bluuebunny/crossref_metadata_2025 huggingface dataset:
Which intercurrent infections are associated with maculopapular cutaneous drug reactions? A case‐control study
Authors: Cohen Arnon D. , Friger Michael , Sarov Batia , Halevy Sima
Published: March 2003

Abstract

Background  Patients with lymphotrophic viral infections are at increased risk for cutaneous drug reactions (CDRs). However, the association between other intercurrent infections and maculopapular CDRs has not been evaluated by epidemiologic methods.

Objective  We conducted a case‐control study in order to evaluate the exposure to intercurrent infections in patients with maculopapular CDRs.

Methods  Data were obtained through assessment of files of 53 patients hospitalized for maculopapular CDRs in the Department of Dermatology and 159 control patients. Exposure to intercurrent infections was recorded in patients and controls.

Results  An intercurrent infectious disease was documented in 31/53 (58.5%) of patients with CDRs, as compared to 12/159 (7.5%) patients in the control group (OR 17.26, 95% CI: 7.24–42.00). Maculopapular CDRs were associated with respiratory tract infections (OR 20.53, 95% CI: 5.20–94.45), and urinary tract infections (OR 20.61, 95% CI: 2.36–465.99), but not with skin infections (OR 3.83, 95% CI: 0.85–17.87) or other infections.

Conclusions  Our study implies that maculopapular CDRs are associated with respiratory tract infections as well as urinary tract infections. Further study is needed to evaluate the role of intercurrent infections in the pathogenesis of CDRs.
Efficacy and safety of terbinafine for nondermatophyte and mixed nondermatophyte and dermatophyte toenail onychomycosis
Authors: Lebwohl Mark G. , Daniel C. Ralph , Leyden James , Mormon Manuel , Shavin Joel S. , Tschen Eduardo , Weiss Jonathan , Zone John
Published: March 2003

Ninety‐seven healthy male and female subjects, 18–70 years of age, entered a randomized, double‐blind, placebo‐controlled, multicenter study conducted over a 24‐week treatment period and a 72‐week follow‐up (study week 96) period without treatment.

Subjects  received: (1) terbinafine 250 mg for 12 weeks followed by placebo for 12 weeks; (2) terbinafine 250 mg for 24 weeks; or (3) placebo for 24 weeks.

Clinical and mycologic evaluations of a target toenail were performed before, during, and after the treatment period. Evaluations consisted of measurements of nail growth, unaffected nail length, and estimated percentage of nail involvement. Cultures and KOH microscopy were used for mycologic evaluations.

The primary efficacy variable was effective treatment, defined as negative mycology and either no nail involvement or at least 5 mm of new unaffected nail growth at 48 weeks. Complete cure, the secondary variable, was defined as negative mycology and zero nail involvement at 48 weeks. Overall efficacy was assessed after 12, 18, and 24 weeks of therapy and every 6 weeks up to week 48 by both investigator and subject using a five‐point scale (excellent, very good, good, fair, and poor).

Adverse events were assessed after 4, 8, 12, 18, and 24 weeks of treatment and after a 6‐week follow‐up period with no treatment. Adverse events were graded by severity (mild, moderate, or severe) and relationship to the study drug (not related, remote or unlikely, possibly, probably, or definitely).
Subcutaneous pheohyphomycosis in India – a case report and review
Authors: Sharma Nand Lal , Mahajan Vikram , Sharma Ramesh Chander , Sharma Ashok
Published: March 2003

Background Pheohyphomycosis is a rare infection caused by dematiaceous fungi, affecting the skin and subcutis, paranasal sinuses, or central nervous system.

Methods A case of subcutaneous pheohyphomycosis in the lumbar region is reported. The Indian literature on subcutaneous pheohyphomycosis is also reviewed.

Results In India, 23 patients with subcutaneous pheohyphomycosis have been reported, distributed throughout the country in a belt from north to south, sparing the eastern and western regions. The age of the patients ranged from 3 to 60 years, with a male to female ratio of 1.3 : 1. A relatively early age of onset was observed. A history of prior injury was recalled by five patients. The lower extremities were involved in eight cases, upper extremities in five, gluteal region in two, lumbar area and submandibular area in one, face in two and disseminated disease was seen in four cases. Three of these cased died during follow up. Osteomyelitis was observed in two cases, hepatosplenomegaly in one, and lymph node involvement in two. Carcinomatous change developed in a long‐standing lesion of 33 years. Thirteen species from seven genera of dematiaceous fungi were isolated. Phialophora dermatidis was the most common isolate.

Conclusions Indian patients with subcutaneous pheohyphomycosis are afflicted at an earlier age. Exophiala dermatidis seems to be associated with more fatalities. Treatment with newer azoles seems promising, and excision alone or combined with azoles is a good therapeutic modality.
Peculiar unilateral fixed drug eruption of the breast
Authors: Li Hong , Wiederkehr Michael , Rao Babar K. , Samady Joseph A. , Gardner Bernard , Lambert W. Clark , Schwartz Robert A.
Published: March 2003

Background Fixed drug eruption (FDE) is a common cutaneous disorder which develops within hours of taking the offending drug and recurs at the same site with subsequent exposure to the same drug. Non‐steroidal anti‐inflammatory drugs (NSAIDs) are common offending drugs.

