bluuebunny/crossref_metadata_2025 huggingface dataset:
One Step Ahead of the Game: Viral Immunomodulatory Molecules
Authors: Spriggs Melanie K.
Published: July 2002

For decades cell biologists have relied on viruses to facilitate the study of complex cellular function. More recently, the tragedy of the AIDS epidemic has focused considerable human and financial resources on both virology and immunology, resulting in the generation of new information relating these disciplines. As the miracle of the mammalian immune system unfolds in the laboratory, the elegance of the mechanisms used by co-evolving viruses to circumvent detection and destruction by the host becomes inescapably obvious. Although many observations of virus-induced phenomena that likely contribute to the virus's escape of immune surveillance are still empirical, many other such phenomena have now been defined at the molecular level and confirmed in in vivo models. Immune modulators encoded within viral genomes include proteins that regulate antigen presentation, function as cytokines or cytokine antagonists, inhibit apoptosis, and interrupt the complement cascade. The identification of such gene products and the elucidation of their function have substantially strengthened our understanding of specific virus-host interactions and, unexpectedly, have contributed to the recognition of potent synergy between viruses, which can result in an unpredictable exacerbation of disease in co-infected individuals. Because many viral immune modulators clearly have host counterparts, viruses provide a valuable method for studying normal immune mechanisms. It is conceivable that an improved understanding of virus-encoded immunomodulators will enhance our ability to design reagents for use in therapeutic intervention in disease and in vaccine development.
FcRECEPTOR BIOLOGY
Authors: Daëron Marc
Published: July 2002

▪ Abstract  This review deals with membrane Fc receptors (FcR) of the immunoglobulin superfamily. It is focused on the mechanisms by which FcR trigger and regulate biological responses of cells on which they are expressed. FcR deliver signals when they are aggregated at the cell surface. The aggregation of FcR having immunoreceptor tyrosine-based activation motifs (ITAMs) activates sequentially src family tyrosine kinases and syk family tyrosine kinases that connect transduced signals to common activation pathways shared with other receptors. FcR with ITAMs elicit cell activation, endocytosis, and phagocytosis. The nature of responses depends primarily on the cell type. The aggregation of FcR without ITAM does not trigger cell activation. Most of these FcR internalize their ligands, which can be endocytosed, phagocytosed, or transcytosed. The fate of internalized receptor-ligand complexes depends on defined sequences in the intracytoplasmic domain of the receptors. The coaggregation of different FcR results in positive or negative cooperation. Some FcR without ITAM use FcR with ITAM as signal transduction subunits. The coaggregation of antigen receptors or of FcR having ITAMs with FcR having immunoreceptor tyrosine-based inhibition motifs (ITIMs) negatively regulates cell activation. FcR therefore appear as the subunits of multichain receptors whose constitution is not predetermined and which deliver adaptative messages as a function of the environment.
LYME DISEASE:A Review of Aspects of Its Immunology and Immunopathogenesis
Authors: Sigal Leonard H.
Published: July 2002

▪ Abstract  Lyme disease, caused by Borrelia burgdorferi, causes a multisystem inflammatory ailment, although the precise means of tissue damage are not well understood. It is clear that the organism is present at the site of inflammation in many organs and that many of the features of the illness are relieved by antibiotic therapy. A complex interaction between spirochete and immune systems of a number of mammalian hosts, in human disease and animal models, has been described. It is clear that T cells and macrophages are intimately associated with the pathogenesis of arthritis and that immune mechanisms are involved in other aspects of disease. Inflammation directed at persistence of Borrelial antigens is a plausible explanation for persisting arthritis. Autoimmunity based on molecular mimicry may play a role in the pathogenesis of Lyme disease. Humoral immunity plays a protective role, prompting interest in vaccine development. Significant variation in certain of the outer surface proteins suggests that multiple proteins, peptides, or chimeric vaccines may be needed to provide a sufficiently broad humoral protective response.
CD40 AND CD154 IN CELL-MEDIATED IMMUNITY
Authors: Grewal Iqbal S. , Flavell Richard A.
Published: July 2002

▪ Abstract  CD40-CD154–mediated contact-dependent signals between B and T cells are required for the generation of thymus dependent (TD) humoral immune responses. CD40-CD154 interactions are however also important in many other cell systems. CD40 is expressed by a large variety of cell types other than B cells, and these include dendritic cells, follicular dendritic cells, monocytes, macrophages, mast cells, fibroblasts, and endothelial cells. CD40- and CD154-knockout mice and antibodies to CD40 and CD154 have helped to elucidate the role of the CD40-CD154 system in immune responses. Recently published studies indicate that CD40-CD154 interactions can influence T cell priming and T cell–mediated effector functions; they can also upregulate costimulatory molecules and activate macrophages, NK cells, and endothelia as well as participate in organ-specific autoimmune disease, graft rejection, and even atherosclerosis. This review focuses on the role of the CD40-CD154 system in the regulation of many newly discovered functions important in inflammation and cell-mediated immunity.
IMMUNOLOGIC BASIS OF ANTIGEN-INDUCED AIRWAY HYPERRESPONSIVENESS
Authors: Wills-Karp Marsha
Published: July 2002

