Alkaloids from Spathelia excelsa: their chemosystematic significance

The methanol extract from the leaves of Spathelia excelsa yielded six alkaloids: 2-(12-oxo-tridecanyl)-3-methoxy-4-quinolone, 2-(10-hydroxy-10-methyldodecanyl)-3-methoxy-4-quinolone, 2-(11-hydroxy-11-methyldodecanyl)-3-methoxy-4-quinolone, 2-(12-hydroxytridecanyl)-3-methoxy-4-quinolone, 7-hydroxy-2-(3-hydroxy-3-methylbutyl)-4-quinolone and 6-hydroxy-2-(3-hydroxy-3-methylbutyl)-4-quinolone, in addition to the known 3-O-beta-d-glucopiranosylsitosterol and (-)-epicatechin. The 2-alkyl-4(1H)-quinolones in S. excelsa display strong similarities with those in Dictyolomatoideae, which contains several 2-alkyl-4-quinolones. The data reported herein thus provide firm support for placing Spathelioideae close to or within the Dictyolomatoideae.     

Cutting edge: the SLAM family receptor Ly108 controls T cell and neutrophil functions

Ly108, a glycoprotein of the signaling lymphocytic activation molecule family of cell surface receptors expressed by T, B, NK, and APCs has been shown to have a role in NK cell cytotoxicity and T cell cytokine responses. In this study, we describe that CD4(+) T cells from mice with a targeted disruption of exons 2 and 3 of Ly108 (Ly108(DeltaE2+3)) produce significantly less IL-4 than wild-type CD4(+) cells, as judged by in vitro assays and by in vivo responses to cutaneous infection with Leishmania mexicana. Surprisingly, neutrophil functions are controlled by Ly108. Ly108(DeltaE2+3) mice are highly susceptible to infection with Salmonella typhimurium, bactericidal activity of Ly108(DeltaE2+3) neutrophils is defective, and their production of IL-6, IL-12, and TNF-alpha is increased. The aberrant bactericidal activity by Ly108(DeltaE2+3) neutrophils is a consequence of severely reduced production of reactive oxygen species following phagocytosis of bacteria. Thus, Ly108 serves as a regulator of both innate and adaptive immune responses.     

A molecular phylogeographic study based on DNA sequences from individual metacercariae of Paragonimus mexicanus from Guatemala and Ecuador

A molecular phylogeographic study of Paragonimus mexicanus collected from Guatemala and Ecuador was performed. Genomic DNA was extracted from individual metacercariae, and two gene regions (partial mitochondrial cytochrome c oxidase subunit 1 (CO1) and the second internal transcribed spacer of the nuclear ribosomal gene repeat (ITS2)) were amplified by the polymerase chain reaction (PCR). Sequences segregated in a phylogenetic tree according to their geographic origins. ITS2 sequences from Ecuador and Guatemala differed at only one site. Pairwise distances among CO1 sequences within a country were always lower than between countries. Nevertheless, genetic distances between countries were less than between geographical forms of P. westermani that have been suggested to be distinct species. This result suggests that populations from Guatemala and Ecuador are genetically differentiated perhaps at the level of subspecies.     

