bluuebunny/crossref_metadata_2025 huggingface dataset:
Lichen planopilaris [cicatricial (scarring) alopecia] in a child
Authors: Sehgal Virendra N. , Bajaj Promila , Srivastva Govind
Published: March 2003

A mother of a 12‐year‐old boy, 2 years ago, noticed that he showed patchy loss of hair on the vertex of the scalp. It was asymptomatic and progressive. Subsequently, similar patches appeared elsewhere on the scalp. Some of these patches joined to form a large bald patch. This was accompanied by dusky blue eruptions over the left upper lip and eyebrows. Later, there was localized loss of hair. A family history of a similar ailment was absent.

Examination of the scalp revealed plaques of alopecia with mild to moderate erythema. The skin was smooth, shiny, and atrophic (Fig. 1). Atrophy was apparent by the presence of wrinkles in places, and by holding the skin between the thumb and the index finger. The periphery of the lesions was well demarcated and was occupied by erythematous, scaly, follicular papules. Lesions were also located on the patches of alopecia. In addition, flat‐topped, dusky blue, papules/plaques were present over the upper lip.

Lichen planopilaris: plaques of alopecia showing smooth, shiny, atrophic skin with erythema

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A study of hematoxylin and eosin‐stained microsections prepared from the upper lip and vertex of the scalp was undertaken. The former revealed hyperkeratosis, hypergranulosis, sawtooth irregular acanthosis, and destruction of the basal cell layer which, in turn, was embraced by a lymphohistiocytic infiltrate disposed in a band‐like fashion. A few cells were seen invading the epidermis. Pigment‐laden histiocytes were found intermingled with the infiltrate. In the scalp skin, on the other hand, atrophy of the epidermis with punctuation of keratin plugs, together with fibrosis of the dermis, was prominent. The walls of the hair follicles were hyperkeratotic, while their lumina were conspicuous by their dilatation and contained keratotic plugs (Fig. 2a,b). Sebaceous and sweat glands were absent.

Lichen planopilaris showing atrophy of the epidermis, fibrosis of the dermis, dilatation of the hair follicle lumina containing keratotic plug(s), and hyperkeratosis of the wall of the follicle (hematoxylin and eosin: a , × 40; b , × 100)

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Response to treatment, comprising ultramicronized griseofulvin (Gris O.D.) 375 mg/day (Sehgal VN, Abraham GJS, Malik GB. Griseofulvin therapy in lichen planus –‐ a double blind controlled trial. Br J Dermatol 1972; 86: 383–385; Sehgal VN, Bikhchandani R, Koranne RV et al. Histopathological evaluation of griseofulvin therapy in lichen planus. A double blind controlled study. Dermatologica 1980; 161: 22–27) and prednisolone 20 mg/day for 6 months, was excellent (Fig. 3). Topical betamethasone dipropionate (Diprovate) lotion was used as a supplement.

Perceptible decline in band‐like lymphohistiocytic inflammatory infiltrate (hematoxylin and eosin, a, × 40; b, × 100)

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Recurrent primary cutaneous adenoid cystic carcinoma of the scrotum
Authors: Koh Bo‐Kyung , Choi Jung‐Min , Yi Jong Yuk , Park Chul‐Jong , Lee Hong‐Won , Kang Sung‐Hak
Published: March 2003

A 60‐year‐old man had asymptomatic erythematous nodule on the right inguinal area, which had progressively grown for 2 years. Excision was performed at the Department of Urology of our hospital. Two months later, there was local recurrence on the excision site, and it extended locally to make several tender erythematous nodules on the right inguinal area and firm plaque on the scrotum (Fig. 1). Histopathologic examination of the excision specimen revealed large cell masses with tubular or cribriform pattern and many small, solid epithelial islands unattached to the overlying epidermis. The tumor was confined to the dermis and subcutaneous tissue. Round spaces formed by malignant epithelial cells and containing amorphophilic basement membrane‐like material occured inside the tumor masses. The tumor cells were basaloid cells with scanty cytoplasm and deeply stained round‐to‐oval nucleus (Fig. 2). There was clear perineural involvement by the tumor cells. A substance in the pseudoglandular spaces, cystic spaces and the stroma was stained strongly with periodic acid‐Schiff (PAS) and alcian blue (pH 2.5). A PAS‐positive substance was digested by diastase pretreatment. These findings suggested the substance to be a neutral mucopolysaccharide. Immunoperoxidase staining for S‐100 protein and cytokeratin were strongly positive with the tumor cells but not with carcinoembryonic antigen. A histopathologic diagnosis of ACC was made. Salivary glands, bronchi, esophagus, and other organs were examined, but there was no evidence of neoplasm in other organs. A diagnosis of primary cutaneous adenoid cystic carcinoma was made but the patient refused all the treatment, including surgery.

Several erythematous nodules on the right inguinal area and indurated plaque on the adjacent scrotum

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The characteristic tubular and cribriform pattern of basaloid cells with round spaces containing mucinous material in the dermis (H&E, × 400)

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Pyoderma gangrenosum: a report of 21 cases
Authors: Mlika Rym Benmously , Riahi Imed , Fenniche Samy , Mokni Mourad , Raouf Dhaoui Mohamed , Dess Néjib , Dhahri Amel Ben Osman , Mokhtar Insaf
Published: March 2003

Background Pyoderma gangrenosum (PG) is an uncommon, destructive, cutaneous ulceration, belonging to the neutrophilic disease spectrum. It is associated with systemic disease in 50% of cases.