▪ Abstract  The incidence, morbidity, and mortality of asthma has increased worldwide over the last two decades. Asthma is a complex inflammatory disease of the lung characterized by variable airflow obstruction, airway hyperresponsiveness (AHR), and airway inflammation. The inflammatory response in the asthmatic lung is characterized by infiltration of the airway wall with mast cells, lymphocytes, and eosinophils. Although asthma is multifactorial in origin, the inflammatory process in the most common form of the disease (extrinsic asthma) is believed to be a result of inappropriate immune responses to common aero-allergens in genetically susceptible individuals. As such, it has been hypothesized that CD4+T cells that produce a Th2 pattern of cytokines play a pivotal role in the pathogenesis of this disease. Through the release of cytokines such as IL-4, IL-13, and IL-5, these cells orchestrate the recruitment and activation of the primary effector cells of the allergic response, the mast cell and the eosinophil. Activation of these cells results in the release of a plethora of inflammatory mediators that individually or in concert induce changes in airway wall geometry and produce the symptoms of the disease. The aim of this review is to discuss our current understanding of the pathophysiologic mechanisms by which Th2 cytokines induce airway disease, and the factors that predispose to the generation of these pathogenic cells in response to inhalation of ubiquitous aero-allergens. Elucidation of the exact immunological basis for allergic asthma may yield immunotherapeutic strategies to reverse the development of pathogenic Th2-mediated immune responses and reduce the morbidity and mortality associated with this disease.
REGULATION OF IMMUNE RESPONSES THROUGH INHIBITORY RECEPTORS
Authors: Long Eric O.
Published: July 2002

▪ Abstract  Major histocompatibility complex class I-specific inhibitory receptors on natural killer cells prevent the lysis of healthy autologous cells. The outcome of this negative signal is not anergy or apoptosis of natural killer cells but a transient abortion of activation signals. The natural killer inhibitory receptors fulfill this function by recruiting the tyrosine phosphatase SHP-1 through a cytoplasmic immunoreceptor tyrosine-based inhibition motif. This immunoreceptor tyrosine-based inhibition motif has become the hallmark of a growing family of receptors with inhibitory potential, which are expressed in various cell types such as monocytes, macrophages, dendritic cells, leukocytes, and mast cells. Most of the natural killer inhibitory receptors and two members of a monocyte inhibitory-receptor family bind major histocompatibility complex class I molecules. Ligands for many of the other receptors have yet to be identified. The inhibitory-receptor superfamily appears to regulate many types of immune responses by blocking cellular activation signals.
The Immunology of Mucosal Models of Inflammation
Authors: Strober Warren , Fuss Ivan J. , Blumberg Richard S.
Published: July 2002

In recent years the status of the inflammatory bowel diseases (IBDs) as canonical autoimmune diseases has risen steadily with the recognition that these diseases are, at their crux, abnormalities in mucosal responses to normally harmless antigens in the mucosal microflora and therefore responses to antigens that by their proximity and persistence are equivalent to self-antigens. This new paradigm is in no small measure traceable to the advent of multiple models of mucosal inflammation whose very existence is indicative of the fact that many types of immune imbalance can lead to loss of tolerance for mucosal antigens and thus inflammation centered in the gastrointestinal tract. We analyze the immunology of the IBDs through the lens of the murine models, first by drawing attention to their common features and then by considering individual models at a level of detail necessary to reveal their individual capacities to provide insight into IBD pathogenesis. What emerges is that murine models of mucosal inflammation have given us a road map that allows us to begin to define the immunology of the IBDs in all its complexity and to find unexpected ways to treat these diseases.
THE MATERIAL BONE: Structure-Mechanical Function Relations
Authors: Weiner S. , Wagner H. D.
Published: July 2002

▪ Abstract  The term bone refers to a family of materials, all of which are built up of mineralized collagen fibrils. They have highly complex structures, described in terms of up to 7 hierarchical levels of organization. These materials have evolved to fulfill a variety of mechanical functions, for which the structures are presumably fine-tuned. Matching structure to function is a challenge. Here we review the structure-mechanical relations at each of the hierarchical levels of organization, highlighting wherever possible both underlying strategies and gaps in our knowledge. The insights gained from the study of these fascinating materials are not only important biologically, but may well provide novel ideas that can be applied to the design of synthetic materials.
Structure Evolution During Processing of Polycrystalline Films
Authors: Thompson C. V.
Published: July 2002

▪ Abstract  Polycrystalline films have wide variety of applications in which their grain structures affect their performance and reliability. Thin film growth techniques and growth conditions affect grain shapes, the distribution of grain sizes, and the distribution of the crystallographic orientations of grains. Variations in these structural properties are affected by the conditions under which grain nucleation, growth, coarsening, coalescence, and thickening occur. General trends in structural evolution in polycystalline films, as a function of processing conditions and materials class, are discussed in terms of these fundamental kinetic processes.
Insights from the Study of Heart Rate Variability
Authors: Stein, PhD P.K. , Kleiger, MD R.E.
Published: July 2002

