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991.
Danielle S. Stolzenberg Ke You Zhang Katharine Luskin Lynsie Ranker Jennifer Bress Michael Numan 《Hormones and behavior》2010,57(1):96-328
A body of evidence supports the idea that the mesolimbic dopamine (DA) system modulates the natural increase in responsiveness female rats show toward offspring (biological or foster) at birth. In the absence of the full hormonal changes associated with pregnancy and birth, female rats do not show immediate responsiveness toward foster offspring. Activation of the mesolimbic DA system can produce an immediate onset of maternal behavior in these females. For example, female rats that are hysterectomized and ovariectomized on day 15 of pregnancy (15HO) and presented with pups 48 hours later normally show maternal behavior after 2-3 days of pup exposure, but will show maternal behavior on day 0 of testing after microinjection of the DA D1 receptor agonist, SKF 38393, into the nucleus accumbens (NA) at the time of pup presentation. DA D1 receptor stimulation is known to activate cAMP intracellular signaling cascades via its stimulation of adenylyl cyclase (AC). However, some DA D1 receptors are also linked to phospholipase C (PLC) and are capable of activating phosphatidylinositol signaling cascades. SKF 38393 stimulates both types of D1 receptors. Here we provide evidence that the facilitatory effects of DA D1 receptor stimulation in the NA on maternal behavior are mediated by AC-linked DA D1 receptors. By examining the effects of intra-NA application of SKF 83822, a drug which selectively binds DA D1-AC receptors, or SKF 83959, a drug which selectively activates D1-PLC-linked receptors, we find that only SKF 83822 facilitates maternal behavior onset. 相似文献
992.
Qingjun You Feng Wang Liang Duan Xiaodong Du Mingdi Xiao Zhenya Shen 《Cell biochemistry and biophysics》2010,57(1):35-43
Objective of this article is to construct and characterize a three-layered small-caliber, artificial vascular stent. The outer
layer of the stent consisted of small intestine submucosa (SIS), the middle layer was the polydioxanone (PDS) vascular stents,
and the inner layer. The SIS and PDS were attached with 8-0 PDS thread. Crosslinking with a 10% collagen/chondroitin sulfate
solution and 0.020% glutaraldehyde secured the structure. The stent was implanted into the muscles on both sides of the canines’
spine at 2, 4, 12, and 24 weeks. A MTT assay using L-929 cells measured the cytotoxicity of the implant. Histological and
microscopy analyses were employed to examine the degradation characteristics of the PDS stent. Biomechanical properties of
the stent were tested and compared to those of normal physiological blood vessels. The PDS stent burst pressure (43.5 ± 8.3)
kPa, rupture intensity (19.1 ± 1.56) N, strain ratio (42.88 ± 3.16)%, and radial compliance (5.96 ± 0.87)%/100 mmHg were similar
to that of physiological vessels. The cytotoxicity test showed that the PDS stent complied with specifications for biological
materials for medical applications, with a cell toxicity ranging from 0 to 1. After 12 weeks, SIS and collagen sponge were
completely replaced by fibrous connective tissue. Although there was some degradation of PDS, inflammatory cell infiltration
subsided. After 24 weeks, the scaffold material began to absorb the new fibers and became filled with inflammatory cells and
macrophages. This artificial vascular stent met the requirements of transplant experiments and should be further investigated
for future clinical applications. 相似文献
993.
Andrew R. Draganski Rashmi S. Tiwari Kasi V. Sundaresan Thomas J. Nack Yumin You Richard D. Ludescher 《Food biophysics》2010,5(4):337-345
The properties of amorphous solid proteins influence the texture and stability of low-moisture foods, the shelf-life of pharmaceuticals,
and the viability of seeds and spores. We have investigated the relationship between molecular mobility and oxygen permeability
in dry food protein films—bovine α-lactalbumin (α-La), bovine β-lactoblobulin (β-Lg), bovine serum albumin (BSA), soy 11S
globulin, and porcine gelatin—using phosphorescence from the triplet probe erythrosin B. Measurements of the phosphorescence
decay in the absence (nitrogen) and presence (air) of oxygen versus temperature provide estimates of the non-radiative decay
rate for matrix-induced quenching (k
TS0) and oxygen quenching (k
Q[O2]) of the triplet state. Since the oxygen quenching constant is the product of the oxygen solubility ([O2]) and a term (k
Q) proportional to the oxygen diffusion coefficient, it is a measure of the oxygen permeability through the films. For all
proteins except gelatin, Arrhenius plots of k
TS0 reveal a gradual increase of apparent activation energy across a broad temperature range starting at ∼50 °C; this suggests
that there is a steady increase in the available modes of molecular motion with increasing temperature within the protein
matrix. Arrhenius plots for k
Q[O2] were linear for all proteins with activation energies ranging from 24 to 29 kJ/mol. The magnitude of the oxygen quenching
constants varied in the different proteins; the rates were approximately 10-fold higher in α-La, β-Lg, and BSA than in 11S
glycinin and gelatin. Although the rate of oxygen permeability was not directly affected by the increased mobility of the
protein matrix, plots of k
Q[O2] versus k
TS0 were linear over nearly three orders of magnitude in the protein films, suggesting that the matrix mobility plays a specific
role in modulating oxygen permeability. This effect may reflect differences in matrix-free volume that directly influence
both mobility and oxygen solubility. 相似文献
994.
