bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurokinin B and nitric oxide plasma levels in pre‐eclampsia and isolated intrauterine growth restriction
Authors: D'Anna Rosario , Baviera Giovanni , Corrado Francesco , Crisafulli Alessandra , Ientile Riccardo , Buemi Michele , Squadrito Francesco
Published: September 2004

Objective  To verify if neurokinin B plasma level is increased in pre‐eclampsia and IUGR. Also, to ascertain if there is a correlation between neurokinin B plasma level and nitric oxide production.

Design  A total of 90 pregnant women were studied. Thirty had a gestation complicated by pre‐eclampsia and 30 by isolated IUGR; the other 30 were controls. In all patients, neurokinin B plasma level and nitric oxide metabolites (nitrites/nitrates) level were measured.

Setting  University, General Hospital, Messina, Italy.

Methods  Neurokinin B blood samples were taken at 33.5 weeks of gestation and at term. Samples for nitric oxide breakdown products were taken at delivery from the antecubital vein and then from the umbilical vein.

Results  Neurokinin B plasma levels in the pre‐eclamptic and IUGR groups were significantly higher than controls. Nitric oxide metabolites levels in pre‐eclamptic and IUGR patients were also higher than controls. Regression analysis showed a significant correlation among neurokinin B plasma values and nitric oxide metabolite levels either in pre‐eclampsia, in IUGR or in the control group.

Conclusion  Neurokinin B could be involved in pregnancy haemodynamic adaptation via nitric oxide production. In pregnancies complicated with pre‐eclampsia and IUGR, increased neurokinin B plasma level, correlated well with increased nitric oxide metabolite level, which may be a compensatory mechanism to improve blood flow to the uteroplacental unit.
Shuttle craft: a candidate quantitative trait gene for Drosophila lifespan
Authors: Pasyukova Elena G. , Roshina Natalia V. , Mackay Trudy F. C.
Published: September 2004

Variation in longevity in natural populations is attributable to the segregation of multiple interacting loci, whose effects are sensitive to the environment. Although there has been considerable recent progress towards understanding the environmental factors and genetic pathways that regulate lifespan, little is known about the genes causing naturally occurring variation in longevity. Previously, we used deficiency complementation mapping to map two closely linked quantitative trait loci (QTL) causing female‐specific variation in longevity between the Oregon (Ore) and 2b strains of Drosophila melanogaster to 35B9–C3 and 35C3 on the second chromosome. The 35B9–C3 QTL encompasses a 50‐kb region including four genes, for one of which, shuttle craft (stc), mutations have been generated. The 35C3 QTL localizes to a 200‐kb interval with 15 genes, including three genes for which mutations exist (reduced (rd), guftagu (gft) and ms(2)35Ci). Here, we report quantitative complementation tests to mutations at these four positional candidate genes, and show that ms(2)35Ci and stc are novel candidate quantitative trait genes affecting variation in Drosophila longevity. Complementation tests with stc alleles reveal sex‐ and allele‐specific failure to complement, and complementation effects are dependent on the genetic background, indicating considerable epistasis for lifespan. In addition, a homozygous viable stc allele has a sex‐specific effect on lifespan. stc encodes an RNA polymerase II transcription factor, and is an attractive candidate gene for the regulation of longevity and variation in longevity, because it is required for motoneuron development and is expressed throughout development. Quantitative genetic analysis of naturally occurring variants with subtle effects on lifespan can identify novel candidate genes and pathways important in the regulation of longevity.
Nuclear accumulation of glycogen synthase kinase‐3 during replicative senescence of human fibroblasts
Authors: Zmijewski Jaroslaw W. , Jope Richard S.
Published: September 2004

Activation of the tumor suppressor protein p53 contributes to cellular senescence. As glycogen synthase kinase‐3 (GSK3) was recently found to interact with p53 and contribute to the actions of p53, this study examined whether GSK3 accumulated in the nucleus and associated with p53 in senescent cells. Compared with young and middle‐aged human WI‐38 fibroblasts, senescent cells were found to contain increased nuclear levels of GSK3β, and also tended to accumulate in the nucleus the other isoform of GSK3, GSK3α. Co‐immunoprecipitation experiments demonstrated that GSK3β and p53 formed a complex in the nucleus. Further experiments tested whether inhibition of GSK3 altered the development of senescence using long‐term treatment with the selective GSK3 inhibitor lithium. Lithium treatment reduced the senescence‐associated accumulation of p53 and caused cells to enter a reversible quiescent state. These results indicate that a portion of the p53 that is activated in senescent cells is modulated by its association with GSK3β in the nucleus, an association that is known to facilitate the actions of p53 and that may contribute to senescence.
The non‐existent aging program: how does it work?
Authors: Bredesen Dale E.
Published: September 2004

Aging and lifespan determination have been viewed, in the most well‐accepted theories, as nonprogrammatic, and are thought to result from the evolutionary selection for early fitness at the expense of late survival. Here, recent data implicating potentially programmatic aspects of aging and lifespan determination are discussed, and analogies between programmed cell death and programmed organismal death are offered. It is hoped that the recognition of at least the possibility of a programmatic aspect, or aspects, to the determination of longevity and the process of aging will help to optimize our chances to identify appropriate therapeutic targets both for longevity enhancement and disease prevention.
A novel ATX‐S10(Na) photodynamic therapy for human skin tumors and benign hyperproliferative skin
Authors: Takahashi Hidetoshi , Itoh Yasuhiro , Nakajima Susumu , Sakata Isao , Iizuka Hajime
Published: September 2004

Background/purpose: Photodynamic therapy (PDT) is a promising treatment for various skin tumors and other skin diseases. We investigated the potential therapeutic effects of PDT using ATX‐S10(Na) ointment and a diode laser in mouse skin models of experimental skin tumors as well as transplanted human samples of superficial skin tumors and lesional psoriatic skin.

