两种甲状腺功能亢进症动物模型的对比研究

目的：复制两种甲状腺功能亢进症动物模型,对比研究它们成型性及可持续性的异同,为研究治疗甲亢的药物提供良好的评价载体。方法优甲乐模型：大鼠灌胃给予优甲乐50μg/100 g鼠重共21 d,于末次给药后第1、7、14天分别于眼底取血和接取尿液,检测相关指标;小肠结肠炎耶尔森氏菌模型：大鼠尾静脉注射小肠结肠炎耶尔森氏菌,于第0、5、10、15、20天共注射5次,并于末次注射后第5、15、25天大鼠眼底取血和接取尿液,检测相关指标。结果优甲乐模型：造模后T3、T4、FT3、FT4显著升高,但造模型后1周即恢复正常,尿液代谢的PCA图中显示模型组整体代谢网络偏离空白组,2周后恢复正常;小肠结肠炎耶尔森氏菌模型：造模后第15天和25天时T3和T4升高,第25天时TSH显著升高,尿液代谢的PCA图中模型组偏离空白组,而第15天和25天时未回到空白组位置。结论优甲乐甲亢模型成型性好但恢复迅速,作为药效评价时适合预防给药;而小肠结肠炎耶尔森氏菌甲亢模型成型性好并且持续性较好,作为药效评价时可采取治疗给药方式。     

A seasonal census of phenolics, fibre and alkaloids in foliage of forest trees in Costa Rica: some factors influencing their distribution and relation to host selection by Sphingidae and Saturniidae

The foliage of 80 species common in the Santa Rosa National Park, Costa Rica, has been analysed for content of total phenolics, condensed tannins, acid detergent fibre and water. Wherever possible analyses were performed at three stages in the life cycle of the leaf: young but fully expanded (coinciding with the beginning of the rainy season); middle-aged (two months later); and old (six months later). A comparison of the three age classes showed no significant change in the levels of phenolics or fibre as leaves aged but water content decreased significantly. A comparison of deciduous and evergreen species in the sample showed that the latter group had leaves with a significantly higher fibre content at all three sampling times, most particularly at the beginning of the rainy season, but other measures were not significantly different. Alkaloids were much more common in the foliage of deciduous species and it was observed that their distribution differed significantly from that of total phenolics and condensed tannins. It is suggested that the interaction that occurs between many tannins and alkaloids would be liable to reduce the defence capability of both classes of compounds if they occurred together.
High levels of defoliation occur in the early rainy season (third to tenth weeks) due to larvae of moths of the Sphingidae and Saturniidae. A comparison of investigated tree species that host larvae of these two taxa shows a striking dichotomy. Species that are selected by Sphingidae tend to be relatively deficient in levels of phenolics but are more likely to contain alkaloids, and probably other small toxic molecules. Saturniidae, on the other hand, appear to prefer host-species rich in phenolics but poor in alkaloids.     

Biochemical systematics and ecology of the toddalioideae in the central part of the West African forest zone

The distribution, ecology and secondary metabolism of five species of Rutaceae (subfamily Toddalioideae), Araliopsis soyauxii, Diphasia angolensis, Oricia suaveolens, Teclea verdoorniana, and Vepris heterophylla, occurring within the central part of the West African Forest Zone is reviewed. It is demonstrated that the five species exhibit niche separation in such a way that no two species with similar complements of secondary metabolites appear to be in direct competition. It is suggested, in support of Janzen's hypothesis, that this situation may have evolved to alleviate pest pressure. The chemical variation between Ghanaian and Nigerian populations of O. suaveolens is discussed in the light of observations on their ecology. Possible phylogenetic relationships between these species are discussed.     

A method for subclassifying the interdigital patterns: a comparative study of the palmar configurations

A method for subtyping the interdigital patterns is introduced, which is based upon the direction of the main line terminations as well as the presence of accessory triradii. The palmar patterns of several population samples from our files representing the Caucasians, Negroes, Miconesians and New Guinean groups are evaluted in terms of the introduced calssification and the results demonstrate a number of differences between the major racial groups. In additin, the thenar/I and hypothenar patterns are subtyped according to the classifications of Cummins and Midlo. These data also indicate the inadequacy of the general open/arch, vestige, loop, whorl identification of the plamar patterns. It is hoped that more data will be studied along these lines for establishment of more accurate frequencies among the various racial groups.     

