bluuebunny/crossref_metadata_2025 huggingface dataset:
Sudden onset of melanuria in a patient with metastatic melanoma and toxic epidermal necrolysis
Authors: Saghari Sogol , Bakshandeh Haleh , Kerdel Francisco
Published: March 2003

A 46‐year‐old man presented to our institution with blisters and eruption on the body and oral mucosa. He had a history of metastatic melanoma to the brain and had undergone radiation therapy to the head and chemotherapy with temozolomide. He was then started on dexamethasone and phenytoin. One month later, he developed a fever of 39.5 °C and an eruption in the axilla and groin. He was admitted to another hospital with a presumptive diagnosis of disseminated herpes zoster and was started on acyclovir, vancomycin, methylprednisolone, and fluconazole. The phenytoin was discontinued. Three days after admission, the eruption progressed and the patient developed respiratory distress. Biopsies from several lesions showed focal necrosis of keratinocytes with minimal superficial perivascular inflammation, consistent with toxic epidermal necrolysis. He was intubated and transferred to our medical center.

On physical examination, the patient had exfoliation of over 70% of his body surface area (Fig. 1), and scattered blisters were observed on the hands, chest, abdomen, and back. He also had crusted hemorrhagic plaques on the lips and conjunctiva. The patient was admitted with a diagnosis of toxic epidermal necrolysis, secondary to phenytoin.

Extensive desquamation over the patient’s flank and thigh

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At the time of admission, the patient was noted to have black urine (Fig. 2). His urine analysis showed moderate proteinuria, 8.0 mg/dL of urobilinogen (normal range, 0.2–1 mg/dL), coarse granular casts, amorphous phosphate crystals, and was nitrate positive. The blood urea nitrogen (BUN) and creatinine levels were within normal limits. A urine sample was sent to the laboratory for cytospin and cell block analysis. Melanin was present in macrophages as detected by Fontana–Masson stain (Fig. 3). A heme stain for iron was negative. The patient was treated with supportive therapy and high‐dose intravenous immunoglobulin (1 g/kg/day × 4). The patient’s skin slowly improved over the 6‐week hospital course with full re‐epithelialization by the end of his hospital stay. Computed tomography (CT) scan of the head showed the presence of multiple hemorrhagic metastases involving the brain bilaterally, edema and compression of the left ventricle, and a midline shift, which was consistent with metastatic melanoma. CT scan of the abdomen and pelvis demonstrated a large low‐density focus within the right lobe of the liver, also consistent with metastatic involvement. There was no evidence of metastatic disease in the kidneys or the urinary tract. Given the extent of his disease, he was discharged to a hospice facility.

Patient’s urine (melanuria) at the time of admission

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Urine cytospin showing melanin within macrophages

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This case is presented because melanuria is a rare complication of metastatic melanoma and, unlike this case, most cases of melanuria have been associated with diffuse melanosis and/or metastasis to the genitourinary tract.
Correspondence
Authors: Franco Roberto Cortés
Published: March 2003

The Correspondence Section serves as a forum for opinion exchange about subjects of general interest such as dermatologic training, relations between dermatologists and pharmaceutical houses, governmental control of dermatology and medical practice in general, peculiarities of dermatology related to geographic, climatic, or racial factors, the flow of information and publications, as well as other concerns the readership might have. Contributions are welcome and should conform to the usual format for correspondence. Manuscripts will undergo standard editorial procedures. Submit all correspondence to Roberto Cortés Franco. MD, Fax: +52 (5) 665 7691. E‐mail: cortesmd@prodigy.net.mx
Evaluation of dietary intake of vitamin E in the treatment of atopic dermatitis: a study of the clinical course and evaluation of the immunoglobulin E serum levels
Authors: Tsoureli‐Nikita Evridiki , Hercogova Jana , Lotti Torello , Menchini Giovanni
Published: March 2003

BackgroundVitamin E (VE) is a potent antioxidant that can improve the immune macrophage‐mediated response, decrease the production and/or release of prostaglandins in humans, and decrease the serum levels of immunoglobulin E (IgE) in atopic subjects.

AimTo compare the effects of placebo (PL) and VE intake (400 IU/day) on subjective symptoms and serum IgE levels in 96 subjects with atopic dermatitis.

Materials and methodsA single‐blind clinical analysis was performed on 96 subjects randomly divided into two groups. Fifty subjects were given orally 400 IU (268 mg) of VE of natural origin, once a day for 8 months, and 46 took PL for the same period. Complete blood count, serum IgE levels, radioallergosorbent test (RAST) score, antinuclear antibodies (ANA), and biochemical analysis were obtained at the time of enrollment and every 15 days during the 8 months of the study. To evaluate VE therapy, a questionnaire was sent to each subject for completion at the end of the study.

