Does injection of prostaglandin F(2alpha) (PGF2alpha) cause ovulation in anestrous Western White Face ewes?

In a previous study in our laboratory, treatment of non-prolific Western White Face (WWF) ewes with PGF(2 alpha) and intravaginal sponges containing medroxyprogesterone acetate (MAP) on approximately Day 8 of a cycle (Day 0 = first ovulation of the interovulatory interval) resulted in ovulations during the subsequent 6 days when MAP sponges were in place. Two experiments were performed on WWF ewes during anestrus to allow us to independently examine if such ovulations were due to the direct effects of PGF(2 alpha) on the ovary or to the effects of a rapid decrease in serum concentrations of progesterone at PGF(2 alpha)-induced luteolysis. Experiment 1: ewes fitted with MAP sponges for 6 days (n = 12) were injected with PGF(2 alpha) (n = 6; 15 mg im), or saline (n = 6) on the day of sponge insertion. Experiment 2: ewes received progesterone-releasing subcutaneous implants (n = 6) or empty implants (n = 5) for 5 days. Six hours prior to implant removal, all ewes received a MAP sponge, which remained in place for 6 days. Ewes from both experiments underwent ovarian ultrasonography and blood sampling once daily for 6 days before and twice daily for 6 days after sponge insertion. Additional blood samples were collected every 4 h during sponge treatment. Experiment 1: 4-6 (67%) PGF(2 alpha)-treated ewes ovulated approximately 1.5 days after PGF(2 alpha) injection; these ovulations were not preceded by estrus or a preovulatory surge release of LH, and resulted in transient corpora hemorrhagica (CH). The growth phase was longer (P < 0.05) and the growth rate slower (P < 0.05) in ovulating versus non-ovulating follicles in PGF(2 alpha)-treated ewes. Experiment 2: in ewes given progesterone implants, serum progesterone concentrations reached a peak (1.7 2 ng/mL; P < 0.001) on the day of implant removal and decreased to basal concentrations (<0.17 ng/mL; P < 0.001) within 24 h of implant removal. No ovulations occurred in either the treated or the control ewes. We concluded that ovulations occurring after PGF(2 alpha) injection, in the presence of a MAP sponge, could be due to a direct effect of PGF(2 alpha) at the ovarian level, rather than a sudden decline in circulating progesterone concentrations.     

Tumor necrosis factor alpha (TNF-α) gene polymorphism in alopecia areata

Tumor necrosis factor alpha (TNF-) phenotypes of two polymorphic systems were determined in 50 patients with alopecia areata, a common inflammatory disease of the skin. The distribution of TNF- T1, T2 phenotypes differed between patients with the patchy form of disease and patients with totalis/universalis disease. There was no significant difference in the distribution of TNF- G,A phenotypes between patient groups. The results of this study provide evidence of genetic heterogeneity between the two forms of alopecia areata, and suggest that the TNF- gene or a closely linked locus within the major histocompatibility complex may play a role in the pathogenesis of the patchy form of disease.     

Urinary 8-isoprostaglandin F(2alpha) level in Behçet's disease

Although its etiology remains unknown, the increased production of reactive oxygen species in Beh?et's disease (BD) have been reported. Furthermore, it has been suggested that vascular and endothelial tissue damage seen in BD is related to elevated reactive oxygen species generated by activated neutrophils from BD patients. To investigate the formation of lipid peroxidation in BD patients in vivo, urinary level of 8-isoprostaglandin F(2alpha) was quantitated by enzyme immunoassay after solid phase extraction in different clinical forms of BD patients. There was no difference in urinary level of 8-isoprostaglandin F(2alpha) between BD patient and healthy control group. There was also no difference in urinary levels of 8-isoprostaglandin F(2alpha) in subgroup analyses of BD patients, i.e. in mucocutaneous and vascular type BD patients; active and inactive BD patients. Contrary to the findings in literature, we found no difference in urinary level of 8-isoprostaglandin F(2alpha) between patients with systemic lupus erythematosus and healthy control group. These findings show no increase in lipid peroxidation despite the augmented formation of reactive oxygen species in BD patients. It may be interesting to assess formation of urinary level of 8-isoprostaglandin F(2alpha) in BD patients who do not take any medication.     

