By G. Akrabor. University of Hartford.
This antigenic loop mediates binding to cellular receptors buy discount repaglinide 0.5 mg on line diabetes insipidus zentralis, an essential step for viralentryintohost cells repaglinide 1 mg with amex diabetic diet for dummies. The pattern of antibody escape mutantsidentiesvarying and unvarying amino acid sites proven repaglinide 2 mg diabetes test when pregnant. The third section continues discussion of binding to host cells and tro- pism for dierent host receptors cheap repaglinide 0.5 mg otc diabetes diet for dummies. Consequently, escape mutants in that conserved region arise readily, demonstrating that the conserved sites play an important role in recognition by anti- bodies. This highlights the dual selective pressures by antibodies and receptor binding that may shape key antigenic sites. The fourth section describes an experimental approach to analyze the tness consequences of amino acid substitutions. Molecular stud- ies can measure changes in binding anity for antibodies and cellular receptors associated with changes in amino acid shape and charge. But substitutions ultimately spread or fail based on their consequences for the dynamics of growth and transmission. I describe one study in which pigs were injected with a wild-type virus and various antibody escape mutants. The rela- tive success of parental and mutant viruses provides clues about how particular amino acid substitutions may inuence evolutionary dynam- ics. General discussions and examples of experimental evolution can be found in Rose (1991), Bennett and Lenski (1999), Landweber (1999), Crill et al. Phylogenetic distance between serotypes correlates reasonably well with antigenic distance measured by cross-reactivity to polyclonal antisera in other words, phylogeny roughly matches serology at a broad scale of sequence divergence (Mateu 1995). By contrast, small-scale phylogenetic divergence does not correspond to patterns of antigenicity. One or a few amino acid substitutions within a serotype can greatly alter antibody recognition (Mateu et al. The loops connecting the chains tend to be exposed on the protein surface, sometimes protruding from the protein core. The three proteins dier in the location and exposure of various loops, as indicateding. Redrawn from Haydon and Woolhouse (1998) based on original work in Harrison (1989, with permission from Nature, www. This loop has about 20 amino acids that contribute to several overlapping epitopes. The three dier- ent proteins group into a structural unit as shown in the lower left. On the capsid, the boldly lined pentagon contains ve structural units arrayed in ve- fold rotational symmetry about the pentagonal center. Each pentagonal vertex denes the intersection of six structural units aligned in threefold rotational symmetry. The wiggly lines labeled on one unit of the capsid show the location of structural loops that occur on the capsid surface (see g. Theblackcircle at the lower right shows the approximate relative size of an antibody-binding region (Fab), illustrating the potential coverage of capsid protein loops that may be involved in immune recognition. Redrawn from Mateu (1995, with permission from Elsevier Sci- ence) based on original work in Harrison (1989, with permission from Nature, www. Discontin- uous epitopes occur when amino acid residues from widely separated sequence locations come together conformationally to form a binding surface for antibodies. Two antigenic sites of serotypes A, O, and C have discontinuous epitopes that have received widespread attention (Mateu et al. The rst discontinuous site occurs near the capsid s threefold axes of symmetry at the vertices of the pentagonal structural units (g. The high specicity of antibodies means that the sequence and conformational dierences between serotypes change the detailed antigenic properties of particular regions. Studies focused on natu- ral selection of particular amino acid residues must account for back- ground dierences of sequence and conformation among test strains. Two problems of interpreting selective pressures arise from an escape map based on natural variants. First, eld isolates do not control the multitude of evolutionary pressures on variation. Lack of variability may result either from lack of antibody pres- sure or from constraining selective pressures such as binding to host receptors. The second problem for interpreting selective pressures from natu- ral isolates concerns lack of control over genetic background. Whether aparticularamino acid site aects antibody anity may depend on conformation-changing variants at other sites. Site-directed mutagenesis controls amino acid replacements in a xed genetic background. One can alter sites that do not vary naturally to test