Morphology and genetics reveal an intriguing pattern of differentiation at a very small geographic scale in a bird species, the forest thrush Turdus lherminieri.

Mobile organisms are expected to show population differentiation only over fairly large geographical distances. However, there is growing evidence of discrepancy between dispersal potential and realized gene flow. Here we report an intriguing pattern of differentiation at a very small spatial scale in the forest thrush (Turdus lherminieri), a bird species endemic to the Lesser Antilles. Analysis of 331 individuals from 17 sampling sites distributed over three islands revealed a clear morphological and genetic differentiation between these islands isolated by 40-50 km. More surprisingly, we found that the phenotypic divergence between the two geographic zones of the island of Guadeloupe was associated with a very strong genetic differentiation (Fst from 0.073-0.153), making this pattern a remarkable case in birds given the very small spatial scale considered. Molecular data (mitochondrial control region sequences and microsatellite genotypes) suggest that this strong differentiation could have occurred in situ, although alternative hypotheses cannot be fully discarded. This study suggests that the ongoing habitat fragmentation, especially in tropical forests, may have a deeper impact than previously thought on avian populations.

Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2011-31 January 2012.

This article documents the addition of 473 microsatellite marker loci and 71 pairs of single-nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Barteria fistulosa, Bombus morio, Galaxias platei, Hematodinium perezi, Macrocentrus cingulum Brischke (a.k.a. M. abdominalis Fab., M. grandii Goidanich or M. gifuensis Ashmead), Micropogonias furnieri, Nerita melanotragus, Nilaparvata lugens Stål, Sciaenops ocellatus, Scomber scombrus, Spodoptera frugiperda and Turdus lherminieri. These loci were cross-tested on the following species: Barteria dewevrei, Barteria nigritana, Barteria solida, Cynoscion acoupa, Cynoscion jamaicensis, Cynoscion leiarchus, Cynoscion nebulosus, Cynoscion striatus, Cynoscion virescens, Macrodon ancylodon, Menticirrhus americanus, Nilaparvata muiri and Umbrina canosai. This article also documents the addition of 116 sequencing primer pairs for Dicentrarchus labrax.

Age-dependent allocation of carotenoids to coloration versus antioxidant defences.

Aging is commonly attributed to age-related changes in oxidative damage due to an increased production of reactive oxygen species (ROS) and a weakened efficacy of enzymatic antioxidants. These age-related changes might therefore modify the use of dietary antioxidants, including carotenoids. As carotenoids are closely associated with the expression of secondary sexual signals, the allocation of carotenoids to sexual signal versus antioxidant defences may vary with age. In this study, we explored how carotenoid-based ornament and antioxidant activity varied with age and how an inflammatory-induced oxidative burst affected ornament and antioxidant activity across a range of ages. Using zebra finches (Taeniopygia guttata) as a model species, we assessed circulating carotenoids, beak coloration and the plasma antioxidant status of birds of different ages before and after an inflammatory challenge. Our results show that old individuals display similar carotenoid-based sexual signals regardless of the availability of circulating carotenoids, suggesting a terminal investment of old individuals in their last reproductive event. Additionally, we found that an inflammatory insult induced a decrease in the total antioxidant activity and in the expression of a carotenoid-based sexual signal in the oldest individuals. These results suggest that old individuals pay an extra cost of immune activation possibly because the efficiency of antioxidant machinery varies with age.

Precocious thymic involution manifest by epithelial injury in the acquired immune deficiency syndrome.