ResultsThe results were as follows: (A) four subjects treated with VE worsened, compared to 36 in the PL group; (B) six subjects in the VE group and five in the PL group showed no change; (C) slight improvement was observed in 10 subjects in the VE group and four in the PL group; (D) 23 of the 50 subjects treated with VE showed great improvement, compared to only one in the PL group; and (E) there was almost complete remission of atopic dermatitis in seven of the 50 subjects in the VE group, but none in the PL group. Females showed less progression of atopic dermatitis than males in both groups and a higher percentage of almost complete remission (five females and two males). The range of serum IgE levels varied markedly from 1005 to 490 IU/mL in the VE group and from 1239 to 812 IU/mL in the PL group over 8 months. Subjects with great improvement and near remission of atopic dermatitis in the VE group demonstrated a decrease of 62% in serum IgE levels based on initial conditions, while, in subjects taking PL, the difference was approximately 34.4%. No complications were observed in either group. A remarkable improvement in facial erythema, lichenification, and the presence of apparently normal skin was reported. Eczematous lesions healed mostly as a result of decreased pruritus.

ConclusionsThe correlation between VE intake, IgE levels, and the clinical manifestations of atopy indicates that VE could be an excellent therapeutic tool for atopic dermatitis.
Are infantile seborrheic and atopic dermatitis clinical variants of the same disease?
Authors: Moises‐Alfaro Celia B. , Caceres‐Rios Hector W. , Rueda Monica , Velazquez‐Acosta Alvaro , Ruiz‐Maldonado Ramon
Published: March 2003

Background  The relationship between infantile seborrheic dermatitis (ISD) and infantile atopic dermatitis (IAD) is controversial.

Methods  Ninety‐six children aged 2–12 months diagnosed with atopic dermatitis and a comparable control group of healthy children were evaluated. Demographic data, personal history of ISD and personal or family history of atopy was considered in both groups.

Results  A personal history of ISD was found in 49% of IAD cases and in 17% of controls (P < 0.05).

Conclusions  Our result and those of the literature do not demonstrate a relationship between ISD and IAD. However, a number of cases of AD have an ISD‐like clinical picture. It is probable that ISD is a syndrome and not a disease.
Extranodal NK/T‐cell lymphoma with extensive subcutaneous involvement, mimicking subcutaneous panniculitis‐like T cell lymphoma
Authors: Kim You Chan , Kim Soo‐Chan , Yang Woo‐Ick , Go Jai‐Hyang , Vandersteen Daniel P.
Published: March 2003

A 22‐year‐old man had a subcutaneous nodule on the left thigh for 3 months. Physical examination showed an ulcerative nodule on the left thigh (Fig. 1). He suffered from a fever for 1 week. Laboratory tests revealed a white blood cell count of 7180/mm3, with 22.4% neutrophils, 68.5% lymphocytes, 8.4% monocytes, 0.3% eosinophils, and 0.4% basophils. Hemoglobin was 9.0 g/dL, hematocrit was 28.1%, and the platelet count was 202 × 109/L. Analysis of serum showed the following abnormal results: aspartate aminotransferase, 102 IU/L (normal, 13–37); alanine aminotransferase, 77 IU/L (normal, 7–43); alkaline phosphatase, 1296 (normal, 70–270); LDH, 1105 (normal, 120–520). Results of other laboratory tests including serum electrolytes, blood and tissue culture, and viral markers for hepatitis were negative or normal. Ultrasonography and computed tomography of abdomen and pelvis showed hepatosplenomegaly with ascites. Whole body bone scan showed an increased long bone activity of the left leg. Bone marrow aspiration was negative for neoplastic cells. Histologic examination from the thigh nodule revealed subcutaneous lymphoid infiltrates with involvement of the deep dermis. Examination at high power magnification showed small, medium, and large‐sized, pleomorphic lymphoid cells with hyperchromatic nuclei, nuclear debris, and phagocytic macrophages. Fat necrosis, partial rimming of fat spaces and clustering around blood vessels by pleomorphic lymphoid cells were also seen (Fig. 2). The immunohistochemical studies on paraffin sections revealed that most of the infiltrated lymphoid cells positively stained for CD56 (Fig. 3), granzyme B, TIA‐1, cytoplasmic CD3, and CD45RO, whereas CD4, CD8, CD20, and CD30 showed no immunoreactivity. Clonality of the infiltrate was analyzed by polymerase chain reaction (PCR). Nested PCR was performed using FR3A and VLJH as primers for IgH gene and Vγ – Jγ for T‐cell receptor γ chain gene. Polymerase chain reaction analysis showed a distinct band for TCR gene, confirming T‐cell monoclonality of infiltrating lymphocytes. EBV‐encoded small nuclear RNA was evident in lesional tissue by in situ hybridization. He was treated with two cycles of chemotherapy with CHOP‐BV (Cytoxan 735 mg, adriamycin 45 mg, vincristine 1.45 mg, prednisolone 75 mg, bleomycin 15 mg, VP‐16 150 mg). He died 5 days after chemotherapy.