Methods A 14‐year‐old girl initially presented with a 1‐year history of a recurrent reddish‐brown plaque around her right areola. The lesion became pruritic and raised during menses, and subsided during the remainder of her menstrual cycle with the exception of persistent residual hyperpigmentation. The patient had a pattern of naproxen use during menses for dysmenorrhea.

Results The skin biopsy specimen revealed focal bullae formation and scattered necrotic keratinocytes in epidermis, hydropic degeneration of the basal cell layer, pigmentary incontinence and a perivascular infiltrate composed of lymphocytes and eosinophils. These changes confirmed the diagnosis of fixed drug eruption.

Conclusion Fixed drug eruption to nonsteroidal anti‐inflammatory drugs is common. However, FDE due to naproxen, one of the NSAIDs, is rarely reported. We describe an unusual case of FDE, which recurred at each menses.
Molecular insights into the hair follicle and its pathology: a review of recent developments
Authors: Stenn K. S.
Published: March 2003

In the last few years by means of the elucidation of the human genome and the acquisition of powerful investigative tools we have begun to understand the molecular basis of hair follicle growth control. In this article I will describe some of the salient recent contributions to the field and review the implications these findings have had on our understanding of mechanisms in dermatology and dermatopathology.
Harnessing expertise: involving peer interviewers in qualitative research with hard‐to‐reach populations
Authors: Elliott Eva , Watson Alison J. , Harries Ursula
Published: March 2003

The use of peer interviewers with privileged access to a particular population group, which is difficult to reach via more conventional methods, has been acknowledged in recent research. This paper explores a number of key issues relating to the employment of peer interviewers by reflecting on a project designed to explore the views and experiences of parents who use illegal drugs. The project presented the research team with a number of challenges. These included the need to provide on‐going support for the interviewers, a sense of distance felt by the researchers from the raw data they collected, and the difficulties of gaining from the skills and experiences of peer interviewers without exploiting their labour. The paper also explores the advantages of involving peer interviewers closely in research work and reflects on the nature and boundaries of expert knowledge that can become evident in such collaborations. The need for a certain amount of flexibility over the roles and domains of control that lay experts and researchers traditionally inhabit is suggested. In conclusion, it is argued that the involvement of peer interviewers in research can be a valuable means of enhancing our knowledge and understanding of a variety of population groups who tend to live beyond the gaze of more orthodox researchers.
Opinions of Swedish citizens, health‐care politicians, administrators and doctors on rationing and health‐care financing
Authors: Rosén Per , Karlberg Ingvar
Published: March 2003

Objective  To compare the views of citizens and health‐care decision‐makers on health‐care financing, the limits of public health‐care, and resource allocation.

Design  A postal survey based on a randomized sample of adults taken by the national registration and stratified samples of health‐care politicians, administrators, and doctors in five Swedish counties.

Participants  A total number of 1194 citizens (response rate 60%) and 427 decision‐makers (response rate 69%).

Results  The general public have high expectations of public health‐care, expectations that do not fit with the decision‐makers' views on what should be offered. To overcome the discrepancy between demand and resources, physicians prefer increased patient fees and complementary private insurance schemes to a higher degree than do the other respondents. Physicians take a more favourable view of letting politicians on a national level exert a greater influence on resource allocation within public health‐care. A majority of physicians want politicians to assume a greater responsibility for the exclusion of certain therapies or diagnoses. Most politicians, on the other hand, prefer physicians to make more rigorous decisions as to which medical indications should entitle a person to public health‐care.

Conclusions  The gap between public expectations and health‐care resources makes it more important to be clear about who should be accountable for resource‐allocation decisions in public health‐care. Significant differences between physicians' and politicians' opinions on financing and responsibility for prioritization make the question of accountability even more important.
A possible mechanism for partitioning between homo‐ and heterodimerization of the yeast homeodomain proteins MATa1 and MATα2
Authors: Ho C.‐Y. , Smith M. , Houston M.E. , Adamson J.G. , Hodges R.S.
Published: March 2003

Abstract: The yeast Saccharomyces cerevisiae has three cell types distinguished by the proteins encoded in their mating‐type (MAT) loci: the a and α haploids, which express the DNA‐binding proteins a1, and α1 and α2, respectively, and the a/α diploid which expresses both a1 and α2 proteins. In a/α cells, a1−α2 heterodimers repress haploid‐specific genes and MATα1, whereas α2 homodimers repress a‐specific genes, indicating dual regulatory functions for α2 in mating‐type control. We previously demonstrated that the two leucine zipper‐like coiled‐coil motifs, called α2A and α2B, in the α2 N‐terminal domain are important to a1−α2 heterodimerization. A unique feature of α2B is the occurrence of three atypical amino acid residues at a positions within the hydrophobic core. We have conducted mutational analyses of α2B peptides and the full‐length protein. Our data suggest that these residues may play a critical role in partitioning of the α2 protein between heterodimerization with a1 and homodimerization with itself.
Generic physical mechanisms of tissue morphogenesis: A common basis for development and evolution
Authors: Newman Stuart A.
Published: March 2003