Taste evaluation of potato glycoalkaloids by the Aymara: A case study in human chemical ecology

A chemical ecological model can be the basis for defining testable hypotheses concerning human interactions with plants. Selection by Aymara subsistence cultivators against toxic glycoalkaloids in the ongoing domestication of the Bolivian potato cultigen Solanum X ajanhuiriwas used as a specific case study of human interactions with phytochemicals. In taste perception tests, Aymara subjects were able to discriminate between concentrations of pure glycoalkaloids in solution only above 20 mg/100 ml. Taste panel tests of potato clones indicated that glycoalkaloid levels are important to the Aymara in determining quality only as part of a decision-making process involving two character states: too high or acceptable. Glycoalkaloids in potatoes are regarded as toxic to humans above 20 mg/100 g fresh weight. Among the Aymara, a breakpoint in the curve for glycoalkaloid preference appears to occur between 20–38 mg/100 g. This distinction is evident in the Aymara potato taxonomy which distinguishes bitter (luq'i ch'oke) from nonbitter (ch'oke) potatoes.     

开放翼腭动脉改良制备大鼠自体血栓脑梗死模型比较

目的：利用大鼠自体血栓,在开放翼腭动脉（ pterygopalatine artery,PPA）的情况下堵塞其大脑中动脉,造成大脑中动脉远端供血区的脑梗死模型。方法开放PPA,结扎颈外动脉（ external carotid artery,ECA）,将栓子通过颈总动脉（common carotid artery,CCA）血流将栓子冲大脑中动脉（middle cerebral artery,MCA）远端,造成梗死模型,按Bederson评分对其神经功能进行评分,TTC染色确定梗死体积。结果两手术组模型比较,评分均升高,且出现白色梗死区,经统计检测分析无明显差异。结论开放PPA大鼠自体血栓制造脑梗死模型可缩短手术时间,降低死亡率。     

A comparative study on the interactions of SMAP-29 with lipid monolayers

This work investigates the discrimination of lipid monolayers by the ovine antimicrobial peptide SMAP-29 and compares it to that of the human LL-37 peptide. Fluid phospholipid monolayers were formed in a Langmuir trough and subsequently studied with the X-ray scattering techniques of X-ray reflectivity and grazing incidence X-ray diffraction. Any changes in the phospholipid structure after injection of peptide under the monolayer were considered to be due to interactions between the peptides and lipids. The data show that SMAP-29 discriminates against negatively charged phospholipids in a similar way to LL-37. However, it is even more interesting to note that despite a higher concentration of SMAP-29 near the monolayer, ensured by its greater charge as compared to LL-37, the amount of SMAP-29 needed to observe monolayer disruption was around three and a half times the number of molecules of LL-37 used to see similar changes with the same system. This result suggests that the structure, amino acid sequence or size of the peptide may well be as important as electrical charge and therefore gives many implications for the further study of antimicrobial peptides with regards to novel drug design and development.     

A seasonal study of the carbon content of planktonic naked amoebae in the Hudson Estuary and in a productive freshwater pond with comparative data for ciliates

The total carbon contents of gymnamoebae and ciliates, dwelling in the water column of the Hudson Estuary and a highly productive freshwater pond, were monitored during a 7-month period from April through October 2006. The carbon contents of the gymnamoebae and the ciliates were greater in the pond compared with the estuary, and carbon contents of gymnamoebae were greater in the spring and autumn in both locations than those of ciliates. Given the global distribution of gymnamoebae, these results suggest that greater attention should be given to the potential role of gymnamoebae in microbial food webs.     

