bluuebunny/crossref_metadata_2025_split huggingface dataset:
FGF‐2 deficiency does not alter vulnerability of the dopaminergic nigrostriatal system towards MPTP intoxication in mice
Authors: Zechel S. , Jarosik J. , Kiprianova I. , Schober A. , Unsicker K. , von Bohlen und Halbach O. 
Published: March 2006

AbstractFibroblast growth factor 2 (FGF‐2) was the first growth factor discovered that exerted prominent protective and regenerative effects in an animal model of Parkinson's disease, the MPTP‐lesioned dopaminergic nigrostriatal system. To address the putative physiological relevance of endogenous FGF‐2 for midbrain dopaminergic neurons, we have analysed densities of tyrosine hydroxylase (TH)‐positive cells in the substantia nigra (SN) and TH‐positive fibers in the striatum and amygdala of adult FGF‐2‐deficient mice. We found that densities of TH‐immunoreactive (ir) cells in the SN as well as densities of TH‐ir fibers in the striatum and amygdala were unaltered as compared with wild‐type littermates. There is evidence to suggest that growth factor deficits do not become apparent unless a system is challenged in a lesioning paradigm. We therefore tested the ability of the nigrostriatal system with respect to its ability to cope with MPTP (1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine) intoxication. Treatment with 20 mg/kg MPTP on three consecutive days reduced dopamine levels in the striatum by about 80%. Densities of TH‐positive neurons in the SN were reduced by 71%. However, both parameters did not significantly differ between FGF‐2(–/–) mice and wild‐type littermates. Our results therefore suggest that FGF‐2, despite its prominent pharmacological potency as a neurotrophic factor for the dopaminergic nigrostriatal system, is not crucial for maintaining its structural integrity and ability to cope with MPTP intoxication.
Experimental support of the scaling rule for demographic stochasticity
Authors: Desharnais Robert A. , Costantino R. F. , Cushing J. M. , Henson Shandelle M. , Dennis Brian , King Aaron A. 
Published: March 2006

AbstractA scaling rule of ecological theory, accepted but lacking experimental confirmation, is that the magnitude of fluctuations in population densities due to demographic stochasticity scales inversely with the square root of population numbers. This supposition is based on analyses of models exhibiting exponential growth or stable equilibria. Using two quantitative measures, we extend the scaling rule to situations in which population densities fluctuate due to nonlinear deterministic dynamics. These measures are applied to populations of the flour beetleTribolium castaneumthat display chaotic dynamics in both 20‐g and 60‐g habitats. Populations cultured in the larger habitat exhibit a clarification of the deterministic dynamics, which follows the inverse square root rule. Lattice effects, a deterministic phenomenon caused by the discrete nature of individuals, can cause deviations from the scaling rule when population numbers are small. The scaling rule is robust to the probability distribution used to model demographic variation among individuals.
Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests
Authors: Muller‐Landau Helene C. , Condit Richard S. , Chave Jerome , Thomas Sean C. , Bohlman Stephanie A. , Bunyavejchewin Sarayudh , Davies Stuart , Foster Robin , Gunatilleke Savitri , Gunatilleke Nimal , Harms Kyle E. , Hart Terese , Hubbell Stephen P. , Itoh Akira , Kassim Abd Rahman , LaFrankie James V. , Lee Hua Seng , Losos Elizabeth , Makana Jean‐Remy , Ohkubo Tatsuhiro , Sukumar Raman , Sun I‐Fang , Nur Supardi M. N. , Tan Sylvester , Thompson Jill , Valencia Renato , Muñoz Gorky Villa , Wills Christopher , Yamakura Takuo , Chuyong George , Dattaraja Handanakere Shivaramaiah , Esufali Shameema , Hall Pamela , Hernandez Consuelo , Kenfack David , Kiratiprayoon Somboon , Suresh Hebbalalu S. , Thomas Duncan , Vallejo Martha Isabel , Ashton Peter 
Published: March 2006

AbstractThe theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 old‐growth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it, and were inconsistent with the predictions of metabolic ecology in all forests.
Plant pathogens drive density‐dependent seedling mortality in a tropical tree
Authors: Bell Thomas , Freckleton Robert P. , Lewis Owen T. 
Published: March 2006