An ulcerative nodule on the left thigh

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(a) Pleomorphic, small, medium and large‐sized lymphocytes with irregular hyperchromatic nuclei, nuclear debris, and phagocytic macrophages in the fat tissue. (b) A vascular involvement of pleomorphic lymphocytes and fat necrosis are seen (hematoxylin and eosin; original magnification × 100)

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Positive immunohistochemical staining for CD56 in atypical tumor cells (original magnification × 400)

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Scleromyxedema revisited
Authors: Pomann John J. , Rudner Earl J.
Published: March 2003

Scleromyxedema is a rare disease characterized by papular mucinous deposits, dermal fibroblast proliferation, and a monoclonal paraproteinemia. Its chronic course tends to be complicated by gastrointestinal, muscular, pulmonary, and neurologic disorders. We review the literature to identify the common systemic manifestations and suggest a clinical approach to this disorder. This should include: identification of the characteristic lesions, a skin biopsy, and serum protein electrophoresis. A thyroid evaluation may help differentiate this condition from others. An early neurologic, gastrointestinal, and cardiovascular evaluation should be considered.
Rational design of α‐helical antifreeze peptides
Authors: Kuiper M.J. , Fecondo J.V. , Wong M.G.
Published: March 2003

Abstract: The alanine‐rich α‐helical antifreeze protein from the winter flounder Pseudopleuronectes americanus adsorbs to specific planes of ice guided by an ice lattice match to threonine residues regularly spaced 16.6 Å apart. We report here that by redesigning the winter flounder antifreeze peptide to incorporate a 27.1‐Å spacing between putative ‘ice‐binding’ threonines, the deduced binding alignment of the helical molecule on the ice lattice is changed from the Miller indices directional vector [] to []. Subsequent ice‐binding characteristics are altered, including changes in adsorption specificity, decreases in thermal hysteresis activity and the formation of rotated hexagonal bipyramid ice crystal morphology.
An integrative analysis of phylogenetic relationships among newts of the genus Triturus (family Salamandridae), using comparative biochemistry, cytogenetics and reproductive interactions
Authors: Macgregor Herbert C. , Sessions Stanley K. , Arntzen J. W.
Published: March 2003

All the currently available data with regard to morphology, palaeontology, biochemical genetics, reproductive interactions and behaviour have been collated and analysed with combinations of phenetic and numerical phylogenetic methods, and integrated into a consensus evolutionary tree for European newts of the genus Triturus.

A range of cytogenetic data are presented including genome sizes (amount of DNA per haploid chromosome set), Giemsa C‐banded karyotypes for mitotic chromosomes, maps of lampbrush chromosomes and locations of nucleolus organisers (genes for ribosomal RNA). We have examined these data in search of evolutionary trends within the genus.

The degree to which cytogenetic data accord with the consensus tree, and the general usefulness of cytogenetic data for the reconstruction of evolutionary history are discussed.

A revised scheme for the taxonomy of Triturus is presented in which the genus is subdivided into two subgenera, Triturus and Palaeotriton is suggested. Subgenus Triturus should include all of the large bodied newts belonging to the T. cristatus species group as well as T. alpestris and T. vittatus. All other species are included in subgenus Palaeotriton.

The elevation of the former subspecies of T. cristatus to full species status is recommended mainly on the basis of information from studies of mitochrondrial DNA.
Queen‐worker conflict over sex ratio: A comparison of primary and secondary sex ratios in the Argentine ant, Iridomyrmex humilis
Authors: Aron Serge , Passera Luc , Keller Laurent
Published: March 2003

We compare the primary sex ratio (proportion of haploid eggs laid by queens) and the secondary sex ratio (proportion of male pupae produced) in the Argentine ant Iridomyrmex humilis with the aim of investigating whether workers control the secondary sex ratio by selectively eliminating male brood. The proportion of haploid eggs produced by queens was close to 0.5 in late winter, decreased to less than 0.3 in spring and summer, and increased again to a value close to 0.5 in fall. Laboratory experiments indicate that temperture is a proximate factor influencing the primary sex ratio with a higher proportion of haploid eggs being laid at colder temperatures. Production of queen pupae ceased in mid‐June, about three weeks before that of male pupae. After this time only worker pupae were produced. During the period of production of sexuals, the proportion of male pupae ranged from 0.30 to 0.38. Outside this period no males were reared although haploid eggs were produced all the year round by queens. Workers thus exert a control on the secondary sex ratio by eliminating a proportion of the male brood during the period of sexual production and eliminating all the males during the remainder of the cycle. These data are consistent with workers preferring a more female‐biased sex ratio than queens. The evolutionary significance of the production of male eggs by queens all the year round is as yet unclear. It may be a mechanism allowing queen replacement in the case of the death of the queens in the colony.
Proximate determination of male horn dimorphism in the beetle Onthophagus taurus (Coleoptera: Scarabaeidae)
Authors: Moczek  , Emlen
Published: March 2003