A comparative study of the ontogenetic development of the cupules inCastanea andLithocarpus (Fagaceae)

Two contradicting theories have been proposed for the morphological nature of fagaceous cupules; the intercalary growth theory and the higher order dichasial branch theory. All the previous ontogenetic studies insist on the latter one, but the genera investigated have been rather restricted and have not covered all the cupule types. A comparative study of the ontogenetic development of cupules inCastanea crenata andLithocarpus edulis, which are representatives of fundamentally different cupule types, revealed that both the theories are incomplete. InL. edulis, the higher order dichasial branches contribute to cupule formation along the anterior portions of the lateral flowers. However, along the adaxial portion of the central flower, the cupule develops as an intercalary growth, represented by rapid increase of tangentially oblong epidermal cells. InCastanea, intercalary growth is not clearly observable, for presumably, the flowers are surrounded by a well-developed partial inflorescence mound from the beginning of development.Contributions from the Osaka Museum of Natural History No. 305.     

A comparative study on the responses of the gills of two mudskippers to hypoxia and anoxia

A comparison of branchial enzyme profiles indicates that the gills of Periophthalmodon schlosseri would have a greater capacity for energy metabolism through glycolysis than those of Boleophthalmus boddaerti. Indeed, after exposure to hypoxia, or anoxia, there were significant increases in the lactate content in the gills of P. schlosseri. In addition, exposure to hypoxia or anoxia significantly lowered the glycogen level in the gills of this mudskipper. It can be deduced from these results that the glycolytic flux was increased to compensate for the decrease in ATP production through anaerobic glycolysis. Different from P. schlosseri, although there was an increase in lactate production in the gills of B. boddaerti exposed to hypoxia, there was no significant change in the branchial glycogen content, indicating that a reversed Pasteur effect might have occurred under such conditions. In contrast, anoxia induced an accumulation of lactate and a decrease in glycogen in the gills of B. boddaerti. Although lactate production in the gills of these mudskippers during hypoxia was inhibited by iodoacetate, the decreases in branchial glycogen contents could not account for the amounts of lactate formed. The branchial fructose-2,6-bisphosphate contents of these mudskippers exposed to hypoxia or anoxia decreased significantly, leaving phosphofructokinase and glycolytic rate responsive to cellular energy requirements under such conditions. The differences in response in the gills of B. boddaerti and P. schlosseri to hypoxia were possibly related to the distribution of phosphofructokinase between the free and bound states.Abbreviations ADP adenosine diphosphate - ALD aldolase - ALT alanine transaminase - AST aspartate transaminase - ATP adenosine triphosphate - CS citrate synthase - EDTA ethylenediaminetetra-acetic acid - EGTA ethylene glycol tetra-acetic acid - F6P fructose-6-phosphate - F-1,6-P₂ fructose-1,6-bisphosphate - F-2,6-P₂ fructose-2,6-bisphosphate - FBPase fructose-1,6-bisphosphatese - GAPDH glyceraldehyde-3-phosphate dehydrogenase - GDH glutamate dehydrogenase - -GDH -glycerophosphate dehydrogenase - GPase glycogen phosphorylase - HK hexokinase - HOAD 3-hydroxyacyl-CoA dehydrogenase - IDH isocitrate dehydrogenase - IOA iodoacetic acid - LDH lactate dehydrogenase - LO lactate oxidizing activity - MDH malate dehydrogenase - 3-PG 3-phosphoglyceric acid - PEP phosphoenolpyruvate - PEPCK phosphoenolpyruvate carboxykinase - PGI phosphoglucose isomerase - PGK phosphoglycerate kinase - PFK 6-phosphofructo-1-kinase - PIPES piperazine-N, N-bis-(2-ethanesulphonic acid) - PK pyruvate kinase - PMSF phenylmethylsulphonyl fluoride - PR pyrurate reducing activity - SE standard error - SW seawater - TPI triosephosphate isomerase     

A comparative study of the structural organization of spheres derived from the adult human subventricular zone and glioblastoma biopsies

Sphere forming assays have been useful to enrich for stem like cells in a range of tumors. The robustness of this system contrasts the difficulties in defining a stem cell population based on cell surface markers. We have undertaken a study to describe the cellular and organizational composition of tumorspheres, directly comparing these to neurospheres derived from the adult human subventricular zone (SVZ). Primary cell cultures from brain tumors were found to contain variable fractions of cells positive for tumor stem cell markers (CD133 (2–93%)/SSEA1 (3–15%)/CXCR4 (1–72%)). All cultures produced tumors upon xenografting. Tumorspheres contained a heterogeneous population of cells, but were structurally organized with stem cell markers present at the core of spheres, with markers of more mature glial progenitors and astrocytes at more peripheral location. Ultrastructural studies showed that tumorspheres contained a higher fraction of electron dense cells in the core than the periphery (36% and 19%, respectively). Neurospheres also contained a heterogeneous cell population, but did not have an organization similar to tumorspheres. Although tumorspheres clearly display irregular and neoplastic cells, they establish an organized structure with an outward gradient of differentiation. We suggest that this organization is central in maintaining the tumor stem cell pool.     