for eects on antibody binding. But this method can only dene changes in antibody binding; it does not show how viral populations actually respond to immune pressure. This al- lows direct control of selective pressure by comparing lines with and without exposure to antibodies. In addition, cultures can be started with genetically monomorphic viruses to control genetic background. The host cells were refreshed from independent stock in each passage and therefore did not coevolve with the virus over the passage history. Controlled studies of laboratory evolution provide some insight into the evolution of this region. Each mutant (except one) escaped antibody neutralization by a single amino acid change. The dierent locations of these muta- tions in the original (C-S8c1) line compared with the serially passaged (C-S8c1p100) line provide the most striking result of this study. Those variants replicated with the same kinetics as the parental viruses of C-S8c1p100, with no loss in tness. The white triangles denote positions that can tolerate certain amino acid replacements without greatly aecting antibody binding. The letters above the sequence summarize the escape mutants of C-S8c1 (original line); letters below the sequence summarize escape mutants of C-S8c1p100 (passaged line). Experimental evolution provides one approach to analyzing those selective forces, as described in the previous section. Integrins are transmembrane glycoproteins composed of two dierent subunits, and. These various studies call attention to the complementary processes of attachment and entry (Haywood 1994). In some cases, viruses may rst attach to host cells based on the kinetics of binding between viral and host attachment sites. Onceviruses bind to host attachment sites, a second-phase kinetic process determines binding between viral and host receptors that initiate viral entry into host cells. The viruses, attracted near the cell surface, may then encounter and bindtotherelativelysparserhost integrin receptors. Viral kinetics may be modulated separately for preliminary attach- ment and secondary binding to the portofentry. Not surpris- ingly, genetic background aects thebindingconsequences of amino acid substitutions and the evolutionary changes that occur in dierent strains.
Crosses were made between three infected and uninfected lines and Wtness was evaluated using the number of eggs buy repaglinide 1 mg lowest price diabetic diet what to eat, egg viability cheap 2 mg repaglinide diabetes type 1 nutrition education, F1 mortality cheap repaglinide 1mg with mastercard diabetic diet 1500 calories exchange chart, and adult sex ratio order 1mg repaglinide with visa diabetes insipidus and siadh. All three crosses indicated the infected females deposited more eggs over 6 days compared to the uninfected females, although egg viabil- ity was not diVerent. Whether this is due to their use of tetracycline to treat the colonies is unknown; we speculate that elimina- tion of gut symbionts (such as Enterobacter, if present) could have reduced vigor in their colonies. Conclusions Although we know a great deal about the biology, behavior, genetics, and eVectiveness of M. We know nothing about the role of pathogens in the population dynamics of this important predator under Weld conditions. This gap in knowledge has occurred in part because there was little recognition that the microbes associated with M. In addition, the tools with which to study these interactions have been lacking until recently and still are underutilized. Furthermore, without the ability to work with strains of mites that have diVering numbers of microbial endosymbionts, it is diYcult to resolve the role(s) these organisms play in the biology of this predator. At present it is unclear whether any of these microorganisms are obligatory or whether they can be eliminated without harm, although the fact that Wolbachia and Cardinium are transovarially transmit- ted suggests these organisms have an especially intimate relationship with their host. It is possible that the use of metagenomic tools may resolve some of these diYculties. If the genomes of these microorganisms were sequenced and the function(s) of the genes analyzed, the physiological roles that these organisms play may be resolved (Handelsman 2004; Woyke et al. Insertion of symbiont genes into the nuclear genome is reminiscent of the steps involved in the evolution of the bacterial symbiont that became the mitochondrial organelle. Clearly, many interesting questions remain to be answered about the relationships between the genomes of Wolbachia, Bacteroidetes, Car- dinium and the nuclear and mitochondrial genomes of M. The electron micrographs published by Poinar and Poinar (1998) suggest that pathogenesis might occur if these microbial