bluuebunny/crossref_metadata_2025 huggingface dataset:
A quantum of neurotransmitter causes minis in multiple postsynaptic cells at the Caenorhabditis elegans neuromuscular junction
Authors: Liu Qiang , Chen Bojun , Hall David H. , Wang Zhao‐Wen
Published: January 2007

The polyadic synapse, where a single presynaptic active zone associates with two or more postsynaptic cells, exists in both mammals and invertebrates. An important but unresolved question is whether synaptic transmission occurs between the presynaptic site and its various postsynaptic partners. Using the dual whole‐cell voltage clamp technique, we analyzed miniature postsynaptic currents (mPSCs or minis) at the C. elegans neuromuscular junction (NMJ), which is a polyadic synapse. We found that neighboring muscle cells at the same position along the body axis had high frequencies of concurrent mPSCs, which could not be explained by pure chance. Although body‐wall muscle cells are electrically coupled, the high frequency of concurrent mPSCs was not due to electrical coupling because there was no correlation between the frequency of concurrent mPSCs and the degree of electrical coupling; the rise time of concurrent mPSCs was identical to that of nonconcurrent mPSCs but distinct from that of junctional currents (Ij); and a mutant defective in electrical coupling showed normal frequency of concurrent mPSCs. Our analyses suggest that a single quantum of neurotransmitter may cause mPSCs in multiple postsynaptic cells at polyadic synapses, and that high‐fidelity synaptic transmission occurs between the presynaptic site and its various postsynaptic partners. Thus, polyadic synapses could be a distinct mechanism for synaptic divergence and for synchronizing activities of postsynaptic cells. © 2006 Wiley Periodicals, Inc. Develop Neurobiol 67: 123–128, 2007.
Genetic and pharmacological studies of GluR5 modulation of inhibitory synaptic transmission in the anterior cingulate cortex of adult mice
Authors: Wu Long‐Jun , Xu Hui , Ren Ming , Zhuo Min
Published: January 2007

In the anterior cingulate cortex (ACC), GluR5‐containing kainate receptor mediated the small portion of excitatory postsynaptic current. However, little is known about its role in modulation of neurotransmitter release in this brain region. In the present study, we address this question by using selective GluR5 agonist and antagonist, as well as GluR5−/− mice. Our results showed that activation of GluR5 induced action potential‐dependent GABA release, which is also required for the activation of voltage‐dependent calcium channel and Ca2+ influx. The effect of GluR5 activation is selective to the GABAergic, but not glutamatergic synaptic transmission. Endogenous activation of GluR5 also enhanced GABA release to ACC pyramidal neurons and the corresponding postsynaptic tonic GABA current. Our results suggest the somatodendritic, but not presynaptic GluR5, in modulation of GABA release. The endogenous GluR5 activation and the subsequent tonic GABA current may play an inhibitory role in ACC‐related brain functions. © 2006 Wiley Periodicals, Inc. Develop Neurobiol 67: 146–157, 2007.
Archazolid‐7‐O‐β‐D‐glucopyranoside – Isolation, Structural Elucidation and Solution Conformation of a Novel V‐ATPase Inhibitor from the Myxobacterium Cystobacter violaceus
Authors: Menche Dirk , Hassfeld Jorma , Steinmetz Heinrich , Huss Markus , Wieczorek Helmut , Sasse Florenz
Published: January 2007

The novel polyketide macrolide archazolid‐7‐O‐β‐D‐glucopyranoside (3) has been isolated from the myxobacterium Cystobacter violaceus and the structure of this first archazolid‐glycoside has been determined by spectroscopic and degradative methods. A synthesis of simplified 7‐O analogues, based on regioselective derivatisation of archazolid A, was elaborated. These structurally novel archazolids of natural and synthetic origin were evaluated in detail for V‐ATPase inhibition and their biological activities are discussed in terms of their solution conformations, as determined by high‐field NMR studies, including J‐based conformation analysis and constrained molecular dynamics simulations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Study on the extraction of dyes into a room‐temperature ionic liquid and their mechanisms
Authors: Li Changping , Xin Baoping , Xu Wenguo , Zhang Qi
Published: January 2007

The investigation of liquid–liquid extraction of dyes is carried out by using ionic liquid—1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM][PF6])—as extraction phase. The effects of its process parameters are studied in detail, such as extraction phase ratio, pH of the aqueous phase, and concentration of dicyclohexyl‐18‐crown‐6 (DCH‐18C6) in the organic phase. Important results are obtained as follows: acid dyes can be extracted with [BMIM][PF6] quantitatively; the removal of reactive dyes is low; however, it can be greatly increased by the addition of DCH‐18C6. The pH value has a great impact on the removal of the acid dye and the reactive dye. However, it does not influence the extraction of the weak acid dye. It is found that the extraction process of acid dyes adopts the form of anion exchange and the soluble part of the ionic liquid plays an important role as counter‐ions. Copyright © 2007 Society of Chemical Industry
Nasal inoculation of an adenovirus vector encoding 11 tandem repeats of Aβ1‐6 upregulates IL‐10 expression and reduces amyloid load in a Mo/Hu APPswe PS1dE9 mouse model of Alzheimer's disease
Authors: Kim Hong‐Duck , Tahara Kazuki , Maxwell J. Adam , Lalonde Robert , Fukuiwa Tatsuya , Fujihashi Kohtaro , Van Kampen Kent R. , Kong Fan‐Kun , Tang De‐chu C. , Fukuchi Ken‐ichiro
Published: January 2007

Background

One of the pathological hallmarks of Alzheimer's disease (AD) is deposits of amyloid β‐peptide (Aβ) in neuritic plaques and cerebral vessels. Immunization of AD mouse models with Aβ reduces Aβ deposits and improves memory and learning deficits. Because recent clinical trials of immunization with Aβ were halted due to brain inflammation that was presumably induced by a T‐cell‐mediated autoimmune response, vaccination modalities that elicit predominantly humoral immune responses are currently being developed.