Methods We report a retrospective study of 21 cases of PG. All cases studied fulfilled the following criteria: (i) clinical features of PG; (ii) histopathology consistent with a diagnosis of PG, and excluding other specific dermatoses.

Results The average age of our patients was 41.8 years. The male to female ratio was 1.1. The typical ulcerative variant was found in 17 patients, bullous PG in two patients, and the granulomatous variant in two patients. Sixty‐two per cent of our patients had lesions on their lower legs. Two patients had neutrophilic pulmonary involvement concurrent with the ulcers. An association with other internal diseases was noted in 12 patients. Histopathologic study showed vasculitis in 13 patients. Of these, 11 were leukocytoclastic and the others predominantly lymphocytic.

Conclusions PG is a rare disease, with the ulcerative variant being most frequent. The lower legs are the most commonly affected sites. The recurrence rate in our study was about 46% regardless of the treatment prescribed. Pulmonary involvement was fatal in two patients.
Cicatricial alopecia; a dermatopathologic and immunopathologic study of 33 patients (pseudopelade of brocq is not a specific clinico‐pathologic entity)
Authors: Amato L , Mei S , Massi D , Gallerani I , Fabbri P
Published: March 2003

Abstract

Background  Pseudopelade of Brocq (PB) is a permanent progressive scarring alopecia characterized by numerous alopecic patches localized only in the scalp, that tend to coalesce into larger, irregular plaques with policyclic borders. PB can be considered either the final atrophic stage of several scarring disorders such as lichen planus pilaris (LPP) and discoid lupus erythematosus (DLE) (secondary PB) or an autonomous disease (primary PB).

The aim of this study was to assess the incidence of primary vs. secondary PB by a combined histopathological and immunopathological study in a series of patients who fulfillled the clinical diagnostic criteria for PB set forth by Braun Falco et al.

Methods  We studied 33 patients (5 males and 28 females, whose age ranged from 24 to 75 years). The duration of the disease (from onset to biopsy) ranged from 3 months to 8 years. Serum samples were tested for circulating auto‐antibodies (antinuclear antibodies anti ENA, anticentromere, anti‐Scl70, antithyroid, antigastric parietal cells) circulating immune complexes, total and single fraction (C3, C4) complement activity. The skin biopsies taken from the active advancing margin of the more recent alopecic patch were bisected vertically, one was sent for histopathological examination, and the other for the immunofluorescence studies.

Results  In all patients the serum tests above were found to be negative or normal. Histopathologically, 11 biopsies (33.3%) displayed findings typical for LPP whereas seven cases (21.2%) showed typical DLE features. In the remaining 15 cases (45.5%) histopathological findings were not suggestive of any specific dermatosis. DIF investigations showed findings typical of LPP in six cases (18.1%) and typical of DLE in seven cases (21%). In three cases we did not find findings typical of LPP, DLE, or any other specific dermatitis. In 11 cases no immunological deposits could be detected and therefore were classified as negative.

Conclusion  In conclusion, PB is a type of scarring alopecia of the scalp associated with a peculiar clinical presentation and evolution, which cannot be considered an autonomous nosologic entity because in 66.6% of patients it is the end stage of other inflammatory chronic diseases such as LPP and DLE. It is conceivable that even in those cases in which the histopathological and immunopathological findings did not allow for a specific diagnosis, LPP and DLE were also involved. It is noteworthy that in our study the histopathological and the immunopathological examinations did not conflict and often the results were even coincidental, thus confirming the compatibility of the combined histo‐immunopathological approach in the diagnostic evaluation of PB.
Multiple eccrine hidrocystomas associated with Graves’ disease
Authors: Kim Yoon‐Dong , Lee Eun‐Ju , Song Min‐Ho , Suhr Ki‐Beom , Lee Jeung‐Hoon , Park Jang‐Kyu
Published: March 2003

A 20‐year‐old Korean woman presented in August 1999 with a 3‐month history of multiple, tiny papules on the periorbital and malar areas (Fig. 1a). She had noted hyperhidrosis for the preceding 6 months, even at room temperature. She had been well and had received no medication prior to her first visit to our clinic. Physical examination showed yellow colored, translucent, small papules, as well as finger tremor, exophthalmos, and a goiter. Histologic examination demonstrated cystic structures in the dermis lined with two layers of cuboidal epithelial cells (Fig. 2). The epidermis was normal and the rete ridges were partially effaced. Immunohistochemical studies revealed that the epithelial cells of the cyst wall were carcinoembryonic antigen (CEA) positive but S‐100 protein negative.