symbionts were to increase in den- sity because the phenotype of the electron micrographs suggest that Cardinium, the unnamed Bacteroidetes, and/or Wolbachia could have been the causative agents of patho- genesis. Acarologists wanting to understand the roles symbionts play in their acarine hosts have signiWcant challenges to meet. It is becoming clear that the microbial communities of humans are characteristic and complex mixtures of many microorganisms that have co-evolved with humans. These microorganisms aVect the nutrient or energetic value of food, the metabolism of xenobiot- ics, are involved in the renewal of gut epithelial cells, and the development and activity of the human immune system. In animal models, even the size of the heart and the behavior of the animal are aVected by the lack of their normal gut fauna (Turnbaugh et al. The human microbial communities and their interactions with their human hosts have only begun to be described, as they have with arthropod-microbial consortia. It is recognized that Only with an integrated approach will it be possible to comprehend the complex ecol- ogy of human health and the many ways in which interactions between humans and micro- organisms can go awry (Dethlefsen et al. This will require studies of model systems other than that of humans for technical and ethical reasons. Experimental models using simple consortia, such as those seen in many invertebrate- microbe communities (including mites or ticks), will facilitate the molecular dissection of interactions in intact natural settings. The genetic tools available for some invertebrate model hosts will allow the identiWcation of genes and proteins that control arthropod host responses and manage the consortia. The Human Microbiome project will attempt to move beyond comparative genomics to an integrated systems metagenomics approach that accounts for microbial community structure (the microbiota), gene content (the microbiome), gene expression (the meta-transcriptome and metaproteome ) and metabo- lism (the meta-metabolome ). It is possible that the relatively simple consortium of microbial associates of M. It may also be true that arthropod-symbiont associations will have to be studied over time to understand that Wne-scale evolutionary processes occur between the host and sym- biont genomes (Riegler and O Neill 2007). Recent papers reviewed in this article indicate that the host symbiont relationship is more dynamic than appreciated, with some insect populations that formerly exhibited a Wtness cost due to Wolbachia infection no longer doing so, perhaps due to adaptation in the Wolbachia genome over a period of about 15 years. In another example cited by Riegler and O Neill (2007), a butterXy with a skewed sex ratio due to Wolbachia was shown to have evolved a resistance to the sex-ratio modify- ing ability of the Wolbachia over a period of a few years. This dynamism indicates that comparing symbiont eVects on diVerent populations of M. Dillon and Dillon (2004) noted A comprehensive understanding of the biology of insects requires that they be studied in an ecological context with microorganisms as an important component of the system. Acknowledgments We are grateful for the invitation to participate in this special edition of Experimental and Applied Acarology and thank the many graduate students and postdoctoral scientists who have contrib- uted to the senior author s work with M. The work was supported in part by the Davies, Fischer and Eckes Endowment in Biological Control to M. Mol Phylogenet Evol 44:267 280 Handelsman J (2004) Metagenomics: application of genomics to uncultured microorganisms. Tetranychid enemies: their biological characters and the impact of spray practices. Proc R Soc B 273:2097 2106 Poinar G Jr, Poinar R (1998) Parasites and pathogens of mites. Practicing dermatologists and dermatologists in training will nd the therapeutic regimens presented here to be practical and helpful. Staff in pharmaceutical and cosmetic companies can benet from understanding the dermatologist s approach to the diagnosis and management of hair and scalp disorders. We rmly believe that anyone interested in hair and scalp diseases will benet from using this book as a resource. Scalp Prostheses: Wigs, Hairpieces, Extensions, and Scalp-Covering Cosmetics 163 Ingrid E. Sources of Alopecia Information for Physicians and Patients 297 Jennifer Conde and Amy J. Callender Department of Dermatology, Howard University College of Medicine, Washington, D. Ana Paula Avancini Caramori Department of Dermatology, Complexo Hospitalar Santa Casa de Porto Alegre, Porto Alegre, Brazil Bryan K. Selection for shorter and ner body hair has resulted in only head hair remaining in any quantity. This however is capable of growing to greater lengths