子囊菌延长因子1 alpha基因密码子偏好性分析(英文)

文中对子囊菌代表类群的延伸因子1 alpha基因密码子的使用模式进行了研究。结果表明:该基因的密码子使用偏好性不仅与核酸碱基组成密切相关,也受到其他选择性压力的影响。统计分析揭示了子囊菌各类群该基因的密码子组成和编码特点,在同义密码子的选择模式上,酵母纲(Saccharomycetes)的成员具有较独特的偏好性。基于密码子用法分歧度的聚类分析方法较合理地反映了大部分类群的分类学地位,但在各个纲的内部,密码子偏好性的变化程度存在差异。     

肌钙蛋白C(Tropnin C)的提纯与鉴定

<正> 肌钙蛋白C(TnC)是肌钙蛋白复合体的钙结合亚基,系骨骼肌和心肌收缩系统的触发因子。研究表明TnC与钙调素(CaM)类似,具有EF手结构和四个特殊的钙结合区。TnC与Ca~(2+)、Mg~(2+)等金属离子的结合可发生构型变化及由此导致的体内一系列酶活性等生理功能的变化。提纯TnC是进行其诸方面研究的基础。     

Is tumor necrosis factor alpha a trigger for the initiation of endometrial prostaglandin F(2alpha) release at luteolysis in cattle?

To determine the physiological significance of tumor necrosis factor alpha (TNFalpha) in the regulation of luteolytic prostaglandin (PG) F(2alpha) release by the bovine endometrium, the effect of TNF-alpha on PGF(2alpha) output by the endometrial tissues in vitro was investigated and compared with the effect of oxytocin (OT). Furthermore, the presence of specific receptors for TNFalpha in the bovine endometrium during the estrous cycle was determined. Endometrial slices (20-30 mg) taken from six stages of the estrous cycle (estrus: Day 0; early I: Days 2-3; early II: Days 5-6; mid-: Days 8-12; late: Days 15-17; and follicular: Days 19-21), as determined by macroscopic examination of the ovaries and uterus, were exposed to TNFalpha (0.06-6 nM) and/or OT (100 nM). OT stimulated PGF(2alpha) output at the follicular stage and at estrus (P < 0.001), but not at the late luteal stage. On the other hand, the stimulatory effects of TNFalpha on PGF(2alpha) output were observed not only at the follicular stage but also at the late luteal stage (P < 0.001). When the endometrial tissues at late luteal stage were simultaneously exposed to TNFalpha (0.6 nM) and OT (100 nM), the stimulatory effect on PGF(2alpha) output was higher than the effect of TNFalpha or OT alone (P < 0.05). Specific binding of TNFalpha to the bovine endometrial membranes was observed throughout the estrous cycle. The concentration of TNF-alpha receptor at the early I luteal stage was less than the concentrations at other luteal stages (P < 0.01). The dissociation constant (K(d)) values of the endometrial membranes were constant during the estrous cycle. The overall results lead us to hypothesize that TNFalpha may be a trigger for the output of PGF(2alpha) by the endometrium at the initiation of luteolysis in cattle.     

Glial tumor necrosis factor alpha (TNFα) generates metaplastic inhibition of spinal learning

Injury-induced overexpression of tumor necrosis factor alpha (TNFα) in the spinal cord can induce chronic neuroinflammation and excitotoxicity that ultimately undermines functional recovery. Here we investigate how TNFα might also act to upset spinal function by modulating spinal plasticity. Using a model of instrumental learning in the injured spinal cord, we have previously shown that peripheral intermittent stimulation can produce a plastic change in spinal plasticity (metaplasticity), resulting in the prolonged inhibition of spinal learning. We hypothesized that spinal metaplasticity may be mediated by TNFα. We found that intermittent stimulation increased protein levels in the spinal cord. Using intrathecal pharmacological manipulations, we showed TNFα to be both necessary and sufficient for the long-term inhibition of a spinal instrumental learning task. These effects were found to be dependent on glial production of TNFα and involved downstream alterations in calcium-permeable AMPA receptors. These findings suggest a crucial role for glial TNFα in undermining spinal learning, and demonstrate the therapeutic potential of inhibiting TNFα activity to rescue and restore adaptive spinal plasticity to the injured spinal cord. TNFα modulation represents a novel therapeutic target for improving rehabilitation after spinal cord injury.     