Methods: ATX‐S10(Na) ointment (1% w/v) was introduced into tape‐stripped mouse skin, transplanted squamous cell carcinoma (SCC) samples and human skin diseases after topical application, then PDT was performed.

Results: ATX‐S10(Na) ointment (1% w/v) was introduced effectively into tape‐stripped mouse skin and transplanted SCC samples after topical application, but was not detected after 48 h, as assessed by fluorescence microscopy. PDT, using 1% ATX‐S10(Na) ointment and diode laser (50 J/cm2), was found to decrease epidermal thickness in 12‐0‐tetradecanoylphorbol‐13‐acetate (TPA)‐treated mouse skin by 6 days. PDT with 1% ATX‐S10(Na) ointment and diode laser (150 J/cm2) was also effective for transplanted SCC, and tumors were eliminated by 6 weeks. PDT against Bowen disease, basal‐cell carcinoma, and psoriasis xenografts onto SCID mice also showed marked suppression of tumor growth and cell proliferation, respectively.

Conclusion: Our results indicate that ATX‐S10(Na)‐PDT is an effective treatment for various skin tumors and psoriasis in experimental mouse models.
Phototoxicity of exogenous protoporphyrin IX and δ‐aminolevulinic acid in the photo hen's egg test
Authors: Neumann Norbert J. , Hanneken Sandra , Ruzicka Thomas , Lehmann Percy
Published: September 2004

Background: Oxygen, appropriate light sources, and special photosensitizers are necessary to induce photochemical damage in tumor cells via photodynamic therapy (PDT) δ‐aminolevulinic acid (ALA) is increasingly used in PDT, because topical or systemic administration of ALA induces accumulation of endogenous porphyrins preferentially in neoplastic tissues. Subsequent radiation with light of approximately 630 nm leads to selective damage of tumor cells. PDT should optimally leave peritumoral tissues unaffected, but only few data are reported on the effects and the time course of ALA‐induced porphyrins in tumor‐free tissues.

Methods: Therefore, we studied the phototoxic effects of protoporphyrin IX (PP) and ALA‐induced porphyrins in a recently established photototoxic model based on tumor‐free tissue, the photo hen's egg test (PHET).

Results: Employing this test procedure, PP provoked strong phototoxic reactions when irradiated with Ultraviolet A immediately and up to 30 h after substance application. In contrast, ALA induced a significant phototoxic effect only if irradiated 24 h after application.

Conclusion: Thus, we observed a delayed phototoxic effect of ALA in tumor‐free tissue of the yolk sac (YS) blood vessel system. This delayed phototoxic response 24 h after ALA application is probably caused by endogenously synthesized porphyrins. In contrast, epithelial tumors show a maximum porphyrin accumulation 4–8 h after ALA application whereas in healthy human skin porphyrin synthesis is less intensive but prolonged with maximum levels 24–48 h after ALA application. Thus, ALA induced virtually the same delayed phototoxic effect in the tumor‐free YS blood vessel tissue as in healthy human skin. These results show that the PHET is a useful model for the predictive preclinical risk assessment of exogenous or endogenous photosensitizers.
Dermatomyositis: comparative studies of cutaneous photosensitivity in lupus erythematosus and normal subjects
Authors: Dourmishev L. , Meffert H. , Piazena H.
Published: September 2004

Purpose: Cutaneous features of dermatomyositis (DM) strongly suggest that ultraviolet (UV) radiation plays an important role in the pathogenesis of the disease. However, the incidence and the nature of photosensitivity in this disorder have not been established. The aim of this study was to investigate the UVB (290–320 nm) minimal erythema dose (MED) in DM patients in comparison with those in lupus erythematosus (LE) and healthy controls.

Methods: Non‐irradiated back skin of 75 Caucasians with skin types II and III according to the Fitzpatrick classification were present in three different subject groups and tested for photomanifestation on non‐irradiated suprascapular back skin with an ETG‐1 Erythemtester. The first group included 19 DM patients, the second 30 patients with LE, and the third 26 healthy control volunteers. The MEDs were determined 24 h after irradiation adjusted according to skin type.

Results: Nine of the 19 DM patients (47.4%) demonstrated reduced MEDs to UVB radiation. Seven DM patients (36.8%) had a history of increased cutaneous photosensivity and four of these (21.1%) reported diseased aggravation after sun exposure. Both the DM and LE patient groups showed reduced MED to UVB radiation (P<0.05) compared with the control group (19.2%). Increased erythemal sensitivity to UVB irradiation was found more frequently in patients with systemic LE and cutaneous discoid LE, than in those with subacute cutaneous LE.

Conclusion: DM patients, similar to those with LE, showed a significantly reduced MED to UVB irradiation compared with healthy persons.
Ergocalciferol promotes in vivo differentiation of keratinocytes and reduces photodamage caused by ultraviolet irradiation in hairless mice
Authors: Mitani Hiroaki , Naru Eiji , Yamashita Mika , Arakane Kumi , Suzuki Tadashi , Imanari Toshio
Published: September 2004

Background: Ergocalciferol (VD2) is usually administered orally and it is metabolized to produce its biologically active metabolites in the liver and kidney. Active vitamin D is a well‐known potent regulator of cell growth and differentiation.

