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1.
Mexican Arnica Anti–Inflammatory Action: Plant Age Is Correlated with the Concentration of Anti–inflammatory Sesquiterpenes in the Medicinal Plant Heterotheca inuloides Cass. (Asteraceae). Mexican árnica (Heterotheca inuloides Cass.) is a widely used anti–inflammatory medicinal plant in Mexican folk medicine. Although it has been suggested that plant age, fertilization, and harvesting regime influence the concentration of secondary compounds affecting the therapeutic activity of the plant, the effect of these variables on the concentration of the Mexican árnica anti–inflammatory compounds was not known. We quantified anti–inflammatory sesquiterpenes (caryolan–1, 9β–diol, cadalen–15–oic acid, 7–hydroxycadalene, 4–hydroxy–2–isopropyl–4, 7–dimethyl–1[4H] naftalinone, 7–hydroxy–4αH–3, 4–dihydrocadalene, β–caryophyllene, and β–caryophyllene epoxide) in Mexican árnica plants subjected to fertilization and successive harvests of flowering stems, conditions that mimic the cultivation and harvesting for árnica in México. Fertilization and successive harvesting and their interaction had no significant effect on the concentration of anti–inflammatory compounds. However, the concentrations of these compounds were 60% higher in flowering stems from 15–month–old plants than in those from 4– or 8–month–old plants and was independent of the number of harvests and fertilization regime applied.  相似文献   

2.
The structures of ZnO graphene–like nanosheets (ZnOGLNS), i.e., ZnO aromatic–like (AL–ZnONS), naphthalene–like (NLL–ZnONS), pyrene–like (PRL–ZnONS), coronene–like (CNL–ZnONS) and circumcoronene–like (CCL–ZnONS) and their oxygen adsorptions were obtained using the B3LYP/LanL2DZ method. Adsorption energies of O2 on AL–ZnONS, NLL–ZnONS, PRL–ZnONS, CNL–ZnONS and CCL–ZnONS are reported. The bond strengths of the most inner Zn–O bonds of ZnOGLNSs are in order: CCL–ZnONS > CNL–ZnONS > PRL–ZnONS. It was found that chemisorptions of O2 occur on the hydride atoms of zinc–hydride in the ZnOGLNSs. Physisorptions of O2 only occurring over the plane of ZnOGLNS were found. All the ZnOGLNSs are oxygen sensitive materials and would be developed to be oxygen sensor based on electrical conductivity.  相似文献   

3.
During development, Bone Morphogenetic Proteins (BMPs) can induce apoptosis, cell growth or differentiation. These different effects are mediated by dimers of two types of BMP–receptors (BMPRs). To identify the responding cells during tooth development and search for possible tissue–or stage–specificities in the receptors involved, the distribution patterns of BMPR–IA, –IB and –II were investigated in the mouse molar, from bud to bell stage. At the bud stage, BMP–2 was suggested to be involved in the formation of an epithelial signaling center, the primary enamel knot (PEK), while BMP–4 would mediate the condensation of the mesenchyme. Immunostaining showed the presence of BMPR–IA and –II in the epithelium instead of BMPR–IB and –II in the mesenchyme. At the cap stage, BMPR–IB was detected in the epithelium but not BMPR–II, suggesting the existence of another type II receptor to form a functional dimer. At the late cap stage in the epithelium, BMP–4, BMPR–IA and –II were restricted to the internal part of the PEK and the stalk: two apoptotic areas. The three proteins were detected in the mesenchyme, showing a strong staining where cusps were about to form. At the late bell stage, BMP–2 or –4 may induce cell differentiation. BMPR–IB and –II were detected in odontoblasts instead of BMPR–IA and –II in ameloblasts. These results provide the first evidence of multiple type I and type II BMP–receptors, expressed in the dental epithelium and mesenchyme at different stages of development, to signal different cellular activities in a time– and tissue–specific way.  相似文献   