Association between carbonyl sulfide uptake and (18)Δ during gas exchange in C(3) and C(4) leaves

Carbonyl sulfide (COS) and C(18)OO exchange by leaves provide potentially powerful tracers of biosphere-atmosphere CO(2) exchange, and both are assumed to depend on carbonic anhydrase (CA) activity and conductance along the diffusive pathway in leaves. We investigated these links using C(3) and C(4) plants, hypothesizing that the rates of COS and C(18)OO exchange by leaves respond in parallel to environmental and biological drivers. Using CA-deficient antisense lines of C(4) and C(3) plants, COS uptake was essentially eliminated and discrimination against C(18)OO exchange ((18)Δ) greatly reduced, demonstrating CA's key role in both processes. (18)Δ showed a positive linear correlation with leaf relative uptake (LRU; ratio of COS to CO(2) assimilation rates, A(s)/A(c), normalized to their respective ambient concentrations), which reflected the effects of stomatal conductance on both COS and C(18)OO exchange. Unexpectedly, a decoupling between A(s) and (18)Δ was observed in comparing C(4) and C(3) plants, with a large decrease in (18)Δ but no parallel reduction in A(s) in the former. This could be explained by C(4) plants having higher COS concentrations at the CA site (maintaining high A(s) with reduced CA) and a high phosphoenolpyruvate carboxylase/CA activity ratio (reducing (18)O exchange efficiency between CO(2) and water, but not A(s)). Similar A(s) but higher A(c) in C(4) versus C(3) plants resulted in lower LRU values in the former (1.16 ± 0.20 and 1.82 ± 0.18 for C(4) and C(3), respectively). LRU was, however, relatively constant in both plant types across a wide range of conditions, except low light (<191 μmol photon m(-2) s(-1)).     

人源蛋白酶体α亚基6(Proteasome subunit alpha 6)在酿酒酵母表面展示

为构建人源蛋白酶体α亚基6(α6)的酵母展示体系,研制其单克隆抗体用于抗体表位分析和研究泛素-蛋白酶体途径,建立绕过重组抗原表达及纯化制备、将展示重组抗原直接应用于抗体检测的方法.在酵母展示表达载体pICAS中引入His.tag标签,将编码α6的基因PSA6_HUMAN克隆到酵母表面展示载体pICAS-H上,用流式细胞仪检测其抗原表位活性,以表面展示α6的重组酵母细胞,结合酶联吸附免疫检测技术,建立酵母(yeast)-ELISA检测技术,应用于检测小鼠单克隆抗体及单抗效价.酵母细胞培养48h后获得抗原α6的高效表面展示,展示的α6具有良好的抗原活性和特异性,将α6的展示酵母用于yeast-ELISA的初步实验结果显示可有效检测和筛选到抗α6抗体.     

Measurement of 2J(H,C)- and 3J(H,C)-coupling constants by α/β selective HC(C)H-TOCSY

A new heteronuclear NMR pulse sequence for the measurement of ⁿJ(C,H) coupling constants, the /selective HC(C)H-TOCSY, is described. It is shown that the S³E element (Meissner et al., 1997a,b) can be used to obtain spin state selective coherence transfer in molecules, in which adjacent CH moieties are labeled with ¹³C. Application of the / selective HC(C)H-TOCSY to a 10nt RNA tetraloop 5-CGCUUUUGCG-3, in which the four uridine residues are ¹³C labeled in the sugar moiety, allowed measurement of two bond and three bond J(C,H) coupling constants, which provide additional restraints to characterize the sugar ring conformation of RNA in cases of conformational averaging.     