Purpose: Active vitamin D such as 1,25‐dihydroxyvitamin D3 (1α,25(OH)2D3) prevents photodamage, including wrinkles and morphologic alterations. However, its clinical and cosmetic use is limited because of its potent, associated effect on calcium metabolism. We examined the efficacy of vitamin D analogues with few adverse effects for preventing skin photodamage.

Method: Topical application of VD2 to hairless mouse dorsal skin, and exposure to solar‐simulating ultraviolet (UV) radiation at a dose of 10.8 J/cm2 (UVA) were performed for 15 weeks, five times a week on weekdays. At the end of the final irradiation, histological and analytical studies were performed.

Results: Topical application of VD2 significantly prevented wrinkle formation and abnormal accumulation of extracellular matrix components. In addition, VD2 suppressed excessive secretion of IL‐6 induced by UV irradiation in cultured human normal keratinocytes, in a dose‐dependent manner.

Conclusion: VD2 promoted keratinocytes differentiation in the epidermis and showed diverse physiological effects, the same as the active form of VD3. The results suggested that the suppression of skin photodamage involved the promotion of keratinocytes differentiation and suppression of IL‐6 secretion induced by exposure to UV. Topical application of VD2 may become an effective means to suppress solar UV‐induced human skin damage.
Development of selective media for the isolation and enumeration of Alternaria species from soil and plant debris
Authors: Hong Soon Gyu , Pryor Barry M
Published: September 2004

A new semi-selective medium, acidified weak potato-dextrose agar (AWPDA) with Mertect (active ingredient: thiabendazole), was developed for the isolation and enumeration of Alternaria species from samples of soil and plant debris. The medium was selected based on growth inhibition tests against Alternaria and several other commonly encountered saprobic fungi utilizing three antifungal agents, Botran (active ingredient: dichloran), Bayleton (active ingredient: triadimefon), and Mertect, and two basal media, acidified potato-dextrose agar (APDA) and AWPDA. Botran inhibited growth of Rhizopus stolonifer moderately, but had little effect on Cladosporium cladosporoides, Fusarium oxysporum, Penicillium chrysogenum, or Trichoderma harzianum. Bayleton inhibited growth of R. stolonifer and C. cladosporoides severely, and inhibited growth of F. oxysporum, P. chrysogenum, and T. harzianum moderately. Mertect inhibited growth of C. cladosporoides, F. oxysporum, P. chrysogenum, and T. harzianum completely, but had little or moderate effect on R. stolonifer. All three antifungal agents inhibited growth of Alternaria species slightly or moderately. The combination of Bayleton and Mertect inhibited growth of all fungi severely. A comparison of recovery rates of Alternaria from soil and plant debris samples on AWPDA with Mertect and weak potato-dextrose agar (WPDA) revealed that Alternaria spp. accounted for 63.6%–81.0% of recovered fungal isolates on AWPDA with Mertect as compared to 0.6%–2.7% of recovered isolates on WPDA. The AWPDA medium with Mertect exhibited superior selective growth of Alternaria species from samples of soil and plant debris, and will be useful in studies where the recovery and enumeration of Alternaria species is necessary.Key words: Alternaria, AWPDA, selective media, sporulation, Mertect.
Colonization and persistence of a plant growth-promoting bacterium Pseudomonas fluorescens strain CS85, on roots of cotton seedlings
Authors: Wang Chunxia , Wang Daoben , Zhou Qi
Published: September 2004

Pseudomonas fluorescens CS85, which was previously isolated from the rhizosphere of cotton seedlings, acts as both a plant growth-promoting bacterium and a biocontrol agent against cotton pathogens, including Rhizoctonia solani, Colletotrichum gossypii, Fusarium oxysporum f sp. vasinfectum, and Verticillium dahliae. Strain CS85 was labeled separately with luxAB and gusA. The labeled strains were stably maintained and had high levels of expression of the marker genes, luxAB and gusA, after successive transfers on nonselective medium, long-term preservation, and after recovery from soil. The labeled strains displayed similar biocontrol characteristics (e.g., antibiosis, effects of growth -promotion and disease -control) to the original strain. The labeled strains colonized all surfaces of the young plant root zones, such as roots hairs and lateral roots, although the distribution of the labeled strains on the root surfaces was not uniform. Moreover, the population densities of the labeled strains on the root surface were stably maintained at high levels during the first 2 weeks of plant growth in the native soil, so that about 107–108 CFU/g root were detected, then decreased gradually. Nevertheless, approximately 106 CFU/g root of the labeled strains were observed on the root surfaces 35 d after planting.Key words: plant growth-promoting bacteria, luxAB, gusA, root colonization.
Lactobacillus casei,Lactobacillus rhamnosus, andLactobacillus zeaeisolates identified by sequence signature and immunoblot phenotype
Authors: Dobson C Melissa , Chaban Bonnie , Deneer Harry , Ziola Barry
Published: September 2004

