Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Interplay”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources
PubMed1995

Interplay of nitric oxide and histamine in the regulation of coronary reactive hyperemia and coronary autoregulation.

Reactive hyperemia following 30 s of coronary occlusion in the isolated guinea pig heart is accompanied by a two-fold increase of nitric oxide (NO) and histamine release, which are significantly reduced in the presence of L-NAME, cimetidine and thioperamide, respectively. Great changes of histamine release occur during autoregulation. However, histamine seems much more important for metabolic dilation below the autoregulatory range. Inhibition of NO synthesis, but not blockade of histamine receptors, widens the autoregulatory range. Changes of the released NO and histamine under conditions employed in this study suggest a positive feed-back relationship between NO and histamine in the regulation of coronary circulation.

Animals↗
PubMed2004

Interplay between growth factor and nutrient signaling: lessons from Drosophila TOR.

During normal development, cellular and organismal growth is coordinately regulated. Each cell and each individual organ integrates information about nutrient availability, hormonal signals, and intrinsic growth programs. Describing the signaling pathways involved in these processes and how they are integrated is important to understand how growth is controlled during development and may also permit the development of means to curb uncontrolled growth in disease. In recent years, the biochemical analysis of cellular growth in cultured cells and the genetic dissection of growth control in model organisms has identified two conserved signaling pathways dedicated to cellular growth. The target of rapamycin (TOR) pathway regulates growth in response to nutrients, and the insulin/IGF pathways are involved in coordinating cellular growth in response to endocrine signals. This review discusses recent advances in the understanding of the interaction between these pathways, with a special focus on the contribution of the genetic analysis of these pathways in Drosophila.

Animals↗
PubMed2003

Interplay between human papillomaviruses and dendritic cells.

The design of the human papillomavirus (HPV) infection cycle is tightly fitted to the differentiation program of its natural host, the keratinocyte. This has important consequences for the role of antigen-presenting cells in the priming of antiviral immunity. The confinement of HPV infection to epithelia puts the epithelial dendritic cell, the Langerhans cell (LC), in charge of the induction of T cell-dependent immunity. Because HPV-infected keratinocytes cannot reach the regional lymphoid organs, and HPV-infection of LCs does not result in viral gene expression, priming of antiviral T cells exclusively depends on cross-presentation of viral antigens by the LC. Sensitization of the immune system in the regional lymphoid organs elicits systemic anti-HPV immunity as well as intraepithelial immune surveillance by memory-type intraepithelial T cells and locally produced antibodies. The high rate of spontaneous rejections of high-risk HPV-infections and HPV-positive premalignant lesions indicates that in general the LC-driven antigen presentation machinery is capable of raising an effective immune defense against HPV. Epidemiological studies also reveal that a decrease in the vigilance of the immune system is readily exploited by HPV to escape immune destruction, resulting in persistent infections and development of HPV-positive cancers. In view of the inherent antigenicity of HPV, immune intervention strategies constitute a promising approach for both the prevention and the therapeutic treatment of HPV-induced diseases. Importantly, the mechanisms that govern the induction and effector phases of the intraepithelial immune surveillance against HPV must be taken into account when designing such strategies.

Antigen-Presenting Cells↗
PubMed1996

Interplay between heterocyclic amines in cooked meat and metabolic phenotype in the etiology of colon cancer.

Although the etiology of colon cancer remains uncertain, an increasing body of epidemiologic evidence indicates that red meat consumption is an important risk factor. The cooking of red meat produces a class of potent experimental carcinogens, the heterocyclic aromatic amines (HAA). These induce cancers in several different sites, including the colon, in rats and mice. Other epidemiologic studies indicate that an individual's genetically determined metabolic phenotype (polymorphisms for N-acetyltransferase and N-hydroxylase) modulates the risk of colon cancer. Both N-acetyltransferase and N-hydroxylase are involved in the metabolism of HAA. An increased risk of colon cancer has been observed in rapid acetylators in four of five studies; further, in two of these the association was found only in meat eaters. The latter observation supports the hypothesis that HAA are involved in colon carcinogenesis. Considerable progress has been made in the study of the molecular pathogenesis of colon cancer, which typically entails the cumulation of several genetic events (mutations and deletions) in oncogenes and tumor suppressor genes. It would now be a crucial contribution to elucidating the causation of colon cancer to show that such mutations are induced in human colonic mucosa by food-borne heterocyclic aromatic amines.

Amines↗
PubMed1992

Modelling of in vivo calcium metabolism. II. Minimal structure or maximum dynamic diversity: the interplay of biological constraints.

The temporal behaviour of the nonlinear compartmental model we have developed for rat calcium metabolism is discussed with respect to the theoretical properties of the self-oscillating autocatalytic subunit around which the model is constructed. Depending on the approximations made, this subunit is described by a minimal two-variable model, SU2, or by a three-variable one, SU3. The diversity of the theoretical dynamic behaviours possible with SU2 is greatly increased with SU3. But the identification of SU3 parameter values in three different experimental situations reveals that biological constraints efficiently preserve a simple circadian rhythm for bone metabolism. This analysis indicates the significant contribution of the available bone crystal pool to the dynamic organization of this tissue, and hence to extracellular calcium homeostasis.

Animals↗
PubMed1996

Bulbocortical interplay in olfactory information processing via synchronous oscillations.