Indices of heart rate variability (HRV) provide a window onto autonomic modulation of the heart. HRV indices, determined in either the time or frequency domain, are closely related and reflect parasympathetic, mixed sympathetic, and parasympathetic and circadian rhythms. In population studies, decreased HRV has had predictive value for mortality among healthy adults. It is a well-established risk factor for arrhythmic events and mortality among post-myocardial-infarction patients but has only moderate sensitivity and specificity. Decreased HRV has had mixed predictive success in congestive heart failure. Reduced HRV identifies diabetic patients with autonomic neuropathy. HRV in combination with other risk stratifiers, e.g. ejection fraction, can identify cardiac patients at especially high risk of mortality. Many but not all interventions associated with increased HRV are also associated with better survival rates.
Lipotoxic Diseases
Authors: Unger Roger H.
Published: July 2002

▪ Abstract  I review evidence that leptin is a liporegulatory hormone that controls lipid homeostasis in nonadipose tissues during periods of overnutrition. When adipocytes store excess calories as triacylglycerol (TG), leptin secretion rises so as to prevent accumulation of lipids in nonadipose tissues, which are not adapted for TG storage. Whenever leptin action is lacking, whether through leptin deficiency or leptin resistance, overnutrition causes disease of nonadipose tissues with generalized steatosis, lipotoxicity, and lipoapoptosis. Examples of such disorders of liporegulation include generalized lipodystrophies, mutations of leptin and leptin receptor genes, and diet-induced obesity. Lipotoxicity of pancreatic β-cells, myocardium, and skeletal muscle leads, respectively, to type 2 diabetes, cardiomyopathy, and insulin resistance. In humans this constellation of abnormalities is referred to as the metabolic syndrome, a major health problem in the United States. When lipids overaccumulate in nonadipose tissues during overnutrition, fatty acids enter deleterious pathways such as ceramide production, which, through increased nitric oxide formation, causes apoptosis of lipid-laden cells, such as β-cells and cardiomyocytes. Lipoapoptosis can be prevented by caloric restriction, by thiazolidinedione treatment, and by administration of nitric oxide blockers. There is now substantial evidence that complications of human obesity may reflect lipotoxicity similar to that described in rodents.
Ischemic Stroke Therapy
Authors: Stapf C. , Mohr J. P.
Published: July 2002

▪ Abstract  Stroke is the most common life-threatening neurologic disease and the leading cause of serious long-term disability. The advent of new treatment options for selected patients suffering ischemic stroke (such as systemic administration of tissue plasminogen activator or catheter-guided intra-arterial thrombolysis), the structural reorganization of patient care facilities into stroke units, and interdisciplinary cerebrovascular centers have broadened the scope of possible therapeutic interventions in the acute and postacute phase after cerebral ischemia. This review summarizes currently available and recommended treatment modalities for acute ischemic stroke from an interdisciplinary perspective, including medical, neurointerventional, and neurosurgical therapies.
DNA Uptake in Bacteria
Authors: Dubnau David
Published: July 2002

▪ Abstract  Natural competence is widespread among bacterial species. The mechanism of DNA uptake in both gram-positive and gram-negative bacteria is reviewed. The transformation pathways are discussed, with attention to the fate of donor DNA as it is processed by the competent cell. The proteins involved in mediating various steps in these pathways are described, and models for the transformation mechanisms are presented. Uptake of DNA across the inner membrane is probably similar in gram-positive and gram-negative bacteria, and at least some of the required proteins are orthologs. The initial transformation steps differ, as expected, from the presence of an outer membrane only in the gram-negative organisms. The similarity of certain essential competence proteins to those required for the assembly of type-4 pili and for type-2 protein secretion is discussed. Finally several hypotheses for the biological role of transformation are presented and evaluated.
Holins: The Protein Clocks of Bacteriophage Infections
Authors: Wang Ing-Nang , Smith David L. , Young Ry
Published: July 2002

▪ Abstract  Two proteins, an endolysin and a holin, are essential for host lysis by bacteriophage. Endolysin is the term for muralytic enzymes that degrade the cell wall; endolysins accumulate in the cytosol fully folded during the vegetative cycle. Holins are small membrane proteins that accumulate in the membrane until, at a specific time that is “programmed” into the holin gene, the membrane suddenly becomes permeabilized to the fully folded endolysin. Destruction of the murein and bursting of the cell are immediate sequelae. Holins control the length of the infective cycle for lytic phages and so are subject to intense evolutionary pressure to achieve lysis at an optimal time. Holins are regulated by protein inhibitors of several different kinds. Holins constitute one of the most diverse functional groups, with >100 known or putative holin sequences, which form >30 ortholog groups.
Iron Metabolism in Pathogenic Bacteria
Authors: Ratledge Colin , Dover Lynn G
Published: July 2002