Species taxonomy within the Lactobacillus casei group of bacteria has been unsettled. With the goal of helping clarify the taxonomy of these bacteria, we investigated the first 3 variable regions of the 16S rRNA gene, the 16S-23S rRNA interspacer region, and one third of the chaperonin 60 gene for Lactobacillus isolates originally designated as L. casei, L. paracasei, L. rhamnosus, and L. zeae. For each genetic region, a phylogenetic tree was created and signature sequence analysis was done. As well, phenotypic analysis of the various strains was performed by immunoblotting. Both sequence signature analysis and immunoblotting gave immediate identification of L. casei, L. rhamnosus, and L. zeae isolates. These results corroborate and extend previous findings concerning these lactobacilli; therefore, we strongly endorse recent proposals for revised nomenclature. Specifically, isolate ATCC 393 is appropriately rejected as the L. casei type strain because of grouping with isolates identified as L. zeae. As well, because all other L. casei isolates, including the proposed neotype isolate ATCC 334, grouped together with isolates designated L. paracasei, we support the use of the single species L. casei and rejection of the name L. paracasei.Key words: Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus zeae, sequence signatures, immunoblot phenotype.
PCR-based identification ofStaphylococcus epidermidistargetinggseAencoding the glutamic-acid-specific protease
Authors: Ikeda Y , Ohara-Nemoto Y , Kimura S , Ishibashi K , Kikuchi K
Published: September 2004

The frequency of the gseA gene encoding a glutamic acid-specific serine protease, GluSE, of Staphylococcus epidermidis was investigated. DNA hybridization analysis demonstrated that gseA existed exclusively in S. epidermidis but not in other bacteria examined. A single step PCR assay with a set of designed primers yielded amplification of gseA from all 69 clinical isolates of S. epidermidis taken from patients and healthy adults, whereas production of GluSE was observed in 74% (51/69) of the isolates. Furthermore, none of the 46 clinical isolates of other species of coagulase-negative staphylococci and 45 clinical isolates of Staphylococcus aureus showed amplification, except a Staphylococcus capitis strain. However, this strain was positive for a S. epidermidis-specific DNA region and the DNA sequence of the 16S rRNA gene showed 99% identity with that of S. epidermidis. Therefore, these results indicated that the present PCR assay for gseA was ubiquitous and highly specific for detection of S. epidermidis.Key words: Staphylococcus epidermidis, glutamic acid-specific protease, PCR assay, molecular identification.
Adrenal 11-beta hydroxysteroid dehydrogenase activity in response to stress
Authors: Zallocchi Marisa , Matkovic Laura , Damasco María C
Published: September 2004

This work studied the effect of stresses produced by simulated gavage or gavage with 200 mmol/L HCl two hours before adrenal extraction, on the activities of the 11β-hydroxysteroid dehydrogenase 1 and 11β-hydroxysteroid dehydrogenase 2 isoforms present in the rat adrenal gland. These activities were determined on immediately prepared adrenal microsomes following incubations with3H-corticosterone and NAD+or NADP+. 11-dehydrocorticosterone was measured as an end-product by TLC, and controls were adrenal microsomes from rats kept under basal (unstressed) conditions. 11β-hydroxysteroid dehydrogenase 1 activity, but not 11β-hydroxysteroid dehydrogenase 2 activity, was increased under both stress-conditions. Homeostatically, the stimulation of 11β-hydroxysteroid dehydrogenase 1 activity would increase the supply of glucocorticoids. These, in turn, would activate the enzyme phenylethanolamine N-methyl transferase, thereby improving the synthesis of epinephrine as part of the stress-response.Key words: acidosis, adrenal, HSD, stress.
Daio-Orengedokudo works as a cell-proliferating compound in endothelial cells
Authors: Cho Ki-Ho , Jung Woo-Sang , Park Sung-Uk , Moon Sang-Kwan , Ko Chang-Nam , Ku Seojin , Chi Sung-Gil , Park Heonyong
Published: September 2004

Daio-Orengedokuto is a combination drug that has inhibitory effects on HMG-CoA reductase and pancreatic lipase. Here we investigated whether Daio-Orengedokuto has effects on vascular endothelial cells. To determine its effects on blood vessels, we examined roles of Daio-Orengedokuto in cell migration, cell apoptosis and cell cycle progression over bovine aortic endothelial cells (BAECs). Interestingly, Daio-Orengedokuto was shown to work as an anti-apoptotic agent, a cell cycle progressive agent and a cell-migration inducing agent in BAECs, whereas it was known to act as a tumor suppressor in cancer cells (unpublished data). The inducing effect of Daio-Orengedokuto on cell-cycle progression and cell migration in endothelium suggests that Daio-Orengedokuto may be referred to as a drug, inducing angiogenesis, healing wounds, and (or) remodeling vascular tissue. Then we further investigated which signaling molecules were activated by Daio-Orengedokuto and found that extracellular signal-regulated kinase (ERK) phosphorylation and IκB degradation were stimulated by the Daio-Orengedokuto treatment in BAECs. More interestingly, pretreatment with PD compound, an ERK inhibitor, blocked the anti-apoptosis induced by Daio-Orengedokuto. In conclusion, Daio-Orengedokuto plays a role in endothelial cell proliferation via activation of MAP kinase.Key words: Daio-Orengedokuto, endothelial cells, proliferation, anti-apoptosis, cell signaling.
Role of nitric oxide in mediating cardiovascular alterations accompanying heart failure in rats
Authors: Cunha Valdeci da , Stefanon Ivanita , Mill José Geraldo
Published: September 2004