Multiple tiny papules on the periorbital and malar areas before (a) and after (b) treatment for Graves’ disease

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Staining with hematoxylin and eosin (× 100); (b) Staining with hematoxylin and eosin (× 200); (c) CEA‐positive epithelial cells; (d) S‐100 protein‐negative epithelial cells

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Because a goiter and finger tremor were noted on physical examination, hyperthyroidism was suspected. Thyroid function test results were: triiodothyronine (T3), 8.0 ng/mL (normal range, 0.7–1.9 ng/mL); free thyroxine (T4), 8.1 ng/mL (0.7–1.9 ng/mL); T4, 35 µg/dL (6.0–11.8 µg/dL); thyroid‐stimulating hormone (TSH), 0.04 IU/mL (0.25–4.0 IU/mL); positive for anti‐TSH receptor antibody. On the basis of these findings, the patient was diagnosed with Graves’ disease and treated with methimazole, 40 mg/day. As the patient's symptoms improved, the therapeutic dose was decreased to 20 mg/day. Four months after the beginning of treatment, the free T4 and T3 values had returned to the normal range (Table 1). The skin lesions, finger tremor, and hyperhidrosis had also disappeared. Exophthalmos was improved, but still present (Fig. 1b).

Comparison of thyroid hormone values in Graves’ disease pretreatment and post‐treatment

T3 (ng/mL)
Free T4 (ng/mL)

Pretreatment
8.0
8.1

Post‐treatment
1.0
0.15

T3, triiodothyronine; T4, thyroxine.
An ultrastuctural study of hair fiber damage and restoration following treatment with permanent hair dye
Authors: Ahn Hyung Jin , Lee Won‐Soo
Published: March 2003

Introduction Hair fibers are comprised of non‐nucleated keratinocytes and are biologically dead. Clinical damage to the hair shaft occurs with the application of hair dye. Whether this damage can be repaired and the time frame involved is of interest and may help to determine the optimal interval between repeat applications.

Aims and methods Ultrastructural changes of hair shafts after application of permanent hair dye were observed sequentially in a 26‐year‐old woman. The dye contained p‐phenylenediamine, m‐aminophenol, resorcin and hydrogen peroxide as an oxidizer. Scanning and transmission electron microscopy was performed immediately before application of the hair dye and again at 30 min, 1 h, 3 h, 6 h, 1 day, 3 days, 1 week, 2 weeks, 4 weeks, 6 weeks and 8 weeks.

Results The hair showed cuticular swelling with focal degeneration. In some places there was exposure of the hair cortex due to extensive cuticular detachment. There were many holes of various size in the endocuticle, small focal lacunae along the intercellular space and an ill‐defined A‐layer especially beneath the area of cuticular detachment. The exocuticle appeared normal. The findings were most dramatic in the 6 h and 1 day specimens and tended to improve gradually thereafter. The 8 week specimen showed near complete restoration of the hair cuticle and return to the precoloring state.

Conclusion Hair returns to its precoloring state and this requires 8 weeks.
Comèl–Netherton syndrome and peeling skin syndrome type B: overlapping syndromes or one entity?
Authors: Sárdy Miklós , Fáy Andrea , Kárpáti Sarolta , Horváth Attila
Published: March 2003

Background  A 42‐year‐old male patient suffering from the rare Comèl–Netherton syndrome is reported, and the symptoms are discussed together with the results of light and electron microscopic examinations.

Case report  Our case presented peeling skin syndrome type B with spontaneous, lifelong skin shedding with underlying erythema; however, with more careful studies, the hidden features of Comèl–Netherton syndrome were identified.

Conclusion  This is an example of a condition where there is no clear border between Comèl–Netherton syndrome and peeling skin syndrome type B, lending credence to a close relationship between the two syndromes.
Clinical and epidemiological observations of cutaneous tuberculosis in Larkana, Pakistan
Authors: Bhutto Abdul Manan , Solangi Aijaz , Khaskhely Noor Mohammad , Arakaki Hajime , Nonaka Shigeo
Published: March 2003

Background Cutaneous tuberculosis is widespread in Pakistan but has not been fully documented. This study was conducted to determine the clinical pattern, nature and existence of the disease in Larkana, Sindh province, Pakistan.

Methods We are reporting 153 cases of patients with cutaneous tuberculosis who visited our department from 1996 to 1999. All cases were diagnosed at the clinic, and the biopsies were examined for histopathological evidence. The patients received three antituberculous treatments during a 9 month course.

Results Clinically, 63 (41.2%) cases of lupus vulgaris, 54 (35.3%) of scrofuloderma, 29 (19.59%) of lupus verrucosa cutis, six (3.92%) of tuberculosis cutis orificialis and one (0.64%) case of disseminated cutaneous tuberculosis were observed in our department from 1996 to 1999. All patients were aged between 3 and 50 years and had experienced the present complaints for 1 to 12 years. Sixty‐nine (45.1%) cases were children aged under 10 years, 50 cases (37.25%) were aged between 10 and 20 years, and 27 cases (17.65%) were aged over 20 years. There was no considerable ratio difference of the disease between male and female patients. Histopathologically, all the specimens showed chronic granulomatous changes; the majority was infiltrated with epitheloid cells, langhans giant cells, plasma cells and other inflammatory cells, such as lymphocytes, eosinophils and neutrophils in ulcerated lesions. Increased numbers of mast cells were seen in upper and lower dermis in two‐thirds of the specimens. Caseating necrosis was visible in half of the specimens while Ziehl‐Neelsen stain was negative in all the sections.