▪ Abstract  The ability of pathogens to obtain iron from transferrins, ferritin, hemoglobin, and other iron-containing proteins of their host is central to whether they live or die. To combat invading bacteria, animals go into an iron-withholding mode and also use a protein (Nramp1) to generate reactive oxygen species in an attempt to kill the pathogens. Some invading bacteria respond by producing specific iron chelators—siderophores—that remove the iron from the host sources. Other bacteria rely on direct contact with host iron proteins, either abstracting the iron at their surface or, as with heme, taking it up into the cytoplasm. The expression of a large number of genes (>40 in some cases) is directly controlled by the prevailing intracellular concentration of Fe(II) via its complexing to a regulatory protein (the Fur protein or equivalent). In this way, the biochemistry of the bacterial cell can accommodate the challenges from the host. Agents that interfere with bacterial iron metabolism may prove extremely valuable for chemotherapy of diseases.
Morphological Changes in Dendritic Spines Associated with Long-Term Synaptic Plasticity
Authors: Yuste Rafael , Bonhoeffer Tobias
Published: July 2002

▪ Abstract  Dendritic spines are morphological specializations that receive synaptic inputs and compartmentalize calcium. In spite of a long history of research, the specific function of spines is still not well understood. Here we review the current status of the relation between morphological changes in spines and synaptic plasticity. Since Cajal and Tanzi proposed that changes in the structure of the brain might occur as a consequence of experience, the search for the morphological correlates of learning has constituted one of the central questions in neuroscience. Although there are scores of studies that encompass this wide field in many species, in this review we focus on experimental work that has analyzed the morphological consequences of hippocampal long-term potentiation (LTP) in rodents. Over the past two decades many studies have demonstrated changes in the morphology of spines after LTP, such as enlargements of the spine head and shortenings of the spine neck. Biophysically, these changes translate into an increase in the synaptic current injected at the spine, as well as shortening of the time constant for calcium compartmentalization. In addition, recent online studies using time-lapse imaging have reported increased spinogenesis. The currently available data show a strong correlation between synaptic plasticity and morphological changes in spines, although at the same time, there is no evidence that these morphological changes are necessary or sufficient for the induction or maintenance of LTP. Still, they highlight once more how form and function go hand in hand in the central nervous system.
The Role and Regulation of Adenosine in the Central Nervous System
Authors: Dunwiddie Thomas V. , Masino Susan A.
Published: July 2002

▪ Abstract  Adenosine is a modulator that has a pervasive and generally inhibitory effect on neuronal activity. Tonic activation of adenosine receptors by adenosine that is normally present in the extracellular space in brain tissue leads to inhibitory effects that appear to be mediated by both adenosine A1and A2Areceptors. Relief from this tonic inhibition by receptor antagonists such as caffeine accounts for the excitatory actions of these agents. Characterization of the effects of adenosine receptor agonists and antagonists has led to numerous hypotheses concerning the role of this nucleoside. Previous work has established a role for adenosine in a diverse array of neural phenomena, which include regulation of sleep and the level of arousal, neuroprotection, regulation of seizure susceptibility, locomotor effects, analgesia, mediation of the effects of ethanol, and chronic drug use.
PROGRESS IN ONE-LOOP QCD COMPUTATIONS
Authors: Bern Zvi , Dixon Lance , Kosower David A.
Published: July 2002

▪ Abstract  We review progress in calculating the one-loop scattering amplitudes required for next-to-leading-order corrections to QCD processes. The underlying technical developments include the spinor helicity formalism, color decompositions, supersymmetry, string theory, factorization, and unitarity. We provide explicit examples that illustrate these techniques.
TASTE PREFERENCES AND FOOD INTAKE
Authors: Drewnowski A.
Published: July 2002

▪ Abstract  Sensory responses to the taste, smell, and texture of foods help determine food preferences and eating habits. However, sensory responses alone do not predict food consumption. The view that a “sweet tooth” leads to obesity through excess sugar consumption is overly narrow. In reality, there are multiple links between taste perceptions, taste preferences, food preferences, and food choices and the amount of food consumed. Taste responses are influenced by a range of genetic, physiological, and metabolic variables. The impact of taste factors on food intake further depends on sex and age and is modulated by obesity, eating disorders, and other pathologies of eating behavior. Food preferences and food choices of populations are further linked to attitudinal, social, and—probably most important—economic variables such as income. Nutrition education and intervention strategies aimed at improving population diets ought to consider sensory pleasure response to foods, in addition to a wide range of demographic and sociocultural variables.
USE OF DRUGS IN THE TREATMENT OF OBESITY
Authors: Atkinson Richard L.
Published: July 2002

▪ Abstract  Obesity has become an epidemic in the United States and in many other countries of the world. Obesity is a chronic disease, not a failure of willpower. Diet, exercise, and behavioral modification of lifestyle are rarely successful over the long term. Medications have been used sparingly, because of concerns about addiction and ineffectiveness, but used chronically, obesity drugs are effective. The two main categories of obesity drugs are centrally active adrenergic and serotonergic agents. These drugs reduce appetite, enhance satiety, and increase energy expenditure. Use of single agents produces modest weight loss and use of combinations increases loss, but few patients reach their goal weight. Co-morbidities associated with obesity resolve or are reduced in severity with weight loss. Adverse events of major concern are changes in brain biochemistry and primary pulmonary hypertension. Published guidelines for use of obesity medications recommend they be used only for medically significant obesity.
Mitochondrial Uncoupling Proteins in Energy Expenditure
Authors: Kozak Leslie P. , Harper Mary-Ellen
Published: July 2002