The present study was designed to evaluate the role of endothelial NO in the hemodynamics and vascular changes that occur in heart failure following myocardial infarction in rats. Left ventricular systolic pressure (LVSP), mean blood pressure (MBP), aortic morphology (media thickness) and reactivity were evaluated in rats with coronary artery ligation (heart failure, HF) or sham operation (SO) untreated or treated for four weeks with either a low dose of NG-nitro-L-arginine methyl ester (L-NAME, 6 mg·kg-1·day-1) or L-arginine (1.5 g·kg-1·day-1). In rats with HF LVSP (HF = 111 ± 8 mmHg; SO = 143 ± 6 mmHg, p < 0.05), MBP (HF = 98 ± 8 mmHg; SO = 127 ± 6 mmHg, p < 0.05) and aortic media thickness (HF = 68 ± 6 µm; SO = 75 ± 2 µm, p < 0.05) were significantly reduced. The contractile response to phenylephrine and the endothelium-independent relaxation to sodium nitroprusside were similar in HF and SO aortas, but the sensitivity (pD2) to acetylcholine (HF = 7.5 ± 0.06; SO = 7.1 ± 0.08, p < 0.05) was significantly increased in HF aortas, indicating an enhanced basal NO release. Treatment with L-NAME (LN) reversed the effects of HF on LVSP (HF-LN = 143 ± 9 mmHg, p < 0.05 vs. HF), MBP (HF-LN = 128 ± 8 mmHg, p < 0.05 vs. HF), sensitivity to acetylcholine (HF-LN = 6.9 ± 0.10, p < 0.05 vs. HF) and aortic media thickness (HF-LN = 79 ± 2 µm, p < 0.05 vs. HF), without changing these parameters in SO rats. L-NAME also selectively increased the maximal response to phenylephrine in HF aortas (HF-LN = 2.4 ± 0.20 g; HF = 1.6 ± 0.17 g, p < 0.05). L-arginine (LA) did not change the effects of HF on LSVP, MBP or aortic media thickness, but it reduced the sensitivity to phenylephrine in aortas from SO rats (SO-LA = 6.5 ± 0.12; SO = 7.0 ± 0.09, p < 0.05). Taken together, these results suggest an important role for endothelial NO in mediating the reduced vascular growth, myocardial dysfunction and hypotension in rats with HF.Key words: nitric oxide, myocardial infarction, heart failure, vascular reactivity.
Chronic treatment with bark infusion fromCroton cajucaralowers plasma triglyceride levels in genetic hyperlipidemic mice
Authors: Bighetti Eliete J.B , Souza-Brito Alba R.M , Faria Eliana C. de , Oliveira Helena C.F
Published: September 2004

Aqueous infusion and preparations containing dehydrocrotonin (DHC) and essential oil from Croton cajucara bark were tested for plasma lipid-lowering effects in genetically modified hyperlipidemic mice. Two mouse models were tested: 1) primary hypercholesterolemia resulting from the LDL-receptor gene knockout, and 2) combined hyperlipidemia resulting from crosses of LDL-receptor knockout mice with transgenic mice overexpressing apolipo protein (apo) CIII and cholesteryl ester-transfer protein. Mice treated with bark infusion, DHC, essential oil, or placebos for 25 days showed no signals of toxicity as judged by biochemical tests for liver and kidney functions. The bark infusion reduced triglyceride plasma levels by 40%, while essential oil and DHC had no significant effects on plasma lipid levels. The bark infusion treatment promoted a redistribution of cholesterol among the lipoprotein fractions in combined hyperlipidemic mice. There was a marked reduction in the VLDL fraction and an increase in the HDL fraction, in such a way that the (VLDL + LDL)/HDL ratio was reduced by half. The bark infusion treatment did not modify cholesterol distribution in hypercholesterolemic mice. In conclusion, C. cajucara bark infusion reduced plasma triglycerides levels and promoted a redistribution of cholesterol among lipoproteins in genetically combined hyperlipidemic mice. These changes modify risk factors for the development of atherosclerotic diseases.Key words: hyperlipidemia, transgenic mice, Croton cajucara, dehydrocrotonin, cholesterol.
Thermoregulation of transgenic growth hormone mice
Authors: Rollo C D , Lai M , Whitehead K , Perreault M L , Lemon J , Chaudhry A M
Published: September 2004

Transgenic growth hormone (TG) mice (Mus musculus L., 1758) obtain enhanced growth via compensatory feeding at intermediate sizes and via higher growth efficiency. The latter involves diverting resources from other functions such as locomotion and wakefulness. Thermogenesis is a major expense for small mammals, so we explored whether TG mice express a trade-off between growth and thermoregulation. TG mice are hypothermic and cannot maintain their body temperature under cold stress. TG mice showed initial enlargement of brown adipose tissue and subsequent age-related decreases not seen in controls. Some TG mice became torpid after fasting durations not known to affect other mice. On a high-calorie diet, TG mice had higher body temperatures even though controls did not. Our background strain developed obesity on a high-protein and high-fat diet, and on a diet supplemented with carbohydrates, whereas TG mice never developed obesity. White adipose tissue deposits of TG females were relatively larger, but those of TG males were relatively smaller, than those of controls fed standard food. We also found significant effects of the three experimental diets, as well as gender, age, body mass, ambient temperature, and behavioural activity, on rectal temperatures of TG mice and controls in a large breeding colony. Thermogenesis of TG mice fed standard food appears energetically constrained, likely contributing to enhanced growth efficiency.
Survey of mites in caves and deep soil and evolution of mites in these habitats
Authors: Ducarme Xavier , Wauthy Georges , André Henri M , Lebrun Philippe
Published: September 2004