The existence of discrete phenotypic variation within one sex poses interesting questions regarding how such intrasexual polymorphisms are produced and modified during the course of evolution. Approaching these kinds of questions requires insights into the genetic architecture underlying a polymorphism and an understanding of the proximate mechanisms determining phenotype expression. Here we explore the genetic underpinnings and proximate factors influencing the expression of beetle horns – a dramatic sexually selected trait exhibiting intramale dimorphism in many species. Two relatively discrete male morphs are present in natural populations of the dung beetle Onthophagus taurus (Scarabaeidae, Onthophagini). Males exceeding a critical body size develop a pair of long, curved horns on their heads, while those smaller than this critical body size remain essentially hornless. We present results from laboratory breeding experiments designed to assess the relative importance of inherited and environmental factors as determinants of male morphology. Using father–son regressions, our findings demonstrate that horn length and body size of male progeny are not predicted from paternal morphology. Instead, natural variation in an environmental factor, the amount of food available to larvae, determined both the body sizes exhibited by males as adults and the presence or absence of horns. The nonlinear scaling relationship between the body size and horn length of males bred in the laboratory did not differ from the pattern of variation present in natural populations, suggesting that nutritional conditions account for variation in male morphology in natural populations as well. We discuss our results by extending ideas proposed to explain the evolution of conditional expression of alternative phenotypes in physically heterogeneous environments toward incorporating facultative expression of secondary sexual traits. We use this synthesis to begin characterizing the potential origin and subsequent evolution of facultative horn expression in onthophagine beetles.
Comparative evidence for costs of secondary sexual characters: adaptive vane emargination of ornamented feathers in birds
Authors: Møller  , Hedenström
Published: March 2003

We used a comparative approach, by comparing bird species with tail ornamentation with sister taxa without ornamentation, to deduce the aerodynamic function of extravagant feather ornaments and the costs of such ornaments in birds. First, the aerodynamic function of tail feather ornaments in birds can be deduced from asymmetry in the width of tail feather vanes, since flightless birds have symmetrical vanes while flying birds without feather exaggeration by sexual selection have asymmetrical vanes. Distal inner vanes at the tip of tail feathers were more narrow in ornamented as compared to nonornamented birds, and vane asymmetry at the tip of the feather was therefore reduced in ornamented species, suggesting marginal aerodynamic function of the distal part of extravagant feather ornaments. Second, the cost of feather ornaments due to parasite drag is proportional to the area of feathers extending beyond the maximum continuous width of the tail, and aerodynamic costs of long tails could therefore be diminished by a reduction in feather width. Consistent with this prediction, the outermost tip of feather ornaments was narrower than the homologous character in nonornamented sister taxa, while the base of the feather had similar width in the two groups of birds. These results suggest that the costs of extravagant ornamentation have been diminished by a reduction in feather width, leading to a reduction in drag. Costs of feather ornaments, as demonstrated by their fine morphology, thus appear to have been extensive during the evolution of these characters.
Stability of European natural populations of Drosophila melanogaster with regard to the P–M system: a buffer zone made up of Q populations
Authors: Bonnivard  , Higuet
Published: March 2003

Current natural populations of Drosophila melanogaster from Eurasia, Africa and Oceania were investigated with regard to the P–M system of hybrid dysgenesis, for both genetic properties (gonadal dysgenesis sterility analyses) and molecular characteristics (number of full-size elements and particular P element deletion-derivatives, the KP elements). Full-size and KP elements are, respectively, at the origin of two distinct regulation systems, the maternally transmitted P cytotype and the KP-mediated repression whose transmission is biparental. The results show both qualitative and quantitative differences in the geographical distribution of P elements. Comparison with distributions observed in 1980–1983 reveals a great stability of natural populations with regard to this system. In particular, the eastward gradient of P susceptibility previously described in Europe is still observed. This stability could result from the existence of a ’buffer zone’ made up of the French and bordering Q populations (with no P activity and completely regulating the transposition of active P elements). Indeed, in such populations repression mechanisms are redundant, as revealed by the study of repression inheritance. These populations are thus potentially able to limit the progression of P elements that occurs by step by step migrations. This distribution also allows us to enrich the P element invasion model, which can be divided into three steps: (1) a decrease in the number of full-size elements which coincides with an increase in the number of KP elements due to a regulatory role or a high transposition capacity; (2) an equilibrium, when the number of KP elements reaches a maximum and in which populations still have some full-size elements; (3) KP elements reduce in number in the absence of full-size elements allowing transposition, the populations losing their repression potential.
Adaptation to the laboratory environment in Drosophila subobscura
Authors: Matos  , Rose  , Pité M. T. Rocha , Rego  , Avelar
Published: March 2003

Adaptation to a novel environment is expected to have a number of features. Among these is a temporal increase in fitness and some or all of its components. It is also expected that additive genetic variances for these fitness characters will fall. Finally, it is expected that at least some additive genetic correlations will decrease, from positive toward negative values.

In a study of several life-history variables in a Drosophila subobscura population sampled from the wild and then cultured in the laboratory, we did not find any such longitudinal trends over the first 29 generations. However, a temporal comparison (over 14 generations) of the later generations of this laboratory-adapted population with a new population, derived from a more recent wild-caught sample, indicated clearly that laboratory adaptation was nonetheless occurring. This study suggests the need for extensive replication and control in studies of the features of adaptation to a novel environment.
Weak sinks could cradle mutualistic symbioses – strong sources should harbour parasitic symbioses
Authors: Hochberg  , Gomulkiewicz  , Holt  , Thompson
Published: March 2003