Jianxin Lu Zhiyuan Li Yi Zhu Aifen Yang Ronghua Li Jing Zheng Qin Cai Guanghua Peng Wuwei Zheng Xiaowen Tang Bobei Chen Jianfu Chen Zhisu Liao Li Yang Yongyan Li Junyan You Yu Ding Hong Yu Jindan Wang Dongmei Sun Min-Xin Guan 《Mitochondrion》2010,10(4):380-390
In this report, we investigated the frequency and spectrum of mitochondrial 12S rRNA variants in a large cohort of 1642 Han Chinese pediatric subjects with aminoglycoside-induced and nonsyndromic hearing loss. Mutational analysis of 12S rRNA gene in these subjects identified 68 (54 known and 14 novel) variants. The frequencies of known 1555A>G and 1494C>T mutations were 3.96% and 0.18%, respectively, in this cohort with nonsyndromic and aminoglycoside-induced hearing loss. Prevalence of other putative deafness-associated mutation at positions 1095 and 961 were 0.61% and 1.7% in this cohort, respectively. Furthermore, the 745A>G, 792C>T, 801A>G, 839A>G, 856A>G, 1027A>G, 1192C>T, 1192C>A, 1310C>T, 1331A>G, 1374A>G and 1452T>C variants conferred increased sensitivity to ototoxic drugs or nonsyndromic deafness as they were absent in 449 Chinese controls and localized at highly conserved nucleotides of this rRNA. However, other variants appeared to be polymorphisms. Moreover, 65 Chinese subjects carrying the 1555A>G mutation exhibited bilateral and sensorineural hearing loss. A wide range of severity, age-of-onset and audiometric configuration was observed among these subjects. In particular, the sloping and flat-shaped patterns were the common audiograms in individuals carrying the 1555A>G mutation. The phenotypic variability in subjects carrying these 12S rRNA mutations indicated the involvement of nuclear modifier genes, mitochondrial haplotypes, epigenetic and environmental factors in the phenotypic manifestation of these mutations. Therefore, our data demonstrated that mitochondrial 12S rRNA is the hot spot for mutations associated with aminoglycoside ototoxicity. 相似文献
995.
Wei qi Li Lei Shi Yuan gang You Yan hua Gong Bin Yin Jian gang Yuan Xiao zhong Peng 《BMC biology》2010,8(1):86
Background
The downstream of tyrosine kinase/docking protein (Dok) adaptor protein family has seven members, Dok1 to Dok7, that act as substrates of multiple receptor tyrosine kinase and non-receptor tyrosine kinase. The tropomyosin-related kinase (Trk) receptor family, which has three members (TrkA, TrkB and TrkC), are receptor tyrosine kinases that play pivotal roles in many stages of nervous system development, such as differentiation, migration, axon and dendrite projection and neuron patterning. Upon related neurotrophin growth factor stimulation, dimerisation and autophosphorylation of Trk receptors can occur, recruiting adaptor proteins to mediate signal transduction. 相似文献996.
997.
The transition of the mammalian cell from quiescence to proliferation is a highly variable process. Over the last four decades, two lines of apparently contradictory, phenomenological models have been proposed to account for such temporal variability. These include various forms of the transition probability (TP) model and the growth control (GC) model, which lack mechanistic details. The GC model was further proposed as an alternative explanation for the concept of the restriction point, which we recently demonstrated as being controlled by a bistable Rb-E2F switch. Here, through a combination of modeling and experiments, we show that these different lines of models in essence reflect different aspects of stochastic dynamics in cell cycle entry. In particular, we show that the variable activation of E2F can be described by stochastic activation of the bistable Rb-E2F switch, which in turn may account for the temporal variability in cell cycle entry. Moreover, we show that temporal dynamics of E2F activation can be recast into the frameworks of both the TP model and the GC model via parameter mapping. This mapping suggests that the two lines of phenomenological models can be reconciled through the stochastic dynamics of the Rb-E2F switch. It also suggests a potential utility of the TP or GC models in defining concise, quantitative phenotypes of cell physiology. This may have implications in classifying cell types or states. 相似文献
998.