Sexual dimorphism in the Atapuerca-SH hominids: the evidence from the mandibles

The pattern of sexual dimorphism in 15 mandibles from the Atapuerca-SH Middle Pleistocene site, attributed to Homo heidelbergensis, is explored. Two modern human samples of known sex are used as a baseline for establishing sexing criteria. The mandible was divided for analysis into seven study regions and differential expression of sexual dimorphism in these regions is analysed. A total of 40 continuous and 32 discrete variables were scored on the mandibles. The means method given in Regh & Leigh (Am. J. phys. Anthrop.110, 95-104, 1999) was followed for evaluating the potential of correct sex attribution for each variable.On average, the mandibles from the Atapuerca-SH site present a degree of sexual dimorphism about eight points higher than in H. sapiens samples. However, mandibular anatomy of the European Middle Pleistocene hominid records sexual dimorphism differentially. Different areas of the Atapuerca-SH mandibles exhibit quite distinct degrees of sexual dimorphism. For instance, variables of the alveolar arcade present very low or practically no sexual dimorphism. Variables related to overall size of the mandible and symphysis region present a medium degree of sex differences. Finally, ramus height, and gonion and coronoid process present a high degree of sexual dimorphism (indexes of sexual dimorphism are all above 130%). Whether this marked sexual dimorphism in specific anatomical systems affects sexual differences in body size is not completely clear and further studies are needed.Sexual differences detected in the mandible of modern humans have at least two components: differences related to musculo-skeletal development and differences related to a different growth trajectory in males and females (relative development of some of the basal border features). The Atapuerca-SH mandibles display little variation in the basal border, however. The limited variation of this mandibular region may indicate that the pattern of sexual variation in H. heidelbergensis is different enough to that of H. sapiens to caution against simple extrapolation of criteria from one pattern to the other.     

Bloodstream infections in late-stage acquired immunodeficiency syndrome patients evaluated by a lysis centrifugation system

Opportunistic infections, which affect acquired immunodeficiency syndrome (Aids) patients, are frequently disseminated and may cause bloodstream infections (BSI). The aim of this study was to evaluate the main causes of BSI in Aids patients with advanced stage of the disease, with special emphasis on the identification of fungemia. During a 21 months period, all patients with Aids (CD4 < 200) and febrile syndrome admitted to 3 university hospitals were systematically evaluated. For each patient presenting fever, a pair of blood cultures was collected and processed by using a commercial lysis-centrifugation system. One hundred and eleven patients (75 males) with a mean age of 36 years (median 33 years) and mean CD4 count of 64 cells/ml were included. Among the 111 patients evaluated we documented 54 episodes of BSI, including 46 patients with truly systemic infections and 8 episodes considered as contaminants. BSI were caused by gram-positive bacteria (43%), fungi (20%), gram-negative bacteria (15%), mycobacteria (15%), and mixed flora (7%). The crude mortality rate of our patients was 39%, being 50% for patients with BSI and 31% for the others. In conclusion, BSI are a common related to systemic infections on Aids patients with advanced stage of disease and is associated with a high rate of mortality.     

Petrosal orientation and mandibular ramus breadth: evidence for an integrated petroso-mandibular developmental unit

The absolute and relative breadths of the mandibular ramus (MRB) display substantial variation in modern humans, and are of analytical value in paleoanthropology. According to Enlow et al. ([1969] Am. J. Orthod. 56:6-23), the ramus is the growth counterpart of the middle cranial fossa (MCF) and the pharynx. Such counterpart principles state that variation in ramus breadth is a frequent function of the horizontal alignment of the MCF, and both structures tend to covary within and between populations. These authors also suggested that lateral parts of the basicranium have a particular importance in the positioning of facial components. In the present study, this hypothesis is tested, and relationships between midline and lateral basicranial elements and ramus breadth variation are explored. Two-dimensional landmarks taken from lateral radiographs of adult crania representative of three modern human populations (Europeans, West Africans, and Japanese) were analyzed by geometric morphometry. Our results are consistent with previous counterpart analyses. Furthermore, our findings highlight the significance of the orientation of the petrous temporal to modern human mandibular ramus variation. Variation in the orientation of the petrosal bone appears to alter the spatial position of the mandible and influences MRB. Developmental integration of a petroso-mandibular unit may have important paleoanthropological implications.     