AbstractOne explanation for the extraordinary diversity of tropical forest trees is that density‐dependent mortality from herbivores or pathogens puts locally rare species at an advantage. Density‐dependent mortality of seeds and small seedlings is particularly intense in tropical forests, but its causes remain uncertain. Here, we show experimentally that pathogens from the Oomycota are associated with intense mortality in seedlings of a neotropical tree, Sebastiana longicuspis. Seedlings in untreated plots experienced eight times higher mortality compared with seedlings in plots treated with fungicide. Mortality was strongly density dependent: in fungicide‐treated plots survival was unaffected by density, but survival in unsprayed plots was over three times higher at low density. Density‐dependent mortality observed in a simultaneous, non‐manipulative study was highly transient, suggesting that short‐term observational studies may underestimate the intensity and form of pathogen‐induced mortality. If such effects are widespread, plant pathogens may play a key role in maintaining and structuring tropical diversity.
Biosynthesis of hopanoids by sulfate‐reducing bacteria (genus Desulfovibrio)
Authors: Blumenberg Martin , Krüger Martin , Nauhaus Katja , Talbot Helen M. , Oppermann Birte I. , Seifert Richard , Pape Thomas , Michaelis Walter 
Published: March 2006

SummarySulfate reduction accounts for about a half of the remineralization of organic carbon in anoxic marine shelf regions. Moreover, it was already a major microbial process in the very early ocean at least 2.4 billion years before the present. Here we demonstrate for the first time the capability of sulfate‐reducing bacteria (SRB) to biosynthesize hopanoids, compounds that are quantitatively important and widely distributed biomarkers in recent and fossil sediments dating back to the late Archean. We found high concentrations (9.8–12.3 mg per gram of dry cells) of non‐extended and extended bacteriohopanoids (bacteriohopanetetrol, aminobacteriohopanetriol, aminobacteriohopanetetrol) in pure cultures of SRB belonging to the widely distributed genus Desulfovibrio. Biohopanoids were found – considered as membrane rigidifiers – in more than 50% of bacterial species analysed so far. However, their biosynthesis appeared to be restricted to aerobes or facultative anaerobes with a very few recently described exceptions. Consequently, findings of sedimentary hopanoids are often used as indication for oxygenated settings. Nevertheless, our findings shed new light on the presence of hopanoids in specific anoxic settings and suggests that SRB are substantial sources of this quantitatively important lipid class in recent but also past anoxic environments.
Identification of a complete methane monooxygenase operon from soil by combining stable isotope probing and metagenomic analysis
Authors: Dumont Marc G. , Radajewski Stefan M. , Miguez Carlos B. , McDonald Ian R. , Murrell J. Colin 
Published: March 2006

SummaryStable isotope probing (SIP) allows the isolation of nucleic acids from targeted metabolically active organisms in environmental samples. In previous studies, DNA‐SIP has been performed with the one‐carbon growth substrates methane and methanol to study methylotrophic organisms. The methylotrophs that incorporated the labelled substrate were identified with polymerase chain reaction and sequencing of 16S rRNA and ‘functional genes’ for methanotrophs (mxaF, pmoA, mmoX). In this study, a SIP experiment was performed using a forest soil sample incubated with 13CH4, and the 13C‐DNA was purified and cloned into a bacterial artificial chromosome (BAC) plasmid. A library of 2300 clones was generated and most of the clones contained inserts between 10 and 30 kb. The library was probed for key methylotrophy genes and a 15.2 kb clone containing a pmoCAB operon, encoding particulate methane monooxygenase, was identified and sequenced. Analysis of the pmoA sequence suggested that the clone was most similar to that of a Methylocystis sp. previously detected in this forest soil. Twelve other open reading frames were identified on the clone, including the gene encoding beta‐ribofuranosylaminobenzene 5′‐phosphate synthase, which is involved in the biosynthesis of the ‘archaeal’ C1‐carrier, tetrahydromethanopterin, which is also found in methylotrophs. This study demonstrates that relatively large DNA fragments from uncultivated organisms can be readily isolated using DNA‐SIP, and cloned into a vector for metagenomic analysis.
Laparoscopic colonic surgery – mission accomplished or work in progress?
Authors: Kehlet H. , Kennedy R. H. 
Published: March 2006