Using a population model of selection on an obligate symbiont and its host, we evaluate how demographic differences across geographical landscapes can produce selection mosaics in interacting species. The model assumes that the host populations vary geographically from demographic sources to sinks in the absence of effects by the symbionts, and that a virulent and a relatively avirulent form of the symbiont compete with one another across all habitats. Our results indicate that productivity gradients can create selection mosaics across habitats, resulting in complex fitness landscapes over which evolution occurs. We find that relatively virulent symbionts only persist if they have an advantage over avirulent strains or species in terms of interference (i.e. competition, and/or cross-transmission) interactions. When such a trade-off exists, we predict that the more virulent symbiont is most likely to be found in habitats where host population growth is highest, whereas the more avirulent symbiont should tend to persist in more marginal habitats or even habitat sinks for symbiont-free hosts. Demographic sinks may be the habitats most likely to favour the origin of new mutualisms. Very productive mutualisms can be exploited by hyperparasites or cheaters. We discuss our findings in terms of geographical scenarios for the emergence of mutualisms, and the long-standing debate about geographical patterns in the maintenance of sex.
Density-dependent natural selection in Drosophila: correlations between feeding rate, development time and viability
Authors: Borash  , Teotónio  , Rose  , Mueller
Published: March 2003

We have previously hypothesized that density-dependent natural selection is responsible for a genetic polymorphism in crowded cultures of Drosophila. This genetic polymorphism entails two alternative phenotypes for dealing with crowded Drosophila larval cultures. The first phenotype is associated with rapid development, fast larval feeding rates but reduced absolute viability, especially in the presence of nitrogenous wastes like ammonia. The second phenotype has associated with it the opposite set of traits, slow development, slow feeding rates and higher viability. We suggested that these traits are associated due to genetic correlations and that an important selective agent in crowded larval cultures was high levels of ammonia. To test this hypothesis we have examined viability and larval feeding rates in populations kept at low larval densities but selected directly for (i) rapid egg-to-adult development, (ii) tolerance of ammonia in the larval environment and (iii) tolerance of urea in the larval environment. Consistent with our hypothesis we found that (i) larvae selected for rapid development exhibited increased feeding rates, and decreased viability in food laced with ammonia or urea relative to controls, and (ii) larvae selected to tolerate either ammonia or urea in their larval environment show reduced feeding rates but elevated survival in toxin-laced food relative to controls. It would appear that development time and larval feeding rate are important characters for larvae adapting to crowded cultures. The correlated fitness effects of these characters provide important insights into the nature of density-dependent natural selection.
Temperature adaptation in a geographically widespread zooplankter, Daphnia magna
Authors: Mitchell  , Lampert
Published: March 2003

Evidence for temperature adaptation in Daphnia magna was inferred from variation in the shape of temperature reaction norms for somatic growth rate, a fitness-related trait. Ex-ephippial clones from eight populations across Europe were grown under standardized conditions after preacclimation at five temperatures (17–29 °C). Significant variation for grand mean growth rates occurred both within populations (among clones) and between populations. Genetic variation for reaction norm shape was found within populations, with temperature-dependent trade-offs in clone relative fitness. However, the population average responses to temperature were similar, following approximately parallel reaction norms. The among-population variation is not evidence for temperature adaptation. Lack of temperature adaptation at the population level may be a feature of intermittent populations where environmentally terminated diapause can entrain the planktonic stage of the life-history within a similar range of temperatures.
Courtship signals and mate choice of the flies of inbred Drosophila montana strains
Authors: Suvanto  , Liimatainen  , Tregenza  , Hoikkala
Published: March 2003

We studied genetic variation in fly mating signals and mate choice in crosses within and between inbred strains of Drosophila montana. Male songs and the cuticular hydrocarbons of both sexes as well as some of the flies’ behavioural traits differed significantly between strains. This did not, however, cause sexual isolation between strains. In fact, courtship was shorter if the female was courted by a male of a foreign strain than when courted by their own male. Heterosis was found for courtship duration and the carrier frequency of male song. Diallel analysis of male song revealed additive genetic variation in four out of the five traits studied. Two traits showed dominance variation and one of these, carrier frequency, expressed unidirectional dominance with alleles for higher carrier frequency being dominant. Direction of dominance in carrier frequency was the same as the direction of sexual selection exercised by D. montana females on this trait, which suggests that sexual selection could be a driving force in the evolution of song towards a higher carrier frequency.
Genetic conflict and changes in heterogametic mechanisms of sex determination
Authors: Caubet  , Hatcher  , Mocquard  , Rigaud
Published: March 2003

The consequences of cytoplasmic sex-ratio distortion and host repression for the evolution of host sex-determining mechanisms are examined. Analytical models and simulations are developed to investigate whether the interplay between sex-ratio distorters and host masculinizers or resistance genes can cause heterogamety switching (changes between male and female heterogamety). Switches from female heterogamety to a system analogous to male heterogamety can occur when selection favours the spread of autosomal masculinizers. However, the evolutionary outcome depends on the type of repressor and costs associated with repression, and also on aspects of population structure. Under most conditions, systems evolved to a polymorphic sex-determining state although many systems were characterized by numerical dominance of male heterogamety.
Monogamous pair bonds and mate switching in the Western Australian seahorse Hippocampus subelongatus
Authors: Kvarnemo C. , Moore G. I. , Jones A. G. , Nelson W. S. , Avise J. C.
Published: March 2003