Morphological evolution is usually considered to occur by the selection of small heritable variations in the expression of anatomical traits, on the basis of improved adaptation to new environmental conditions. An alternative mode of morphological evolution is proposed here: the production of a spectrum of forms by the action of intrinsic physical properties of cell aggregates, followed by intense selection for biochemical mechanisms that make the generation of a subset of viable morphologies, and pathways of transition between morphologies, more reliable. This view provides an account of the origins of important features of metazoan body plans and organ forms, including gastrulation and other types of tissue multilayering, lumen formation, and segmentation. It also implies that most major morphological innovations would occur early in phylogeny, often more than once, with much subsequent genetic selection being of a stabilizing or canalizing variety. Consistent with recent findings, this view predicts that functional redundancy among developmentally important genes and genetic circuits should be prevalent.
How geitonogamous selfing affects sex allocation in hermaphrodite plants
Authors: Jong T. J. De , Klinkhamer  , Rademaker
Published: March 2003

Does the mode of self-pollination affect the evolutionarily stable allocation to male vs. female function? We distinguish the following scenarios. (1) An ‘autogamous’ species, in which selfing occurs within the flower prior to opening. The pollen used in selfing is a constant fraction of all pollen grains produced. (2) A species with ‘abiotic pollination’, in which selfing occurs when pollen dispersed in one flower lands on the stigma of a nearby flower on the same plant (geitonogamy). The selfing rate increases with male allocation but a higher selfing rate does not mean a reduced export of pollen. (3) An ‘animal-pollinated’ species with geitonogamous selfing. Here the selfing rate also increases with male allocation, but pollen export to other plants in the population is a decelerating function of the number of simultaneously open flowers.

In all three models selfing selects for increased female allocation. For model 3 this contradicts the general opinion that geitonogamous selfing does not affect evolutionarily stable allocations. In all models, the parent benefits more from a female-biased allocation than any other individual in the population. In addition, in models 2 and 3, greater male allocation results in more local mate competition.

In model 3 and in model 2 with low levels of inbreeding depression, hermaphroditism is evolutionarily stable. In model 2 with high inbreeding depression, the population converges to a fitness minimum for the relative allocation to male function. In this case the fitness set is bowed inwards, corresponding with accelerating fitness gain curves.

If the selfing rate increases with plant size, this is a sufficient condition for size-dependent sex allocation (more allocation towards seeds in large plants) to evolve.

We discuss our results in relation to size-dependent sex allocation in plants and in relation to the evolution of dioecy.
Cannibalizing Harmonia axyridis (Coleoptera: Coccinellidae) larvae use endogenous cues to avoid eating relatives
Authors: Joseph  , Snyder  , Moore
Published: March 2003

Cannibalism is widespread among many different organisms, and can have both negative and positive fitness consequences. Avoiding eating relatives can minimize negative fitness consequences of cannibalism. Such avoidance requires kin discrimination, but evidence for this ability among cannibals is limited with little data that address the cues used in such discrimination. We examined whether larvae of the ladybird beetle Harmonia axyridis avoid eating their relatives. We further manipulated environmental factors to create individuals that had similar or dissimilar rearing environments to begin to test for endogenous versus exogenous recognition cues. In our experiments, third-instar larvae were much less likely to cannibalize if they were interacting with a relative. Larvae that did cannibalize kin required more encounters, and significantly delayed cannibalism, compared to larvae cannibalizing unrelated individuals. Acquired cues were less important. Even though the different rearing environment resulted in significantly different phenotypic effects, similarity or dissimilarity of rearing environment had no effect on cannibalism, and there was no interaction between environments and relatedness in cannibalism. We suggest that H. axyridis has a well-developed kin discrimination system, and that kin recognition in this ladybird beetle is based on endogenous rather than exogenous cues. We also argue that these cues reflect either direct or indirect genetic effects on larval phenotypes.
Evolution of kleptoparasitism as a war of attrition
Authors: Ruxton  , Broom
Published: March 2003

Previous models of kleptoparasitism (resource stealing) assume that contests over resource items are of fixed duration. Here we suggest that such contests will often be well represented as a war of attrition, with the winner being the individual who is prepared to contest for the longer time. Given that time spent in contests cannot be used to search for other resource items, we provide an analytical expression for the evolutionarily stable distribution of contest times. This can be used to investigate the circumstances under which we would expect kleptoparasitism to evolve. In particular, we focus on situations where searching for conspecifics to kleptoparasitize can only be achieved at a cost of reduced resource discovery by other means; under such circumstances we show that kleptoparasitism is not evolutionarily stable.
Variation of plastic responses to oxygen availability within the hybridogenetic Rana esculenta complex
Authors: Plénet  , Pagano  , Joly  , Fouillet
Published: March 2003