Four recently discovered homologues of the brown adipose tissue–specific mitochondrial uncoupling protein (UCP1) vary from 29% to 58% in their similarity to UCP1. Although these homologues share important structural features with UCP1 and like UCP1 can reduce the mitochondrial membrane potential when expressed in yeast, there is no clear evidence that they can function thermogenically in vivo. On the other hand, evidence continues to accumulate indicating that the up-regulation of Ucp1 reduces excessive adiposity.
DIETARY AND GENETIC EFFECTS ON LOW-DENSITY LIPOPROTEIN HETEROGENEITY
Authors: Krauss Ronald M
Published: July 2002

▪ Abstract  We have tested whether differences in distribution and dietary responsiveness of low-density lipoprotein (LDL) subclasses contribute to the variability in the magnitude of LDL-cholesterol reduction induced by diets low in total and saturated fat and high in carbohydrate. Our studies have focused on a common, genetically influenced metabolic profile, characterized by a predominance of small, dense LDL particles (subclass pattern B), that is associated with a two- to threefold increase in risk for coronary artery disease. We have found that healthy normolipidemic individuals with this trait show a greater reduction in LDL cholesterol and particle number in response to low-fat, high-carbohydrate diets than do unaffected individuals (subclass pattern A). Moreover, such diets result in reduced LDL particle size, with induction of pattern B in a substantial proportion of pattern A men. Recent studies have indicated that this response is under genetic influence. Future identification of the specific genes involved may lead to improved targeting of dietary therapies aimed at reducing cardiovascular disease risk.
SUCCESSFUL WEIGHT LOSS MAINTENANCE
Authors: Wing Rena R , Hill James O
Published: July 2002

▪ Abstract  Obesity is now recognized as a serious chronic disease, but there is pessimism about how successful treatment can be. A general perception is that almost no one succeeds in long-term maintenance of weight loss. To define long-term weight loss success, we need an accepted definition. We propose defining successful long-term weight loss maintenance as intentionally losing at least 10% of initial body weight and keeping it off for at least 1 year. According to this definition, the picture is much more optimistic, with perhaps greater than 20% of overweight/obese persons able to achieve success. We found that in the National Weight Control Registry, successful long-term weight loss maintainers (average weight loss of 30 kg for an average of 5.5 years) share common behavioral strategies, including eating a diet low in fat, frequent self-monitoring of body weight and food intake, and high levels of regular physical activity. Weight loss maintenance may get easier over time. Once these successful maintainers have maintained a weight loss for 2–5 years, the chances of longer-term success greatly increase.
REGULATION OFENZYMES OF THEUREACYCLE ANDARGININEMETABOLISM
Authors: Morris Sidney M.
Published: July 2002

▪ Abstract  The urea cycle is comprised of five enzymes but also requires other enzymes and mitochondrial amino acid transporters to function fully. The complete urea cycle is expressed in liver and to a small degree also in enterocytes. However, highly regulated expression of several enzymes present in the urea cycle occurs also in many other tissues, where these enzymes are involved in synthesis of nitric oxide, polyamines, proline and glutamate. Glucagon, insulin, and glucocorticoids are major regulators of the expression of urea cycle enzymes in liver. In contrast, the “urea cycle” enzymes in nonhepatic cells are regulated by a wide range of pro- and antiinflammatory cytokines and other agents. Regulation of these enzymes is largely transcriptional in virtually all cell types. This review emphasizes recent information regarding roles and regulation of urea cycle and arginine metabolic enzymes in liver and other cell types.
ENZYMATIC METHYLATION OF ARSENIC SPECIES AND OTHER NEW APPROACHES TO ARSENIC TOXICITY
Authors: Aposhian H. Vasken
Published: July 2002

▪ Abstract  Arsenic metabolism has typically been studied by administering arsenate or arsenite into animals and humans and then studying the metabolites excreted in the urine. Although such studies have yielded information about the beginning and the end of the metabolic pathways for the metabolism of inorganic arsenic compounds, any statements as to the molecular mechnisms of these reactions have had to be highly speculative. Now that the rabbit and the rhesus monkey liver enzymes that transfer methyl groups from S-adenosylmethionine to arsenite and monomethlyarsonic acid have been purified and the reactions characterized, meaningful investigations of species diversity and polymorphism of these enzymes have become possible. New World animals studied thus far appear to be deficient in or totally lacking these enzymes. Old World animals, with the exception of the chimpanzee, have ample amounts of arsenite and monomethylarsonic acid methyltransferases. A hypothesis that the lack of arsenite methlytransferases may have had an evolutionary advantage for certain species is proposed.
Teratology of Retinoids
Authors: Collins Michael D. , Mao Gloria E.
Published: July 2002