亚热带人工林松树~(13)C/~(12)C比率和水分利用效率

1 引言 亚热带季风阔叶林自然林被破坏后,代之以人工林,由于自然林郁密的树冠层的消失,引起环境因素明显变化,如太阳辐射的增强,气温变幅变大,同时由于风速增大,加大了蒸腾的需要量,造成空气相对湿度降低和土壤水分亏缺,特别是在干旱季节尤为显著。该林地中除被动适应这一生境的1年生草本外,尚有灌木桃金娘(Rhodomyrtus tomentosa)、三叉苦(Euodia     

Developmental sensitivity of the bovine corpus luteum to prostaglandin F2alpha (PGF2alpha) and endothelin-1 (ET-1): is ET-1 a mediator of the luteolytic actions of PGF2alpha or a tonic inhibitor of progesterone secretion?

We examined the responsiveness of large luteal cells (LLC), small luteal cells (SLC), and endothelial cells of the Day 4 and Day 10 bovine corpus luteum (CL) to prostaglandin (PG) F2alpha and endothelin (ET)-1. Using a single-cell approach, we tested the ability of each agonist to increase the cytoplasmic concentration of calcium ions ([Ca2+]i) as function of luteal development. All tested concentrations of agonists significantly (P = 0.05) increased [Ca2+]i in all cell populations isolated from Day 4 and Day 10 CL. Day 10 steroidogenic cells were more responsive than Day 4 cells to PGF2alpha and ET-1. Response amplitudes and number of responding cells were affected significantly by agonist concentration, luteal development, and cell type. Response amplitudes were greater in LLC than in SLC; responses of maximal amplitude were elicited with lower agonist concentrations in Day 10 cells than in Day 4 cells. Furthermore, on Day 10, as the concentration of PGF2alpha increased, larger percentages of SLC responded. Endothelial cells responded maximally, regardless of agonist concentration and luteal development. In experiment 2, we tested the developmental responsiveness of total dispersed and steroidogenic-enriched cells to the inhibitory actions of PGF2alpha and ET-1 on basal and LH-stimulated progesterone accumulation. The potency of PGF2alpha steroidogenic-enriched cells on Day 4 was lower than on Day 10; in contrast, the potency of ET-1 was not different. Therefore, ET-1 was a tonic inhibitor of progesterone accumulation rather than a mediator of PGF2alpha action. The lower efficacy of PGF2alpha in the early CL more likely is related to signal transduction differences associated with its receptor at these two developmental stages than to the inability of PGF2alpha to up-regulate ET-1.     

金丝猴(Rhinopithecus)甲状腺的C细胞

本文以HE和镀银显示法研究了三种金丝猴甲状腺C细胞的形态与分布。结果表明,金丝猴的C细胞为圆形或椭圆形,主要分布在甲状腺外侧叶上1/3偏内侧的深部,在下1/3外侧缘浅表面也有少量细胞分布。细胞数量少,分布范围窄,主要位于滤泡内和滤泡之间,以单个细胞分布为主,但在滤泡之间偶尔见到有2—3个细胞在一起的。其他部位未见C细胞。三种金丝猴C细胞的形态、数量和分布无明显差异。     

The 25(OH)D(3)/1alpha,25(OH)(2)D(3)-24R-hydroxylase: a catabolic or biosynthetic enzyme?