than that of any other mammal (Fig. It is worth mentioning some of the salient features that relate to the human hair shaft. The cross section of the hair shaft has three major components: the cuticle, the cortex, and the medulla (Fig. The cortex, the main bulk of a fully keratinized hair shaft, contributes almost all the mechanical properties of the hair, including strength and elasticity (2). The cuticle consists of six to eight layers of attened overlapping cells with their free edges directed upward to the tip of the hair shaft (2). Innermost is the endocuticle, derived from the developing cell cytoplasm contents. The exocu- ticle lies closer to the external surface and comprises three parts: the b-layer, the a-layer, and the epicuticle. The epicuticle is a hydrophobic lipid layer of 18-methyleicosanoic acid on the surface of the ber, or the f-layer. The normal cuticle has a smooth appearance, allowing light reection and limiting fric- tion between the hair shafts. The cuticle may be damaged by frictional forces (brushing, combing or blow-drying) as chemical removal of the f-layer, particularly by oxidation, eliminates the rst hydrophobic defense and leaves the hair more porous and vulnerable. Cuticle disruption with alkaline chemicals is the rst step in permanent hair styling (3).
Excludes: complications of external orthopedic device order 1mg repaglinide free shipping diabetes symptoms stomach pain, such as: pressure ulcer due to cast (707 trusted repaglinide 2mg diabetes mellitus low blood sugar. This will be a fairly rare occurrence among hospital inpatients order repaglinide 1 mg with visa blood sugar testing equipment, but will be relatively more common among hospital outpatients and patients of family practitioners repaglinide 2 mg visa diabetes symptoms foot pain, health clinics, etc. Such factors may be elicited during population surveys, when the person may or may not be currently sick, or be recorded as an additional factor to be borne in mind when the person is receiving care for some current illness or injury classifiable to categories 001-999. In the latter circumstances the V code should be used only as a supplementary code and should not be the one selected for use in primary, single cause tabulations. Examples of these circumstances are a personal history of certain diseases, or a person with an artificial heart valve in situ. The following fourth-digit subdivisions are for use with categories V30-V39: 0 Born in hospital 1 Born before admission to hospital 2 Born outside hospital and not hospitalized The following two fifths-digits are for use with the fourth-digit. Excludes: follow-up examination for medical surveillance following treatment (V67. V70 General medical examination Use additional code(s) to identify any special screening examination(s) performed (V73. For these, the "E" code classification should be used as an additional code for more detailed analysis. Machinery accidents [other than those connected with transport] are classifiable to category E919, in which the fourth digit allows a broad classification of the type of machinery involved. If a more detailed classification of type of machinery is required, it is suggested that the "Classification of Industrial Accidents according to Agency," prepared by the International Labor Office, be used in addition; it is included in this publication. Definitions and examples related to transport accidents (a) A transport accident (E800-E848) is any accident involving a device designed primarily for, or being used at the time primarily for, conveying persons or goods from one place to another. Includes: accidents involving: aircraft and spacecraft (E840-E845) watercraft (E830-E838) motor vehicle (E810-E825) railway (E800-E807) other road vehicles (E826-E829) In classifying accidents which involve more than one kind of transport, the above order of precedence of transport accidents should be used. Excludes: accidents: in sports which involve the use of transport but where the transport vehicle itself was not involved in the accident involving vehicles which are part of industrial equipment used entirely on industrial premises occurring during transportation but unrelated to the hazards associated with the means of transportation [e. Excludes: accidents: in repair shops in roundhouse or on turntable on railway premises but not involving a train or other railway vehicle (c) A railway train or railway vehicle is any device with or without cars coupled to it, designed for traffic on a railway. It is defined as a motor vehicle traffic accident or as a motor vehicle nontraffic accident according to whether the accident occurs on a public highway or elsewhere. A motor vehicle accident is assumed to have occurred on the highway unless another place is