Methods

We have nasally immunized a young AD mouse model with an adenovirus vector encoding 11 tandem repeats of Aβ1‐6 fused to the receptor‐binding domain (Ia) of Pseudomonas exotoxin A (PEDI), AdPEDI‐(Aβ1‐6)11, in order to evaluate the efficacy of the vector in preventing Aβ deposits in the brain. We also have investigated immune responses of mice to AdPEDI‐(Aβ1‐6)11.

Results

Nasal immunization of an AD mouse model with AdPEDI‐(Aβ1‐6)11 elicited a predominant IgG1 response and reduced Aβ load in the brain. The plasma IL‐10 level in the AD mouse model was upregulated after immunization and, upon the stimulation with PEDI‐(Aβ1‐6)11, marked IL‐10 responses were found in splenic CD4+ T cells from C57BL/6 mice that had been immunized with AdPEDI‐(Aβ1‐6)11.

Conclusions

These results suggest that the induction of Th2‐biased responses with AdPEDI‐(Aβ1‐6)11 in mice is mediated in part through the upregulation of IL‐10, which inhibits activation of dendritic cells that dictate the induction of Th1 cells. Copyright © 2007 John Wiley & Sons, Ltd.
Wage differentials between the public and private sectors in India
Authors: Glinskaya Elena , Lokshin Michael
Published: January 2007

This study uses 1993–94 and 1999–2000 rounds of India Employment and Unemployment survey to investigate wage differentials between the public and private sectors. To obtain robust estimates of the wage differential, we apply three econometric techniques each relying on a different set of assumptions about the process of job selection and wage formation. All three methods show that differences in wages between public sector workers and workers in the formal‐private and informal‐casual sectors are positive and high. On average, the public sector premium ranges between 62 and 102 per cent over the private‐formal sector, and between 164 and 259 per cent over the informal‐casual sector, depending on the choice of methodology. The wage differentials in India tend to be higher in rural as compared to urban areas, and are higher among women than among men. The wage differential also tends to be higher for low‐skilled workers. There is considerable evidence of an increase in the wage differential between 1993–1994 and 1999–2000. Copyright © 2007 John Wiley & Sons, Ltd.
On more ambitious conditional cash transfers, social protection and permanent reduction of poverty
Authors: Cuesta José
Published: January 2007

Conditional Cash Transfer Programs (CCTPs) show a remarkable flexibility. Based on that property, CCTPs might be extended to provide a more comprehensive and cohesive social protection umbrella. These programs might widen their scope by facilitating sector specific reforms and providing protection to large‐scale contingencies. By mobilising assets other than human capital and targeting more selectively population groups in changing circumstances, these programs might well become effective instruments to crack permanent poverty. This note discusses enabling changes to achieve such ambitious goals. Copyright © 2007 John Wiley & Sons, Ltd.
The implications of recent research on trans fatty acids
Authors: Stanley John
Published: January 2007

The link between the intake of industrially produced trans fatty acids and risk of coronary heart disease (CHD) has been reviewed recently. The authors concluded that elimination of industrially produced trans fatty acids from the USA diet might avert 22% of the 1.2 million CHD events in the USA every year. Denmark has introduced legislation which limits the trans fatty acid content of oils and fats destined for human consumption to 2% of total fatty acids. This has reduced trans fatty acid intake in Denmark to insignificant levels and it will be interesting to see what effects this has on risk of CHD. By contrast in the USA the FDA has chosen the labelling option which puts the onus on the consumer to make the right food choices although New York City has adopted a more interventionist approach in its restaurants and food outlets. The Danish approach is far more effective as can be seen from the amounts of trans fatty acids present in French fries and chicken nuggets purchased from McDonalds and KFC in the two countries.
Atypical localization of membrane type 1‐matrix metalloproteinase in the nucleus is associated with aggressive features of hepatocellular carcinoma
Authors: Ip Ying Chi , Cheung Siu Tim , Fan Sheung Tat
Published: January 2007

Membrane type 1‐matrix metalloproteinase (MT1‐MMP) is a versatile proteinase and recent studies indicated it could be internalized. Our earlier study found that it is overexpressed in hepatocellular carcinoma (HCC) and could promote intrahepatic metastasis. The present study was conducted to examine its subcellular localization and its clinicopathological significance in HCC after curative partial hepatectomy. Localization of MT1‐MMP in 101 pairs of HCCs and their adjacent liver tissues, and 8 normal liver tissues was examined by the immunohistochemical method. MT1‐MMP protein was localized at membrane and cytoplasm of hepatocytes in the normal and tumor adjacent liver tissues. In contrast, the HCCs were highly heterogeneous with variable degrees of membrane, cytoplasmic, and even nuclear staining. Interestingly, patients with presence of nuclear MT1‐MMP were associated with poor overall survival (log‐rank test, P = 0.043) and large tumor size (>5 cm) (Fisher's exact test, P = 0.031). Subcellular distribution was further demonstrated by Western blotting and immunofluorescence with Hep3B stable transfectant overexpressing MT1‐MMP. Western blot analyses of subcellular fractions confirmed a differential partitioning of various post‐translationally modified MT1‐MMP in these fractions. Different antibodies corroborated the presence of MT1‐MMP in the nuclear fraction. Concomitant nuclear presence of MMP2 with MT1‐MMP further indicated its potential involvement in the nuclear functions. MT1‐MMP co‐localized with caveolin‐1 at the perinuclear region, suggesting nuclear translocation of MT1‐MMP via caveolae‐mediated endocytosis. In summary, the association of nuclear MT1‐MMP with aggressive tumor features including poor prognosis and large tumor expands its functional repertoire and further indicates a new functional role of MMPs within nuclei of tumor cells. © 2006 Wiley‐Liss, Inc.
A novel low‐molecular weight inhibitor of focal adhesion kinase, TAE226, inhibits glioma growth
Authors: Shi Qing , Hjelmeland Anita B. , Keir Stephen T. , Song Linhua , Wickman Sarah , Jackson Dowdy , Ohmori Osamu , Bigner Darell D. , Friedman Henry S. , Rich Jeremy N.
Published: January 2007

