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1.
Although cryopreservation has been developed and optimized over the past decades, it causes various stresses, including cold shock, osmotic stress, and ice crystal formation, thereby reducing fertility. During cryopreservation, addition of cryoprotective agent (CPA) is crucial for protecting spermatozoa from freezing damage. However, the intrinsic toxicity and osmotic stress induced by CPA cause damage to spermatozoa. To identify the effects of CPA addition during cryopreservation, we assessed the motility (%), motion kinematics, capacitation status, and viability of epididymal spermatozoa using computer-assisted sperm analysis and Hoechst 33258/chlortetracycline fluorescence staining. Moreover, the effects of CPA addition were also demonstrated at the proteome level using two-dimensional electrophoresis. Our results demonstrated that CPA addition significantly reduced sperm motility (%), curvilinear velocity, viability (%), and non-capacitated spermatozoa, whereas straightness and acrosome-reacted spermatozoa increased significantly (p < 0.05). Ten proteins were differentially expressed (two decreased and eight increased) (>3 fold, p < 0.05) after CPA, whereas NADH dehydrogenase flavoprotein 2, f-actin-capping protein subunit beta, superoxide dismutase 2, and outer dense fiber protein 2 were associated with several important signaling pathways (p < 0.05). The present study provides a mechanistic basis for specific cryostresses and potential markers of CPA-induced stress. Therefore, these might provide information about the development of safe biomaterials for cryopreservation and basic ground for sperm cryopreservation. 相似文献
2.
3.
Andrew W. Saxe Ji-Won Yoon Phillip Gorden Murray F. Brennan 《In vitro cellular & developmental biology. Plant》1982,18(10):884-890
Summary Dispersed cells from both fresh and cryopreserved human insulinoma have been maintained in cell culture. Initial yield of
viable cells was 50% for fresh and 25% for cryopreserved tissue. Viability of cells in culture was documented by increasing
numbers of cells (doubling time approximately 5 d initially and 2 d at the sixth subculture for both fresh and cryopreserved
tissue) and continued release of insulin over time (approximately 100 ng/ml per 105 cells at 10 d and 175 ng/ml per 105 cells at 30 d of culture for both fresh and cryopreserved tissue). Evidence that cells growing in culture were beta cells
was provided by: (a) recovery of intracellular and extracellular immunoreactive insulin (IRI), (b) electron microscopic morphology,
and (c) immunohistochemical staining. Cells from fresh insulinoma incubated with increasing concentrations of extracellular
glucose released increasing amounts of IRI up to approximately 15 mM glucose, which paralleled changes in plasma insulin obtained during a preoperative glucose tolerance test.
Under an Intergovernmental Personnel Act Exchange from the Department of Surgery, University of California, Davis, Sacramento
Medical Center. 相似文献
4.
Previous studies by us and others established that cell-cell adhesion is mediated by specific carbohydrate-to-carbohydrate
interaction (CCI). Those previous studies were based on various biochemical and biophysical approaches, including the use
of labeled glycosyl epitopes with fluorescent tag. However, these methods ideally require that the glycosyl epitope must be
fixed to a solid phase molecule, preferably with multivalency. The purpose of the present study is to establish a CCI process
using specific glycosyl residues conjugated to biotinylated diaminopyridine (BAP), and to observe: (i) clear occurrence of
homotypic CCI between “Os Fr.B” having 5–6 GlcNAc termini, vs. absence of such homotypic CCI between “Os Fr.1” having 2 GlcNAc termini; (ii) occurrence of heterotypic CCI between GM3
ganglioside and Os Fr.B, vs. absence of such heterotypic CCI between GM3 and Os Fr.1. Interaction between Os Fr.B-BAP conjugate and Os Fr.B-ceramide
mimetic (Os Fr.B-mCer) was demonstrated based on two experiments: (i) dose-dependent binding of Os Fr.B-BAP conjugate to polystyrene
plates coated with Os Fr.B-mCer was observed in the presence of bivalent cation, a prerequisite for all CCI processes, and
such binding was abolished by EDTA; (ii) binding between equal nanomolar Os Fr.B-BAP and Os Fr.B-mCer was inhibited by mM
concentration Os Fr.B without conjugate, in dose-dependent manner. Thus, cell adhesion processes based on homotypic CCI between
N-linked glycans having multiple GlcNAc termini, and heterotypic CCI between GM3 and such glycans, were clearly observed using
BAP conjugates of glycosyl epitopes. 相似文献
5.
急性脑梗死约占全部脑卒中的70%,病死率和致残率高,且极易复发。但目前针对急性脑梗死在时间窗内溶栓、抗凝等治疗手段不能从根本上切实有效地修复受损脑组织,且伴有出血等风险。寻找脑梗死形成发展的原因并予以治疗迫在眉睫。酸中毒是引起缺血性脑损伤的重要机制。大量实验研究表明,酸中毒能加重神经元的缺血性损伤,且其梗死面积与酸中毒的程度直接相关。但缺血产生的酸中毒如何引起神经元损伤的确切机制尚不明确。最近研究发现酸中毒能激活一种在中枢及周围神经中广泛存在的膜通道,即酸敏感离子通道,它对Ca2+通透,能引起细胞内Ca2+超载,同时能激活胞内酶引起细胞内蛋白质、脂类及核酸的降解,加重缺血后脑损伤。本文就酸敏感离子通道1a与脑梗死做一综述。 相似文献
6.