The hypothesis of superiority of hybrid phenotype to explain the maintenance of hybridogenesis (exclusion of one parental genome in the germline before meiosis) was investigated in the Rana esculenta complex. Survival and growth of progenies from each parental and hybrid lineages were compared across contrasted conditions of oxygen availability (this factor is suspected to influence habitat utilization of each form of the complex). Whereas growth and development were strongly affected by constant hypoxic conditions in the R. ridibunda lineage, they were not altered in the R. lessonae lineage. Because the performance of the hybrid (R. esculenta) lineage proved to be intermediate between the parental species, no heterosis effect was detected. These results supported the intermediate niche hypothesis as an alternative to the heterotic hybrid superiority hypothesis. The ecological and evolutionary implications are then discussed.
Local population success in heterogeneous habitats: reciprocal transplant experiments completed on a desert spider
Authors: Riechert  , Hall
Published: March 2003

Reciprocal transplant experiments were completed to test for selection against the mixing of behavioural phenotypes in a desert spider. Most Agelenopsis aperta populations experience low prey abundances and competition for web-sites that provide shelter from thermal extremes. These conditions favour aggressiveness towards both prey and conspecifics (an ‘arid-land behavioural phenotype’). The spider also occupies narrow stretches of riparian habitat bordering spring-fed streams and rivers. Here it is released from competition for prey and foraging sites, but is subject to predation by birds. A less aggressive/more fearful behaviour is selected for in these riparian habitats (a ‘riparian behavioural phenotype’). Previous work with this spider indicates that there is genetic differentiation between arid-land and riparian populations. However, the degree to which genetic differentiation is achieved may be limited by gene flow. Reciprocal sets of enclosures were established in: (1) a dry evergreen woodland site (arid-land phenotype) and (2) a neighbouring riparian site (riparian phenotype) in south-eastern Arizona. Equal numbers of field collected, early instar A. aperta were introduced into native and transplant enclosures in each habitat. After 6 months of site-imposed selection, survivorship was determined and growth estimates and behavioural trials completed on spiders remaining in the different enclosures. The same behavioural test was subsequently applied to lab-reared offspring of the spiders surviving the respective selection regimes.

Riparian transplants showed both poor survival and retarded growth in the dry woodland habitat when compared with both arid-land and riparian natives. Arid-land transplants that survived, however, grew equally well in riparian habitat as did dry woodland and riparian natives. Behavioural assays conducted on test subjects after selection and on their offspring reared in a controlled laboratory environment indicate that phenotypes that were inappropriate to the respective habitats were selected against in the transplant experiments. The frequency distribution of transplant spider behaviour on a continuum from fearful to aggressive was intermediate between that exhibited by respective native riparian and dry woodland spiders. It is concluded that while arid-land and riparian behavioural ecotypes do exist, directional gene flow of arid-land phenotypes into riparian habitat limits population subdivision.
Genetic consequences of the metapopulation biology of a facultatively sexual freshwater invertebrate
Authors: Freeland  , Noble  , Okamura
Published: March 2003

Theoretical models of the impact of a metapopulation structure on the genetics of a species have resulted in multiple predictions that have seldom been empirically evaluated. Here we present microsatellite data from 14 populations of a freshwater bryozoan, Cristatella mucedo, collected along a waterfowl migratory route in north-western Europe. C. mucedo is facultatively sexual and has the unusual tactic of dispersing via asexually generated propagules. These propagules are likely to be dispersed by waterfowl and therefore the populations that we sampled were expected to maintain some degree of connectivity. Our data illustrate a metapopulation comprising well-differentiated populations connected by low levels of ongoing gene flow, patterns that agree with predictions based on theoretical work. However, contrary to expectations of a metapopulation, particularly one in which asexual reproduction predominates, genetic variation within populations was often high. This diversity seems to be at least partially attributable to the gene flow that results from ongoing dispersal.
Cryptic speciation among intestinal parasites (Trematoda: Digenea) infecting sympatric host fishes (Sparidae)
Authors: Jousson  , Bartoli  , Pawlowski
Published: March 2003

In the north-western (NW) Mediterranean, the teleosts Diplodus sargus, D. vulgaris and D. annularis coexist in infralittoral habitats. These fishes are infected by two species of the Digenea (Platyhelminthes, Trematoda): Macvicaria crassigula (Opecoelidae) and Monorchis parvus (Monorchiidae) for which we obtained Internal Transcribed Spacer rDNA sequences. Each parasite species represents a complex of two cryptic species, one restricted to D. annularis, and the other shared by D. sargus and D. vulgaris. Cytochrome b mtDNA sequences were used to infer host phylogenetic relationships which showed that the distribution of parasites in Diplodus hosts is not a consequence of coevolutionary interactions. We used diet analyses available for the fish hosts to assess the degree of overlap in the use of food among the three species. The feeding overlap was significant only between D. sargus and D. vulgaris, but not for the other fish pairs. The possible mechanisms involved in the speciation of the digenean fauna of Diplodus fishes are discussed.
Genetic variation and asexual reproduction in the facultatively parthenogenetic cockroach Nauphoeta cinerea: implications for the evolution of sex
Authors: Corley L. S. , Blankenship J. R. , Moore A. J.
Published: March 2003