Glioblastomas are highly lethal cancers that resist current therapies. Novel therapies under development target molecular mechanisms that promote glioblastoma growth. In glioblastoma patient specimens, the non‐receptor tyrosine kinase focal adhesion kinase (FAK) is overexpressed. Upon growth factor receptor stimulation or integrin engagement, FAK is activated by phosphorylation on critical tyrosine residues. Activated FAK initiates a signal transduction cascade which promotes glioma growth and invasion by increasing cellular adhesion, migration, invasion, and proliferation. We find that human glioma cell lines express different levels of total FAK protein and activating phosphorylation of tyrosine residues Tyr397, Tyr861, and Tyr925. As all glioma cell lines examined expressed phosphorylated FAK, we examined the efficacy of a novel low‐molecular weight inhibitor of FAK, TAE226, against human glioma cell lines. TAE226 inhibited the phosphorylation of FAK as well as the downstream effectors AKT, extracellular signal‐related kinase, and S6 ribosomal protein in multiple glioma cell lines. TAE226 induced a concentration‐dependent decrease in cellular proliferation with an associated G2 cell cycle arrest in every cell line and an increase in apoptosis in a cell‐line‐specific manner. TAE226 also decreased glioma cell adhesion, migration, and invasion through an artificial extracellular matrix. Together, these data demonstrate the potential benefit of TAE226 for glioma therapy. © 2007 Wiley‐Liss, Inc.
On transport equations driven by a non‐divergence‐free force field
Authors: Arlotti L. , Banasiak J. , Lods B.
Published: January 2007

The paper is devoted to initial boundary value problems for transport equations with non‐divergence‐free external field. The crucial role is played by integration along characteristics and associated Green's formula for which we provide a new proof which generalizes and clarifies previous versions. The paper concludes with an application of general theory to the Spencer–Lewis equation. Copyright © 2007 John Wiley & Sons, Ltd.
Dominant manifestation of pluripotency in embryonic stem cell hybrids with various numbers of somatic chromosomes
Authors: Vasilkova Anna A. , Kizilova Helen A. , Puzakov Mikhail V. , Shilov Alexander G. , Zhelezova Antonina I. , Golubitsa Alevtina N. , Battulin Nariman R. , Vedernikov Vitaly E. , Menzorov Alexey G. , Matveeva Natalia M. , Serov Oleg L.
Published: January 2007

Developmental potential was assessed in 8 intra‐specific and 20 inter‐specific hybrid clones obtained by fusion of embryonic stem (ES) cells with either splenocytes or fetal fibroblasts. Number of chromosomes derived from ES cells in these hybrid clones was stable while contribution of somatic partner varied from single chromosomes to complete complement. This allowed us to compare pluripotency of the hybrid cells with various numbers of somatic chromosomes. Three criteria were used for the assessment: (i) expression of Oct‐4 and Nanog genes; (ii) analyses of teratomas generated by subcutaneous injections of the tested cells into immunodeficient mice; (iii) contribution of the hybrid cells in chimeras generated by injection of the tested cells into C57BL blastocysts. All tested hybrid clones showed expression of Oct‐4 and Nanog at level comparable to ES cells. Histological and immunofluorescent analyses demonstrated that most teratomas formed from the hybrid cells with different number of somatic chromosomes contained derivatives of three embryonic layers. Tested hybrid clones make similar contribution in various tissues of chimeras in spite of significant differences in the number of somatic chromosomes they contained. The data indicate that pluripotency is manifested as a dominant trait in the ES hybrid cells and does not depend substantially on the number of somatic chromosomes. The latter suggests that the developmental potential derived from ES cells is maintained in ES‐somatic cell hybrids by cis‐manner and is rather resistant to trans‐acting factors emitted from the somatic one. Mol. Reprod. Dev. 74: 941–951, 2007. © 2007 Wiley‐Liss, Inc.
Expression of estrogen receptors α and β in the corpus luteum and uterus from non‐pregnant and pregnant llamas
Authors: Powell Susan A. , Smith Bradford B. , Timm Karen I. , Menino Alfred R.
Published: January 2007