Thymuses from six heterosexual Haitian patients with the acquired immune deficiency syndrome (AIDS) were studied by light microscopy and the findings were compared with those from three control groups. The control groups included 1) five age-matched Haitian hospital patients; 2) ten age- and sex-matched Montreal patients who had died suddenly or had had brief illnesses; and 3) 20 middle-elderly Montreal patients who had experienced chronic, wasting illnesses or prolonged hospitalization. Thymuses from patients with AIDS demonstrated pronounced involution, effacement of the cortex and medulla, marked thymocyte depletion, variable degrees of plasma cell infiltration and fibrosis, and, above all, absence of Hassall's corpuscles. Thymuses from Haitian and Montreal control subjects who had died suddenly or had brief illnesses demonstrated minimal involution and abundant Hassall's corpuscles. Although thymuses from 12 of the chronically ill control subjects demonstrated marked involution, architectural effacement, and absence of Hassall's corpuscles, partial architectural preservation and variable numbers of Hassall's corpuscles were observed in eight of these subjects. Thus, the extent of thymic involution observed in patients with AIDS antedates that incurred with aging and supersedes that induced by sustained stress and inanition. The loss of Hassall's corpuscles in patients with AIDS suggests that the thymic epithelium either incurs a form of injury or undergoes precocious involution during the illness. Whether this lesion is central to the pathogenesis of AIDS or merely a reflection of intense, sustained stress coupled with accelerated physiologic involution is unknown. It is possible that the disappearance of Hassall's corpuscles may indicate important, although as yet cryptic events within the thymic microenvironment in this syndrome.

Acquired immune deficiency syndrome: specific aspects of the disease in Haiti.

PIP: This paper presents clinical data on 41 patients (29 male and 12 female) from Haiti who presented with acquired immunedeficiency syndrome (AIDS). Their mean age was 32 years (range 17-61 years). 4 of thes cases were homosexual or bisexual; none was an illicit drug user or a hemophiliac. In addition, 3 of the female patients had sexual contact with a male partner with AIDS. 4 patients had received blood transfusions before their illness. The most prominent clinical symptom in this series was chronic diarrhea of 2-33 months' duration, which occurrred in 39 patients (95%). Also reporte were marked weight loss (95%), fatigue (95%), prolonger fever (90%), and nodular or maculopapular skin lesions (54%). Opportunistic infections in this series included oroesophageal candidiasis (88%) and intestinal cryptosporidiosis (31%). Tuberculosis developed in 22% of patients. Immunologic evaluation revealed profoundly depressed T-helper cells and an inverted T-helper/T-suppressor cell ratio. Biologic markers included elevated alpha-1 thymosin and beta-2 microglobulin levels, elevated immune complexes, and the presence of acid-labile interferon. Of interest were differences in the clinical expression of AIDS between this series and cases in the US. The Haitian data suggest a higher incidencs of female cases,a predominance of gastrointestinal symptoms rather than respiratory symptoms and lymphadenopathy, a frequent association with tuberculosis, and a relatively low incidence of Kaposi's sarcoma or P. carinii pneumonia compared to the situation in the US. As in the US, where most AIDS cases are concentrated in New York and California, most AIDS cases in Haiti are found in residents of Port-au-Prince and Carrefour, which are centers for male and female prostitution.^ieng

Acquired immunodeficiency syndrome with severe gastrointestinal manifestations in Haiti.

29 patients (19 males and 10 females) in Haiti were diagnosed as having acquired immunodeficiency syndrome. Their clinical presentation was characterised by unexplained chronic diarrhoea, prolonged fever, extreme weight loss, anorexia, and severe infections. The infectious agents included: Candida albicans (27 patients), Mycobacterium tuberculosis (7 patients), Cryptosporidium (11 patients), Pneumocystis carinii (2 patients), cytomegalovirus (4 patients), and herpes virus (3 patients). In 1 woman Kaposi's sarcoma developed during the course of her disease. Immunological studies of 20 patients revealed profound cell-mediated immune deficiency with cutaneous anergy, marked decrease in the number of T helper cells, and impairment of lymphocyte proliferation. 18 patients died.

[Unusual aspects of domestic trichinosis in regard to a familial infestation discovered in Montreal]. / Aspects originaux de la trichinose domestique à partir d'une infestation familiale découverte à Montréal

An outbreak of domestic trichinosis occurred in an Italian family living in Montreal. All patients had a fever, facial edema and extreme eosinophilia, and results of serologic tests were positive. Larvae of Trichinella spiralis were seen in a muscle biopsy from one of the patients. The discussion emphasizes some characteristic clinical, serologic and histopathological aspects.