A comparison of the floristics and leaf chemistry of the tree flora in two Malaysian rain forests and the influence of leaf chemistry on populations of colobine monkeys in the Old World

A comparative floristic survey of lowland tropical rain forest at Kuala Lompat, Krau Game Reserve, West Malaysia and at Sepilok Virgin Jungle Reserve, Sabah, East Malaysia, revealed significant differences in the composition of canopy species, notably in the relative paucity of Dipterocarpaceae and abundance of Leguminosae at Kuala Lompat. A further comparison with data from other sites in Malesia indicated that Kuala Lompat was rather atypical, representing an extreme example of the relatively legume rich and dipterocarp poor forests of West Malaysia. Conversely, the predominance of dipterocarps and lack of legumes at Sepilok was similar to other sites in Borneo. Young and mature leaves were collected from a representative sample of the canopy flora of the two study sites; the levels of nitrogen, fibre, total phenolics and condensed tannins, and degree of digestibility by cellulase and pepsin, were measured. Levels of fibre, nitrogen and phenolics differed significantly between the two floras; foliage from Kuala Lompat being, on the whole, richer in nitrogen but lower in phenolics and fibre. As a consequence of the lower levels of fibre, and less certainly of phenolics, the Kuala Lompat foliage was comparatively more digestible. Possible reasons for the differences in foliar biochemistry between the two sites are discussed. Differences in rainfall and in soil quality are regarded as potential evolutionary causes. A further comparison of the chemical profiles with data for other forests in India and Africa indicate that Sepilok is a site in which trees invest heavily in quantitative defences such as fibre and phenolics whereas trees at Kuala Lompat place a lower emphasis on the production of these. Finally, attention is drawn to the use of foliar chemical profiles in predicting the carrying capacity for colobine monkeys at each of the five Old World forests where data are available. It was found that the ratio of nitrogen to fibre correlated well with the biomass of colobines at the five sites.     

Quantitative determination of the protein content of citrus leaf extracts: A comparative study

Three spectrophotometric methods for the quantitative determination of proteins were compared taking as a reference the method of Kjeldahl. The abnormally high protein values obtained when these methods were applied to soluble extracts were decreased by using protective and precipitating agents. The method of M. M. Bradford (Anal. Biochem. 72, 248–254 (1976)) gave values identical to the method of Kjeldahl when ethylenediaminetetracetic acid, 2-mercaptoethanol, and polyvinylpolypyrrolidone were added to the extraction medium and the soluble proteins were precipitated with trichloroacetic acid prior to protein determination.     

A comparative study of the effect of cholesterol on bicelle model membranes using X-band and Q-band EPR spectroscopy

X-band and Q-band electron paramagnetic resonance (EPR) spectroscopic techniques were used to investigate the structure and dynamics of cholesterol containing phospholipid bicelles based upon molecular order parameters (S_mol), orientational dependent hyperfine splittings and line shape analysis of the corresponding EPR spectra. The nitroxide spin-label 3-β-doxyl-5-α-cholestane (cholestane) was incorporated into DMPC/DHPC bicelles to report the alignment of bicelles in the static magnetic field. The influence of cholesterol on aligned phospholipid bicelles in terms of ordering, the ease of alignment, phase transition temperature have been studied comparatively at X-band and Q-band. At a magnetic field of 1.25 T (Q-band), bicelles with 20 mol% cholesterol aligned at a much lower temperature (313 K), when compared to 318 K at a 0.35 T field strength for X-band, showed better hyperfine splitting values (18.29 G at X-band vs. 18.55 G at Q-band for perpendicular alignment and 8.25 G at X-band vs. 7.83 G at Q-band for the parallel alignment at 318 K) and have greater molecular order parameters (0.76 at X-band vs. 0.86 at Q-band at 318 K). Increasing cholesterol content increased the bicelle ordering, the bicelle-alignment temperature and the gel to liquid crystalline phase transition temperature. We observed that Q-band is more effective than X-band for studying aligned bicelles, because it yielded a higher ordered bicelle system for EPR spectroscopic studies.     

