bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toll‐like receptor‐4‐mediated macrophage activation is differentially regulated by progesterone via the glucocorticoid and progesterone receptors
Authors: Jones Leigh A. , Anthony Jean‐Paul , Henriquez Fiona L. , Lyons Russell E. , Nickdel Mohammad B. , Carter Katharine C. , Alexander James , Roberts Craig W. 
Published: March 2008

SummaryMacrophage function has been demonstrated to be subject to modulation by progesterone. However, as this steroid hormone can act through the glucocorticoid receptor as well as the progesterone receptor, the mechanism of action has not been precisely characterized. To determine the mode of action, we compared the ability of progesterone, norgestrel (a synthetic progesterone‐receptor‐specific agonist) and dexamethasone (a synthetic glucocorticoid receptor agonist) to modulate macrophage function following stimulation of the Toll‐like receptor‐4 (TLR‐4) ligand lipopolysaccharide (LPS). The results demonstrate that following stimulation of TLR‐4 with LPS and cotreatment with either progesterone or dexamethasone, but not norgestrel, there is a significant reduction in nitric oxide (NO) production, indicating that this progesterone‐mediated effect is through ligation of the glucocorticoid receptor. In contrast, LPS‐induced interleukin‐12 (IL‐12) production could be downregulated by all three steroids, indicating that ligation by progesterone of either the glucocorticoid or the progesterone receptors or both could mediate this effect. While progesterone downmodulated NO‐mediated killing of Leishmania donovani by activated macrophages in vitro, most probably via the glucocorticoid receptor, it had little effect on Toxoplasma gondii growth in these cells. This would suggest that progesterone‐mediated increased susceptibility to T. gondii during pregnancy is more likely to be related to the ability of the hormone to downregulate IL‐12 production and a type‐1 response utilizing the progesterone as well as the glucocorticoid receptors.
Spermatogonial morphology, kinetics and niches in hamsters exposed to short‐ and long‐photoperiod
Authors: Do Nascimento H. F. , Drumond A. L. , De França L. R. , Chiarini‐Garcia H. 
Published: March 2008

SummaryPrevious studies have shown that under short photoperiod exposure spermatogenesis in golden hamster regresses leading to sexual inactivity. It is known that this regression is related to changes in somatic and germ cells (spermatocytes and spermatids). However, the photoperiod effects on spermatogonial biology have not been studied in detail yet. In this regard, this study was carried out to investigate the morphology, kinetics and niches of different spermatogonial types in golden hamsters under long‐ and short‐photoperiod. Six spermatogonial generations such as type A undifferentiated (Aund), type A differentiating (A1, A2, A3), intermediate (In) and type B spermatogonia were characterized, and were morphologically similar irrespective of the photoperiod exposure. The short photoperiod was inhibitory to Aundspermatogonia and preleptotene but had no effect on the number of differentiating (A1to B) spermatogonia. In golden hamsters exposed to stimulatory‐photoperiod, the interstitial components were positioned mainly in triangular areas around the seminiferous tubules and, in this situation, the Aundspermatogonia were clearly positioned in niches (p < 0.05) in all stages studied. On the other hand, during the inhibitory‐photoperiod where the seminiferous tubules have smaller diameter, the interstitial components were more homogenously distributed and the triangular areas were not clearly observed. In this case, the niches were identified only at stage VII (p < 0.05), although there was a trend of being positioned in niches area in all the stages studied. Thus, these findings suggest that the Aundspermatogonia location in the seminiferous epithelium and the niche position are directly related to the position of the interstitial components.
Top predators and biodiversity: much debate, few data
Authors: Sergio Fabrizio , Newton Ian , Marchesi Luigi 
Published: March 2008