4.
The traditional cranioscopic traits possess undoubted taxonomic value in interpreting interpopulational relationships. However, there is a lack of studies on the correlations between particular traits. In order to fill this gap, the following set of 4 traits was analysed by use of the multiple stachastic correlations method of Wanke: 1. prominence of maxilla, 2. lower margin of nasal aperture, 3. depth of canine fossa and 4. depth of maxillary incisure. These traits were examined by use of the photographic scales of Michalski within the series of 104 crania from a local population of Wislica, Poland, dated to the Early Medieval Period. The significant associations appeared in the combinations 1–2, 1–3, 3–4, 1–2–3, 1–2–4, 1–3–4, 2–3–4 and 1–2–3–4. After removal of all the possible interactions, still significant associations remained in 1–2–4, 2–3–4, and 1–3–4. Moreover, the places of significant surpluses appeared in the extreme places, i.e. those characterising the Europoid and Mongoloid crania.  相似文献   

5.
In-vitro incubation of human cerebrospinal fluid (CSF) obtained from patients ranging from 22–78 years with 10 μM of dynorphin A1–13 (Dyn A1–13) resulted in several cleavage products. Dyn A1–12 and A2–13 were identified as the major CSF metabolites by matrix-assisted laser desorption mass spectrometry (LD-MS). Further metabolites were Dyn A1–6, A2–12 and A4–12. LD-MS further suggested the formation of Dyn A1–8, A1–7, A1–10, A7–10, A3–12, A7–12, A3–13, A7–13 and A8–13. The metabolic half-life of Dyn A1–13 at 37°C was approximately 2.5 h (range 1.75–8.5 h), compared to less than one minute in plasma. The half-life of Dyn A1–13 decreased markedly with age or age-associated processes (n=20, r2=0.498). Noncompartmental kinetic analysis in the absence or presence of enzyme inhibitors (leucinethiol 10 μM, captopril 100 μM and GEMSA 20 μM) suggested that Dyn A1–13 is mainly metabolized by carboxypeptidase to A1–12 (51%) and by aminopeptidases to A2–13 (35%). The generation of A1–6 (13%) was only detected under enzyme inhibition. The extent of conversion into the main metabolites did not follow an age-associated trend, thus over-all enzyme levels but no specific enzymatic systems are elevated with age.  相似文献   

6.
7.
Monolene helenensis sp. nov. is described on the basis of seven specimens collected from the eastern tropical Atlantic Ocean. This new bothid flounder differs from all known congeners by the following combination of characters: 108–116 dorsal and 89–92 anal fin rays, 101–111 lateral line scales, 7–10+10–15=18–25 gill rakers, 10–12+37–38=48–50 vertebrae, body depth 2.58–2.77 in standard length, ocular side pectoral fin length 1.34–1.59, in head length and upper half of pectoral fin blackish.  相似文献   

8.
To investigate the functional role of the striatum in visuo-motor adaptation, we extend the DIRECT-model for visuo-motor reaching movements formulated by Bullock et al.(J Cogn Neurosci 5:408–435,1993) through two parallel loops, each modeling a distinct contribution of the cortico–cerebellar–thalamo–cortical and the cortico–striato–thalamo–cortical networks to visuo-motor adaptation. Based on evidence of Robertson and Miall(Neuroreport 10(5): 1029–1034, 1999), we implement the function of the cortico–cerebellar–thalamo–cortical loop as a module that gradually adapts to small changes in sensorimotor relationships. The cortico–striato–thalamo–cortical loop on the other hand is hypothesized to act as an adaptive search element, guessing new sensorimotor-transformations and reinforcing successful guesses while punishing unsuccessful ones. In a first step, we show that the model reproduces trajectories and error curves of healthy subjects in a two dimensional center-out reaching task with rotated screen cursor visual feedback. In a second step, we disable learning processes in the cortico–striato– thalamo–cortical loop to simulate subjects with Parkinson’s disease (PD), and show that this leads to error curves typical of subjects with PD. We conclude that the results support our hypothesis, i.e., that the role of the cortico–striato–thalamo–cortical loop in visuo-motor adaptation is that of an adaptive search element.  相似文献   