ER stress responses in the absence of apoptosome: A comparative study in CASP9 proficient vs deficient mouse embryonic fibroblasts

Cells respond to endoplasmic reticulum (ER) stress through the unfolded protein response (UPR), autophagy and cell death. In this study we utilized casp9^+/+ and casp9^−/− MEFs to determine the effect of inhibition of mitochondrial apoptosis pathway on ER stress-induced-cell death, UPR and autophagy. We observed prolonged activation of UPR and autophagy in casp9^−/− cells as compared with casp9^+/+ MEFs, which displayed transient activation of both pathways. Furthermore we showed that while casp9^−/− MEFs were resistant to ER stress, prolonged exposure led to the activation of a non-canonical, caspase-mediated mode of cell death.     

A comparative study of the composition of the collagens of the foot of two lamellibranch molluscs occurring in different habitats

A comparative study of the collagen of the foot ofLamellidens Sp. and that of the unmodified part of the foot inMytilus edulis shows marked differences in physical properties, amino acid composition and in the degree of stabilization. But both conform to type I collagen of vertebrates. In these respects, the latter shows agreement with the features characteristic of byssus collagen, which is highly crosslinked, involving dimers and trimers of tyrosine. It is suggested that such differences may reflect the different functions of the organs concerned, the foot ofLamellidens being a locomotary organ of the animal, while the foot ofMytilus edulis is modified for anchorage of the animal. The vertigial part though not morphologically modified shows the essential compositional characteristics of the byssus being a mere remanant of it. The work reported forms part of the thesis approved by the University of Madras for the award of the Ph.D. degree to the first author.     

A comparative light microscopic study of two types of root nodule bacteria dispersal into the bacteroid zone cells

Root nodule bacterial dispersal into the cells and formation of bacteroid zone cells of root nodules have been observed in several species of Leguminosae. Two different types of bacterial dispersal were recognized comparable to those briefly mentioned by a few authors. Cell division type: From the very beginning of nodule development there exist two different kinds of cell in the meristematic region. In bacteria-containing cells the bacteria are distributed into two new cells with host cell division, the bacteria being located outside the spindle region during mitosis. In those cells not containing bacteria, amyloplasts develop in the cytoplasm. These cells also divide mitotically, increasing the numbers of amyloplast-containing cells. These two different cell populations compose the bacteroid zone. This type was seen inSophora flavescens andCytisus scoparius. Infection thread type: In the transitional zone from the nodule meristem to the bacteroid zone, some cells are penetrated by infection threads and others are not. Infected cells become bacteroid-filled cells, no mitosis taking place after penetration of the infection thread. Uninfected cells become amyloplast-containing cells, increasing their numbers by mitosis. These two cell populations compose the bacteroid zone. This type was seen inVicia sativa, V. faba, Trifolium repens andAstragalus sinicus.     

The tight junctions of rabbit choroid plexus and ciliary body epithelia. A comparative study using the double replica freeze-fracture technique

The spatial arrangement of tight junctions in choroid plexus and ciliary body rabbit epithelia has been determined by studying freeze-fracture complementary replicas. In the choroid plexus epithelium, the interruptions of the junctional P-face fibrils were measured to be 14% of their total length. In the ciliary body epithelium, where the fibrils were found to be more fragmented than in the choroid plexus, the P-face fibril interruptions accounted for 12 % of the total length of the zonulae occludentes sealing the non-pigmented cells and 30% in the focal linear tight junctions connecting the non-pigmented and pigmented cells at their apices. In both epithelia, the interruptions of the ridges are precisely complemented by particles or short bars of similar length found in the E-face furrows. Consequently, it is possible to conclude that the junctional fibrils are continuous in these two epithelia. For the zonulae occludentes, this continuity appears to be inconsistent with the ‘leaky’ properties of these epithelia shown by some physiological investigations.