Influence of dietary carbohydrate on the metabolism of juvenile Litopenaeus stylirostris

Cockles Cerastoderma edule were fed two different concentrations ( approximately 0.8 and 2 mm(3) l(-1)) of two diets with different qualities ( approximately 10 and 60% of organic content) which were achieved by mixing different proportions of ashed silt particles with cells of the microalgae Tetraselmis suecica. Clearance, ingestion and absorption rates of organic matter and biochemical components were measured after 3 days (acute response) and 11 days (acclimated response) of exposure to the diets. With low quality diets cockles were found to reject part of the filtered matter ( approximately 25-35%) through pseudofaeces production both in the acute and acclimated responses. In the acute response, absorption rate of organic matter was positively dependent on food quality and quantity, but the physiological response to increasing food concentrations differed with food quality: with low qualities, increasing absorption rate resulted from the simultaneous increase of clearance ( approximately 2 times) and ingestion rate ( approximately 4 times) as well as absorption efficiency of organic matter ( approximately 22%). However, those fed high qualities, were found to compensate increasing food concentration by reducing ( approximately 50%) clearance rate. The resulting moderate increase of ingestion rate ( approximately 1.6 times) was accompanied with a reduction in absorption efficiency ( approximately 20%). Irrespective of food quality and quantity, protein and lipids were absorbed, respectively, with the highest (from 61.7 to 80.0%) and the lowest (from 42.6 to 66.8%) efficiency. Acclimated response was entirely affected by food quality: with low qualities, cockles greatly improved the energetic intake from available ration ( approximately 4 and 2 times, with low and high food concentrations, respectively). Both preingestive and digestive mechanisms were involved in this response: at the preingestive level, clearance rate and preingestive selection efficiency were significantly increased. At the digestive level, cockles were capable of maintaining absorption efficiency of organic matter with rising ingestion rate. On the contrary, acclimation to high quality diets brought about no significant increase in organic absorption rate: with low ration, clearance rate was kept constant, whereas with high ration the increase in clearance and ingestion rate ( approximately 2 times) promoted a compensatory reduction in absorption efficiency. However, the biochemical composition of the absorbed matter was found to be absolutely modified, both at low and high food rations, due to an strong reduction of lipid absorption efficiency. The observed modifications of absorption rate and/or the biochemical composition of the absorbed matter suggests the capability of cockles to adjust the digestive performance.     

Eudesmane sesquiterpenes from Eupatorium Quadrangulare

The aerial part of Eupatorium quadrangulare afforded in addition to known compounds, a possible biosynthetic intermediate, quadrangulin A, of the eudesmanolides found in this species.     

Occurrence of neanderthal features in mandibles from the Atapuerca-SH site

Analysis of variation and distribution of evolutionary novelties is meaningful in understanding evolutionary processes. The mandible, as a morphological complex, comprises a large number of derived Neanderthal features. The present study investigates whether the features usually considered as European lineage apomorphies evolved independently; the occurrence of these features is studied in the mandibles from the Sima de los Huesos (SH) site (Atapuerca, Spain). For comparative purposes, a large sample of Neanderthal mandibles as well as older fossil Homo specimens have been used for the study. Chi-square tests were employed to test for independence. The SH mandibles present a set of features that clearly show the basic architecture of the Neanderthal mandible. A highly significant association is detected in the variation of the position of the mental foramen, the lateral prominence, and the anterior marginal tubercle, as well as in the development of retromolar space. However, a much weaker association is detected in the features of the internal aspect of the mandible, with a few exceptions. Features of the external aspect of the mandible occur chronologically earlier than those observed in the internal aspect. The hypothesis that two distinct and consecutive morphological processes have driven the emergence of the European lineage throughout the Middle Pleistocene is proposed. A first transformation affects the mandible by means of backwards displacement of the structures located at the external aspect, as well as the position of the condyle. A second process would modify the features of the internal aspect of the mandible, in which the relief of the masseteric and pterygoid fossae are affected, in association with a spatial rearrangement of the corpus and ramus. Analyzed individually, some of the considered features may be questioned as Neanderthal apomorphies (Trinkaus,1993; Franciscus and Trinkaus, 995); however, the joint occurrence of many of them suggests that the complex is an evolutionary novelty.