Growth hormone induces two mRNA species of the serine protease inhibitor gene family in rat liver 总被引:2,自引:0,他引:2
In order to study the molecular actions of growth hormone on gene expression, we have cloned and characterized two unique, but related, cDNA sequences from rat liver, lambda Spi-1 and lambda Spi-2. These two cDNA sequences are complementary to rat hepatic mRNA species previously designated as Spots 3 and 20 when assayed by in vitro translation and two-dimensional gel electrophoresis. By Northern blot, the two mRNAs are both 1900 bases in length and growth hormone administered to hypophysectomized rats increases the levels of both of these mRNAs. In contrast, the combined administration of thyroxine, corticosterone, and dihydrotestosterone to hypophysectomized rats did not augment these mRNAs. The simultaneous administration of all four hormones resulted in a level greater than that observed for animals treated with growth hormone alone. Analysis of genomic DNA suggests the presence of two similar, but not identical, genes. DNA sequencing of lambda Spi-1 and lambda Spi-2 revealed that they were 90% homologous at the nucleotide level and 87% homologous at the amino acid sequence level. lambda Spi-2 has 78% homology with mouse contrapsin, 60% with human alpha 1-antichymotrypsin, and 51-55% with alpha 1-antitrypsins, all members of the serine protease inhibitor gene family. The nucleotide and deduced amino acid sequences of lambda Spi-1 and lambda Spi-2 which align with the reactive centers of known members of this family differ substantially from each other and from other members of the family. The difference in the reactive center suggests that the specificity or function of these proteins may differ from other members of serine protease inhibitor gene family. 相似文献
7.
黑龙江省三江平原丹顶鹤的数量分布 总被引:2,自引:0,他引:2
在地面调查的基础上,我们使用Y-11轻型飞机对黑龙江省三江平原地区的丹顶鹤的数量分布近行了调查,调查时飞行高度80米,航速140公里/小时,续航里程共3748公里。调查结果表明,丹顶鹤在三江平原主要分布在8个地区,其中嘟噜河下游、洪河自然保护区、七星河流域和兴凯湖低地是主要繁殖地,总数量共309只。 相似文献
8.
在整理青海省蚤类标本中,发现长刺双蚤 Amphipsylla longispina Scalon, 1950一新亚种,记述如下。 长刺双蚤共和亚种 Amphipsylla longis pina gongheensis新亚种 鉴别特征 新亚种可动突前缘较直,不动突较细长,阳茎钩突端部似鸟头状; 相似文献
9.
Structural relatedness of lysis proteins from colicinogenic plasmids and icosahedral coliphages 总被引:4,自引:0,他引:4
The host-lysis-inducing functions of phi X174 protein E and MS2 protein L
were recently shown to reside on the N-terminal and C-terminal halves of
the two respective lysis proteins. In the present study it is shown that
the small lysis proteins encoded in various colicinogenic plasmids share
local sequence similarities and certain structural characteristics with the
essential peptides of their coliphage-coded counterparts. Despite their
dissimilar sizes and origins, it is suggested that the colicinogenic lysis
proteins are functionally analogous and evolutionarily related to those of
icosahedral single- stranded DNA and RNA phages.
相似文献
10.
Chemical mechanism of the adenosine cyclic 3',5'-monophosphate dependent protein kinase from pH studies 总被引:5,自引:0,他引:5
The pH dependence of kinetic parameters and inhibitor dissociation constants for the adenosine cyclic 3',5'-monophosphate dependent protein kinase reaction has been determined. Data are consistent with a mechanism in which reactants selectively bind to enzyme with the catalytic base unprotonated and an enzyme group required protonated for peptide (Leu-Arg-Arg-Ala-Ser-Leu-Gly) binding. Binding of the peptide apparently locks both of the above enzyme residues in their correct protonation state. MgATP preferentially binds fully ionized and requires an enzyme residue (probably lysine) to be protonated. The maximum velocity and V/KMgATP are pH independent. The V/K for Ser-peptide is bell-shaped with pK values of 6.2 and 8.5 estimated. The pH dependence of 1/Ki for Leu-Arg-Arg-Ala-Ala-Leu-Gly is also bell-shaped, giving pK values identical with those obtained for V/KSer-peptide, while the Ki for MgAMP-PCP increases from a constant value of 650 microM above pH 8 to a constant value of 4 mM below pH 5.5. The Ki for uncomplexed Mg2+ obtained from the Mg2+ dependence of V and V/KMgATP is apparently pH independent. 相似文献