9.
Concentrations of selected metals were determined using ICP-MS in canned bonito, sardines and mackerel commercialized in Turkey. Thirty samples and two different brands were sampled for each fish species. The minimum and maximum concentrations of trace metals in canned bonito, sardines and mackerel were found as 0.000–34.742, 0.000–89.015, 0.000–28.725 mg/kg for iron, 2.388–26.620, 10.930–41.340, 4.778–29.270 mg/kg for zinc, 0.331–1.548, 0.599–2.242, 0.336–2.884 mg/kg for copper, 0.000–0.065, 0.000–0.113, 0.000–0.115 mg/kg for cadmium, 0.000–0.190, 0.000–0.158, 0.000–0.385 mg/kg for tin, 0.000–0.111, 0.000–0.223, 0.000–0.208 mg/kg for mercury and 0.000–3.046, 0.000–2.875, 0.000–3.529 mg/kg for lead, respectively. These levels are similar those found in other studies. Although the samples have concentrations within permissible limits for Zn, Cu, Sn and Hg, some of them contained Fe, Cd and Pb above these limits. Periodical controls of metals in canned fish are essential both to protect human health and to provide data on this subject.  相似文献   

10.
On the basis of a combination of previously published experimental procedures, ultraviolet–visible spectroscopy, transmission electron microscopy, and energy-dispersive X-ray measurements, a systematic investigation was carried out on the phase-transfer characteristics of different bimetallic nanoparticles (Ag–Au, Ag–Pt, Ag–Ru, Au–Pt, Au–Ru, and Pt–Ru) formed by the seed-mediated growth reactions. The different phase-transfer characteristics of the monometallic nanoparticles of Au, Ag, Pt, and Ru were used to form the basis of differentiation between various possible structures existing in the bimetallic systems (core-shell particles or a physical mixture of nanoparticles). The experimental results indicate clearly the formation of core-shell nanoparticles of Ag–Au, Ag–Pt, Ru–Ag, Pt–Au, Au–Ru, and Pt–Ru when the nanoparticles of the first metal were used as the seeds in the seed-mediated growth reactions. However, when the order of the synthesis was reversed using the nanoparticles of the second metal as the seeds, only a physical mixture of the two metal nanoparticles was obtained instead.Parts of the data on Au–Ru and Ag–Pt systems have been published in Analytica Chimica Acta (2005, 537, 279–284) and Journal of Physical Chemistry B (2005, 109, 5468–5472), respectively.  相似文献   

11.
Bovine serum albumin (BSA)-coated CdTe/ZnS quantum dots (BSA–QDs) were selected to conjugate with folic acid (FA), forming FA–BSA–QDs. This study aims to develop these small FA–BSA–QDs (less than 10 nm) for the diagnosis of cancers in which the FA receptor (FR) is overexpressed. The enhancement of cellular uptake in FR-positive human nasopharyngeal carcinoma cells (KB cells) for FA–BSA–QDs was found by means of confocal fluorescence microscopy under single-photon and two-photon excitation. The uptake enhancement for FA–BSA–QDs was further evaluated by flow-cytometric analysis in 104 KB cells, and was about 3 times higher than for BSA–QDs on average. The uptake enhancement was suppressed when KB cells had been pretreated with excess FA, reflecting that the enhancement was mediated by the association of FR at cell membranes with FA–BSA–QDs. When human embryonic kidney cells (293T) (FR-negative cells) and KB cells, respectively, were incubated with FA–BSA–QDs (1 μM) for 40 min, the FA–BSA–QD uptake by 293T cells was much weaker than that by KB cells, demonstrating that FA–BSA–QDs could undergo preferential binding on FR-positive cancer cells. These characteristics suggest that FA–BSA–QDs are potential candidates for cancer diagnosis.  相似文献   