Apparently monogamous animals often prove, upon genetic inspection, to mate polygamously. Seahorse males provide care in a brood pouch. An earlier genetic study of the Western Australian seahorse demonstrated that males mate with only one female for each particular brood. Here we investigate whether males remain monogamous in sequential pregnancies during a breeding season. In a natural population we tagged males and sampled young from two successive broods of 14 males. Microsatellite analyses of parentage revealed that eight males re-mated with the same female, and six with a new female. Thus, in this first study to document long-term genetic monogamy in a seahorse, we show that switches of mates still occur. Polygynous males moved greater distances between broods, and tended to have longer interbrood intervals, than monogamous males, suggesting substantial costs associated with the breaking of pair bonds which may explain the high degree of social monogamy in this fish genus.
Facultative sex allocation in snow skink lizards (Niveoscincus microlepidotus)
Authors: Olsson M. , Shine R.
Published: March 2003

Mathematical models suggest that reproducing females may benefit by facultatively adjusting their relative investment into sons vs. daughters, in response to population-wide shifts in operational sex ratio (OSR). Our field studies on viviparous alpine skinks (Niveoscincus microlepidotus) document such a case, whereby among- and within-year shifts in OSR were followed by shifts in sex allocation. When adult males were relatively scarce, females produced male-biased litters and larger sons than daughters. The reverse was true when adult males were relatively more common. That is, females that were courted and mated by few males produced mainly sons (and these were larger than daughters), whereas females that were courted and mated by many males produced mainly daughters (and these were larger than sons). Maternal body size and condition also covaried with sex allocation, and the shifting pattern of sexual size dimorphism at birth may reflect these correlated effects rather than a discrete component of an evolved sex-allocation strategy.
Size-dependent sex allocation in a simultaneous hermaphrodite parasite
Authors: Schärer L. , Karlsson L. M. , Christen M. , Wedekind C.
Published: March 2003

Most models of sex allocation distinguish between sequential and simultaneous hermaphrodites, although an intermediate sexual pattern, size-dependent sex allocation, is widespread in plants. Here we investigated sex allocation in a simultaneous hermaphrodite animal, the tapeworm Schistocephalus solidus, in which adult size is highly variable. Sex allocation was determined using stereological techniques, which allow measuring somatic and reproductive tissues in a common currency, namely volume. We investigated the relationships between individual volume and allocation to different reproductive tissues using an allometric model. One measure of female allocation, yolk gland volume, increased more than proportionally with individual volume. This is in contrast to the measure of male allocation, testis volume, which showed a strong tendency to increase less than proportionally with individual volume. Together these patterns led to sex allocation being strongly related to individual volume, with large individuals being more biased towards female allocation. We discuss these findings in the light of current ideas about size-dependent sex allocation in, primarily, plants and try to extend them to simultaneous hermaphrodite animals.
Selection of evolutionary models for phylogenetic hypothesis testing using parametric methods
Authors: Emerson B. C. , Ibrahim K. M. , Hewitt G. M.
Published: March 2003

Recent molecular studies have incorporated the parametric bootstrap method to test a priori hypotheses when the results of molecular based phylogenies are in conflict with these hypotheses. The parametric bootstrap requires the specification of a particular substitutional model, the parameters of which will be used to generate simulated, replicate DNA sequence data sets. It has been both suggested that, (a) the method appears robust to changes in the model of evolution, and alternatively that, (b) as realistic model of DNA substitution as possible should be used to avoid false rejection of a null hypothesis. Here we empirically evaluate the effect of suboptimal substitution models when testing hypotheses of monophyly with the parametric bootstrap using data sets of mtDNA cytochrome oxidase I and II (COI and COII) sequences for Macaronesian Calathus beetles, and mitochondrial 16S rDNA and nuclear ITS2 sequences for European Timarcha beetles. Whether a particular hypothesis of monophyly is rejected or accepted appears to be highly dependent on whether the nucleotide substitution model being used is optimal. It appears that a parameter rich model is either equally or less likely to reject a hypothesis of monophyly where the optimal model is unknown. A comparison of the performance of the Kishino–Hasegawa (KH) test shows it is not as severely affected by the use of suboptimal models, and overall it appears to be a less conservative method with a higher rate of failure to reject null hypotheses.
Sexual cannibalism in Nephila plumipes as a consequence of female life history strategies
Authors: Schneider J. M. , Elgar M. A.
Published: March 2003

The evolution of sexual cannibalism has been modelled as both an adaptive and nonadaptive female strategy. Recent evidence from several species suggests a connection between female foraging and sexual cannibalism, but the precise benefits for females have remained obscure. Here, we investigate the difference between cannibalistic and noncannibalistic female Nephila plumipes by removing the potential nutritional benefit of cannibalism. Courting and mating males that were killed by a female were immediately removed so that the female could not consume them. Nevertheless, cannibalistic females gained more mass from maturation to oviposition and produced larger first clutches than noncannibalistic females, although cannibalistic females matured at a smaller size and mass than noncannibalistic females. In juvenile instars, mass gain was generally smaller in females that moulted in a good condition but intermoult intervals were shorter. However, the time from maturity to oviposition was not shorter in females that matured in a good condition. Male behaviour did not differ according to the risk of cannibalism. We suggest that sexual cannibalism in N. plumipes is a side-effect of an increased foraging vigour of females that matured at a smaller size and body mass. Selection pressure on males to avoid cannibalism may be weak because of limited mating opportunities.
Size-dependent resource allocation and sex allocation in herbaceous perennial plants
Authors: Zhang D.-Y. , Jiang X.-H.
Published: March 2003