Either an excess or a deficiency of vitamin A and related compounds (retinoids) causes abnormal morphological development (teratogenesis). Potential retinoid sources come from dietary intake, nutritional supplements, and some therapeutic drugs. Therefore, understanding the mechanisms of retinoid teratogenesis is important. This review first gives an overview of the principles of teratology as they apply to retinoid-induced malformations. It then describes relevant aspects of the biochemical pathway and signal transduction of retinoids. The teratogenic activity of various retinoid compounds, the role of the retinoid receptors, and important toxicokinetic parameters in teratogenesis are reviewed.
ATOMIC AND MOLECULAR DYNAMICS IN INTENSE OPTICAL FIELDS
Authors: Sheehy B. , DiMauro L. F.
Published: July 2002

▪ Abstract  The unprecedented high intensities made accessible by the development of ultrashort pulse laser systems have uncovered a host of new phenomena and changed the way that we think about atomic and molecular dynamics. We review these developments in the context of some of the basic models that have evolved to explain them. The successes and limitations of simple semiclassical models of strong-field atomic phenomena are discussed. Photodissociation dynamics have shown a rich complexity in strong fields—bond softening, above-threshold dissociation, coulomb explosion—which we review. The promise of the new laser systems in the field of coherent control of molecular dynamics is also discussed.
MECHANISMS AND KINETICS OF SELF-ASSEMBLED MONOLAYER FORMATION
Authors: Schwartz Daniel K
Published: July 2002

▪ Abstract  Recent applications of various in situ techniques have dramatically improved our understanding of the self-organization process of adsorbed molecular monolayers on solid surfaces. The process involves several steps, starting with bulk solution transport and surface adsorption and continuing with the two-dimensional organization on the substrate of interest. This later process can involve passage through one or more intermediate surface phases and can often be described using two-dimensional nucleation and growth models. A rich picture has emerged that combines elements of surfactant adsorption at interfaces and epitaxial growth with the additional complication of long-chain molecules with many degrees of freedom.
MOLECULARTHEORY OFHYDROPHOBICEFFECTS: “She is too mean to have her name repeated.”
Authors: Pratt Lawrence R.
Published: July 2002

▪ Abstract  This paper reviews the molecular theory of hydrophobic effects relevant to biomolecular structure and assembly in aqueous solution. Recent progress has resulted in simple, validated molecular statistical thermodynamic theories and clarification of confusing theories of decades ago. Current work is resolving effects of wider variations of thermodynamic state, e.g., pressure denaturation of soluble proteins, and more exotic questions such as effects of surface chemistry in treating stability of macromolecular structures in aqueous solution.
TENSEGRITY: THE ARCHITECTURAL BASIS OF CELLULAR MECHANOTRANSDUCTION
Authors: Ingber D. E.
Published: July 2002

▪ Abstract  Physical forces of gravity, hemodynamic stresses, and movement play a critical role in tissue development. Yet, little is known about how cells convert these mechanical signals into a chemical response. This review attempts to place the potential molecular mediators of mechanotransduction (e.g. stretch-sensitive ion channels, signaling mollecules, cytoskeleton, integrins) within the context of the structural complexity of living cells. The model presented relies on recent experimental findings, which suggests that cells use tensegrity architecture for their organization. Tensegrity predicts that cells are hard-wired to respond immediately to mechanical stresses transmitted over cell surface receptors that physically couple the cytoskeleton to extracellular matrix (e.g. integrins) or to other cells (cadherins, selectins, CAMs). Many signal transducing molecules that are activated by cell binding to growth factors and extracellular matrix associate with cytoskeletal scaffolds within focal adhesion complexes. Mechanical signals, therefore, may be integrated with other environmental signals and transduced into a biochemical response through force-dependent changes in scaffold geometry or molecular mechanics. Tensegrity also provides a mechanism to focus mechanical energy on molecular transducers and to orchestrate and tune the cellular response.
ION CHANNELS OF NOCICEPTION
Authors: McCleskey Edwin W. , Gold Michael S.
Published: July 2002

▪ Abstract  Nociceptors are the first cells in the series of neurons that lead to the sensation of pain. The essential functions of nociceptors—transducing noxious stimuli into depolarizations that trigger action potentials, conducting the action potentials from the peripheral sensory site to the synapse in the central nervous system, and converting the action potentials into neurotransmitter release at the presynaptic terminal—all depend on ion channels. This review discusses recent results in the converging fields of nociception and ion channel biology. It focuses on (a) the capsaicin receptor and its possible role in thermosensation, (b) ATP-gated channels, (c) proton-gated channels, and (d) nociceptor-specific Na+channels.
Flight Respiration and Energetics
Authors: Harrison Jon F. , Roberts Stephen P.
Published: July 2002

▪ Abstract  We use a comparative approach to examine some of the physiological traits that make flight possible. Comparisons of related fliers and runners suggest that fliers generally have higher aerobic metabolic capacities than runners but that the difference is highly dependent on the taxa studied. The high metabolic rates of fliers relative to runners, especially in insects, are correlated with high locomotory muscle cycle frequencies and low efficiences of conversion of metabolic power to mechanical power. We examine some factors that produce variation in flight respiration and energetics. Air temperature strongly affects the flight metabolic rate of some insects and birds. Flight speed interacts with flier mass, so that small fliers tend to exhibit a Jshaped power curve and larger fliers a U-shaped power curve. As body size increases, mass-specific aerobic flight metabolism decreases in most studies, but mass-specific power output is constant or increases, leading to an increase in efficiency with size. Intraspecific studies have revealed specific genetically based effects on flight metabolism and power output and multiple ecological correlates of flight capabilities.
Prolactin: The New Biology of an Old Hormone
Authors: Goffin Vincent , Binart Nadine , Touraine Philippe , Kelly Paul A.
Published: July 2002