AbstractLaparoscopic colonic resection may facilitate early postoperative recovery due to reduced surgical stress, pain and ileus. However, large randomised studies have only shown marginal improvements in outcome compared with open surgery, reporting a median hospital stay of about 5–7 days. Concomitant with these developments multimodal rehabilitation, which involves a revision of general postoperative care principles, improved pain relief with epidural analgesia and early oral nutrition and mobilization, has demonstrated greater improvements in recovery after open surgery, resulting in a median hospital stay of about 2–4 days. Recent single centre, randomised studies where laparoscopic and open colonic resection are combined with multimodal rehabilitation have not resolved the debate regarding which is the optimal operative technique. Therefore, new strategies are required to integrate laparoscopy with multimodal rehabilitation in order to establish its advantages, cost effectiveness and indications in specific groups of patients or colorectal procedures, thus justifying widespread application of the laparoscopic technique.
Comparative myology of the forelimb of Liolaemus sand lizards (Liolaemidae)
Authors: Abdala Virginia , Moro Silvia 
Published: March 2006

AbstractThe lizard genus Liolaemus includes numerous constituent clusters of putatively related taxa, one of which is the Liolaemus boulengeri group, which in turn includes the sand lizards (of the Liolaemus wiegmannii subgroup). Members of the sand lizard group exhibit three different modes of burying into sand. The general morphology of the forelimb muscles of those Liolaemus species is analysed.Herein, we present a study of the forelimb musculature of all species considered by Halloy et al. (1998). This study has three principal goals. First, we are seeking myological characters that will be useful in formulating phylogenetic hypothesis about the species of Liolaemus. With these characters, we also wish to compile morphological data that represent the morphological space implied in the diverse locomotor behaviours of these animals. Second, we are looking for derived features that reflect functional changes in the use of forelimb. Third, we wish to provide a cladistic analysis that can be used to test phylogenetic hypothesis derived from other sources of data. We present 48 characters in a data set and analyse it cladistically. We obtained a hypothesis of relationships of the Liolaemus species and compared this with previous hypotheses based on other characters. The trees obtained are not congruent with previously proposed phylogenies. We were unable to identify in our trees nodes that are based on structures reflecting functional changes in the use of the forelimb. The morphological similarities in the forelimb musculature of all species analysed seems to conform a very conservative general anatomical pattern with which Liolaemus sand lizards perform most of their locomotor behaviours.
Taxonomy and distribution of the hydrozoan and protozoan epibionts on Pagurus bernhardus (Linnaeus, 1758) (Crustacea, Decapoda) from Scotland
Authors: Fernandez‐Leborans Gregorio , Gabilondo Regina 
Published: March 2006

AbstractProtozoan and hydrozoan epibionts on the hermit crab Pagurus bernhardus and its shell, collected near Cumbrae Island (Scotland) were studied. The epibionts found were the following: (1) protozoans: the suctorian ciliates Ephelota plana, Acineta compressa, Conchacineta constricta, Corynophrya anisostyla; the peritrich ciliates Cothurnia mobiusi and Zoothamnium plumula; the chonotrich ciliate Chilodochona quennerstedti; and (2) hydrozoans: the species Leuckartiara sp. and Clytia sp. The morphological characteristics of the epibionts were analysed, as well as their taxonomic position. The distribution of epibionts on the crab surface and its shell was studied, and the density and biomass of epibionts were calculated on each anatomic unit. There was a differential distribution according to the type of epibiont: hydrozoans dominated in biovolume and were present mainly on the shell, meanwhile protozoans represented the highest fraction of density and they were found exclusively on the crab (principally on eyes, antennulae, antennae, maxillipeds, pereopods and uropods). The anterior area of the cephalothorax was the most colonized. On this area, the maxillipeds and second pereopods showed the highest densities. The location of each epibiont species was described. There was a correlation between the length of the crab and the total number of hydrozoans. There was a significant correlation between the right and the left units of the crab, taking into consideration the mean densities of epibionts on each anatomical unit. The shell was colonized by the same species of hydrozoa that appeared on the crab, although in a much higher density (mean 3024.38 per shell; 6.9 per crab). There was a significant difference between both species of hydrozoan epibionts with respect to the mean densities on the different areas of the shell. The zone of the shell more occupied by Clytia sp. was the apical zone of the shell, while the highest densities of Leuckartiara sp. were registered near the aperture of the shell. The hydrozoan and protozoan epibiont species found on P. bernhardus in this study represent the first mention of their presence on this hermit crab.
Brood care among basommatophorans: a unique reproductive strategy in the freshwater limpet snailProtancylus(Heterobranchia: Protancylidae), endemic to ancient lakes on Sulawesi, Indonesia
Authors: Albrecht Christian , Glaubrecht Matthias 
Published: March 2006