Asexual reproduction could offer up to a two-fold fitness advantage over sexual reproduction, yet higher organisms usually reproduce sexually. Even in facultatively parthenogenetic species, where both sexual and asexual reproduction is sometimes possible, asexual reproduction is rare. Thus, the debate over the evolution of sex has focused on ecological and mutation-elimination advantages of sex. An alternative explanation for the predominance of sex is that it is difficult for an organism to accomplish asexual reproduction once sexual reproduction has evolved. Difficulty in returning to asexuality could reflect developmental or genetic constraints. Here, we investigate the role of genetic factors in limiting asexual reproduction in Nauphoeta cinerea, an African cockroach with facultative parthenogenesis that nearly always reproduces sexually. We show that when N. cinerea females do reproduce asexually, offspring are genetically identical to their mothers. However, asexual reproduction is limited to a nonrandom subset of the genotypes in the population. Only females that have a high level of heterozygosity are capable of parthenogenetic reproduction and there is a strong familial influence on the ability to reproduce parthenogenetically. Although the mechanism by which genetic variation facilitates asexual reproduction is unknown, we suggest that heterosis may facilitate the switch from producing haploid meiotic eggs to diploid, essentially mitotic, eggs.
Phylogeography of Caribbean lizard malaria: tracing the history of vector-borne parasites
Authors: Perkins S. L.
Published: March 2003

The Anolis lizards of the eastern Caribbean islands are parasitized by several species of malaria parasites (Plasmodium). Here I focus on two species of Plasmodium, using molecular data (mitochondrial cytochrome b sequences) to recover the phylogeography of the parasites throughout the Lesser Antilles and Puerto Rico. The two parasites were originally described as a single species, P. azurophilum, which infects both red and white blood cells. Here the two species are termed P. azurophilum Red and P. azurophilum White based on their host cell type. Six haplotypes were found in 100 infections sequenced of P. azurophilum Red and six in 45 infections of P. azurophilum White. Nested clade analysis revealed a significant association of geographical location and clades as well as a pattern of past fragmentation of parasite populations. This is consistent with the hypothesis that vector-borne parasites such as malaria may be subject to frequent local extinctions and recolonizations. Comparison of the phylogeography of the lizard and parasites shows only weak concordance; that is, the parasites colonized the lizards in the islands, but dispersal events between islands via vectors or failed lizard colonizations were present. The two parasites had different histories, P. azurophilum Red colonized the islands from both the north and south, and P. azurophilum White originated in the central Lesser Antilles, probably from P. azurophilum Red, then moved to both north and south. This is the first study to examine the biogeography of a pair of sibling species of vector-borne parasites within an island archipelago system.
Mate-choice copying by females: the advantages of a prudent strategy
Authors: Sirot E.
Published: March 2003

Mate choice by females may be influenced by both advertizing traits of males, and behaviour of other females. Here, a simple genetic and behavioural model studies the advantages of mate-choice copying. From a genetic point of view, a female preferring to copy others’ mate choice adopts a prudent strategy, because her offspring will inherit the same alleles from their father as the other young in the population. The model predicts that a female should copy others’ mate-choice, unless she encounters a relatively more attractive male than the one she has observed mating, and the attractiveness of the male reflects his genotype. For low or moderate reliability of male signalling, mate-copying is always predicted, even if the newcoming male is more attractive than the first male. This effect is attenuated, however, when the number of females that have already chosen the first male increases.
Quantitative genetics of immune function and body size in the house cricket, Acheta domesticus
Authors: Ryder J. J. , Siva-Jothy M. T.
Published: March 2003

Female house crickets are attracted to male calling song containing a relatively high number of syllables per ‘chirp’, which tends to be produced by large males. In a previous study, we showed that this song characteristic is also positively and independently correlated with haemocyte load, an important determinant of the ability to produce an encapsulation response in insects. Females will therefore tend to select males with high encapsulation ability (and large body size) as mates. The present study demonstrates that variation in haemocyte load and body size, together with a second parameter of immune function (the ability to encapsulate a synthetic substrate), is heritable in the same population. Moreover, all three traits are shown to be positively genetically correlated. In favouring males that produce calling song with the preferred characteristics, females should therefore also tend to produce larger offspring with a greater ability to produce an encapsulation response.
Kin recognition and cannibalism in a subsocial spider
Authors: Bilde T. , Lubin Y.
Published: March 2003

Evolution of cooperation and group living in spiders from subsocial family groups may be constrained by their cannibalistic nature. A tendency to avoid cannibalizing kin may facilitate tolerance among spiders and implies the ability to identify relatives. We investigated whether the subsocial spider Stegodyphus lineatus discriminates kin by recording cannibalism among juveniles in experiments during which amount of food and size difference among spiders in groups were varied. We hypothesized that family groups should be less cannibalistic than groups of mixed-parental origin. Further, we tested whether food-stress would influence cannibalism rates differently in kin and nonkin groups and the effect of relatedness on cannibalism within groups of spiders of variable size compared with those of homogenous size. In groups of six spiders, more spiders were cannibalized in nonsib groups than in sib groups under low food conditions. A tendency for nonkin biased cannibalism in starved spider pairs supported that kin recognition in S. lineatus is expressed when food is limited. Size variance of individuals within well-fed groups of siblings and unrelated spiders had no influence on cannibalism rates. Apparently, both hunger and high density are important promoters of cannibalism. In addition to inclusive fitness benefits, we suggest that an ability to avoid cannibalizing kin will favour the evolution of cooperation and group living in phylogenetically pre-adapted solitary species.
Comparing molecular measures for detecting inbreeding depression
Authors: Slate J. , Pemberton J. M.
Published: March 2003