Summary

In two recent papers, we found support for the hypothesis of an association between the occurrence of top predators and biodiversity. Such results were recently criticized.
Cabeza, Arponen & Van Teeffelen (2008) claim that the proper way to test the investigated relationship was to conduct a regional‐level complementarity analysis that pools all predators across all habitat‐types. However, such an approach may not help in assessing the performance of predators as surrogates for wider biodiversity, because: (a) management programmes on top predators almost invariably focus on a single species; (b) conservation planning and management often occur within habitats, not only across them; and (c) the required surveys and analyses may often be logistically unfeasible. Re‐analysis of our data suggests that a different methodology would not change the results.
Kéry, Royle & Schmid (2008) used data from a Swiss volunteers’ monitoring scheme to claim that we missed a large number of species in our estimates of avian richness. However, we list 10 reasons why their calculations were inflated, given major differences in surface‐coverage, habitat‐sampling, field effort and in the way that secretive species were treated. Furthermore, our results for birds were replicated in analyses of butterflies and trees, which could not suffer from the same detectability biases.
Roth & Weber (2008) analysed the same Swiss database and found that a group of lower‐trophic‐level species (tits) out‐performed raptors as indicators of butterfly richness (but not of bird richness). However, their analyses did not control for ecosystem identity, and data on raptor locations were of dubious quality. Furthermore, because tits are major caterpillar predators, the reported findings could have been expected on other grounds.
Synthesis and applications. We disagree with Cabeza and colleagues that local studies are of limited importance. Given the paucity of available information, many more local studies are needed to check the generality of the ecological pattern we found. Until further analyses become available, polarized positions for or against top predators as biodiversity indicators are premature. Meanwhile, like any tools, top predators should be employed in conservation decision‐making with appropriate caution.
Molecular phylogeny and historical biogeography of the genus Tuber, the ‘true truffles’
Authors: Jeandroz Sylvain , Murat Claude , Wang Yongjin , Bonfante Paola , Tacon François Le 
Published: March 2008

AbstractAim  Various data sets and methods of analysis were combined to produce the first comprehensive molecular phylogeny of the genus Tuber and to analyse its biogeography.Location  Europe, North Africa, China, Asia, North America.Methods  Phylogenetic relationships among Tuber species were reconstructed based on a data set of internal‐transcribed spacer (ITS) sequences and various phylogenetic inference methods, specifically maximum parsimony, Bayesian analysis and neighbour joining. Tajima’s relative rate test showed that Tuber 18S rRNA, 5.8S rRNA, 5.8S‐ITS2 rRNA and β‐tubulin sequences evolved in a clock‐like manner. These genes, combined or not, were employed for molecular clock estimates after construction of linearized trees using mega 3.1. We reconstructed ancestral areas in the Northern Hemisphere by means of a dispersal–vicariance analysis (diva 1.1) based on current distribution patterns of the genus Tuber determined from the literature.Results  The resulting molecular phylogeny divided the genus Tuber into five distinct clades, in agreement with our previously published studies. The Puberulum, Melanosporum and Rufum groups were diversified in terms of species and geographical distribution. In contrast, the Aestivum and Excavatum groups were less diversified and were located only in Europe or North Africa. Using a global molecular clock analysis, we estimated the divergence times for the origin of the genus and for the origin of several groups. diva inferred nine dispersal events and suggested that the ancestor of Tuber was originally present in Europe or was widespread in Eurasia. Equally optimal distributions were obtained for several nodes, suggesting different possible biogeographical patterns.Main conclusions  Our analyses identified several discrepancies with the classical taxonomy of the genus, and we propose a new phylogenetic classification. According to molecular clocks, the radiation of the genus Tuber could have started between 271 and 140 Ma. Used in combination with the results obtained from time divergence estimates, this allows us to propose two equally probable scenarios of intra‐ and inter‐continental diversification of the genus according to the geographic distribution of the most recent common ancestor in Europe or Eurasia. The biogeographical patterns imply intra‐continental dispersal events between Europe and Asia and inter‐continental dispersal events between North America and Europe or Asia, which are compatible with land connections during the Tertiary.
Historical climate modelling predicts patterns of current biodiversity in the Brazilian Atlantic forest
Authors: Carnaval Ana Carolina , Moritz Craig 
Published: March 2008