Emergence of synchronous oscillatory activity is an inherent feature of the olfactory systems of insects, mollusks and mammals. A class of simple computational models of the mammalian olfactory system consisting of olfactory bulb and olfactory cortex is constructed to explore possible roles of the related neural circuitry in olfactory information processing via synchronous oscillations. In the models, the bulbar neural circuitry is represented by a chain of oscillators and that of cortex is analogous to an associative memory network with horizontal synaptic connections. The models incorporate the backprojection from cortical units to the bulbar oscillators in particular ways. They exhibit rapid and robust synchronous oscillations in the presence of odorant stimuli, while they show either nonoscillatory states or propagating waves in the absence of stimuli, depending on the values of model parameters. In both models, the backprojection is shown to enhance the establishment of large-scale synchrony. The results suggest that the modulation of neural activity through centrifugal inputs may play an important role at the early stage of cortical information processing.

Animals↗
PubMed1994

On the interplay between insulin secretion and sensitivity as determinants of glucose tolerance.

Both insulin secretion and sensitivity have been claimed to be the main characteristics in the determination of future deterioration in glucose tolerance. In this cross-sectional study insulin secretion and insulin sensiturity were determined in 228 subjects with varying degrees of glucose tolerance. Insulin secretion was measured in an intravenous glucose tolerance test (IVGTT) and insulin sensitivity by the hyperinsulinaemic euglycaemic clamp test. Both the early insulin response in the IVGTT (increment) and the glucose disposal rate in the clamp test (M-value) were found to be related hyperbolically to fasting glucose (r = -0.63 and -0.66, respectively; both P < 0.0001) and in a second-order polynomial manner to the glucose disappearance rate (k-value) in the IVGTT (r = 0.53 and 0.48, respectively; both P < 0.0001). Multiple regression analysis showed the insulin increment in the IVGTT and the M-value in the clamp test to be equally important determinants of glucose tolerance, together explaining about 50% of the variation in fasting glucose and the k-value in the IVGTT. In conclusion, in this cross-sectional study insulin secretion and sensitivity studied over a broad range of glucose tolerance were found to be of almost equal importance in the determination of glucose tolerance. However, low levels of insulin increment in the IVGTT were more often associated with glucose intolerance than was a low insulin sensitivity.

Aged↗
PubMed1982

Reexamination of the interplay between dibasic amino acids and I-cystine/L-cysteine during tubular reabsorption.

UNLABELLED: Interactions of L-cysteine (= cys) and L-cystine (= cys-cys), and dibasic amino acids were investigated during tubular reabsorption by microperfusion experiments in rat kidney. The following results were obtained: The dibasic amino acids L-ornithine and L-canavanine were strong inhibitors of cys-cys reabsorption. The arginine analogue agmatine and the lysine analogue 2,6-diaminopimelic acid had no effect. The oxidizing agent azodicarboxylic acid bis-dimethylamide (= diamide) decreased the fractional reabsorption rate (= FRR) of cys-cys (0.08 mmol X l-1) from 84% to 60% when present in the perfusion fluid in a concentration of 10 mmol X l-1. Diamide did not affect the reabsorption of a dibasic amino acid (L-arginine) nor of a neutral amino acid (L-phenylalanine). The FRR of L-arginine and L-ornithine could not be decreased by adding cys-cys to the perfusion fluid. Cys had just as little effect on the reabsorption of L-arginine like agmatine. In the presence of alpha-aminoisobutyric acid a slight reduction of the FRR of L-arginine could be observed. The dibasic amino acids L-arginine and L-canavanine had no influence on the FRR of cys when dithioerythritol was added to the perfusion fluid. CONCLUSIONS: More than one site exists for tubular reabsorption of cys-cys. One of these may be shared by dibasic amino acids. Cys is reabsorbed by a separate and specific transport system. A reduction of cys-cys to cys takes place rather in the tubular cell than in the lumen.

Absorption↗
PubMed1995

A complex interplay of positive and negative elements is responsible for the different transcriptional activity of liver NF1 variants.

A full-length cDNA of the rat liver Nuclear Factor 1 (NF1L21) has been cloned and expressed in S. cerevisiae to analyse the architecture of its activation domain. NF1L21 displays a specific DNA-binding activity, as well as the ability to activate transcription from an artificial NF 1-responsive promoter in yeast. Interaction of two or more NF1L21 molecules with multiple sites on the same promoter activated transcription in a synergistic fashion. Functional analysis of the activation domain of NF1L21 reveals a tripartite structure. Two distinct positive elements are required for NF1L21 -mediated transcription activation. A proline-rich element sandwiched between these two positive domains attenuates their transactivation potential. A shorter NF1L variant (NFlL4) in which the distal positive element is replaced by a different sequence was also isolated. NF1L4 displays the same DNA-binding activity and dimerisation properties as NF1L21, but is unable to activate transcription in yeast.

Amino Acid Sequence↗
PubMed1984

The interplay between host and viral genes in adenovirus gene expression.

Only the left end of adenovirus DNA comprising the early E1A and E1B regions is required for transformation of rodent cells and for tumorigenicity in mice and rats. The E1A early region encodes a protein which probably indirectly through a cellular component controls mRNA expression from at least four other early regions at the transcriptional or post-transcriptional level. Viral early proteins also combine with or control the expression of the cellular transplantation antigens to prepare the host cell for tumor rejection or alternatively to suppress the cellular immune response. DNA replication of the viral genome requires three virus-coded proteins and two cellular proteins and is the first mammalian system where DNA can be efficiently replicated in an in vitro system. Adenovirus late expression is also subject to cellular controls since the virus uses the host cell machinery for transcription and splicing. A late translational control has also been identified which is mediated by a small virus coded RNA (VAI RNA) transcribed by the cellular polymerase III. The viral RNA is probably complexed with a cellular protein when exerting its effect. All these control mechanisms, involving both viral and cellular genes, are now being dissected, and several of the molecules involved have been identified.

Adenoviruses, Human↗