12.
Using hydrophilicity and recognition values of amino acids, the antigenic sites of theΒ-subunits of human choriogonadotropin and luteinizing hormone were computed from their amino acid sequences. Six antigenic sites were calculated for human choriogonadotropinΒ-subunits: residues 3–8, 17–22, 59–65,100–106,110–116 and 134–139. For luteinizing hormoneΒ-chain three antigenic sites were calculated: residues 17–22,59–65, and 100–106; all these three sites of luteinizing hormoneΒ being identical to the corresponding sites in human choriogonadotropinΒ. There was no antigenic site in luteinizing hormone that was also not found in human choriogonadotropin. On the other hand, there were unique determinants in human choriogonadotropin that were not found in luteinizing hormone; these determinants were residues 3–8, 110–116 and 134–139  相似文献   

13.
Lignans have been part of both diet and herbal medicines for centuries. It is only in the last half century that phytochemists have described the structures of the lignans. Pharmacologists have only become interested in the biological activity of lignans in the last few decades. Much of the early interest focused on podophyllotoxin type lignans and their derivatives. Recent literature has recorded very many new lignans or lignan derivatives with a diverse range of biological activities. In 1955, the isolation from flax seed and the structure of the lignan derivative secoisolariciresinol diglucoside (SDG) was reported. Possible biological activity of SDG, and the mammalian lignan metabolites, enterolactone and enterodiol, was initially reported about 20 years later. During the next 30 years, there has been extensive research on the biological effects of both flax seed and rye lignans since both are metabolized into the mammalian lignans. Research on the activity of lignans on breast, colon, prostate and thyroid cancer has generally shown beneficial effects although there are some studies with either no conclusive or negative effect. Lignans have been shown to have positive effects in lowering relative risk factors for heart disease. Use of flax seed or SDG has been shown to have positive effects in both lupus and polycystic kidney disease models. Studies of both type I and II diabetes models have reported positive results when using SDG. Flax seed has also been reported to be hepatoprotective. Reproductive effects have been observed with flax seed or SDG and have been found to be dose and time related. There are many possible mechanistic explanations for the observed bioactivities including involvement in hormonal metabolism or availability, angiogenesis, anti-oxidation and gene suppression. Abbreviations: ALA – alpha linolenic acid; ApcMin – adenomatous polyposis coli multiple intestinal neoplasia; BBdp – BioBreeding diabetic prone; CCl4– carbon tetrachloride; CDC – Crop Development Centre; CHD – cardiovascular heart disease; DMBA – dimethylbenzanthracene; DNA – deoxyribonucleic acid; ER – estrogen receptor; λGT –γ-glutamyltranspeptidase; HDL – high-density lipoprotein; HMGA – hydroxymethyl glutaric acid; IDDM – insulin dependent diabetes mellitus; LDL – low-density lipoprotein; MRL/lpr, Murine Lupus/lymphoproliferative; MDA – malondiadehyde; NIDDM – non-insulin dependent diabetes mellitus; ORF – oxygen free radical; PAF – platelet activating factor; PKD – Polycystic kidney disease; PEPCK – phosphoenolpyruvate carboxykinase; PMNL – polymorphonuclear monocytes; STZ – streptozoticin; TC – total cholesterol; TG – triglycerides; SDG – secoisolariciresinol diglucoside; ZDF – Zucker diabetic fatty. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

14.
Embryonic, larval and juvenile development of the catadromous roughskin sculpin,Trachidermus fasciatus, were described using eggs spawned in an aquarium. The eggs, measuring 1.98–2.21 mm in diameter, were light reddish-yellow and had many oil globules, 0.05–0.18 mm in diameter. Hatching occurred 30 days after spawning at 2.3–11.3°C. The newly-hatched larvae, measuring 6.9–7.3 mm BL, had a single oil globule, 9–10+25–26=34–36 myomeres and 6 or 7 large stellate melanophores dorsally along the gut. The yolk was almost resorbed, number of pectoral-fin rays attained 16–17, and two parietal, one nuchal and four preopercular spines were formed, 5 days after hatching, at 8.2–8.4 mm BL. The oil globule disappeared, and one supracleithral spine was formed, 11 days after hatching, at 8.9–9.5 mm BL. Notochord flexion began 15 days after hatching, at 9.7–10.3 mm BL. A posttemporal spine was formed 20 days after hatching, at 10.7–10.9 mm BL. The first dorsal fin spines (VII–VIII), second dorsal fin and anal fin rays (18–19, 16–18, respectively) appeared 23 days after hatching, at 12.0–13.7 mm BL. The pelvic fin spine and rays (I, 4) were formed and black bands on the head and sides of the body began to develop 27 days after hatching, at 13.8–15.8 mm BL. Newly-hatched larvae swam just below the surface in the aquaria. Preflexion larvae (8.9–9.5 mm BL), in which the oil globule had disappeared, swam in the middle layer, while juveniles (13.8–15.8 mm BL) began swimming on the bottom of the aquaria. Swimming behavior observed in the aquaria suggested that the fish started to change to a demersal existence at the juvenile stage.  相似文献   