Individuals within a population often differ considerably in size or resource status as a result of environmental variation. In these circumstances natural selection would favour organisms not with a single, genetically determined allocation, but with a genetically determined allocation rule specifying allocation in relation to size or environment. Based on a graphical analysis of a simple evolutionarily stable strategy (ESS) model for herbaceous perennial plants, we aim to determine how cosexual plants within a population should simultaneously adjust their reproductive allocation and sex allocation to their size. We find that if female fitness gain is a linear function of resource investment, then a fixed amount of resources should be allocated to male function, and to post-breeding survival as well, for individuals above a certain size threshold. The ESS resource allocation to male function, female function, and post-breeding survival positively correlate if both male and female fitness gains are a saturating function of resource investment. Plants smaller than the size threshold are expected to be either nonreproductive or functionally male only.
Sexual size dimorphism and timing of spring migration in birds
Authors: Kissner K. J. , Weatherhead P. J. , Francis C. M.
Published: March 2003

Sexually selected traits are limited by selection against those traits in other fitness components, such as survival. Thus, sexual selection favouring large size in males should be balanced by higher mortality of larger males. However, evidence from red-winged blackbirds (Agelaius phoeniceus) indicates that large males survive better than small males. A survival advantage to large size could result from males migrating north in early spring, when harsh weather favours large size for energetic reasons. From this hypothesis we predicted that, among species, sex differences in body size should be correlated with sex differences in timing of spring migration. The earlier males migrate relative to females, the larger they should be relative to females. We tested this prediction using a comparative analysis of data collected from 30 species of passerine birds captured on migration. After controlling for social mating system, we found that sexual size dimorphism and difference in arrival dates of males and females were significantly positively correlated. This result is consistent with the hypothesis that selection for survival ability promotes sexual size dimorphism (SSD), rather than opposes SSD as is the conventional view. If both natural selection and sexual selection favour large adult males, then limits to male size must be imposed before males become adults.
Spatial ecological and genetic structure of a mixed population of sexual diploid and apomictic triploid dandelions
Authors: Meirmans P. G. , VloT E. C. , Den Nijs J. C. M. , Menken S. B. J.
Published: March 2003

Ecological differentiation is widely seen as an important factor enabling the stable coexistence of closely related plants of different ploidy levels. We studied ecological and genetic differentiation between co-occurring sexual diploid and apomictic triploid Taraxacum section Ruderalia by analysing spatial patterns both in the distribution of cytotypes and in the distribution of genetic variation within and between the cytotypes. A significant relationship between ploidy level and elevation was found. This mode of ecological differentiation however, was not sufficient to explain the significant spatial structure in the distribution of diploids and triploids within the population. Strong congruence was found between the spatial genetic patterns within the diploids and within the triploids. We argue that this congruence is an indication of gene flow between neighbouring plants of different ploidy levels.
Human T‐cell leukaemia/lymphoma virus risk may be enhanced in some selected donor populations
Authors: Price J. , Cant B. A. , Barbara J. A. J. , Tedder R. S.
Published: March 2003

Background and Objectives

Certain patient ethnic groups may require blood components from donors under‐represented in the UK donor population. Selective recruitment of Afro‐Caribbean donors is therefore necessary but was considered to pose an increased risk of human T‐cell leukaemia/lymphoma virus (HTLV) infection. To assess this a seroprevalence study of HTLV was undertaken in Afro‐Caribbean and Caucasian donors.

Materials and Methods

Sera from 1100 Afro‐Caribbean and 1100 Caucasian donors were tested for antibody to HTLV. Reactive samples were confirmed for specificity using an algorithm comprising two additional assays and polymerase chain reaction (PCR) where possible.

Results

Six Afro‐Caribbean donors (0·55%) were considered to be infected with HTLV I.

Conclusion

Donor selection in this case caused a significantly elevated prevalence of HTLV infection and serves as a warning of the need for care in the design of policies for selective donor recruitment.
Including polymerase chain reaction in screening for hepatitis C virus RNA in blood donations is not cost‐effective
Authors: Loubière S. , Rotily M. , Durand‐Zaleski I. , Costagliola D.
Published: March 2003

Background and Objectives

To assess the cost and effectiveness of adding a system of polymerase chain reaction (PCR) testing to the current enzyme‐linked immunosorbent assay (ELISA) screening for hepatitis C virus (HCV) in blood donations.

Materials and Methods

We performed a cost‐effectiveness analysis comparing three HCV screening strategies in French blood donors: detection of antibodies against HCV by an ELISA on blood donations (the current policy) vs. ELISA and PCR either on each blood donation or on blood pools. We combined national surveillance data on HCV antibody‐positive blood donors with a literature review in a Markov model for natural history of HCV disease and its treatment.