Xuewen Wang Tongjian You Leon Lenchik Barbara J. Nicklas 《Obesity (Silver Spring, Md.)》2010,18(1):86-91
It is controversial whether weight loss reduces resting energy expenditure (REE) to a different magnitude in black and white women. This aim of this study was to determine whether changes in REE with weight loss were different between black and white postmenopausal women, and whether changes in body composition (including regional lean and fat mass) were associated with REE changes within each race. Black (n = 26) and white (n = 65) women (age = 58.2 ± 5.4 years, 25 < BMI < 40 kg/m2) completed a 20‐week weight‐loss intervention. Body weight, lean and fat mass (total body, limb, and trunk) via dual‐energy X‐ray absorptiometry, and REE via indirect calorimetry were measured before and after the intervention. We found that baseline REE positively correlated with body weight, lean and fat mass (total, limb, and trunk) in white women only (P < 0.05 for all). The intervention decreased absolute REE in both races similarly (1,279 ± 162 to 1,204 ± 169 kcal/day in blacks; 1,315 ± 200 to 1,209 ± 185 kcal/day in whites). REE remained decreased after adjusting for changes in total or limb lean mass in black (1,302–1,182 kcal/day, P = 0.043; 1,298–1,144 kcal/day, P = 0.006, respectively), but not in white, women. Changes in REE correlated with changes in body weight (partial r = 0.277) and fat mass (partial r = 0.295, 0.275, and 0.254 for total, limb, and trunk, respectively; P < 0.05) independent of baseline REE in white women. Therefore, with weight loss, REE decreased in proportion to the amount of fat and lean mass lost in white, but not black, women. 相似文献
999.
Chenyang Hao Lanfen Wang Xueyong Zhang Guangxia You Yushen Dong Jizeng Jia Xu Liu Xunwu Shang Sancai Liu Yongsheng Cao 《中国科学:生命科学英文版》2006,49(3):218-226
Genetic diversity of 1680 modern varieties in Chinese candidate core collections was analyzed at 78 SSR loci by fluorescence detection system. A total of 1336 alleles were detected, of which 1253 alleles could be annotated into 71 loci. For these 71 loci, the alleles ranged from 4 to 44 with an average of 17.6, and the PIC values changed from 0.19 to 0.89 with an average of 0.69. (1) In the three genomes of wheat, the average genetic richness was B>A>D, and the genetic diversity indexes were B>D>A. (2) Among the seven homoeologous groups, the average genetic richness was 2=7>3>4>6>5>1, and the genetic diversity indexes were 7>3>2>4>6>5>1. As a whole, group 7 possessed the highest genetic diversity, while groups 1 and 5 were the lowest. (3) In the 21 wheat chromosomes, 7A, 3B and 2D possessed much higher genetic diversity, while 2A, 1B, 4D, 5D and 1D were the lowest. (4) The highest average genetic diversity index existed in varieties bred in the 1950s, and then it declined continually. However, the change tendency of genetic diversity among decades was not greatly sharp. This was further illustrated by changes of the average genetic distance between varieties. In the 1950s it was the largest (0.731). Since the 1960s, it has decreased gradually (0.711, 0.706, 0.696, 0.695). The genetic base of modern varieties is becoming narrower and narrower. This should be given enough attention by breeders and policy makers. 相似文献
1000.
In the field of proteomics, the increasing difficulty to unify the data format, due to the different platforms/instrumentation and laboratory documentation systems, greatly hinders experimental data verification, exchange, and comparison. Therefore, it is essential to establish standard formats for every necessary aspect of proteomics data. One of the recently published data models is the proteomics experiment data repository [Taylor, C. F., Paton, N. W., Garwood, K. L., Kirby, P. D. et al., Nat. Biotechnol. 2003, 21, 247-254]. Compliant with this format, we developed the systematic proteomics laboratory analysis and storage hub (SPLASH) database system as an informatics infrastructure to support proteomics studies. It consists of three modules and provides proteomics researchers a common platform to store, manage, search, analyze, and exchange their data. (i) Data maintenance includes experimental data entry and update, uploading of experimental results in batch mode, and data exchange in the original PEDRo format. (ii) The data search module provides several means to search the database, to view either the protein information or the differential expression display by clicking on a gel image. (iii) The data mining module contains tools that perform biochemical pathway, statistics-associated gene ontology, and other comparative analyses for all the sample sets to interpret its biological meaning. These features make SPLASH a practical and powerful tool for the proteomics community. 相似文献