We studied adaptations to subterranean environments in Acari. Mite populations of two caves and of the mineral horizon of soil from three forest sites were analysed. In the soil, body length was limited by the pore size. The proportions of (i) predators, (ii) phoretic mites, and (iii) primitive oribatids were higher in caves. This was potentially explained by (i) polyphagy or predation on other groups and reduced interspecific competition, (ii) the fragmented structure and liability to flooding of the cave habitat, and (iii) the higher humidity in caves. Adaptations to dry habitats probably greatly influenced the evolution in Oribatida. It is proposed that numerous mites colonized caves directly from deep soil without a surface stage.
Adult survival and temporary emigration in the common toad
Authors: Frétey Thierry , Cam Emmanuelle , Garff Bernard Le , Monnat Jean-Yves
Published: September 2004

In vertebrates exhibiting intermittent breeding, breeding activity is a factor of critical importance in capture–recapture studies using data from individually marked animals. Nonbreeders can be absent from locations used by breeders and can be considered "temporary emigrants". We addressed the influence of sex on survival in common toads, Bufo bufo (L., 1758), using the Joly–Seber model and the existance of temporary emigration in male common toads by assessing trap-dependence and by conducting a robust design analysis. We addressed the hypothesis that the probability of the presence of an individual in the study area depends on the presence of the individual the year before (i.e., that transitions between reproductive states are a first-order Markovian process). Results provided support for the hypotheses of random temporary emigration, of sex-specific differences in survival, and of the presence of "transients" in males. Females had intermediate survival compared with the groups of "transients + residents" and "resident" males. Females had lower recapture probability under the Joly–Seber model, which may be interpreted as evidence of lower breeding probability or lower detectability of breeding females. Behaviour may explain this difference in that females may attend ponds for shorter periods. This may be common in species where females aggregate to seek fertilization and lay eggs in locations attended by males and in species with a "resource-based lek" mating system.
Are frog calls modulated by the environment? An analysis with anuran species from Bolivia
Authors: Bosch J , De la Riva I
Published: September 2004

Studies have shown that long-range songs of birds and primates are structurally adapted to local habitat acoustics. The evolution of frog calls, however, seems to be less influenced by habitat. Frogs are extremely dependent on energetically costly acoustic signals, which frequently have to be transmitted over large distances to elicit an encounter with the opposite sex. Different acoustic properties of advertisement calls from 95 Bolivian anuran species were analyzed according to their taxonomic position and the habitat characteristics where each species occurred. The majority of call characteristics, such as diversity of notes, number of pulses per note, or dominant frequency, appear strongly related to taxonomic position. Large-scale habitat characteristics (ecoregion and macrohabitat type) were not related to call characteristics, whereas small-scale habitat (microhabitat) complexity appeared to explain some of the variation in dominant frequency modulation. Species that call in closed microhabitats are more likely to use frequency-modulated calls, which may allow for more efficient sound transmission. To further the understanding of frog-call evolution in response to habitat selection, this and other studies have indicated that studies at finer spatial scales are needed, as well as additional studies restricted to the genus or species level.
An extensive study of the foraging ecology of beavers (Castor canadensis) in relation to habitat quality
Authors: Gallant D , Bérubé C H , Tremblay E , Vasseur L
Published: September 2004

The objective of this study was to examine the foraging behaviour of the beaver (Castor canadensis Kuhl, 1820) and to explain its selection of terrestrial woody plant species according to central place foraging theory. Limitations in variety of food items in most studies with regard to size and (or) distance from the central place and information on availability of forage choices give a partial view of the subject. In this study, the theory is tested in a natural environment with high variability in food items with regard to these factors. Foraging choices by beavers were inspected by measuring variables on cut and uncut trees of every species encountered within 1 m of trail systems made by 25 beaver colonies in Kouchibouguac National Park in New Brunswick, Canada, thereby quantifying the availability of the different food items. The effect of habitat quality (food availability) on the foraging behaviour of beavers was also tested. The results of this study suggest that with increasing distance from the pond, beavers in high-quality habitats selected fewer, but larger, trees and are more species selective. This selectivity was diminished in habitats of lower quality. The results of this study are consistent with the predictions of the central foraging theory.
The control of color change in the Pacific tree frog, Hyla regilla
Authors: Stegen James C , Gienger C M , Sun Lixing
Published: September 2004

A number of environmental variables have been identified as affecting anuran color, but rarely have the interactions between these variables been investigated. In attempt to elucidate the function of color change, we conducted a within-subject, full factorial experiment designed to determine the simple and interactive effects of background, temperature, and light intensity on the rate of color change in the Pacific tree frog (Hyla regilla Baird and Girard, 1852). Color was investigated holistically, as well as by decomposing it into its constituent parts (hue, chroma, and lightness), using digital photography. The rate of color change was faster on the green versus the brown background, at 10 versus 25 °C, and at low versus high light intensity. There was also a significant effect of the interaction between background color and temperature on the rate of color change. We found increased rates of hue, chroma, lightness, and color change with increasing initial hue, chroma, lightness, and color distances between the Pacific tree frog and its background, respectively. In addition, initial color distance covaried with changes in environmental variables. After controlling for initial color distance, and thus the effects of background matching, background color and temperature still showed a significant interaction for their effects on rate of color change. These results suggest that crypsis (i.e., background matching) is not the only function of physiological color change in H. regilla. Physiological color change may also be used to hydro- and (or) thermo-regulate.
Transgenic growth hormone mice exposed to lifetime constant illumination: gender-specific effects
Authors: Perreault M L , Rollo C D
Published: September 2004