Results

PCR testing performed in parallel with ELISA will potentially add less than 1 year of life for all French recipients compared to ELISA screening alone. The incremental costs per life year saved were, respectively, ∈84·6 million with ELISA and PCR testing of blood pools, and ∈891·1 million with testing of individual blood donations.

Conclusion

PCR testing performed in parallel with antibody screening, either on pools or on single donations is not currently a cost‐effective option for the detection of HCV RNA virus in blood donors.
Early detection of hepatitis B surface antigen and detection of HBsAg mutants: a comparison of five assays
Authors: Zaaijer H. L. , Vrielink H. , Koot M.
Published: March 2003

Background and Objectives

Assays for the detection of hepatitis B surface antigen (HBsAg) face two challenges: the emergence of sensitive techniques for detection of hepatitis B virus DNA and the existence of HBsAg mutant hepatitis B viruses. We studied the sensitivity of five modern assays for detection of HBsAg.

Materials and Methods

The sensitivity of two mini robot‐based assays – IMx HBsAg V2 and Vidas HBsAg – and three enzyme‐linked immunosorbent assays (ELISAs) with microtitre plate format – Hepanostika Uni‐Form II v1.2, Monolisa Ag HBs Plus and HBsAg Test System 3 – was compared testing 11 HBsAg seroconversion series, serial dilutions prepared from three HBsAg standards and nine HBsAg mutant samples.

Results and Conclusion

Overall, the IMx HBsAg V2 assay showed the highest sensitivity. It outperformed the Vidas HBsAg in analytical sensitivity and in detection of HBsAg mutants. Among the microtitre plate ELISAs, the Monolisa Ag HBs Plus outperformed the HBsAg Test System 3 in detection of HBsAg mutants and it surpassed the Hepanostika Uni‐Form II v1.2 in analytical sensitivity.
Apoptosis in leucodepleted packed red blood cells
Authors: Bontadini A. , Tazzari P. L. , Manfroi S. , Tassi C. , Conte R.
Published: March 2003

Background and Objectives Packed red blood cells (pRBCs) contain apoptotic white cells. We studied apoptotic cells in pRBCs after filtration and at various time‐points during storage.

Materials and Methods To maintain the same subset of cells, seven pRBC units were pooled in a single bag and divided equally into seven aliquots. Two series of five experiments were performed: in the first we utilized the Biofil R01 Max filter, and in the second the Pall BPF4 filter was used. One aliquot was immediately leucodepleted while the others were stored at 4 °C and filtered on days 3, 7, 10, 14, 21 and 42 of storage. The postfiltration leucocyte counts and apoptotic evaluations were performed by using the Nageotte chamber and flow cytometry.

Results The absolute number of residual leucocytes was always less than 0·5 × 106 in each experiment. Nageotte chamber counts showed a greater number of white blood cells than flow cytometry during the 42 days of storage. On day 0, the percentage of apoptotic cells in non‐leucodepleted pRBCs was 1·1 ± 0·4 and 1·2 ± 0·4, while in filtered pRBCs it was high from day 0, at 53·5 ± 16·3 and 52 ± 18·5, respectively, with Biofil and Pall filters. On day 10 of storage, apoptotic cells reached a percentage of 42·5 ± 15·8 and 41·6 ± 18·6 in non‐leucodepleted pRBCs, while in filtered units an average value of ≈ 90% was found with both filters.

Conclusions The percentage of apoptotic cells was higher in leucodepleted than in non‐leucodepleted pRBCs. After filtration, the degree of apoptosis was already high on day 0, and reached a mean of ≈ 90% by day 10. The difference in residual WBC counts between the Nageotte chamber and flow cytometry could be related to the presence of a high percentage of apoptotic cells in filtered blood components, and to the method used to distinguish viable from apoptotic cells.
Non‐steroidal anti‐inflammatory analgesics: a review of current practice
Authors: Mathews Karol A.
Published: March 2003

Objective:This review is intended to update the reader on the clinical aspects of the non‐steroidal anti‐inflammatory analgesics (NSAIAs) currently used in veterinary practice. Most NSAIAs act by selectively, or preferentially, inhibiting the synthesis of cyclooxygenase (COX)‐1 or COX‐2, or both COX‐1 and COX‐2 enzymes which oxidize arachadonic acid to a series of prostenoids. The prostenoids are precursors of various prostaglandins required for many homeostatic functions throughout the body. The COX‐1 and COX‐2 enzymes are constitutive, however the COX‐2 enzyme is also induced following injury or inflammation facilitating the transmission of pain. As the newer NSAIAs focus on the inhibition of COX‐2, this review offers a more detailed discussion of this enzyme.

Data synthesis:This data was obtained from recent review articles and original published reports in both the veterinary and human literature. A CAB and Medline search was also used.

Conclusions:The NSAIAs are effective analgesics for managing moderate to severe pain in many species of animals; however, potential adverse effects may occur if used inappropriately. Guidelines, including indications, contraindications and dosing regimens for the commonly available NSAIAs are included.