Conclusions The observed number of patients was moderately large, thus indicating a high incidence of cutaneous tuberculosis in Larkana. Lupus vulgaris, a form of cutaneous tuberculosis, was widespread in this area and prevalent in adults, while scrofuloderma was prevalent in children. Moreover, the existing rate of the disease was higher in children aged under 10 years and lower in adults. This indicates that children are more prone to this disease than adults.
Lupus erythematosus panniculitis: a clinicopathologic study
Authors: Ng Patricia Pei‐Lin , Tan Suat Hoon , Tan Tulip
Published: March 2003

Background Lupus erythematosus panniculitis is a clinical variant of lupus erythematosus which involves the deep dermis and the subcutaneous fat. The purpose of this study was to ascertain the clinical profile of Asian patients with this condition.

Methods This was a retrospective study of all histologically confirmed lupus panniculitis seen at our center between 1992 and 1997. The age, sex, past history/subsequent diagnosis of systemic lupus erythematosus (SLE), presence of clinical discoid lupus erythematosus (DLE) changes on overlying skin, direct immunofluorescence, serologic, and histologic findings were analyzed.

Results There were 12 cases of lupus panniculitis, two of which were in patients already diagnosed with SLE and one in which the patient subsequently evolved into SLE. The mean age at diagnosis was 31.3 years. The face (50%), upper limbs (33%), and scalp (25%) were the most common sites of involvement. Thirty‐three per cent had clinical evidence of DLE on the overlying skin, whilst 67% had histologic features of DLE on the overlying skin. A lupus band was present in 36%. Antinuclear antibody (ANA) was positive in three of 11 cases; these were in the two patients who already had SLE and in the only patient who progressed to SLE. All of the cases showed fat necrosis and, in the majority of cases, there was associated lobular and paraseptal inflammation. Thirty‐three per cent showed lymphocytic vasculitis and 75% had mucin deposition. None had lymphoid nodules, subepidermal hyalinization, or calcification.

Conclusions Lupus panniculitis affects a younger age group in Asians as compared with the Western population. Although about one‐third of patients show clinical evidence of overlying DLE, two‐thirds of patients show histologic evidence of DLE. It tends to have a mild disease course in the majority of cases.
Primary cutaneous amoebiasis: case report with review of the literature
Authors: Parshad Sanjeev , Grover P. S. , Sharma Ashok , Verma D. K. , Sharma Anuradha
Published: March 2003

Background Primary cutaneous amoebiasis is a rare clinical entity. The lesions can be successfully treated if suspected and correctly diagnosed. We report an interesting case with review of the literature.

Methods A 25‐year‐old man presenting with primary cutaneous amoebiasis with extensive involvement of the anterior abdominal wall is described. Correct diagnosis eluded us for 2 years. Clinical suspicion and a simple bedside test (wet drop preparation examination) were sufficient to diagnose the lesion. Successful treatment was achieved with oral Metronidazole followed by split skin grafting. Only six cases of primary cutaneous amoebiasis could be traced in the literature.

Conclusions Primary cutaneous amoebiasis is extremely rare. Diagnosis is usually not suspected because of its rarity. Cutaneous amoebiasis responds readily to proper treatment, yet, if unrecognized and neglected, produces significant morbidity and may be fatal.
Leprosy in a high‐prevalence Egyptian village: epidemiology and risk factors
Authors: Hegazy Aly A. , Abdel‐Hamid Ibrahim A. , Ahmed El‐Shahat F. , Hammad Sabry M. , Hawas Samia A.
Published: March 2003

Background  The epidemiology of leprosy in rural Egypt is unknown. This prospective household survey was conducted in a high‐prevalence Egyptian village in order to explore the epidemiologic characteristics of the disease and to determine the possible socioeconomic and HLA genotype risk factors.

Methods The subjects of the study were the residents of Kafr‐Tambul village in the Dakahlia governorate, Egypt. There were 10,503 inhabitants of the village, of whom 9643 (91.8%) had a complete visual skin examination, and suspected leprosy patients were subjected to histopathological examination and slit skin smears. Each household was interviewed to record personal data on family members, family size, education, occupation, crowding index at sleep, social score and source of water supply. Human leukocyte antigen (HLA) class II genotypes were analyzed in all leprosy patients and in a number of both household (N = 124) and non‐household (N = 30) contacts.

Results The overall prevalence of clinical leprosy in the village studied was 24.9/10,000 (95%CI = 16.3–37.6). Individuals above the age of 40 years were 4 times more likely to develop leprosy (OR = 4, P= 0.01). The degree of education, crowding index at sleep, social score and source of water supply were found to be unlikely to increase the risk of leprosy (P > 0.05). The frequencies of HLA‐DR2 and ‐DQ1 were significantly associated with leprosy (OR = 3.33 and 5.4; CI = 0.95–12.07 and 1.08–30.19, respectively, all P < 0.05).