Correlations between heterozygosity and components of fitness have been investigated in natural populations for over 20 years. Positive correlations between a trait of interest and heterozygosity (usually measured at allozyme loci) are generally recognized as evidence of inbreeding depression. More recently, molecular markers such as microsatellites have been employed for the same purpose. A typical study might use around five to ten markers. In this paper we use a panel of 71 microsatellite loci to: (1) Compare the efficacy of heterozygosity and a related microsatellite-specific variable, mean d2, in detecting inbreeding depression; (2) Examine the statistical power of heterozygosity to detect such associations. We performed our analyses in a wild population of red deer (Cervus elaphus) in which inbreeding depression in juvenile traits had previously been detected using a panel of nine markers. We conclude that heterozygosity-based measures outperform mean d2-based measures, but that power to detect heterozygosity-fitness associations is nonetheless low when ten or fewer markers are typed.
Evolution of syncarpy in angiosperms: theoretical and phylogenetic analyses of the effects of carpel fusion on offspring quantity and quality
Authors: Armbruster W. S. , Debevec E. M. , Willson M. F.
Published: March 2003

The repeated evolution of fused carpels (syncarpy) is one of the dominant features of angiosperm macroevolution. We present results of new phylogenetic and theoretical analyses to assess the frequency and nature of transitions to syncarpy, and the possible advantages of syncarpy over apocarpy under a variety of ecological conditions. Using a recent molecular estimate of angiosperm phylogeny, we ascertained that a minimum of 17 independent evolutionary transitions from apocarpy to syncarpy have occurred; about three-quarters of these transitions allowed pollen tubes to cross between carpels and fertilize ovules that would otherwise be left unfertilized. Most of these transitions also intensified competition between pollen, potentially enhancing offspring fitness. The high proportion of evolutionary transitions promoting pollen competition and pollen-tube access to all carpels supports the hypothesis that the main advantage of syncarpy is in increasing offspring quality and quantity. The potential advantages of syncarpy were more thoroughly evaluated by analytical and simulation studies. These showed that the advantage of syncarpy over apocarpy involving increased offspring-quantity held under conditions of marginal pollination and declined with increasing pollination. The offspring-quality advantage persisted over a wider range of conditions, including under quite high pollination rates.
The continuity of microevolution and macroevolution
Authors: Simons Andrew M.
Published: March 2003

A persistent debate in evolutionary biology is one over the continuity of microevolution and macroevolution – whether macroevolutionary trends are governed by the principles of microevolution. The opposition of evolutionary trends over different time scales is taken as evidence that selection is uncoupled over these scales. I argue that the paradox inferred by trend opposition is eliminated by a hierarchical application of the ‘geometric-mean fitness’ principle, a principle that has been invoked only within the limited context of microevolution in response to environmental variance. This principle implies the elimination of well adapted genotypes – even those with the highest arithmetic mean fitness over a shorter time scale. Contingent on premises concerning the temporal structure of environmental variance, selectivity of extinction, and clade-level heritability, the evolutionary outcome of major environmental change may be viewed as identical in principle to the outcome of minor environmental fluctuations over the short-term. Trend reversals are thus recognized as a fundamental property of selection operating at any phylogenetic level that occur in response to event severities of any magnitude over all time scales. This ‘bet-hedging’ perspective differs from others in that a specified, single hierarchical selective process is proposed to explain observed hierarchical patterns of extinction.
Mechanistic and experimental analysis of condition and reproduction in a polymorphic lizard
Authors: Svensson E.I. , Sinervo B. , Comendant T.
Published: March 2003

The importance of genetic and environmental variation in condition in shaping evolutionary trade-offs have recently been subject to much theoretical discussion, but is very difficult to investigate empirically in most field-based systems. We present the results from mechanistic experimental manipulations of reproductive investment and condition in two female colour morphs (‘orange’ and ‘yellow’) of side-blotched lizards (Uta stansburiana). We investigated the interactions between throat colour morphs, condition, local social environment and female survival using path-analysis. Using follice-ablation experiments, we show that large clutch size has a negative effect on field survival among yellow females, and that this effect is partly mediated by immunosuppressive effects of large clutches. In orange females these effects were less pronounced, and there was a negative survival effect of strong antibody responses. Hence, we experimentally confirmed our previous findings of correlational selection between female morphotype and immunocompetence, an important condition trait. Manipulation of corticosterone revealed multiple (‘pleiotropic’) direct and indirect effects of this hormone on both condition and reproductive traits. We argue that interaction effects (e.g. between local environments and genotypes) could explain a substantial fraction of variation in condition and reproduction in natural populations. Increased attention to such interaction effects and their fitness consequences will provide novel insights in field studies of selection and reproductive allocation.
Suboptimal timing of reproduction in Lobelia inflata may be a conservative bet-hedging strategy
Authors: Simons A. M. , Johnston M. O.
Published: March 2003