Photoperiod affects most of the features altered in transgenic growth hormone (TG) mice, and laboratory rats and mice retain some sensitivity to photoperiod. We examined growth, feeding, longevity, and reproduction of TG mice and normal control mice (Mus musculus L., 1758) in 12 h light : 12 h dark (LD) and 24 h light (LL) photoperiods. Sexual dichotomy in growth and hepatic gene expression are considered to require gender-specific patterns of growth hormone secretion that are absent in TG mice. Regardless, in the LD photoperiod mature TG females were 82.8% (46.8 g) of the mass of TG males (56.5 g, p < 0.05), whereas control mice showed no size dichotomy (≈33 g). Mature masses of TG males and of control mice of either gender were unaffected by the LL photoperiod. TG females, however, reached a mature mass 92% (50.9 g) of that of mature TG males in the LL photoperiod, attenuating the sexual size dichotomy expressed in the LD photoperiod. Growth of females was slower than that of males, even in the control group. TG females in the LL photoperiod expressed faster growth, higher reproduction, and greater mean longevity than TG females in the LD photoperiod. Differences in age-related feeding associated with gender and photoperiod reflected differential growth rates. Females grew more slowly and ate more than males of similar age because they were smaller (i.e., had lower growth efficiencies). The LL photoperiod improved the energy balance of TG females. Possible mechanisms mediating such gender-specific effects are explored.
Conspecifics influence call design in the Brazilian free-tailed bat,Tadarida brasiliensis
Authors: Ratcliffe John M , Hofstede Hannah M. ter , Avila-Flores Rafa , Fenton M Brock , McCracken Gary F , Biscardi Stephania , Blasko Jennifer , Gillam Erin , Orprecio Jasmine , Spanjer Genvieve
Published: September 2004

The Brazilian free-tailed bat, Tadarida brasiliensis (Saint-Hilaire, 1824), uses calls that represent a broad continuum of design variation which is dependent upon habitat and situation, and exhibits characteristic changes in call design as bats close in on airborne targets. Here we demonstrate the influence of conspecifics on call design. We found that the peak frequency used in calls varies more as the number of bats flying in the same space increases (measured from single bats and pairs of bats). We investigated this phenomenon through comparing call-parameter differences found between two bats recorded flying together (actual pairs) with call-parameter differences between two bats each recorded flying alone at different locations that were randomly assigned to one another (virtual pairs). We found that actual pairs of bats used calls which differed in peak frequency more so than did virtual pairs. This result is particularly striking given that these frequency differences were greater between bats in the same space than between bats in two different habitats. We argue that these differences indicate that this species is practicing jamming avoidance, air traffic control, or both.
RETRIEVING IMAGES BY COMPARING HOMOGENEOUS COLOR AND TEXTURE OBJECTS IN THE IMAGE
Authors: YOO HUN-WOO , JANG DONG-SIK , SEO KWANG-KYU , LEE MYUNG-EUI
Published: September 2004

An object-based image retrieval method is addressed in this paper. For that purpose, a new image segmentation algorithm and image comparing method between segmented objects are proposed. For image segmentation, color and textural features are extracted from each pixel in the image and these features are used as inputs into VQ (Vector Quantization) clustering method, which yields homogeneous objects in terms of color and texture. In this procedure, colors are quantized into a few dominant colors for simple representation and efficient retrieval. In the retrieval case, two comparing schemes are proposed. Comparisons between one query object and multi-objects of a database image and comparisons between multi-query objects and multi-objects of a database image are proposed. For fast retrieval, dominant object colors are key-indexed into the database.
SECURE IMAGE HIDING SCHEME BASED UPON VECTOR QUANTIZATION
Authors: HU YU-CHEN , LIN MIN-HUI
Published: September 2004

In this paper, a novel gray-level image-hiding scheme is proposed. The goal of this scheme is to hide multiple important gray-level images into another meaningful gray-level image. The secret images to be protected are first compressed using the vector quantization scheme. Then, the DES cryptosystem is conducted on the VQ indices and related parameters to generate the encrypted message. Finally, the encrypted message is embedded into the rightmost two bits of each pixel in the cover image.

According to the experimental results, average image qualities of 44.320 dB and 30.885 dB are achieved for the embedded images and the retrieved secret images, respectively. In other words, multiple secret images can be effectively hidden into one host image of the same size. In addition, the proposed scheme strengthens the protection of the secret images by conducting the DES cryptosystem on the related parameters and the VQ indices of the compressed secret images. Therefore, the proposed scheme provides a secure approach to embed multiple important images into another meaningful image of the same size.
INTER-FRAME INTERPOLATION BY SNAKE MODEL AND GREEDY ALGORITHM
Authors: SHIH FRANK Y. , ZHANG KAI
Published: September 2004

In this paper, we present a novel method to solve the inter-frame interpolation problem in image morphing. We use our improved snake model that is associated with the gravitational force field to locate control points in the object contours. Afterwards, we apply the greedy algorithm in free-form deformations to achieve optimal warps among feature point pairs in starting and ending frames. The new method uses an energy-minimization function under the influence of inter-frames. The energy serves to impose frame-wise and curve-wise constraints among the interpolated frames.
AN EFFICIENT APPROACH FOR FACE DETECTION AND FACIAL FEATURE LOCATION USING PRUNE-AND-SEARCH TECHNIQUE
Authors: CHANG CHIN-CHEN , YU YUAN-HUI
Published: September 2004