Conclusions Our study provides the first picture of the epidemiology of leprosy in a high‐prevalence village in rural Egypt. Leprosy detection campaigns should be initiated and directed towards high‐prevalence villages. Provision of leprosy control activities in rural health units is necessary in order to detect new cases. The risk for leprosy is associated with HLA‐DR2 and ‐DQ1 markers, and these markers appear to increase personal susceptibility to leprosy in this village.
B‐cell lymphomas involving the skin associated with hepatitis C virus infection
Authors: Viguier Manuelle , Rivet Jacqueline , Agbalika Félix , Kerviler Ericde , Brice Pauline , Dubertret Louis , Bachelez Hervé
Published: March 2003

Background A role for hepatitis C virus (HCV) infection has been suggested in the pathogenesis of non‐Hodgkin lymphomas (NHL).

Aim To evaluate the characteristics of cutaneous lymphomas occurring in HCV‐infected patients, and to investigate the hypothesis of a direct infection of malignant cells.

Methods Three patients showing a positive serology for HCV and a cutaneous lymphoma were studied. Analysis of HCV replication was performed using reverse transcriptase–polymerase chain reaction. The presence of HCV RNA was also assessed in biopsies from lesional skin and in a lymph node in one case. Genotype characterization was carried out on the basis of LiPA genotyping assays using viral genomic amplification products.

Results Cutaneous NHL occurred in patients with chronic and replicative HCV infection, and exhibited a B‐cell phenotype (one diffuse large B‐cell lymphoma, one follicular lymphoma, and one marginal zone B‐cell lymphoma). All patients were male; two of them were former intravenous drug abusers, while the HCV contamination route was unknown in the third. The search for HCV RNA in the skin and in lymph nodes yielded negative results. HCV genotypes were 1b in two cases and 3a in one case.

Conclusion These results show that a subset of B‐cell cutaneous NHL is associated with a replicative HCV infection and suggest that HCV is not involved in lymphomagenesis through a direct infection of malignant cells. The ability of HCV to trigger a chronic B‐cell lymphoproliferation could represent another mechanism, while a fortuitous association cannot be excluded.
Familial anetoderma
Authors: Thomas Jean E. , Mehregan Darius R. , Holland Jean , Mehregan David A.
Published: March 2003

A 31‐year‐old Caucasian male presented with a history of erythematous, saccular outpouchings of the skin on his back, shoulders, and upper extremities (Fig. 1). The patient reported that his mother and aunt had a similar skin disorder, which initially began with inflammation, but healed leaving lax skin in its wake. He did not recall the name of the skin condition.

Extensive outpouching of the skin involving the entire back and upper arms

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Physical examination revealed large confluent zones of sac‐like protrusions of erythematous skin on the back and shoulders. Histopathologic examination of the excisional biopsy revealed a relatively unremarkable epidermis. Perivascular lymphocytes were present in small numbers in the papillary dermis. Adnexal structures and deep dermis remained intact. The acid‐orcein‐Giemsa stain highlighted the absence of elastic fibers within the mid and lower reticular dermis (Fig. 2a,b), consistent with anetoderma.

(a,b) Dermis shows extensive loss of elastic fibers with only rare, fragmented elastic fibers present (acid Orsein‐giemsa stain. Magnification: (a)×90, (b) ×240

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Analysis of γβ, βγ, γγ, ββ continuous turns in proteins
Authors: Guruprasad K. , Prasad M.S. , Kumar G.R.
Published: March 2003

Abstract: We report the observation of continuous turns in proteins which comprise individual γ‐turns or β‐turns or both that are situated immediately one after the other along the polypeptide chain. The continuous turns were identified from a representative data set of three‐dimensional protein crystal structures. The γβ/βγ, γγ and ββ continuous turns represent peptides of varying amino acid residue lengths and conformations. The continuous turns frequently observed in proteins were: γβ, between a coil and a strand; βγ, between a helix and a strand; γγ, between coils; and ββ, either between a strand and a coil or between strands or coils. We determined the statistically significant amino acid residue preferences at individual positions in the turn, calculated amino acid positional potentials and analyzed main chain hydrogen bonds and side‐chain interactions likely to stabilize the continuous turns. The data on continuous turns have been integrated in the database of structural motifs in proteins (DSMP) on our web server at (http://www.cdfd.org.in/dsmp.html). This is useful to make queries on sequences compatible with different continuous turns.
Patterns of fluctuating asymmetry in flowers: Implications for sexual selection in plants
Authors: Møller Anders Pape , Eriksson Mats
Published: March 2003

Characters in animals used in signalling and subjected to strong directional selection often demonstrate (i) an elevated level of fluctuating asymmetry (small random deviations from bilateral symmetry) and (ii) a negative relationship between the degree of individual fluctuating asymmetry and the size of a given character. We tested these two predictions in plants since flowers are subjected to strong directional selection and are involved in signalling to pollinators, whereas leaves are supposed not to be directly involved in signalling. The overall level of fluctuating asymmetry in a number of plant species with bilaterally or radially symmetric flowers was not generally higher in floral traits than in leaves. The level of fluctuating asymmetry in plants was sometimes significantly consistent within individuals. The absolute degree of individual fluctuating asymmetry in floral traits was generally negatively related to the size of the trait, while there was a positive relationship for leaves. The degree of individual fluctuating asymmetry in floral traits was marginally negatively related to the degree of individual fluctuating asymmetry in leaf traits. These patterns of fluctuating asymmetry in plants suggest that (i) the degree of asymmetry in flowers signals different aspects of quality than does the degree of asymmetry in leaves, and that (ii) fluctuating asymmetry in flowers often reflects the phenotypic quality of individual plants.
Geographical variation in wing polymorphism of the waterstrider Aquarius najas (Heteroptera, Gerridae)
Authors: Ahlroth  , Alatalo  , Hyvärinen  , Suhonen
Published: March 2003