Age and size at reproduction are important components of fitness, and are variable both within and among angiosperm species. The fitness consequences of such life-history variation are most readily studied in organisms that reproduce only once in their lifetime. The timing of the onset of reproduction (bolting) in the monocarpic perennial, Lobelia inflata, occurs over a range of dates within a season, and may be postponed to a later year. Empirical relationships among life-history traits, derived from over 950 wild-growing and experimentally manipulated plants in the field, are used to model an optimal changing size threshold (norm of reaction) for bolting over the growing season. Comparisons are made between observed and expected norms of reaction governing bolting. An apparently suboptimal bolting schedule that precludes bolting beyond an early (conservative) date is observed, and is found to be qualitatively consistent with conservative bet hedging under unpredictable season lengths. On this basis we propose the schedule of bolting as a plausible example of a conservative bet-hedging strategy. The results underscore the critical need for long-term studies of fluctuating selection to distinguish suboptimality from bet hedging.
Fcγ receptor‐mediated immune phagocytosis depends on the class of FcγR and on the immunoglobulin‐coated target cell
Authors: Flesch B. K. , Vöge K. , Henrichs T. , Neppert J.
Published: March 2003

Background and Objectives

Three human Fcγ receptors (FcγR) are known to mediate immune phagocytosis. A variety of different phagocytic assays have been described, but their comparability is complicated by the use of different effector cells and different antibody‐coated target cells. The aim of this study was to determine the influence of these variable components on the FcγR‐mediated phagocytosis.

Materials and Methods

We sensitized human red blood cells (RBC) with polyclonal human anti‐D (huaD), or with human monoclonal anti‐D of the isotypes IgG1 (huIgG1) or IgG3 (huIgG3). Sheep RBC coated with rabbit immunoglobulin (RBC‐RAS) were also used. Monocytes or polymorphonuclear neutrophils (PMN) were incubated with different FcγR‐specific antibodies or their F(ab′)2 fragments to determine the contribution of the different FcγRs on these effector cells in the phagocytic process of different antibody‐coated target cells.

Results

huaD‐RBC and huIgG1‐RBC were preferentially ingested via the FcγRI on monocytes and, to a minor extent, also by the FcγRII. PMN ingested these target cells only after induction of the FcγRI by interferon‐γ (IFN‐γ). huIgG3‐RBC extensively formed rosettes with monocytes but were seldom ingested. RAS‐RBC phagocytosis was induced primarily via the FcγRI on monocytes and was mediated by the FcγRII on PMN.

Conclusion

When performing phagocytosis assays with different effector and target cells, one has to take into account that phagocytosis is mediated by different FcγR, making comparability of these assays more difficult.
Monoclonal anti‐D for immunoprophylaxis
Authors: Scott M. L.
Published: March 2003

Routine antenatal prophylaxis with anti‐D has become accepted as desirable, but concerns have been expressed about the adequacies of supply and safety of polyclonal anti‐D. Human monoclonal anti‐D has been produced using Epstein–Barr virus (EBV)‐transformed peripheral B cells, sometimes coupled with fusions to myeloma cell lines. More recently, molecular biology techniques have been used to produce human monoclonal anti‐D in a variety of different ways. Many monoclonal antibodies (mAbs) have been characterized for fine specificity and in vitro functional activity in International Workshops. Two mAbs have been shown to cause red cell clearance and immunosuppression in male volunteers. Considerations for the future development of monoclonal anti‐D for prophylactic use are reviewed.
Meta‐analysis of randomized controlled trials comparing the risk of postoperative infection between recipients of allogeneic and autologous blood transfusion
Authors: Vamvakas E. C.
Published: March 2003

Background and Objectives A previous meta‐analysis of randomized controlled trials (RCTs), comparing the risk of postoperative infection between recipients of allogeneic blood or autologous blood obtained by preoperative autologous blood donation (PABD), did not detect an immunomodulatory (TRIM) effect of allogeneic blood transfusion (ABT). If such a TRIM effect was mediated by white blood cell (WBC)‐derived soluble mediators accumulating during storage, however, stored autologous blood obtained by PABD would not prevent the TRIM effect, whereas unstored autologous blood obtained by acute normovolemic haemodilution (ANH), intraoperative blood recovery (IBR), or postoperative blood recovery (PBR), would abrogate the TRIM effect.

Materials and Methods RCTs reported through January 2002 were retrieved, and five studies met the criteria for meta‐analysis. Summary odds ratios (ORs) of postoperative infection in recipients of allogeneic vs. autologous blood were calculated across studies.

Results No difference in the risk of infection between the comparison arms was detected across all five RCTs [summary OR = 1·22, 95% confidence interval (95% CI): 0·75–1·98], or when the results of studies using PABD or ANH/IBR/PBR were integrated separately (summary OR = 1·35; 95% CI: 0·45–4·08; and summary OR = 1·49; 95% CI: 0·69–3·22, respectively).