Because estrogen may be involved in maternal recognition of pregnancy and embryonic migration in llamas, expression of estrogen receptor subtypes α (ERα) and β (ERβ) was evaluated in corpus luteum (CL), endometrium, and uterus using relative RT‐PCR. Tissues were recovered from sterile‐mated (SM) and pregnant (PG) females during Days 7–11 and 7–13 (Day 0 = day of mating), respectively, and follicular phase and juvenile females. Luteal expression of ERα and β was similar (P > 0.10) in SM and PG females and within Days 7–11, however, expression of ERα in ovarian tissue from follicular phase females was greater (P < 0.05) than Days 7 and 9 CL. Uterus expressed less ERα and β compared to endometrium (P = 0.07 and P < 0.01, respectively). Expression of ERα was greater (P < 0.05) in Day 7 and follicular phase uteri than Days 9 and 11, Day 13 PG and juvenile uteri. Uterine ERβ expression was greater (P = 0.09) in PG versus SM females and in mated compared to follicular phase females (P < 0.05). Endometrial expression of ERα and β did not differ (P > 0.10) between SM and PG females or by day. The presence of luteal ER during this period may mean a role for estradiol in maternal recognition of pregnancy. Observed increases in uterine ER expression with no changes in endometrium suggest expression increased in myometrium and/or perimetrium. Upregulation of myometrial ERβ in PG females may be involved in supporting uterine migration of the embryo. Mol. Reprod. Dev. 74: 1043–1052, 2007. © 2007 Wiley‐Liss, Inc.
Sensory ataxic neuropathy and esophageal achalasia in a patient with Sjogren's syndrome
Authors: Poglio Fabio , Mongini Tiziana , Cocito Dario
Published: January 2007

We describe a patient who developed an ataxic sensory syndrome associated with xerophthalmia and progressive dysphagia with regurgitation. Electrophysiological findings were consistent with an axonal sensory neuropathy, and superficial peroneal nerve biopsy showed a reduction in number of myelinated fibers with epineurial inflammation. Rheumatoid factor, anti‐SSA/SSB and antinuclear antibodies were positive and a diagnosis of Sjogren's syndrome was made. An endoscopic investigation revealed esophageal achalasia. We suggest that there may be a common autoimmune mechanism directed to different targets on the basis of this rare association. Muscle Nerve, 2007
Preparation of monodisperse hydrophilic polymer microspheres with N,N′‐methylenediacrylamide as crosslinker by distillation precipitation polymerization
Authors: Liu Guangyu , Yang Xinlin , Wang Yongmei
Published: January 2007

Highly crosslinked cauliflower‐like poly(N,N′‐methylenebisacrylamide) particles were prepared by distillation precipitation polymerization in neat acetonitrile with 2,2′‐azobisisobutyronitrile as initiator. Monodisperse hydrophilic polymer microspheres with various functional groups, such as amide, pyrrolidone and carboxylic acid, with a spherical shape and smooth surface in the size range 120–600 nm were prepared by distillation precipitation copolymerizations of functional comonomers including N‐isopropylacrylamide, N‐vinylpyrrolidone, methacrylic acid with N,N′‐methylenebisacrylamide as crosslinker. The polymer particles were formed and precipitated out from the reaction medium during the distillation of the solvent from the reaction system through an entropic precipitation manner. The effects of the solvent and the degree of crosslinking on the morphology and the loading capacity of the functional groups of the resultant polymer particles were investigated. The resulting polymer particles were characterized with scanning electron microscopy, transmission electron microscopy, dynamic light scattering and Fourier transform infrared spectroscopy. Copyright © 2007 Society of Chemical Industry
Vibrational spectroscopic investigation of light‐induced polymerization process of epoxy resin, polytetrahydrofuran and spirobislactone
Authors: Zhang Yujie , Xu Jingwei , Chen Zhengjun , Qin Chuangye , Dou Yanli
Published: January 2007

The light‐induced polymerization process of bisphenol F diglycidyl ether (BFDGE), 5,5′‐dicarboxylic‐7,7′‐dioxo‐2,2′‐spirodi(benzotetrahydrofuran) (DCSBL) and polytetrahydrofuran (pTHF‐250) was studied. 4‐[(2‐Hydroxytetradecyl)oxy]phenyl‐phenyliodoniumhexafluoroantimonate, camphorquinone and ethyl 4‐dimethylaminobenzoate were used as a photoinitiator system. The polymerization process was induced by light and monitored using Fourier transform infrared spectroscopy. A novel combination‐initiation polymerization process was proposed: first, cationic copolymerization of BFDGE and pTHF‐250 was initiated by the photoinitiator system and heat was released by this polymerization; then, copolymerization of BFDGE and DCSBL was induced by that heat while pTHF‐250 served as an anionic initiator. Copyright © 2007 Society of Chemical Industry
The Hsp90 inhibitor, 17‐AAG, prevents the ligand‐independent nuclear localization of androgen receptor in refractory prostate cancer cells
Authors: Saporita Anthony J. , Ai Junkui , Wang Zhou
Published: January 2007

BACKGROUND

Androgen receptor (AR) is the key molecule in androgen‐refractory prostate cancer. Despite androgen ablative conditions, AR remains active and is necessary for the growth of androgen‐refractory prostate cancer cells. Nuclear localization of AR is a prerequisite for its transcriptional activation. We examined AR localization in androgen‐dependent and androgen‐refractory prostate cancer cells.

METHODS AND RESULTS

We demonstrate increased nuclear localization of a GFP‐tagged AR in the absence of hormone in androgen‐refractory C4‐2 cells compared to parental androgen‐sensitive human prostate cancer LNCaP cells. Analysis of AR mutants impaired in ligand‐binding indicates that the nuclear localization of AR in C4‐2 cells is truly androgen‐independent. The hsp90 inhibitor, 17‐allylamino‐17‐demethoxygeldanamycin (17‐AAG), inhibits basal PSA expression and disrupts the ligand‐independent nuclear localization of AR at doses much lower than required to inhibit androgen‐induced nuclear import.