AbstractAim  We aim to propose validated, spatially explicit hypotheses for the late Quaternary distribution of the Brazilian Atlantic forest, and thereby provide a framework for integrating analyses of species and genetic diversity in the region.Location  The Atlantic forest, stretching along the Brazilian coast.Methods  We model the spatial range of the forest under three climatic scenarios (current climate, 6000 and 21,000 years ago) with BIOCLIM and MAXENT. Historically stable areas or refugia are identified as the set of grid cells for which forest presence is inferred in all models and time projections. To validate inferred refugia, we test whether our models are matched by the current distribution of the forest and by fossil pollen data. We then investigate whether the location of inferred forest refugia is consistent with current patterns of species endemism and existing phylogeographical data.Results  Forest models agree with pollen records and predict a large area of historical forest stability in the central corridor (Bahia), as well as a smaller refuge (Pernambuco) along the Brazilian coast, matching current centres of endemism in multiple taxa and mtDNA diversity patterns in a subset of the species examined. Less historical stability is predicted in coastal areas south of the Doce river, which agrees with most phylogeographical studies in that region. Yet some widely distributed taxa show high endemism in the southern Atlantic forest. This may be due to limitations of the modelling approach, differences in ecology and dispersal capability, historical processes not contemplated by the current study or inadequacy of the available test data sets.Main conclusions  Palaeoclimatic models predict the presence of historical forest refugia in the Atlantic rain forest and suggest spatial variation in persistence of forests through the Pleistocene, predicting patterns of biodiversity in several local taxa. The results point to the need for further studies to document genetic and species endemism in the relatively poorly known and highly impacted areas of Atlantic rain forests of north‐eastern Brazil.
Imprint of post‐glacial history in a narrowly distributed endemic spruce, Picea alcoquiana, in central Japan observed in nuclear microsatellites and organelle DNA markers
Authors: Aizawa Mineaki , Yoshimaru Hiroshi , Katsuki Toshio , Kaji Mikio 
Published: March 2008

AbstractAim  We aim to infer the post‐glacial history of the narrowly distributed endemic spruce Picea alcoquiana in Japan, and to assess the hypothesis that the existing narrow natural range of the species has resulted from the diminution of the past natural range since the last glacial period.Location  Mountainous forests in central Honshu Island in Japan.Methods  We assessed the geographical patterns of genetic variation across nine populations of P. alcoquiana across its natural range using five nuclear microsatellites and polymerase chain reaction–restriction fragment length polymorphism markers for chloroplast (cp) and mitochondrial (mt) DNA. This study focuses on the genetic differentiation between northern peripherally isolated and southern core populations within the natural range of the species in central Honshu. In addition, based on diagnostic morphological traits of the cone, we used reliable macrofossil evidence to gain further insight into the past natural range of the species.Results  Picea alcoquiana shows a level of genetic differentiation among populations (ΦST = 0.082) that was higher than the levels observed in nuclear microsatellites for other anemophilous and widespread tree species in Japan. A notable finding for the nuclear microsatellites was the loss of rare alleles and strong evidence of a recent bottleneck in the peripherally isolated populations. Analysis of molecular variance in cpDNA and mtDNA markers showed an absence of genetic differentiation between the peripherally isolated and core populations. Macrofossil evidence indicated that the past natural range of the species extended to a lower elevation and c. 135 km north of the existing peripherally isolated populations during the last glacial period (c. 28,000 yr bp).Main conclusions  During the last glacial period, P. alcoquiana had a wider natural range in which the peripherally isolated and core populations could have been geographically continuous with each other, and effective gene flow by means of pollen and seeds might have occurred. The recent bottleneck and consequent loss of rare alleles in the peripherally isolated populations might have evolved during the diminution and retreat of the northern part of the past natural range southwards to the core area and during the subsequent separation of the peripherally isolated populations from the core area since the last glacial period.
The biogeographical assignment of a west Kenyan rain forest remnant: further evidence from analysis of its reptile fauna
Authors: Wagner Philipp , Köhler Jörn , Schmitz Andreas , Böhme Wolfgang 
Published: March 2008