Conclusions The finding of no TRIM effect of ABT across RCTs using ANH/IBR/PBR to obtain autologous blood does not support the hypothesis that a TRIM effect of ABT is mediated by WBC‐derived soluble mediators accumulating during storage. The null finding of the overall meta‐analysis also does not support a TRIM effect of ABT mediated by other blood constituents.
Androgenetische Alopezie beim Mann
Authors: Hoffmann R.
Published: March 2003

Zusammenfassung:Die androgenetische Alopezie (AGA) ist die häufigste Form des Haarausfalls bei Männern. Die relativ ausgeprägte Konkordanz der Glatzenausprägung bei Vätern und ihren Söhnen unterliegt keinem gewöhnlichen Mendelschen Erbgang, sondern beruht wahrscheinlich auf einer polygenen Vererbung. Die prädisponierenden Gene für eine AGA sind bis heute unbekannt und die molekularen Grundlagen des Androgen‐abhängigen Bartwuchses versus Androgen‐abhängigen Haarausfalls sind ungeklärt, die AGA kann jedoch als Dihydrotestosteron (DHT)‐abhängiger Prozess mit kontinuierlicher Miniaturisierung der empfindlichen Haarfollikel beschrieben werden. Die 2, 5‐α‐Reduktase spielt eine zentrale Rolle bei der intrafollikulären Konversion von Testosteron (T) zu Dihydrotestosteron. Da das Wissen auf diesem Gebiet ständig zunimmt, soll diese Arbeit aktuelle Erkenntnisse kritisch beleuchten.
Tumorimmunabwehr und Autoimmunität: Erkenntnisse für die Entwicklung moderner Melanomvakzinen aus tierexperimentellen Studien
Authors: Tüting T. , Reinhard G.
Published: March 2003

Zusammenfassung: Studienergebnisse zur unspezifischen Immuntherapie des Melanoms mit rekombinanten Zytokinen zeigen bei einem kleinen Teil der Patienten einen positiven Einfluss auf den Verlauf der Erkrankung. Die molekulare Identifikation von T‐Zell‐erkannten Melanomantigenen erlaubt die Entwicklung von spezifischen Vakzinen. In tierexperimentellen Studien können Einblicke in die Möglichkeiten zur Generierung

 und Aufrechterhaltung von Immunantworten gegen Melanomantigene zum Nutzen zukünftiger klinischer Projekte gewonnen werden. Hierbei zeigt sich, dass Mechanismen der peripheren Immuntoleranz die Stimulation von melanomspezifischen T‐Zellen limitieren. In Labormäusen lässt sich diese Immuntoleranz mit Hilfe neuartiger Genvakzinen aufheben. Hierzu ist die Verwendung von kultivierten dendritischen Zellen als biologisches Adjuvans oder die Kopplung der antigenkodierenden cDNA mit immunstimulierenden Proteinen erforderlich. Zusätzlich müssen in einer therapeutischen Modellsituation melanomspezifische T‐Zellen durch proinflammatorische Signale in das Tumorgewebe gelockt werden. Nach unserer Ansicht haben diese Erfahrungen aus den murinen Systemen wesentliche Bedeutung für die weitere Entwicklung moderner Melanomvakzinen zur Anwendung beim Menschen.
Differences in the Effects of Temperature and Photoperiod on Progress to Flowering among Diverse Mucuna spp.
Authors: Qi Aiming , Ellis R. H. , Keatinge J. D. H. , Wheeler T. R. , Tarawali S. A. , Summerfield R. J.
Published: March 2003

The use of Mucuna spp. in cover crop and green manure technologies is proving to be successful in the tropics and subtropics following intensive efforts in technology transfer to farmers by NGOs (Non‐Governmental Organizations). This includes the transfer of seeds of Mucuna spp. for which the range of adaptation and the effect of environment on crop phenology are poorly understood. A selection of Mucuna spp. germplasm was evaluated over a range of contrasting photothermal conditions in controlled‐environment glasshouses. Dates of emergence and first flowering were recorded. Where possible, triple‐plane rate of development models were fitted to the first flowering data to quantify the relative sensitivity of each species to photoperiod and temperature. All accessions showed short‐day responses but there were substantial differences in the sensitivity of rate of progress to first flowering to environment, particularly to photoperiod. This results in differences in maturity period between accessions which, with appropriate understanding, could be functionally exploited by NGOs and NARS. However, if ignored, it could result in the promotion and use of accessions ill adapted to the environment in which they are tested. In consequence there might be unnecessary resistance from farmers to the adoption of green manure and cover crops technologies which are vital to the design and maintenance of sustainable farming systems in low‐income countries in the tropics.
Effect of Iron and Iron Chelators on the Decomposition of Wheat Residue
Authors: Hunter W. J. , Kuykendall L. D.
Published: March 2003

The influence of two iron sources, FeCl3 and iron ethylenediaminetetraacetic acid (FeEDTA), and an iron chelator, ethylenediamine di‐o‐hydroxyphenylacetic acid, on wheat straw decomposition was monitored in laboratory incubations. Adding FeCl3 or FeEDTA to the incubation buffer did not alter the rate of decomposition, but the addition of the iron chelator, EDDHA, slowed decomposition significantly. These data suggest that microorganisms that produce iron chelators might be used to reduce residue decomposition in the field.