CONCLUSIONS

Hsp90 is a key regulator of ligand‐independent nuclear localization and activation of AR in androgen‐refractory prostate cancer cells. Prostate 67: 509–520, 2007. © 2007 Wiley‐Liss, Inc.
Crosstalk between the subunits of the homodimeric enzyme triosephosphate isomerase
Authors: Zomosa‐Signoret Viviana , Aguirre‐López Beatriz , Hernández‐Alcántara Gloria , Pérez‐Montfort Ruy , de Gómez‐Puyou Marietta Tuena , Gómez‐Puyou Armando
Published: January 2007

Homodimeric triosephosphate isomerase (TIM) from Trypanosoma cruzi (TcTIM) and T. brucei (TbTIM) are markedly similar in amino acid sequence and three‐dimensional structure. In their dimer interfaces, each monomer has a Cys15 that is surrounded by loop3 of the adjoining subunit. Perturbation of Cys15 by methylmethane thiosulfonate (MMTS) induces abolition of catalysis and structural changes. In the two TIMs, the structural arrangements of their Cys15 are almost identical. Nevertheless, the susceptibility of TcTIM to MMTS is nearly 100‐fold higher than in TbTIM. To ascertain the extent to which the characteristics of the interface Cys depend on the dynamics of its own monomer or on those of the adjacent monomer, we studied MMTS action on mutants of TcTIM that had the interface residues of TbTIM, and hybrids that have only one interfacial Cys15 (C15ATcTIM‐wild type TbTIM). We found that the solvent exposure of the interfacial Cys depends predominantly on the characteristics of the adjoining monomer. The maximal inhibition of activity induced by perturbation of the sole interface Cys in the C15ATcTIM‐TbTIM hybrid is around 60%. Hybrids formed with C15ATcTIM monomers and catalytically inert TbTIM monomers (E168DTbTIM) were also studied. Their activity drops by nearly 50% when the only interfacial Cys is perturbed. These results in conjunction with those on C15ATcTIM‐wild type TbTIM hybrid indicate that about half of the activity of each monomer depends on the integrity of each of the two Cys15‐loop3 portions of the interface. This could be another reason of why TIM is an obligatory dimer. Proteins 2007; © 2007 Wiley‐Liss, Inc.
Toxicological studies on hydroalcohol extract of Calendula officinalis L.
Authors: Silva Erick J. R. , Gonçalves Eduardo S. , Aguiar Fábio , Evêncio Liriane B. , Lyra Mariana M. A. , Coelho Maria Cristina O. C. , Fraga Maria do Carmo C. A. , Wanderley Almir G.
Published: January 2007

The hydroalcohol extract (HAE) of Calendula officinalis L. was evaluated for its acute toxicity by the oral route in rats and mice and for the subacute effect on hematological, biochemical and morphologic parameters in rats. In the acute toxicity test, HAE failed to cause death in the animals after administration of oral doses up to 5.0 g/kg. Oral treatment with HAE at 0.025, 0.25, 0.5 and 1.0 g/kg did not induce hematological alterations when compared with the control group. In the biochemical parameters, there was an increase in blood urea nitrogen (BUN) and in alanine transaminase (ALT) levels. Morphological examination of the brain, kidney and heart did not show any alteration. However, inflammatory sites were found in the lung and liver, which were associated, respectively, with oral gavage and a possible hepatotoxic effect. HAE was non‐toxic in rats, although there was evidence of renal and liver overload. Copyright © 2007 John Wiley & Sons, Ltd.
In Vivo antimalarial activity of aqueous extracts from Kenyan medicinal plants and their Chloroquine (CQ) potentiation effects against a blood‐induced CQ‐resistant rodent parasite in mice
Authors: Muregi Francis W. , Ishih Akira , Suzuki Tohru , Kino Hideto , Amano Teruaki , Mkoji Gerald M. , Miyase Toshio , Terada Mamoru
Published: January 2007

Hot water extracts from eight medicinal plants representing five families, used for malaria treatment in Kenya were screened for their in vivo antimalarial activity in mice against a chloroquine (CQ) resistant Plasmodium berghei NK65, either alone or in combination with CQ. Extracts of three plants, Toddalia asiatica (root bark), Rhamnus prinoides (leaves and root bark) and Vernonia lasiopus (root bark) showed high chemosuppression in the range 51%–75%. Maytenus acuminata, M. heterophylla, M. senegalensis and Rhamnus staddo had moderate activities of 33%–49% parasitaemia suppression in the root bark and/or leaf extracts, while Withania somnifera (root bark) had a non‐significant suppression (21%). In combination with CQ, extracts of V. lasiopus (all parts), leaf extracts of M. senegalensis, R. prinoides and T. asiatica as well as root barks of M. heterophylla, R. staddo and T. asiatica had improved parasitaemia suppression in the range 38%–66%, indicating synergistic interactions. Remarkable parasitaemia suppression by the extracts, either alone or in combination with CQ resulted into longer survival of mice relative to the controls, in some cases by more than 2 weeks. Plants, which showed significant antimalarial activity including V. lasiopus, T. asiatica and R. prinoides, should further be evaluated in the search for novel agents against drug‐resistant malaria. Copyright © 2007 John Wiley & Sons, Ltd.
Serum leptin and insulin levels in lactating protein-restricted rats: implications for energy balance
Authors: Ferreira C. L. P. , Macêdo G. M. , Latorraca M. Q. , Arantes V. C. , Veloso R. V. , Carneiro E. M. , Boschero A. C. , Nascimento C. M. O. , Gaíva M. H.
Published: January 2007