AbstractAim  The Kakamega Forest, western Kenya, has been biogeographically assigned to both lowland and montane forest biomes, or has even been considered to be unique. Most frequently it has been linked with the Guineo‐Congolian rain forest block. The present paper aims to test six alternative hypotheses of the zoogeographical relationships between this forest remnant and other African forests using reptiles as a model group. Reptiles are relatively slow dispersers, compared with flying organisms (Aves and Odonata) on which former hypotheses have been based, and may thus result in a more conservative biogeographical analysis.Location  Kakamega Forest, Kenya, Sub‐Saharan Africa.Methods  The reptile diversity of Kakamega Forest was evaluated by field surveys and data from literature resources. Faunal comparisons of Kakamega Forest with 16 other African forests were conducted by the use of the ‘coefficient of biogeographic resemblance’ using the reptile communities as zoogeographic indicators. Parsimony Analysis of Endemism and Neighbour Joining Analysis of Endemism were used to generate relationship trees based on an occurrence matrix with paup*.Results  The analysis clearly supports the hypothesis that the Kakamega Forest is the easternmost fragment of the Guineo‐Congolian rain forest belt, and thus more closely related to the forests of that Central–West African complex than to any forest further east, such as the Kenyan coastal forests. Many Kenyan reptile species occur exclusively in the Kakamega Forest and its associated forest fragments.Main conclusions  The Kakamega Forest is the only remnant of the Guineo‐Congolian rain forest in the general area. We assume that the low degree of resemblance identified for the Guineo‐Congolian forest and the East African coastal forest reflect the long history of isolation of the two forest types from each other. Kenyan coastal forests may have been historically connected through forest ‘bridges’ of the southern highlands with the Congo forest belt, allowing reptile species to migrate between them. The probability of a second ‘bridge’ located in the region of southern Tanzanian inselbergs is discussed. Although not particularly rich in reptile species, the area should be considered of high national priority for conservation measures.
Speciation and radiations track climate transitions since the Miocene Climatic Optimum: a case study of southern African chameleons
Authors: Tolley Krystal A. , Chase Brian M. , Forest Félix 
Published: March 2008

AbstractAim  The high amount of species diversity concentrated in southern Africa has been attributed to palaeoclimatic factors, and the timing of radiations in some taxa corresponds to global palaeoclimatic trends. Using dwarf chameleons (Bradypodion: Chamaeleonidae) as a model system, we explored the relationship between palaeoclimatic fluctuations and cladogenesis with respect to both temporal and spatial patterns in an effort to understand the process of speciation in southern Africa.Location  South Africa, with particular emphasis on the Cape Floristic Region and the Maputaland–Pondoland–Albany hotspot.Methods  Mitochondrial sequence data (ND2 and 16S) were used to estimate the timing of major radiations and to examine the number of lineages through time. A dated phylogeny was constructed using Bayesian phylogenetic reconstruction, and a Bayesian relaxed molecular clock was used to estimate divergence times. Spatial data and lineage‐through‐time plots were used to identify geographic regions that underwent diversification in connection with major climatic events. Both parsimony and likelihood optimizations of habitat type on the phylogeny were used to determine whether major habitat shifts have occurred. On a coarse scale (half‐degree grid cells), phylogenetic diversity (sum of the branch lengths linking terminals) was compared with species richness (absolute number of species) to identify areas of conservation importance.Results  The complete species phylogeny of dwarf chameleons shows that the timing and mode of diversification exhibit spatio‐temporal patterns that link to phases in the evolution of southern Africa’s climate over the last 14 Myr. Optimizations of habitat on the phylogenetic tree show a progression from closed to open habitats since the Mid‐Miocene, corresponding to the shift from C3 to C4 environments, and later with the development of south‐western Africa’s winter‐rainfall regime. These shifts are not simultaneous across the region, with different geographic centres of diversity generated during different time periods.Main conclusions  Regions that are prominent centres of chameleon diversification are encompassed by the current biodiversity hotspots as shown by chameleon species richness and phylogenetic diversity. Diversity within the Cape Floristic Region appears to be the result of a Late Pliocene radiation, whereas the diversity encompassed within the Maputaland–Pondoland–Albany hotspot is an aggregate of asynchronous radiation events, probably influenced by lineage losses. Overall, dwarf chameleons have experienced a shift in habitat types, with recent radiations occupying open habitats, and older lineages persisting in relictual forested habitats, corresponding to the continental shift of vegetation types since the Miocene Climatic Optimum.
Complications of chronic use of skin lightening cosmetics
Authors: Olumide Yetunde M. , Akinkugbe Ayesha O. , Altraide Dan , Mohammed Tahir , Ahamefule Ngozi , Ayanlowo Shola , Onyekonwu Chinwe , Essen Nyomudim 
Published: March 2008