15.
Thymic blood and lymphatic vessels in humans and laboratory animals have been investigated in morphological studies. However, occasionally a clear distinction between blood vessels and lymphatic vessels cannot be made from morphological characteristics of the vasculature. To visualize thymic lymphatics in normal adult BALB/c mice, we used antibodies against specific markers of lymphatic endothelial cells. Expression of vascular endothelial growth factor receptor–3 (VEGFR–3) was detected throughout the thymus, i.e., the capsule, cortex, and medulla. Most thymic lymphatics were present in capillaries of ~20 μm in caliber. The plexuses of lymphatic capillaries were occasionally detectable. Lymphatic vessels were frequently adjacent to CD31–positive blood vessels, and some lymphatic vessels were seen in the immediate vicinity of or within the perivascular spaces around postcapillary venules. The identity of VEGFR–3–positive vessels as lymphatics was further confirmed by staining with additional markers: LYVE–1, Prox–1, neuropilin–2, and secondary lymphoid tissue chemokine (SLC). The distributions of LYVE–1 were similar to those of VEGFR–3. Most lymphatic vessels were also identified by Prox–1. Neuropilin–2 was restricted to lymphatic vessels in the thymus. The most abundant expression of SLC in the thymus was in medullar epithelial cells; SLC was also expressed in lymphatic vessels and blood vessels. Thus, lymphatic endothelium in mouse thymus was characterized by positive staining with antibodies to VEGFR–3, LYVE–1, Prox–1, neuropilin–2, or SLC, but not with an antibody to CD31. Our results suggest the presence of lymphatic capillary networks throughout the thymus.  相似文献   

16.
Immunogenic properties of synthetic peptides corresponding to regions 122–133, 136–147, 154–164, and 314–328 of the heavy chain (HA1) of A/Aichi/2/68 virus hemagglutinin were studied. Peptides 122–133 and 136–147 together form a nearly complete antigenic determinant A, peptide 154–164 is a part of determinant B, and peptide 314–328 corresponds to the C-terminal HA1 fragment. In a model influenza A/Aichi/2/68 infection in CBA mice, a protective effect of conjugates of BSA with peptides 136–147 and 314–328 was shown. Immunization of animals with conjugates BSA-(136–147) and BSA-(314–328) in combination with interferon inducers (larifan and ridostin) and a plant immunomodulator (immunomax) intensified the protection of mice against the influenza infection.  相似文献   

17.
A new species of armored searobin, Paraheminodus longirostralis, is described from five specimens collected from New Caledonia at depths of 412–467 m. It is distinguishable from its three known congeners in having 34 bony plates in the upper lateral row, a forward-directed spine on each plate between the 23rd–26th and 31st–32nd plates in the upper lateral row, 6–7 + 1 + 20–21 = 27–28 gill rakers, an elongate body posterior to the anus (49.9–52.1% standard length), an elongate rostral projection (53.0–59.3% head length), short upper jaw (42.1–43.4% head length), an elongate pectoral fin (70.6–79.4% head length), and long preopercular spine (39.2–57.7% head length).  相似文献   