The present study analysed the effect of protein restriction on serum insulin and leptin levels and their relationship with energy balance during lactation. Four groups of rats received isocaloric diets containing 170 g protein/kg or 60 g protein/kg from pregnancy until the 14th day of lactation: control non-lactating, control lactating (both fed a control diet), low-protein non-lactating and low-protein lactating. Energy intake, body composition, energy balance, serum insulin and leptin concentrations and the relationship between these hormones and several factors related to obesity were analysed. Low-protein-intake lactating rats exhibited hypoinsulinaemia, hyperleptinaemia, hypophagia and decreased energy expenditure compared with control lactating rats. The protein level in the carcasses was lower in the low-protein lactating group than in the control lactating group, resulting in a higher fat content in the first group compared with the latter. Body fat correlated inversely with serum insulin and positively with serum leptin level. There was a significant negative correlation between serum leptin and energy intake, and a positive relationship between energy intake and serum insulin level in lactating rats and in the combined data from both groups. Energy expenditure was correlated positively with serum insulin and negatively with serum leptin in lactating rats and when data from control non-lactating and lactating rats were pooled. Lactating rats submitted to protein restriction, compared with lactating control rats, showed that maternal reserves were preserved owing to less severe negative energy balance. This metabolic adaptation was obtained, at least in part, by the hypoinsulinaemia that resulted in increased insulin sensitivity favouring enhanced fat deposition, hyperleptinaemia and hypophagia.
Dose-dependent modulation of the T cell proteome by ascorbic acid
Authors: Grant Melissa M. , Mistry Nalini , Lunec Joseph , Griffiths Helen R.
Published: January 2007

To investigate the hypothesis that the micronutrient ascorbic acid can modulate the functional genome, T cells (CCRF-HSB2) were treated with ascorbic acid (up to 150 μm) for up to 24 h. Protein expression changes were assessed by two-dimensional electrophoresis. Forty-one protein spots which showed greater than two-fold expression changes were subject to identification by matrix-assisted laser desorption ionisation time of flight MS. The confirmed protein identifications were clustered into five groups; proteins were associated with signalling, carbohydrate metabolism, apoptosis, transcription and immune function. The increased expression of phosphatidylinositol transfer protein (promotes intracellular signalling) within 5 min of ascorbic acid treatment was confirmed by Western blotting. Together, these observations suggest that ascorbic acid modulates the T cell proteome in a time- and dose-dependent manner and identify molecular targets for study following antioxidant supplementation in vivo.
The lipoprotein/lipid profile is modulated by a gene–diet interaction effect between polymorphisms in the liver X receptor-α and dietary cholesterol intake in French-Canadians
Authors: Robitaille Julie , Houde Alain , Lemieux Simone , Gaudet Daniel , Pérusse Louis , Vohl Marie-Claude
Published: January 2007

Genetic and nutritional factors interact together and modulate the plasma lipid profile. We identified variations in the gene encoding the liver X receptor α (LXRα) and investigated their effects on the plasma lipoprotein/lipid profile. We also examined whether the association between cholesterol intake and plasma lipid profile was modulated by LXRα variants. The LXRα gene was sequenced in thirty-five French-Canadian men with high plasma total cholesterol (>5·0 mmol/l) and LDL-cholesterol (>3·5 mmol/l) concentrations. Dietary cholesterol was obtained from a food-frequency questionnaire. The LXRα c.-115G>A, c.-840C>A and c.-1830T>C genotypes were determined by direct sequencing in 732 subjects. Molecular screening of the LXRα gene revealed sixteen variants. Genotypes c.-115G>A, c.-840C>A and c.-1830T>C (rare allele frequency of 14·3 %, 14·2 % and 11·0 %, respectively) were analysed further. Plasma total cholesterol concentrations were higher in carriers of the -115A, -840A and -1830C allele, compared with the -115G/G, -840C/C and -1830T/T homozygotes (P ≤ 0·05). In a model including the c.-115G>A polymorphism, cholesterol intake, the interaction term c.-115G>A × cholesterol intake (mg/d) and covariates, LXRα-115G>A explained 1·8 % and 2·1 % of the variance in total cholesterol and LDL-cholesterol concentrations (P = 0·02 andP = 0·01), whereas the interaction term explained 2·9 % (P = 0·002) and 2·8 % (P = 0·005), respectively. When subjects were divided into four groups according to the median of cholesterol (290·8 mg) and -115G>A genotypes, high cholesterol intake was associated with higher cholesterol levels in -115A carriers. Similar results were observed for c.-840C>A and c.-1830T>C. These results suggest that cholesterol intake interacts with LXRα variants to modulate the plasma lipid profile.
The effects of changes in nutritional demand on gastrointestinal parasitism in lactating rats
Authors: Normanton Heidi , Houdijk Jos G. M. , Jessop Neil S. , Knox Dave P. , Kyriazakis Ilias
Published: January 2007