AbstractIn molluscan taxa inhabiting marine environments oviparity and reproduction via planktonic larvae is predominant while incubation and viviparity is most frequently found in taxa inhabiting brackish or freshwater aquatic habitats. Brooding has evolved repeatedly and independently in several limnic taxa among Bivalvia and Gastropoda. However, among basommatophoran gastropods no such cases were yet known. We here report on a unique reproductive strategy involving brood care in the lacustrine freshwater limpet genusProtancylus, endemic to the ancient lakes on central Sulawesi (former Celebes), Indonesia, namely the Lake Poso and the Malili lake system, because this constitutes the first known case of this behaviour among the Basommatophora.Protancyluslive exclusively as epizoans on those pachychilid gastropods of the viviparous genusTylomelania, also a Sulawesi endemic species, that inhabit mostly soft substrates. We found that the two known speciesProtancylus pileolusfrom Lake Poso andP. adhaerensfrom the Malili lake system both retain gelatinous egg strings underneath their outer mantle, where up to 15 (mostly eight or nine) shelled juveniles are brooded. Nourishment is provided within the egg capsule only. Thus, brood care inProtancylusresembles the reproductive strategy found recently among pachychilid gastropodsJagorafrom the Philippines, but differs from euviviparous (i.e. matrotrophic) incubation among thiarid gastropods possessing a brood pouch with juveniles being nourished via a ‘pseudoplacenta’ in several taxa.
Novel pathways for glycoprotein import into chloroplasts
Authors: Faye L. , Daniell H. 
Published: March 2006

SummaryAlthough the chloroplast contains its own genome, majority of its protein components are encoded by nuclear genes and must be imported post‐translationally. In general, proteins synthesized by cytosolic ribosomes are post‐translationally targeted to the chloroplast through interactions between their N‐terminal transit sequence and protein translocon Toc/Tic complexes in the chloroplast membranes. An alternative pathway that mediates post‐translational delivery of proteins to the chloroplast via the secretory pathway was recently described. This pathway provides new opportunities for complementation of the chloroplast protein maturation machinery with chaperones needing endoplasmic reticulum and/or Golgi typical maturations such as N‐glycosylation for their biological activity or using chloroplasts as a storage compartment for glycoproteins.
Craniofacial morphology and feeding behavior inCanis dirus, the extinct Pleistocene dire wolf
Authors: Anyonge W. , Baker A. 
Published: March 2006

AbstractThe craniofacial morphology of the extinct late Pleistocene dire wolfCanis diruswas compared with that of the living gray wolfCanis lupus, the spotted hyaenaCrocuta crocutaand the extinct late Miocene bone‐cracking canidBorophagus secundus. Fifteen indices that have previously been shown to reflect functional significance in the skull, jaws and related musculature of carnivorans were computed from a series of measurements made on the skulls of the four species and subjected to an analysis of variance and a principal components analysis. The results indicated that the extinct dire wolf was similar to the living gray wolf in 11 of the 15 indices. The dire wolf did not differ significantly from the gray wolf in the relative length of resistance arms to various tooth positions in the lower jaw or in the relative size, mechanical advantage and moment arm of the masseter muscle. The dire wolf was characterized by a relatively larger temporalis muscle that was capable of generating more force than that in the gray wolf. The extinct late Miocene borophagine dogB. secunduswas intermediate between the two wolves and the spotted hyaena in most of the cranial and jaw indices, but displayed more similarity to the latter in several key features that can be attributed to their specialization for bone cracking.Borophagus secundusand the spotted hyaena tended to have short resistance arms and large jaw muscles with increased mechanical advantage for bites at various teeth. It is inferred that the dire wolf exhibited feeding behavior that approached that of the living gray wolf, but may have differed in killing technique, where it held longer to its struggling prey.
Puncturing ability of idealized canine teeth: edged and non‐edged shanks
Authors: Freeman P. W. , Lemen C. 
Published: March 2006