▪ Abstract  Prolactin (PRL) is a paradoxical hormone. Historically known as the pituitary hormone of lactation, it has had attributed to it more than 300 separate actions, which can be correlated to the quasi-ubiquitous distribution of its receptor. Meanwhile, PRL-related knockout models have mainly highlighted its irreplaceable role in functions of lactation and reproduction, which suggests that most of its other reported target tissues are presumably modulated by, rather than strictly dependent on, PRL. The multiplicity of PRL actions in animals is in direct opposition to the paucity of arguments that suggest its involvement in human pathophysiology other than effects on reproduction. Although many experimental data argue for a role of PRL in the progression of some tumors, such as breast and prostate cancers, drugs lowering circulating PRL levels are ineffective. This observation opens new avenues for research into the understanding of whether local production of PRL is involved in tumor growth and, if so, how extrapituitary PRL synthesis is regulated. Finally, the physiological relevance of PRL variants, such as the antiangiogenic 16K-like PRL fragments, needs to be elucidated. This review is aimed at critically discussing how these recent findings have renewed the manner in which PRL should be considered as a multifunctional hormone.
RESISTANCE TO PHENYLAMIDE FUNGICIDES:A Case Study with Phytophthora infestans Involving Mating Type and Race Structure
Authors: Gisi U. , Cohen Y.
Published: July 2002

▪ Abstract  Phenylamide-resistant isolates of Phytophthora infestans have gradually become an important part of populations in many countries. However, fungicide mixtures containing a phenylamide component are still an effective strategy for the control of late blight in potato and tomato. The proportion of phenylamide-resistant isolates fluctuates from year to year and within the season. Almost concurrent with the appearance of resistant isolates was the discovery of the A2 mating type of P. infestans in many European countries and in other parts of the world. However, no genetic correlation exists between resistance and mating type, and the proportion of A2 isolates in European populations remains small. Resistance to phenylamides became established in A1 populations before the appearance of A2 type. Resistant isolates express equal or greater fitness than sensitive isolates, but no correlation was detected between resistance and race structure. The continuous changes in P. infestans populations require careful adaptation of successful disease control programs.
Impacts of Molecular Diagnostic Technologies on Plant Disease Management
Authors: Martin Robert R. , James Delano , Lévesque C. André
Published: July 2002

Detection and diagnosis of plant viruses has included serological laboratory tests since the 1960s. Relatively little work was done on serological detection of plant pathogenic bacteria and fungi prior to the development of ELISA and monoclonal antibody technologies. Most applications for laboratory-based tests were directed at virus detection with relatively little emphasis on fungal and bacterial pathogens, though there was some good work done with other groups of plant pathogens. With the advent of molecular biology and the ability to compare regions of genomic DNA representing conserved sequences, the development of laboratory tests increased at an amazing rate for all groups of plant pathogens. Comparison of ITS regions of bacteria, fungi, and nematodes has proven useful for taxonomic purposes. Sequencing of conserved genes has been used to develop PCR-based detection with varying levels of specificity for viruses, fungi, and bacteria. Combinations of ELISA and PCR technologies are used to improve sensitivity of detection and to avoid problems with inhibitors or PCR often found in plants. The application of these technologies in plant pathology has greatly improved our ability to detect plant pathogens and is increasing our understanding of, their ecology and epidemiology.
THE PARTY FAMILY AND ITS STUDY
Authors: Mair Peter , Mudde Cas
Published: July 2002

▪ Abstract  Although the notion of the party family, with the various cross-national and cross-temporal similarities it implies, underlies much of the standard work on comparative party politics, it nevertheless remains one of the most under-theorized and least specified approaches to the general classification of parties. Four of the principal approaches that are used to identify party families are discussed: origins and sociology, transnational links, policy and ideology, and party name. The advantages and disadvantages of each approach are assessed, as are some of the more generic problems that may be associated with all four approaches. The two approaches that appear best suited to the specification and classification of party families are those based on the origin of parties and their ideology, but these should be developed in parallel rather than as alternatives. Both tap into what parties are rather than what parties do and hence are more likely to uncover core identities and shared political goals.
BOUNDED RATIONALITY
Authors: Jones Bryan D.
Published: July 2002