The waterstrider Aquarius najas is wingless in Northern Europe, while winged individuals occur frequently in Central and Southern Europe. To test if the latitudinal difference is genetically controlled, we collected mature individuals from 10 different populations and raised their offspring in ‘common garden’ laboratory conditions. Half of these populations were from southern and the other half from central Finland. Daylength and temperature do influence wing development among other species of waterstriders, and thus we maintained a similar short daylength and warm conditions for all populations. These conditions should be favourable for wing development in general. Among laboratory-bred individuals several winged individuals appeared, and their proportion varied between populations. The relative frequency of winged individuals was highest in the southern populations. Thus, apart from phenotypic plasticity there seems to be some genetic control over the occurrence of wings, and the latitudinal trend coincides with the direction in natural populations over a larger European scale. Overwinter survival in our laboratory conditions was higher among the wingless individuals. The survival cost may explain why the proportion of winged individuals was lower in the northern populations with more extreme overwintering conditions than in the southern ones.
Selection for starvation resistance in Drosophila melanogaster : physiological correlates, enzyme activities and multiple stress responses
Authors: Harshman  , Hoffmann  , Clark
Published: March 2003

Correlated responses to artificial selection for stress tolerance can provide insight into underlying genetic variation and the physiological basis of stress resistance. Lines of Drosophila melanogaster held in the absence of food or with an unsuitable resource, specifically decomposing lemon, responded to selection by becoming starvation resistant. The lemon-selected lines also adapted by evolving a resource-based induction response. Compared to control lines, the selected lines tended to store more lipid, develop slower and have a larger body size. Additional responses included resistance to desiccation and acetone fumes, suggesting multiple stress resistance is a correlated result of selection for starvation resistance. The specific metabolic rate was lower in the starvation selected lines and enzyme activities changed in response to selection. In particular, enzyme activities indirectly associated with lipid biogenesis increased in both types of selected lines. The correlated responses to the two selection regimes were sufficiently consistent to indicate a common basis for starvation resistance. Specific responses to starvation selection appeared to oppose the short-term phenotypic responses to starvation. Thus, a common response to stress selection may be to ameliorate the immediate physiological impact of the stress factor.
Effect of habitat saturation on the number and turnover of queens in the polygynous ant, Myrmica sulcinodis
Authors: Pedersen J.S. , Boomsma J.J.
Published: March 2003

In polygynous social insects more than one queen reproduces in a colony. In such populations ecological factors affecting survival and reproduction of queens are likely to be of prime importance for social organization. In particular, habitat saturation leading to severe limitations in the availability of nest sites has been suggested to promote high queen number. In this study we examine the social and genetic structure of colonies in the polygynous ant Myrmica sulcinodis. We investigated a single breeding population in two adjacent habitats which differed markedly in the availability of nest sites. In the main habitat M. sulcinodis occupied almost all suitable nest sites, whereas in the other (marginal) habitat most sites were unoccupied by ants, due to a recent fire. In support of the habitat saturation hypothesis, the number of queens per colony which could explain the estimated relatedness among workers was almost five times higher for the main habitat than for the marginal habitat. This is the first demonstration that the kin structure of a social insect population is plastic and responds adaptively to short-term changes in ecological constraints such as nest site availability. Based on combined genetic and demographic data we discuss queen reproductive strategies and suggest that a special class of queen ‘floaters’ only stays ephemerally in the colonies, thus causing a substantial turnover of reproducing queens across years.
Genetic differentiation between individuals
Authors: Rousset
Published: March 2003

I describe a method of analysis of genetic differentiation which is suitable for the comparison of genetic and demographic estimates of the ‘neighborhood size’– more precisely the product of density and second moment of dispersal distance σ2– in continuous populations sampled at the smallest scale. This method is based on results of models of isolation by distance common to a wide variety of dispersal distances. The performance of this method is tested by simulation for some highly leptokurtic dispersal distributions, and it is applied to a previous study of a kangaroo-rat (Dipodomys spectabilis) population. In this case, genetic and demographic estimates are within a factor of two from each other. Thus, in line with some previous examples, this study shows that a better agreement may be attained than is usually recognized between genetic and demographic estimates.
The evolution of courtship display repertoire size in the dabbling ducks (Anatini)
Authors: Johnson
Published: March 2003