AbstractIdealized edged and non‐edged indenters, mimicking canine teeth, were used to puncture thin materials and thick materials. Less force was needed for the edged (triangular in cross section) indenter to penetrate thin Mylar, paper, leather, beetle elytra and turkey skin than the non‐edged (circular in cross‐section) indenter. Oak, grass and magnolia leaves responded equally to both indenters. In thick materials, the edged indenter punctured beetles, shrimp, bananas, and chicken flesh more easily than the non‐edged indenter. Apple, tomato and avocado were punctured equally well. The edged indenter directs cracks at the corners so that the material can fold away in the direction of puncture, whereas cracks form unpredictably with the non‐edged indenter. Edged indenters have the advantage in many of the materials tested.
Final steps in the catabolism of nicotine
Authors: Chiribau Calin‐Bogdan , Mihasan Marius , Ganas Petra , Igloi Gabor L. , Artenie Vlad , Brandsch Roderich 
Published: March 2006

New enzymes of nicotine catabolism instrumental in the detoxification of the tobacco alkaloid by Arthrobacter nicotinovorans pAO1 have been identified and characterized. Nicotine breakdown leads to the formation of nicotine blue from the hydroxylated pyridine ring and of γ‐N‐methylaminobutyrate (CH3‐4‐aminobutyrate) from the pyrrolidine ring of the molecule. Surprisingly, two alternative pathways for the final steps in the catabolism of CH3‐4‐aminobutyrate could be identified. CH3‐4‐aminobutyrate may be demethylated to γ‐N‐aminobutyrate by the recently identified γ‐N‐methylaminobutyrate oxidase [Chiribau et al. (2004) Eur J Biochem271, 4677–4684]. In an alternative pathway, an amine oxidase with noncovalently bound FAD and of novel substrate specificity removed methylamine from CH3‐4‐aminobutyrate with the formation of succinic semialdehyde. Succinic semialdehyde was converted to succinate by a NADP+‐dependent succinic semialdehyde dehydrogenase. Succinate may enter the citric acid cycle completing the catabolism of the pyrrolidine moiety of nicotine. Expression of the genes of these enzymes was dependent on the presence of nicotine in the growth medium. Thus, two enzymes of the nicotine regulon, γ‐N‐methylaminobutyrate oxidase and amine oxidase share the same substrate. The Km of 2.5 mm and kcat of 1230 s−1 for amine oxidase vs. Km of 140 µm and kcat of 800 s−1 for γ‐N‐methylaminobutyrate oxidase, determined in vitro with the purified recombinant enzymes, may suggest that demethylation predominates over deamination of CH3‐4‐aminobutyrate. However, bacteria grown on [14C]nicotine secreted [14C]methylamine into the medium, indicating that the pathway to succinate is active in vivo.
Xanthogranulomatous Inflammation of Corpus Cavernosum
Authors: Seo Young , Jo Hyang Jeong , Rim Joung Sik 
Published: March 2006

ABSTRACT

Introduction
Xanthogranulomatous inflammation is a rare, chronic destructive inflammatory lesion. The pathological finding is typically lymphocyte and plasma cell infiltration, surrounded by accumulating lipid-laden macrophages.

Methods
A 65-year-old healthy man presented with a 3-week history of a painless palpable mass in the penis.

Results
The patient underwent an excision of the mass with a tunica albuginea, and a graft from the tunica vaginaglis. Histopathological findings showed the diffuse xanthogranulomatous inflammation.

Conclusions
Xanthogranulomatous inflammation of corpus cavernosum in old men is a rare condition. The inflammatory mass should be treated by complete excision and graft.