The kidney is the major source of the circulating dihydroxylated metabolites of vitamin D, 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)] and 24R,25-dihydroxyvitamin D(3) [24R,25(OH)(2)D(3)]. The enzymes which catalyze the production of these two dihydroxylated vitamin D metabolites are the 25(OH)D(3)-1alpha-hydroxylase (1alpha-hydroxylase) and -24R-hydroxylase (24R-hydroxylase), respectively. While there is no controversy regarding the fundamental importance of the 1alpha-hydroxylase in the production of the steroid hormone 1alpha,25(OH)(2)D(3), the biologic significance of the 24R-hydroxylase has been the subject of ongoing discussion. Some hold that it is strictly catabolic, leading to side chain oxidation and cleavage of 25-hydroxylated vitamin D sterols, and others hold that it plays a biosynthetic role in the production of 24R,25(OH)(2)D(3) which has biologic activities distinct from those of 1alpha,25(OH)(2)D(3). The 24R-hydroxylase has properties in common with other multicatalytic steroidogenic enzymes: (1) the enzyme carries out multiple oxidative and carbon-carbon bond cleavages; (2) it utilizes two natural substrates; (3) its regulation varies depending on the cell or tissue in which it occurs. The purpose of this paper is to review the current literature relevant to the characteristics of the 24R-hydroxylase and its regulation in the context of other multicatalytic steroid hydroxylases in order to provide a perspective regarding its possible function as both a catabolic and activating enzyme in the vitamin D endocrine system.     

Genetic polymorphims of estrogen receptor alpha −397 PvuII (T>C) and −351 XbaI (A>G) in a portuguese population: prevalence and relation with breast cancer susceptibility

Estrogen receptor alpha (ERα), that mediates the biologic effects of estrogen in estrogen-sensitive tissues like breast, is genetically polymorphic. To evaluate the association between ?397 PvuII (T>C) and ?351 XbaI (A>G) restriction fragment length polymorphisms (RFLPs) in intron 1 of ERα gene and susceptibility of breast cancer, we undertook a case–control study in BRCA1 185delAG and 5382insC/BRCA2 6174delT negative Portuguese women. The study population consisted of 107 patients with histological diagnosis of breast cancer and 121 women with no history of breast cancer. Genomic DNA was extracted from blood samples and genotyping analyses were performed by PCR–RFLP. XbaI polymorphism was associated with a significant reduced risk of breast cancer for carriers of the x allele in homozygozity (OR 0.178; 95 % CI 0.070–0.456; P < 0.001) or heterozigozity (OR 0.223; 95 % CI 0.089–0.561; P = 0.001). The PvuII polymorphism was associated with a non-significantly reduced risk. The combined analysis of PvuII and XbaI polymorphisms revealed none synergistic effect of the two genotypes, except for simultaneous carriers of pp and xx genotypes, that have a reduced risk of breast cancer (OR 0.226; 95 % CI 0.049–1.035; P = 0.044). The combination of PvuII and XbaI genotypes into haplotypes showed that carriers of two copies of the px (ppxx) haplotype had a reduced risk of breast cancer (OR 0.405; 95 % CI 0.194–0.843; P = 0.014), compared with PX (PPXX + PPXx + PpXX + PpXx) haplotypes. PvuII and XbaI polymorphisms were in linkage disequilibrium both in cases (D = 0.044, r² = 0.049, X² = 5.216, P = 0.022) and controls (D = 0.090, r² = 0.139, X² = 16.819, P < 0.001), but not in the entire sample population analyzed as a whole (D = 0.087, r² = 0.0076, X² = 1.733, P = 0.188). In conclusion, in this case–control study we found that ERα gene XbaI polymorphism may modify individual susceptibility for breast cancer in this population.     

靶点药物Cetuximab(C225)研究新进展

在许多肿瘤组织中均有表皮生长因子受体(epidermal growthfactor receptor,EGFR)的过表达,它的失调与肿瘤对化疗和放疗的耐受以及不良预后相关,为肿瘤的治疗提供了一个理想的分子靶点.Cetuximab(C225)是特异性EGFR单克隆抗体,与化疗或放疗联合应用时具有协同作用,具有毒副作用少、靶向性好等优点.Cetuximab(C225)已被批准用于对伊利替康抵抗的结直肠癌和头颈部鳞癌的治疗,对非小细胞肺癌、乳腺癌、胰腺癌等具有EGFR高表达肿瘤治疗的临床试验正在进行之中,为肿瘤治疗开辟了一个全新的领域.