Many animals possess multiple ornaments or behaviours that seem to have evolved via sexual selection. A complete understanding of sexual selection requires an explanation for such multiple traits. The dabbling ducks (Tribe: Anatini) exhibit considerable variation among species in the number of displays in the male courtship repertoire. I tested five hypotheses concerning the evolution of the variation in display repertoire size of dabbling ducks: (1) species recognition, (2) courtship habitat, (3) sexual selection intensity, (4) display media tradeoff and (5) time constraints on pair formation. I tested these hypotheses, using an explicit phylogenetic hypothesis developed from DNA sequences for the dabbling ducks, with two types of statistical comparative methods (discrete and continuous character). The variation observed in male courtship display repertoire size in dabbling ducks was consistent with the courtship habitat and sexual selection intensity hypotheses. Specifically, the size of the display repertoire was larger in species that exhibit courtship exclusively on water and larger in species with dimorphic plumage. These results suggest that ecological (habitat) as well as social (sexual selection) factors may be important in driving the evolution of displays in the dabbling ducks.
The fitness of twin mothers: evidence from rural Gambia
Authors: Sear R. , Shanley D. , Mcgregor I. A. , Mace R.
Published: March 2003

We used a longitudinal database from a natural fertility population in rural Gambia to compare the overall fertility of mothers who had given birth to twins at some point in their reproductive history and mothers who had only ever given birth to singletons. We found that twin mothers had shorter birth intervals, higher age-specific fertility and more surviving children than singleton mothers. This suggests that, despite the considerably higher mortality of twins found in this population, twin mothers have a fitness advantage over singleton mothers, even in the absence of modern medical care. We ran a simple simulation model to estimate the relative fitness of twin and singleton mothers, and found that the model also estimated higher fitness for twin mothers. Further, girls who went on to become twin mothers were of higher anthropometric status during their teenage years than those who became singleton mothers.
Low relatedness among cooperatively breeding workers of the greenhead ant Rhytidoponera metallica
Authors: Chapuisat M. , Crozier R.
Published: March 2003

The greenhead ant Rhytidoponera metallica has long been recognized as posing a potential challenge to kin selection theory, because it has large queenless colonies where apparently many of the morphological workers are mated and reproducing. However, this species has never been studied genetically and important elements of its breeding system and kin structure remain uncertain. We used microsatellite markers to measure the relatedness among nestmates, unravel the fine-scale population genetic structure, and infer the breeding system of R. metallica. The genetic relatedness among worker nestmates is very low but significantly greater than zero (r=0.082 ± 0.015), which demonstrates that nests contain many distantly related breeders. The inbreeding coefficient is very close to and not significantly different from zero, indicating random mating and lack of microgeographic genetic differentiation. On average, closely located nests are not more similar genetically than distant nests, which is surprising, as new colonies form by budding and female dispersal is restricted. Lack of inbreeding and absence of population viscosity indicates high gene flow mediated by males. Overall, the genetic pattern detected in R. metallica suggests that a high number of moderately related workers mate with unrelated males from distant nests. This breeding system results in the lowest relatedness among nestmates reported for social insect species where breeders and helpers are not morphologically differentiated.
Seasonal variation in sex ratio and sexual egg dimorphism favouring daughters in first clutches of the spotless starling
Authors: Cordero P. J. , Viñuela J. , Aparicio J. M. , Veiga J. P.
Published: March 2003

We investigated possible pre-hatching mechanisms of sex-differential investment by females that may contribute to offspring sex-ratio adjustment enhancing the fitness return from reproductive effort in the spotless starling (Sturnus unicolor). We found a seasonal shift in sex ratio from daughters to sons as the season advances. Furthermore, the probability of breeding at 1-year old and recruitment into the breeding population in daughters is associated with laying date but not with mass at fledging. The reverse is true for males which rarely bred at 1-year old. We also found that eggs containing female embryos are significantly heavier than those containing males in spite of the slight sexual dimorphism in favour of males. This suggests maternal control of provisioning, favouring daughters that may balance sibling mortality and competition with their brothers. Our results on seasonal variation in sex ratio and differential egg provisioning are consistent with an adaptive tactic in which mothers increase their reproductive return by enhancing the probability that daughters survive and breed in their first year of life.
Ecomorphology of plesiosaur flipper geometry
Authors: O'Keefe F. R.
Published: March 2003

The Plesiosauria is an extinct group of marine reptiles once common in mesozoic seas. Previous work on plesiosaur hunting styles has suggested that short-necked, large-headed animals were pursuit predators, whereas long-necked, small-headed animals were ambush predators. This study presents new data on the aspect ratios (ARs) of plesiosaur flippers, and interprets these data via comparison with AR in birds, bats and aircraft. Performance trade-offs implicit in AR variation are well-understood in the context of aircraft design, and these trade-offs have direct ecomorphological analogues in birds and bats. Knowledge of these trade-offs allows interpretation of variation in plesiosaur AR. By analogy, short-necked taxa were specialized for manoeuvrability and pursuit, whereas long-necked taxa were generally specialized for efficiency and cruising. These interpretations agree with previous assessments of maximum swimming speed.
The evolutionary transition to coloniality promotes higher blood parasitism in birds
Authors: Tella J. L.
Published: March 2003