specified, except in the case of accidents involving only off-road motor vehicles which are classified as nontraffic accidents unless the contrary is stated. A roadway is that part of the public highway designed, improved, and ordinarily used, for vehicular travel. Includes: approaches (public) to: docks public building station Excludes: driveway (private) parking lot ramp roads in: airfield farm industrial premises mine private grounds quarry (i) A motor vehicle is any mechanically or electrically powered device, not operated on rails, upon which any person or property may be transported or drawn upon a highway. Any object such as a trailer, coaster, sled, or wagon being towed by a motor vehicle is considered a part of the motor vehicle. Includes: motorized: bicycle [moped] scooter tricycle (k) An off-road motor vehicle is a motor vehicle of special design, to enable it to negotiate rough or soft terrain or snow. Examples of special design are high construction, special wheels and tires, driven by treads, or support on a cushion of air. Includes: animal carrying a person or goods animal-drawn vehicle animal harnessed to conveyance bicycle [pedal cycle] streetcar tricycle (pedal) Excludes: pedestrian conveyance [definition (q)] (n) A streetcar is a device designed and used primarily for transporting persons within a municipality, running on rails, usually subject to normal traffic control signals, and operated principally on a right-of-way that forms part of the traffic way. Includes: interurban or intraurban electric or streetcar, when specified to be operating on a street or public highway tram (car) trolley (car) (o) A pedal cycle is any road transport vehicle operated solely by pedals. Includes: bicycle pedal cycle tricycle Excludes: motorized bicycle [definition (i)] (p) A pedal cyclist is any person riding on a pedal cycle or in a sidecar attached to such a vehicle. Includes: airplane [any type] balloon bomber dirigible glider (hang) military aircraft parachute (v) A commercial transport aircraft is any device for collective passenger or freight transportation by air, whether run on commercial lines for profit or by government authorities, with the exception of military craft. Excludes: intending passenger waiting at station (8) unauthorized rider on railway vehicle (8) 2Pedestrian See definition (r) 3 Pedal cyclist See definition (p) 8 Other specified person Intending passenger or bystander waiting at station Unauthorized rider on railway vehicle 9 Unspecified person E800 Railway accident involving collision with rolling stock Requires fourth digit. Includes: collision of railway train with: buffers fallen tree on railway gates platform rock on railway streetcar other nonmotor vehicle other object Excludes: collision with: aircraft (E840. E803 Railway accident involving explosion, fire, or burning Requires fourth digit. Includes: fall while alighting from or boarding railway train Excludes: fall related to collision, derailment, or explosion of railway train (E800. Excludes: motor vehicle collision with object set in motion by railway train (E815. Includes: collision between motor vehicle which accidentally leaves the roadway then re- enters the same roadway, or the opposite roadway on a divided highway, and another motor vehicle Excludes: collision on the same roadway when none of the motor vehicles involved have left and re-entered the roadway (E812. Includes: collision between motor vehicle, any kind, and: other road (nonmotor transport) vehicle, such as: animal carrying a person animal-drawn vehicle pedal cycle streetcar Excludes: collision with: object set in motion by nonmotor road vehicle (E815. Includes: motor vehicle: failing to make curve and: colliding with object off the highway overturning stopping abruptly off the highway going out of control (due to) blowout and: colliding with object off the highway overturning stopping abruptly off the highway burst tire and: colliding with object off the highway overturning stopping abruptly off the highway driver falling asleep and: colliding with object off the highway overturning stopping abruptly off the highway driver inattention and: colliding with object off the highway overturning stopping abruptly off the highway excessive speed and: colliding with object off the highway overturning stopping abruptly off the highway failure of mechanical part and: colliding with object off the highway overturning stopping abruptly off the highway Excludes: collision on highway following loss of control (E810. Includes: fall down stairs of motor bus while boarding or alighting fall from car in street while boarding or alighting injured by moving part of the vehicle while boarding or alighting trapped by door of motor bus boarding or alighting while boarding or alighting E818 