Lactating rats experience a breakdown of immunity to parasites, i.e. they carry larger worm burdens after re-infection compared to their non-lactating counterparts. Feeding high-protein foods to lactating rats results in reduced worm burdens. This could be attributed to changes in gastrointestinal environment or to overcoming effects of nutrient scarcity on host immunity. The latter hypothesis was addressed through a manipulation of nutrient demand by manipulating litter size. Twenty-three rats were immunized prior to mating and re-infected on day 2 of lactation with 1600 infective Nippostrongylus brasiliensis larvae. From parturition onwards, rats received ad libitum a low-protein food (100 g crude protein/kg). Litter sizes were standardised to nine (LS9), six (LS6) or three (LS3) pups, by day 2 of lactation. After a further 10 d, LS9 and LS6 rats carried more worms than LS3 rats. However, feeding treatments did not affect concentrations of mucosal inflammatory cells. Achieved feed intake did not differ consistently between the treatment groups. However, LS9 and LS6 rats lost weight, whilst LS3 rats gained weight during lactation. The results support the view that resistance to N. brasiliensis is sensitive to changes in nutrient demand, and the improved resistance to N. brasiliensis is likely due to effects of overcoming nutrient scarcity on host immunity.
Main intestinal markers associated with the changes in gut architecture and function in piglets after weaning
Authors: Montagne Lucile , Boudry Gaëlle , Favier Christine , Huërou-Luron Isabelle Le , Lallès Jean-Paul , Sève Bernard
Published: January 2007

We analysed the spatio-temporal sequence of events concerning the morphology, physiology and ecology of the gut of piglets during the 2 weeks following weaning, in order to provide a limited number of variables that could be relevant markers of the gut post-weaning changes. An experiment was conducted on sixty piglets fasted for 2 d, then administered a weaning diet with a moderate or a high content of wheat using controlled gastric feeding, and slaughtered at different time-points post-weaning. Sixty-nine variables were analysed by principal component analysis. The results showed that the temporal changes induced in the gut by weaning can be divided into two periods: an acute period happening immediately after weaning, followed after day 5 by a more progressive adaptative and maturational phase. The main factors of this adaptation were the refeeding process and the time, while the dietper sehad little influence. The villus length, lactase activity, macromolecule fluxes across the jejunum and the plasma cholecystokinin were proposed as markers of the acute phase. The mass of the jejunum, the weight of the pancreas, the content of stomach, the trypsin activity and the theophylline-induced secretion in jejunum were related to the re-feeding. Markers proposed to follow the gut maturation were the maltase activity, the glucose absorption and the basal resistance in the ileum, the lactobacilli and enterococci in the colon, and the pH of colonic and caecal contents. These markers might be helpful to design suitable diets to limit post-weaning gut disorders in pigs.
Short duration of breast-feeding as a risk-factor for β-cell autoantibodies in 5-year-old children from the general population
Authors: Holmberg Hanna , Wahlberg Jeanette , Vaarala Outi , Ludvigsson Johnny ,   for the ABIS study group
Published: January 2007

Breast-feeding has been suggested to have a protective effect against the development of type 1 diabetes. In the present study, we investigated the relation between duration of breast-feeding and β-cell autoantibodies in 5-year-old non-diabetic children who participated in a prospective population-based follow-up study (the All Babies in Southeast Sweden study). Autoantibodies to insulin (IAA), glutamic acid decarboxylase (GADA) and the protein tyrosine phosphatase-like IA-2 (IA-2A) were measured by radiobinding assays. A short duration of total breast-feeding was associated with an increased risk of GADA and/or IAA above the ninety-fifth percentile at 5 years of age (OR 2·09, 95 % CI 1·45, 3·02; P < 0·000) as well as with an increased risk of IAA above the ninety-fifth percentile at this age (OR 2·89, 95 % CI 1·81, 4·62; P < 0·000). A short duration of exclusive breast-feeding was associated with an increased risk of GADA, IAA and/or IA-2A above the ninety-ninth percentile (OR 2·01, 95 % CI 1·08, 3·73; P = 0·028) as well as with an increased risk of IA-2A above the ninety-ninth percentile (OR 3·50, 95 % CI 1·38, 8·92; P = 0·009) at 5 years of age. An early introduction of formula was associated with an increased risk of GADA, IAA and/or IA-2A above the ninety-ninth percentile (OR 1·84, 95 % CI 1·01, 3·37; P = 0·047) at 5 years of age. The positive association between a short duration of both total and exclusive breast-feeding, as well as an early introduction of formula, and positivity for β-cell autoantibodies in children from the general population suggests that breast-feeding modifies the risk of β-cell autoimmunity, even years after finishing breast-feeding
Determinants of childhood overweight and obesity in China
Authors: Li Y. , Zhai F. , Yang X. , Schouten E. G. , Hu X. , He Y. , Luan D. , Ma G.
Published: January 2007

In order to investigate the determinants of childhood overweight and obesity in China, the prevalence of overweight (including obesity) was compared according to different dietary and physical activity patterns and parental body weight status. A total of 6826 children aged 7–17 years from the 2002 China National Nutrition and Health Survey were included in the study. Information for dietary intake was collected using three consecutive 24-h recalls by trained interviewers. The amounts of cooking oil and condiments consumed were weighed. An interview-administered 1-year physical activity questionnaire was used to collect physical activity information. The results showed that the heavier the parental body weight, the higher the overweight prevalence in children. The prevalence ratio increased if parent(s) were overweight and/or obese, up to 12·2 if both parents were obese. Overweight children consumed significantly more dietary energy, protein and fat, but less carbohydrate than their normal weight counterparts. On average, overweight children spent 0·5 h less on moderate/vigorous activities and 2·3 h more on low intensity activities per week. The following prevalence ratios were statistically significant: walking to and from school (0·6); moderate/vigorous activities ≥ 45 min/d (0·8); low intensity physical activities >2 h/d (1·3); the consumption of ≥ 25 g/d cooking oil (1·4); ≥ 200 g/d meat and meat products consumption (1·5); ≥ 100 g/d dairy products (1·8). After adjustment for parental body weight status and socioeconomic status, only cooking oil consumption and walking to and from school remained significantly related to child overweight. In conclusion, parental weight status is an important determinant. Fat intake, low intensity activities and active transport to/from school may be suitable entry points for overweight prevention among Chinese school children.
Foliar nitrogen and phosphorus resorption and decomposition in the nitrogen-fixing tree Lysiloma microphyllum in primary and secondary seasonally tropical dry forests in Mexico
Authors: Cárdenas Israel , Campo Julio
Published: January 2007

