-1) and MECA-32 (undefined molecule) within 3 to 5 days of graft implantation. Daily treatment of the allograft recipients with pentoxifylline (PTX), soluble TNF receptor (TNFR:Fc), anti-interleukin-4 (IL-4) mAb (11B11), or soluble IL-4 receptor, each abrogate the expression of endothelial VCAM-1 and reduce the endothelial reactivity with the mAbs YN1.1/74 and MECA-32 to levels found in cardiac isografts. This is accompanied by a reduction, but not an elimination, of interstitial leukocytic infiltration. Despite this, cardiac allograft recipients treated with PTX or the mAb 11B11 rejected allografts at the same rate as untreated allograft recipients, ie, within 10 to 12 days after graft implantation. These rejected grafts contained mRNAs for TNF-alpha and IL-4, as well as for all other cytokines that have been associated with rejecting allografts. This suggests that endothelial VCAM-1 expression, which is characteristic of rejection, is not an essential element of the rejection process. Interestingly, the grafts from the PTX-treated recipients continued to display rare, isolated VCAM-1 positive cells in the interstitium, which may be dendritic cells. In general, these studies demonstrate a role for IL-4 and TNF-alpha in the alterations of vascular endothelial phenotype observed in rejecting cardiac allografts. They also demonstrate that endothelial VCAM-1 expression is not essential for the allograft rejection process, and that the role of VCAM-1 in this process may be more subtle than was initially suspected.

Animals↗

PubMed1996

Efficient translation of distal cistrons of a polycistronic mRNA of a plant pararetrovirus requires a compatible interaction between the mRNA 3' end and the proteinaceous trans-activator.

Caulimoviruses, a type of plant pararetrovirus, employ a highly unusual mechanism to express the multiple cistrons of their pregenomic RNA. It involves translation of a polycistronic mRNA utilizing cis-acting viral RNA sequences and a transacting virus-encoded protein (P6). In addition to its role in polycistronic translation, the translational trans-activator protein P6 also activates its own expression from a monocistronic subgenomic RNA. Using Nicotiana Edwardsonii cell suspension protoplasts, we analyzed the ability of P6 proteins from three different caulimoviruses to activate viral RNA-based reporter constructs. Cis-acting elements present in figwort mosaic caulimovirus (FMV) are functional not only in the presence of the cognate P6 activator protein, but also in the presence of the heterologous activators from cauliflower mosaic caulimovirus (CaMV) and peanut chlorotic streak caulimovirus (PCISV). However, when 3' cis-acting elements essential for efficient polycistronic expression of FMV are replaced by their counterparts from PCISV, reporter gene expression is only observed in the presence of PCISV P6. Derepression of monocistronic reporter constructs tailed with FMV or CaMV 3' proximal sequences is less efficient in the presence of PCISV P6 than with either FMV or CaMV P6, but more efficient when the constructs contain a cognate PCISV 3' cis-element. Efficient expression of polycistronic and monocistronic caulimovirus mRNAs in plant cells thus requires compatible interactions between P6, a translational trans-activator, and its cognate cis-element at the 3' end of the mRNA.

Caulimovirus↗

PubMed1995

The bacterial actin nucleator protein ActA of Listeria monocytogenes contains multiple binding sites for host microfilament proteins.

BACKGROUND: Several intracellular pathogens, including Listeria monocytogenes, use components of the host actin-based cytoskeleton for intracellular movement and for cell-to-cell spread. These bacterial systems provide relatively simple model systems with which to study actin-based motility. Genetic analysis of L. monocytogenes led to the identification of the 90 kD surface-bound ActA polypeptide as the sole bacterial factor required for the initiation of recruitment of host actin filaments. Numerous host actin-binding proteins have been localized within the actin-based cytoskeleton that surrounds Listeria once it is inside a mammalian cell, including alpha-actinin, fimbrin, filamin, villin, ezrin/radixin, profilin and the vasodilator-stimulated phosphoprotein, VASP. Only VASP is known to bind directly to ActA. We sought to determine which regions of the ActA molecule interact with VASP and other components of the host microfilament system. RESULTS: We used the previously developed mitochondrial targeting assay to determine regions of the ActA protein that are involved in the recruitment of the host actin-based cytoskeleton. By examining amino-terminally truncated ActA derivatives for their ability to recruit cytoskeletal proteins, an essential element for actin filament nucleation was identified between amino acids 128 and 151 of ActA. An ActA derivative from which the central proline-rich repeats were deleted retained its ability to recruit filamentous actin, albeit poorly, but was unable to bind VASP. CONCLUSIONS: Our studies reveal the initial interactions that take place between invading Listeria and host microfilament proteins. The listerial ActA polypeptide contains at least two essential sites that are required for efficient microfilament assembly: an amino-terminal 23 amino-acid region for actin filament nucleation, and VASP-binding proline-rich repeats. Hence, ActA represents a prototype actin filament nucleator. We suggest that host cell analogues of ActA exist and are important components of structures involved in cell motility.

Actins↗