AbstractSkin lightening (bleaching) cosmetics and toiletries are widely used in most African countries. The active ingredients in these cosmetic products are hydroquinone, mercury and corticosteroids. Several additives (conconctions) are used to enhance the bleaching effect. Since these products are used for long duration, on a large body surface area, and under hot humid conditions, percutaneous absorption is enhanced. The complications of these products are very serious and are sometimes fatal. Some of these complications are exogenous ochronosis, impaired wound healing and wound dehiscence, the fish odor syndrome, nephropathy, steroid addiction syndrome, predisposition to infections, a broad spectrum of cutaneous and endocrinologic complications of corticosteroids, including suppression of hypothalamic‐pituitary‐adrenal axis. In this era of easy travels and migration, African patients with these complications can present to physicians anywhere in the world. It is therefore critical for every practicing physician to be aware of these complications.
Creatine phosphokinase values during isotretinoin treatment for acne
Authors: Kaymak Yesim 
Published: March 2008

AbstractBackground  Muscle‐related complaints and high creatine phosphokinase (CPK) blood levels have been reported in 15–50% of patients with acne treated with isotretinoin. Clinical investigations about CPK levels in isotretinoin therapy were few, and most of them were case reports. The aim of this study was to investigate the incidence, course, and clinical significance of severe hyperphosphokinasemia in isotretinoin therapy for acne.Methods  A total of 89 patients were treated with isotretinoin for moderate or severe acne at our dermatology department. At the initial visit and during the monthly follow‐up visits, hemoglobin, hematocrit, leukocytes, thrombocyte, renal function tests (urea and creatinine), direct and indirect bilirubin, liver enzymes [serum glutamate oxaloacetate (SGOT), serum glutamate pyruvate transaminase (SGPT), gamma glutamil transpeptidase (GGT), and alkaline phosphotase (ALP)], lipid profile [total cholesterol, very low density lipoproteins (VLDL), low density lipoproteins (LDL), high density lipoproteins (HDL), and triglycerides], urine analysis, and CPK were requested. We asked all patients about muscle‐related complaints, weakness, exercise, and compared CPK levels.Results  Elevated CPK levels were recorded in only five patients during treatment period. Maximum serum CPK values recorded for each patient ranged between 292 and 569 IU/l. Only one patient out of five had myalgia and four patients were completely asymptomatic.Conclusions  In conclusion, marked hyperCPKemia with or without muscle‐related complaints in isotretinoin‐treated patients with acne is a benign phenomenon; therefore, it is logical to reserve measurement of CPK levels as well as renal tests for cases with severe muscle pain.
A case of dyskeratosis congenita with Chiari 1 malformation, absence of inferior vena cava, webbed neck, and low posterior hair neck
Authors: Çakmak Seray Külcü , Gönül Müzeyyen , Kılıç Arzu , Gül Ülker , Koçak Oğuzhan , Demiriz Murat 
Published: March 2008

AbstractDyskeratosis congenita (DC) is a rare inherited disorder that is usually seen in males, consisting of the triad of leukoplakia of the mucous membranes, nail dystrophy, and skin pigmentation. We present a case of DC associated with esophageal stricture, Chiari 1 malformation, absence of inferior vena cava, webbed neck, and low posterior hair neck.A 22‐year‐old man attended our clinic with leukoplakia of the oral mucosa and nail dystrophy. In addition to these findings, poikilodermia on his neck and upper and lower extremities, bilateral ectropion, webbed neck, and low posterior hair neck was detected on dermatologic examination. Esophagoscopy demonstrated esophageal stricture. Cranial magnetic resonance imaging showed tonsillar herniation, and thoracoabdominal computed tomography revealed absence of inferior vena cava.