The tree Lysiloma microphyllum (Fabaceae) dominates in the seasonally tropical dry forests of central Mexico. In this study foliar N and P concentrations (on leaf mass basis), foliar N and P resorption efficiency and proficiency, as well as the decomposition of senescent leaves of L. microphyllum were studied in primary and in regenerating, secondary seasonally tropical dry forests. Our study included an area of early successional forest (10 y old), with phosphorus-poor soils and comparatively abundant nitrogen, an area of late-successional forest (∼60 y old), in which soil P and N were comparatively abundant, and an area of primary forest, in which soil P was comparatively abundant and N was less abundant than in the secondary counterparts. N and P concentrations in mature leaves varied across forests, reflecting soil nutrient availability. Nitrogen concentration in senescent leaves did not change among sites, which led to very different patterns of N resorption. In contrast, P concentration in senescent leaves was lower in the early than in late-successional and primary forests, which resulted in similar patterns of resorption. Leaf decomposition increased from 70% mass loss in the first year in the early successional to ∼80% in the same period in late-successional and primary forests. The element loss during decomposition change across forests in the following order: for N, early successional = late-successional > primary forest, and for P, primary forest > late-successional > early successional forest. Overall, the pattern of variation in leaf chemistry and nutrient release on the forest floor among sites is consistent with soil nutrient availability along this sequence, while decomposition rate may be related with the P concentration in senescent leaves.
Asynchrony in daily activity patterns of butterfly models and mimics
Authors: Pinheiro Carlos E. G.
Published: January 2007

Bates' theory of mimicry (Bates 1862) postulates that vertebrate predators avoid attacks on chemically defended butterflies, and a profitable species, usually referred to as the mimic, can obtain protection by resembling one or more unpalatable models. The evolution of Batesian mimicry requires that predators meet, taste and learn to avoid the models before meeting the mimics. For this reason, some authors have adopted the assumption that mimic population sizes must be smaller than the models' populations (Fisher 1930, Huheey 1980, Lindström et al. 1997).
Spatial patterns of tropical forest trees in Western Polynesia suggest recruitment limitations during secondary succession
Authors: Franklin Janet , Rey Sergio J.
Published: January 2007

Spatial analysis can be used to relate the patterns of tree species to their regeneration syndromes – pioneer to late-successional – and is a first step in refining hypotheses about the species traits and biotic and abiotic factors that give rise to forest community dynamics. This study examines the spatial pattern of the most abundant trees in three 0.45-ha plots in species-poor lowland rain forests on oceanic islands in Tonga, Western Polynesia, that experience frequent natural disturbance and have a 3000-y history of shifting cultivation. We contrast secondary vs. remnant late-successional forest, with particular attention paid to the spatial dispersion and clustering of tree species, and the presence of spatial dependence in the density of seedlings and saplings. Shade-tolerant species were not strongly clustered at any scale. They did not appear to be dispersal limited, in late successional forest, and only some showed patterns consistent with density-dependent mortality (more clumped when small). Shade-tolerant species were more clumped in secondary forest, and may be dispersal-limited there because vertebrate dispersers prefer primary forest. Shade-intolerant species were clumped in gaps in late-successional forest, but some were also clumped in secondary forest, indicating that they too may be dispersal limited during secondary succession. We also compared the species composition of seedlings and saplings in the centre of plots with trees in the surrounding area and inferred that active dispersal (by vertebrate frugivores) contributed as much as 50% to site species richness.
Are floristic and edaphic patterns in Amazonian rain forests congruent for trees, pteridophytes and Melastomataceae?
Authors: Ruokolainen Kalle , Tuomisto Hanna , Macía Manuel J. , Higgins Mark A. , Yli-Halla Markku
Published: January 2007

Studies in western Amazonian forests have found that similarities in soil cation concentration and texture explain floristic similarities between sites, when these are measured using trees, pteridophytes or Melastomataceae. However, it is not known to what extent the three plant groups react to the same soil characteristics, because tree studies have almost always been conducted in different areas than studies on the understorey plant groups. We made inventories in 23 sites representing non-inundated rain forests on clayey to loamy soil in three regions of western Amazonia. Significant Mantel correlations between the floristic patterns of trees and pteridophytes were found in all three regions when floristic differences were measured with species presence–absence data. When species abundance data were used, and when the floristic patterns of trees and Melastomataceae were compared, significant correlations were found in one or two regions. Mantel correlations between plant groups were highest in the two regions where the observed variation in soil characteristics was largest. In all regions, the same soil variables emerged with significant Mantel correlations with trees, pteridophytes and Melastomataceae. Soil calcium and magnesium were most frequently retained in the models of multiple regression on distance matrices. On average, soil differences explained 50% of the variation in floristic differences (range = 14–84%), and geographical distances explained 16% (range = 0–64%). Our results demonstrate that beta diversities of the three plant groups are highly correlated, and that much of this congruence is explained by similar reactions to soil variation. These results support the idea that pteridophytes, and to a lesser degree Melastomataceae, can be used as indicators of general floristic and edaphic patterns in Amazonian rain forests. Since understorey plants are much quicker to inventory than trees, this would make it possible to recognize and map floristic patterns over huge areas of lowland Amazonia within a reasonable time.