Other noncollision motor vehicle traffic accident Requires fourth digit. Includes: accidents involving motor vehicles being used in recreational or sporting activities off the highway collision and noncollision motor vehicle accidents occurring entirely off the highway Excludes: accidents involving motor vehicle and: aircraft (E840. Includes: breakage of part of motor-driven snow vehicle (not on public highway) fall from motor-driven snow vehicle (not on public highway) hit by motor-driven snow vehicle (not on public highway) overturning of motor-driven snow vehicle (not on public highway) run over or dragged by motor-driven snow vehicle (not on public highway) collision of motor-driven snow vehicle with: animal (being ridden) (-drawn vehicle) another off-road motor vehicle other motor vehicle, not on public highway railway train other object, fixed or movable injury caused by rough landing of motor-driven snow vehicle (after leaving ground on rough terrain) Excludes: accident on the public highway involving motor driven snow vehicle (E810. Includes: fall while boarding or alighting from motor vehicle except off-road motor vehicle, not on public highway injury from moving part of motor vehicle while boarding or alighting from motor vehicle except off-road motor vehicle, not on public highway trapped by door of motor vehicle while boarding or alighting from motor vehicle except off-road motor vehicle, not on public highway E825 Other motor vehicle nontraffic accident of other and unspecified nature Requires fourth digit. For definitions of other road vehicle and related terms see definitions (m) to (o). Includes: accidents involving other road vehicles being used in recreational or sporting activities Excludes: collision of other road vehicle [any] with: aircraft (E840. Includes: watercraft accidents in the course of recreational activities Excludes: accidents involving both aircraft, including objects set in motion by aircraft, and watercraft (E840. Includes: submersion and drowning due to: boat overturning boat submerging falling or jumping from burning ship falling or jumping from crushed watercraft ship sinking other accident to watercraft E831 Accident to watercraft causing other injury Requires fourth digit. Includes: any injury, except submersion and drowning, as a result of an accident to watercraft burned while ship on fire crushed between ships in collision crushed by lifeboat after abandoning ship fall due to collision or other accident to watercraft hit by falling object due to accident to watercraft injured in watercraft accident involving collision struck by boat or part thereof after fall or jump from damaged boat Excludes: burns from localized fire or explosion on board ship (E837. Includes: injuries in water transport caused by: deck machinery engine room machinery galley machinery laundry machinery loading machinery E837 Explosion, fire, or burning in watercraft Requires fourth digit. Includes: explosion of boiler on steamship localized fire on ship Excludes: burning ship (due to collision or explosion) resulting in: submersion or drowning (E830. Includes: hit by aircraft without accident to aircraft hit by object falling from aircraft without accident to aircraft injury by or from machinery on aircraft without accident to aircraft injury by or from rotating propeller without accident to aircraft injury by or from voluntary parachute descent without accident to aircraft poisoning by carbon monoxide from aircraft while in transit without accident to aircraft sucked into jet without accident to aircraft any accident involving other transport vehicle (motor) (nonmotor) due to being hit by object set in motion by aircraft (powered) Excludes: air sickness (E903) effects of: high altitude (E902. Includes: launching pad accident Excludes: effects of weightlessness in spacecraft (E928. They may also be used to indicate external causes of localized effects classifiable to 001-799. The "late effects" include conditions reported as such or as sequelae, which may occur at any time after the acute accidental injury. E929 Late effects of accidental injury Excludes: late effects of: surgical and medical procedures (E870. The "late effects" include conditions reported as such or as sequelae which may occur at any time after the attempted suicide or self-inflicted injury. The "late effects" include conditions reported as such, or as sequelae which may occur at any time after the injury purposely inflicted by another person. The "late effects" include conditions reported as such, or as sequelae which may occur at any time after the injury due to legal intervention. E980 Poisoning by solid or liquid substances, undetermined whether accidentally or purposely inflicted E980.
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