18.
PTEN is involved in the regulation of normal cellular functions in addition to its well–known role as a tumor suppressor. In the present study, we have shown that stable transfection of the PTEN gene into PTEN–mutated endometrial carcinoma cells leads to contact inhibition accompanied by a decreased level of phosphorylated–Akt (p–Akt) expression, an increase in p27Kip1, and a decrease in β–catenin. PTEN–induced cells with contact inhibition exhibit G0–G1 cell-cycle arrest, and the Ki–67 labeling index is reduced. These changes are canceled by transfection of a double–stranded short–interfering RNA against the PTEN gene. Normal endometrial stromal cells increase their PTEN expression when reaching confluence; this is followed by changes in the expression of Akt–related proteins in the same way as in tumor cells. These results indicate that PTEN, p–Akt, p27, and β–catenin are involved in the signal transduction of contact inhibition and suggest that PTEN may, in part, control the proliferation of endometrial carcinoma cells through the induction of contact inhibition.  相似文献   

19.
Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. From past and present nucleotide sequence analyses of the B. aphidicola genome, we have assembled a 34.7-kilobase (kb) DNA segment. This segment contains genes coding for 32 open reading frames (ORFs), which corresponded to 89.9% of the DNA. All of these ORFs could be identified with homologous regions of the Escherichia coli genome. The order of the genes with established functions was groELS–trmE–rnpA–rpmH–dnaA–dnaN–gyrB–atpCDGAHFEB–gidA–fdx–hscA– hscB–nifS–ilvDC–rep–trxA–rho. The order of genes in small DNA fragments was conserved in both B. aphidicola and E. coli. Most of these fragments were in approximately the same region of the E. coli genome. The latter organism, however, contained many additional inserted genes within and between the fragments. The results of the B. aphidicola genome analyses indicate that the endosymbiont has many properties of free-living bacteria. Received: 15 August 1997 / Accepted: 29 August 1997  相似文献   

20.
In this work, the distribution of nine metals in two types of cultivated mushroom had been investigated. For Agaricus bisporus, the biomass was separated into caps and stalks, and for Pleurotus ostreatus, the entire mushrooms were taken for analysis. Electrothermal atomic absorption spectrometry was used for total element determination in acid digests. For accuracy checking, the certified reference material (NIST 1571, citrus leaves) was analyzed. The results obtained for the two fungi species were within the ranges of concentration reported previously by other authors. Subcellular fractionation was accomplished by centrifugation of cell homogenates, which has been suspended in Tris-HCl buffer. In the first centrifugation (7300g, 4°C, 10 min), cell walls were separated (pellet I), and the second centrifugation (147,000g, 4°C, 60 min) yielded mixed membrane fraction (pellet II) and cytosol (supernatant II). Recoveries of the fractionation procedure were in the range 70–100% (with the exception of Fe). For all elements studied, the highest relative contributions were found in cytosol fractions of the fruiting bodies (63–72%, 49–76%, 44–93%, 26–87pc, 55–85%, 50–68%, 41–78%, 39–78%, 54–67% respectively for Al, Bi, Cd, Cr, Cu, Fe, Mn, Ni, and Pb. Lower contributions were found in cell walls (respectively 22–32%, 24–44%, 6.1–47%, 12–52%, 7.3–37%, 7.9–32%, 19–52%, 20–42%, and 25–38%) and only minute amounts in the mixed membrane fraction (3.0–5.8%, 0.7–7.0%, 0.7–8.3%, 1.0–22%, 7.5–14%, 16–24%, 1.1–19%, and 5.1–7.7%). The results obtained indicate that small water-soluble molecules were the primary forms of nine elements in two mushroom species studied. On the other hand, the evidence has been provided on elements binding to larger, water-insoluble molecules contained in the structures of cell wall and membranes. The relative distribution was both element and fungi dependent. Thus, in P. ostreatus, total element levels were higher than in A. bisporus, with the preference for their accumulation in cytosol. On the contrary, total element content in the latter fungi was lower; however, a clear tendency toward more efficient element incorporation to the water-insoluble structures was observed (no apparent differences between stalks and caps). These findings might contribute in a better understanding of the accumulation of metals in mushrooms.  相似文献   

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