▪ Abstract  Findings from behavioral organization theory, behavioral decision theory, survey research, and experimental economics leave no doubt about the failure of rational choice as a descriptive model of human behavior. But this does not mean that people and their politics are irrational. Bounded rationality asserts that decision makers are intendedly rational; that is, they are goal-oriented and adaptive, but because of human cognitive and emotional architecture, they sometimes fail, occasionally in important decisions. Limits on rational adaptation are of two types: procedural limits, which limit how we go about making decisions, and substantive limits, which affect particular choices directly. Rational analysis in institutional contexts can serve as a standard for adaptive, goal-oriented human behavior. In relatively fixed task environments, such as asset markets or elections, we should be able to divide behavior into adaptive, goal-oriented behavior (that is, rational action) and behavior that is a consequence of processing limits, and we should then be able to measure the deviation. The extent of deviation is an empirical issue. These classes are mutually exclusive and exhaustive, and they may be examined empirically in situations in which actors make repeated similar choices.
COPING WITH TRAGEDIES OF THE COMMONS
Authors: Ostrom Elinor
Published: July 2002

▪ Abstract  Contemporary policy analysis of the governance of common-pool resources is based on three core assumptions: (a) resource users are norm-free maximizers of immediate gains, who will not cooperate to overcome the commons dilemmas they face; (b) designing rules to change incentives of participants is a relatively simple analytical task; and (c) organization itself requires central direction. The chapter shows that these assumptions are a poor foundation for policy analysis. Findings from carefully controlled laboratory experiments that challenge the first assumption are summarized. A different assumption that humans are fallible, boundedly rational, and norm-using is adopted. The complexity of using rules as tools to change the structure of commons dilemmas is then discussed, drawing on extensive research on rules in field settings. Viewing all policies as experiments with a probability of failure, recent research on a different form of general organization—that of complex adaptive systems—is applied to the process of changing rules. The last sections examine the capabilities and limits of a series of completely independent resource governance systems and the importance of encouraging the evolution of polycentric governance systems.
HAROLD D. LASSWELL'S LEGACY TO MAINSTREAM POLITICAL SCIENCE: A Neglected Agenda
Authors: Eulau Heinz , Zlomke Susan
Published: July 2002

▪ Abstract  Harold D. Lasswell's extensive and wide-ranging books and essays are extraordinarily rich sources of ideas, methods, and topics for the study of political behavior. Whether and how the legacy of his writings is used by contemporary political scientists and theorists is reported here by way of an investigation of references to his work appearing in mainstream political science journals (available through JSTOR) for the 17 years following the end of his academic career. We find that most references to Lasswell are superficial (perfunctory, suggestive, deferential), although a few are more substantial (critical, extending). We conclude that Lasswell's legacy is today undervalued and underused, to the discipline's detriment.
The Psychological Foundations of Identity Politics
Authors: Monroe Kristen Renwick , Hankin James , Vechten Renée Bukovchik Van
Published: July 2002

This chapter reviews social psychological theories relating to political identity and group behavior. We define individual and social identity, examine the main social psychological explanations of social identity, and discuss work on intergroup relations, boundaries, and conflict. We suggest several particular substantive political debates that would benefit from knowledge of this literature.
VISUAL ATTENTION: Control, Representation, and Time Course
Authors: Egeth Howard E. , Yantis Steven
Published: July 2002

▪ Abstract  Three central problems in the recent literature on visual attention are reviewed. The first concerns the control of attention by top-down (or goal-directed) and bottom-up (or stimulus-driven) processes. The second concerns the representational basis for visual selection, including how much attention can be said to be location- or object-based. Finally, we consider the time course of attention as it is directed to one stimulus after another.
Emotion, Regulation, and Moral Development
Authors: Eisenberg Nancy
Published: July 2002

Research and theory on the role of emotion and regulation in morality have received considerable attention in the last decade. Much relevant work has concerned the role of moral emotions in moral behavior. Research on differences between embarrassment, guilt, and shame and their relations to moral behavior is reviewed, as is research on the association of these emotions with negative emotionality and regulation.

Recent issues concerning the role of such empathy-related responses as sympathy and personal distress to prosocial and antisocial behavior are discussed, as is the relation of empathy-related responding to situational and dispositional emotionality and regulation. The development and socialization of guilt, shame, and empathy also are discussed briefly. In addition, the role of nonmoral emotions (e.g. anger and sadness), including moods and dispositional differences in negative emotionality and its regulation, in morally relevant behavior, is reviewed.
Causes of Eating Disorders
Authors: Polivy Janet , Herman C. Peter
Published: July 2002

▪ Abstract  Anorexia nervosa and bulimia nervosa have emerged as the predominant eating disorders. We review the recent research evidence pertaining to the development of these disorders, including sociocultural factors (e.g., media and peer influences), family factors (e.g., enmeshment and criticism), negative affect, low self-esteem, and body dissatisfaction. Also reviewed are cognitive and biological aspects of eating disorders. Some contributory factors appear to be necessary for the appearance of eating disorders, but none is sufficient. Eating disorders may represent a way of coping with problems of identity and personal control.
The New Public Health Litigation
Authors: Parmet W. E. , Daynard R. A.
Published: July 2002

▪ Abstract  In recent years there has been an increasing use of litigation as a public health tool. Litigation has been brought to advance policies concerning such matters as tobacco, gun violence, and lead paint. This article discusses this development and the criticism that can be leveled at using litigation to develop public health policy. The article concludes that, although litigation may not always be successful, it can deter dangerous activities and play an important role in advancing the political and social struggle for public health.