This paper proposes an efficient approach for human face detection and exact facial features location in a head-and-shoulder image. This method searches for the eye pair candidate as a base line by using the characteristic of the high intensity contrast between the iris and the sclera. To discover other facial features, the algorithm uses geometric knowledge of the human face based on the obtained eye pair candidate. The human face is finally verified with these unclosed facial features. Due to the merits of applying the Prune-and-Search and simple filtering techniques, we have shown that the proposed method indeed achieves very promising performance of face detection and facial feature location.
PROJECT CellNet: EVOLVING AN AUTONOMOUS PATTERN RECOGNIZER
Authors: KHARMA N. , KOWALIW T. , CLEMENT E. , JENSEN C. , YOUSSEF A. , YAO J.
Published: September 2004

We describe the desire for a black box approach to pattern classification: a generic Autonomous Pattern Recognizer, which is capable of self-adapting to specific alphabets without human intervention. The CellNet software system is introduced, an evolutionary system that optimizes a set of pattern-recognizing agents relative to a provided set of features and a given pattern database. CellNet utilizes a new genetic operator designed to facilitate a canalization of development: Merger. CellNet utilizes our own set of arbitrarily chosen features, and is applied to the CEDAR Database of handwritten Latin characters, as well as to a database of handwritten Indian digits provided by CENPARMI. CellNet's cooperative co-evolutionary approach shows significant improvement over a more standard Genetic Algorithm, both in terms of efficiency and in nearly eliminating over-fitting (to the training set). Additionally, the binary classifiers autonomously evolved by CellNet return validation accuracies approaching 98% for both Latin and Indian digits, with no global changes to the system between the two trials.
PARALLEL SPLICING ON IMAGES
Authors: CHANDRA P. HELEN , SUBRAMANIAN K. G. , THOMAS D. G.
Published: September 2004

In this paper, splicing on images of rectangular arrays is introduced as a simple and effective extension of the operation of splicing on strings extensively studied in the context of DNA computing. A comparison of the resulting class of splicing array languages with the local two-dimensional array languages and two-dimensional right linear languages is made. Certain closure properties are obtained. Furthermore, the notion of self cross-over of strings is extended to arrays with respect to the splicing of arrays introduced here.
Diurnal Modulation of the Na+/K+-ATPase and Spontaneous Firing in the Rat Retinorecipient Clock Neurons
Authors: Wang Han-Ying , Huang Rong-Chi
Published: September 2004

The ventral “core” suprachiasmatic nucleus (vSCN) neurons are the retinorecipient neurons in the mammalian circadian clock and maintain a diurnal firing rhythm in reduced preparations. We tested the possibility that daily changes in Na+/K+-ATPase accompany diurnal variation in spontaneous electrical activity. In control, bath application of 9 μM strophanthidin increased the spontaneous firing both at day and night but to different extents. In the presence of 1 mM Ni2+to block spontaneous firing, addition of 9 μM strophanthidin, but not higher concentrations (6.5–20 mM) of external K+, induced the silenced cells to fire action potentials in a diurnal rhythm, suggesting a diurnal change in Na+/K+-ATPase activity. Consistently, voltage-clamp recordings demonstrated that the pump current blocked by 9 μM strophanthidin was approximately three times larger in daytime than nighttime and was little affected by the presence of 1 mM Ni2+. Experiments with various concentrations of strophanthidin further suggests day-night differences in maximum Na+/K+-ATPase activity, amounting to 6 pA of pump current at day and down to 3.5 pA at night, and in its half-block concentrations, changing from a daytime value of 4 μM to a nighttime value of 8 μM. Our results indicate that the vSCN neurons exhibit a diurnal rhythm in the Na+/K+-ATPase the activity of which is higher during the day when the firing rate is also higher. Mechanistically, the modulation could be accounted for in terms of changes in the maximum activity of Na+/K+-ATPase and its ability to block by strophanthidin.
Threshold Firing Frequency–Current Relationships of Neurons in Rat Somatosensory Cortex: Type 1 and Type 2 Dynamics
Authors: Tateno T. , Harsch A. , Robinson H. P. C.
Published: September 2004

Neurons and dynamical models of spike generation display two different types of threshold behavior, with steady current stimulation: type 1 [the firing frequency vs. current ( f– I) relationship is continuous at threshold) and type 2 (discontinuous f– I)]. The dynamics at threshold can have profound effects on the encoding of input as spikes, the sensitivity of spike generation to input noise, and the coherence of population firing. We have examined the f– I and frequency–conductance ( f– g) relationships of cells in layer 2/3 of slices of young (15–21 DIV) rat somatosensory cortex, focusing in detail on the nature of the threshold. Using white-noise stimulation, we also measured firing frequency and interspike interval variability as a function of noise amplitude. Regular-spiking (RS) pyramidal neurons show a type 1 threshold, consistent with their well-known ability to fire regularly at very low frequencies. In fast-spiking (FS) inhibitory interneurons, although regular firing is supported over a wide range of frequencies, there is a clear discontinuity in their f– I relationship at threshold (type 2), which has not previously been highlighted. FS neurons are unable to support maintained periodic firing below a critical frequency fc, in the range of 10 to 30 Hz. Very close to threshold, FS cells switch irregularly between bursts of periodic firing and subthreshold oscillations. These characteristics mean that the dynamics of RS neurons are well suited to encoding inputs into low-frequency firing rates, whereas the dynamics of FS neurons are suited to maintaining and quickly synchronizing to gamma and higher-frequency input.