Parasitism has been argued as one of the major costs of breeding sociality in birds. However, there is no clear evidence for an increased parasite pressure associated with the evolutionary transition from solitary to colonial breeding. I used the pairwise comparative method to test whether colonial bird species incur in a greater risk of infection and if they must to face with a greater diversity of blood parasites (Haematozoa), by comparing pairs of congeners that included one solitary and one colonial breeding species. The richness, both in terms of number of species and number of genera, as well as the prevalence of blood parasites resulted higher in colonial species than in their solitary breeding sisters, while controlling for differences in research effort and other potentially confounding effects. These results point towards higher transmission rates of blood parasites among colonial hosts. Given the detrimental effects of blood parasites on their host fitness, the higher risk of infection and the exposition to a more diverse parasite fauna may have imposed an important cost associated to the evolution of avian coloniality. This may help to explain why colonial species have larger immune system organs, as well as to explore differences in other host life history traits potentially shaped by blood parasites.
The experimental evolution of specialists, generalists, and the maintenance of diversity
Authors: Kassen R.
Published: March 2003

Environmental heterogeneity may be a general explanation for both the quantity of genetic variation in populations and the ecological niche width of individuals. To evaluate this hypothesis, I review the literature on selection experiments in heterogeneous environments. The niche width usually – but not invariably – evolves to match the amount of environmental variation, specialists evolving in homogeneous environments and generalists evolving in heterogeneous environments. The genetics of niche width are more complex than has previously been recognized, particularly with respect to the magnitude of costs of adaptation and the putative constraints on the evolution of generalists. Genetic variation in fitness is more readily maintained in heterogeneous environments than in homogeneous environments and this diversity is often stably maintained through negative frequency-dependent selection. Moreover environmental heterogeneity appears to be a plausible mechanism for at least two well-known patterns of species diversity at the landscape scale. I conclude that environmental heterogeneity is a plausible and possibly very general explanation for diversity across the range of scales from individuals to landscapes.
Seed sex ratio in dioecious plants depends on relative dispersal of pollen and seeds: an example using a chessboard simulation model
Authors: De Jong T. J. , Van Batenburg F. H. D. (EKE) , Van Dijk J.
Published: March 2003

Two principles are important for the optimal sex ratio strategy of plants. (1) Sib mating. Because seed dispersal is restricted, sib mating may occur which selects for a female bias in the seed sex ratio. (2) Local resource competition (LRC). If a plant produces pollen its nuclear genes are dispersed in two steps: first through the pollen and then, if the pollen is successful in fertilizing an ovule on another plant, through the seed. If the plant produces an ovule, its genes are dispersed only through the seed. By making pollen instead of ovules the offspring of a single plant is then spread out over a wider area. This reduces the chance that genetically related individuals are close together and need to compete for the same resource. The effect is the strongest if pollen is dispersed over a much wider area than seeds. Less LRC for paternally vs. maternally derived offspring selects for a male bias in sex allocation.

We study the above-mentioned opposite effects in dioecious plants (with separate male and female individuals), with maternal control over the sex ratio (fraction males) in the seeds. In a two-dimensional spatial model female-biased sex ratios are found when both pollen and seed dispersal are severely restricted. If pollen disperses over a wider area than seeds, which is probably the common situation in plants, the seed sex ratio becomes male-biased. If pollen and seeds are both dispersed over a wide area, the sex ratio approaches 0.5. Our results do not change if the offspring of brother–sister matings are less fit because of inbreeding depression.
Consequences of inbreeding for offspring fitness and gender in Silene vulgaris, a gynodioecious plant
Authors: Emery S. N. , McCauley D. E.
Published: March 2003

In gynodioecious plants, hermaphrodite and female plants co-occur in the same population. In these systems gender typically depends on whether a maternally inherited cytoplasmic male sterility factor (CMS) is counteracted by nuclear restorer alleles. These restorer alleles are often genetically dominant. Although plants of the female morph are obligatorily outcrossing, hermaphrodites may self. This selfing increases homozygosity and may thus have two effects: (1) it may decrease fitness (i.e. result in inbreeding depression) and (ii) it may increase homozygosity of the nuclear restorer alleles and therefore increase the production of females. This, in turn, enhances outcrossing in the following generation. In order to test the latter hypothesis, experimental crosses were conducted using individuals derived from four natural populations of Silene vulgaris, a gynodioecious plant. Treatments included self-fertilization of hermaphrodites, outcrossing of hermaphrodites and females using pollen derived from the same source population as the pollen recipients, and outcrossing hermaphrodites and females using pollen derived from different source populations. Offspring were scored for seed germination, survivorship to flowering and gender. The products of self-fertilization had reduced survivorship at both life stages when compared with the offspring of outcrossed hermaphrodites or females. In one population the fitness of offspring produced by within-population outcrossing of females was significantly less than the fitness of offspring produced by crossing females with hermaphrodites from other populations. Self-fertilization of hermaphrodites produced a smaller proportion of hermaphroditic offspring than did outcrossing hermaphrodites. Outcrossing females within populations produced a smaller proportion of hermaphrodite offspring than did crossing females with hermaphrodites from other populations. These results are consistent with a cytonuclear system of sex determination with dominant nuclear restorers, and are discussed with regard to how the mating system and the genetics of sex determination interact to influence the evolution of inbreeding depression.