Regulation of Na,K-pump-mediated transport by prolactin in cultured human prostate epithelial cells.

The prostate gland is unique in its ability to secrete large amounts of zinc and citrate, suggesting that it employs unusual transport mechanisms. Intracellular ionic homeostasis in prostate is likely to be mediated by the Na,K-pump, yet there have been few studies of its regulation in this tissue. Accordingly, we explored the expression of the Na,K-pump in PC3 cells, an established cell line of human prostate epithelial cells. Total RNA from confluent monolayers of PC3 cells was isolated, reverse transcribed, and the resulting complementary DNA was amplified by polymerase chain reaction using primers specific for each of the pump's constituent subunits. The amplification revealed a complex pattern of Na,K-pump expression, with detection of mRNAs encoding the alpha1-, alpha3-, alpha4-, betal-, beta2- and beta3-isoforms. We next examined the effect on pump activity of prolactin, an important mediator of cell proliferation in prostate cancer. Monolayers exposed to 10 nM prolactin for 24 hr revealed an inhibition of 40% in ouabain-sensitive 86Rb+ uptake, a sensitive measure of pump-mediated transport. These experiments suggest that the unique transport properties of prostate may depend, at least in part, on a complicated pattern of Na,K-pump expression and regulation.     

Photosynthetic induction times in shade-tolerant species with long and short-lived leaves

In the understory of a tropical rainforest, light flecks can contribute 10–80% of the total light flux. We investigated the capacity of eight shade-tolerant species to use light flecks by examining the time required for full induction of photosynthesis during an artificial light fleck. CO₂ fixation rates were measured with a portable LiCor gas-exchange system for plants growing in the field on Barro Colorado Island, Panama. In all species induction to 50% of maximum CO₂ fixation occurred quickly, from 1 to 3 min. In species with short leaf lifetimes (1 year), induction to 90% of maximum also occurred quickly, in 3–6 min. In contrast, the species with longer lived leaves (>4 years) required 11–36 min for induction to 90% of maximum. Induction times for leaves from gap and understory plants of the same species were indistinguishable. Elevated CO₂ did not eliminate the slow induction phase of long-lived leaves. This suggests that slow induction did not result from stomatal limitation. O₂ evolution, measured on excised leaf disks, induced in 3–4 min in species with short-lived leaves, and 4–8 min in species with long-lived leaves. The rapid induction of O₂ evolution indicates that the slower induction of CO₂ fixation in long-lived leaves was not caused by a delay in the induction of electron transport. Activation of rubisco may be the major factor limiting response times in species with long-lived leaves. Species from Panama with short-lived leaves had remarkably rapid induction times that are comparable to those of algae or higher plant chloroplasts. We also found that understory forest plants induced two to seven times more quickly than did potted plants.     

内蒙古魏家窝铺遗址陶器内淀粉粒反映的古人类食谱及相关问题

魏家窝铺遗址位于内蒙古赤峰市红山区文钟镇魏家窝铺村,是一处大型的红山文化中期环壕聚落遗址。在2009-2011年发掘出土的陶器中,许多平底器类标本内壁表面都发现有细腻的黑色灰烬,我们对这些灰烬和几件不含灰烬的陶器标本进行了植物残留物提取和鉴定,从六份样品中观测到了植物淀粉粒,这些淀粉粒可根据形态分为四种类型,分别代表了禾本科、植物地下储藏器官、疑似坚果的植物种类和未知种类。大量的禾本科淀粉粒在形态上与粟类(小米)淀粉粒极为相似,加之遗址中出土的大量炭化粟,我们推测,这些陶罐中的黑色灰烬为内部盛装的粟炭化分解所致,这些陶器正是红山文化中的食物储藏器。存在的其他类型淀粉粒表明,尽管魏家窝铺遗址出土的植物遗存已显示了较为确凿的农业经济,但采集经济也仍占有重要地位。     

Desiccation tolerance of five tropical seedlings in panama. Relationship to a field assessment of drought performance

Studies of the desiccation tolerance of the seedlings of five tropical trees were made on potted plants growing in a greenhouse. Pots were watered to field capacity and then dehydrated for 3 to 9 weeks to reach various visual wilting stages, from slightly wilted to dead. Saturated root hydraulic conductance was measured with a high-pressure flowmeter, and whole-stem hydraulic conductance was measured by a vacuum chamber method. Leaf punches (5.6-mm diameter) were harvested for measurement of leaf water potential by a thermocouple psychrometer method and for measurement of fresh and dry weight. In a parallel study, the same five species were studied in a field experiment in the understory of a tropical forest, where these species frequently germinate. Control seedlings were maintained in irrigated plots during a dry season, and experimental plants were grown in similar plots with rain exclusion shelters. Every 2 to 4 weeks, the seedlings were scored for wilt state and survivorship. After a 22-week drought, the dry plots were irrigated for several weeks to verify visual symptoms of death. The field trials were used to rank drought performance of species, and the greenhouse desiccation studies were used to determine the conditions of moribund plants. Our conclusion is that the desiccation tolerance of moribund plants correlated with field assessment of drought-performance for the five species (r(2) > 0.94).     

Depletion of CD4+ T cells during immunization with nonviable Listeria monocytogenes causes enhanced CD8+ T cell-mediated protection against listeriosis

Immunization of mice with nonviable Listeria monocytogenes generates an insufficient CD8(+) T cell response and consequently only limited protection against subsequent L. monocytogenes infection. We have recently demonstrated that depletion of regulatory CD4(+) T cells during immunization significantly enhances CD8(+) T cell responses. In the present study, we determined the impact of CD4(+) T cell depletion on the CD8(+) T cell response against heat-killed LISTERIA: Treatment of mice with anti-CD4 mAb during boost immunization with heat-killed Listeria significantly increased numbers of Listeria-specific CD8(+) T cells and improved protection against subsequent infection with L. monocytogenes. During challenge infection, numbers of Listeria-specific CD8(+) T cells were enhanced, and these cells expressed effector functions in terms of IFN-gamma production. In summary, we demonstrate that combining nonviable L. monocytogenes vaccination and CD4(+) T cell depletion improves generation of long-lasting and functional Listeria-specific CD8(+) memory T cells.     

Cinnamoyl glucosides of catechin and dimeric procyanidins from young leaves of Inga umbellifera (Fabaceae)

The rapidly growing, nearly achlorophyllous, young leaves of Inga umbellifera express high concentrations of mono and dimeric 3-O-gluco-cinnamoyl catechin/epicatechin, rare forms of substituted flavan-3-ols. Here we present structures for five novel compounds in this class: three monomers [catechin-3-O-beta-D-gluco(2-cinnamoyl)pyranoside, catechin-3-O-beta-D-gluco(6-cinnamoyl) pyranoside, catechin-3-O-beta-D-gluco(2,6-biscinnamoyl)pyranoside] and two dimeric procyanidins [catechin-3-O-beta-D-glucopyrano-(4alpha-->8)-catechin-3-O-beta-D-gluco(2-cinnamoyl)pyranoside and catechin-3-O-beta-D-glucopyrano-(4alpha-->8)-epicatechin-3-O-beta-D-gluco(6-cinnamoyl)pyranoside]. The young leaves of Inga umbellifera express high concentrations of 3-O-(cinnamoyl)glucosides of catechin and epicatechin.     

非小细胞肺癌的治疗方案及影响预后的重要因素

目的:回顾分析各种非小细胞肺癌(non-small cell lung cancer,NSCLC)的治疗方案及影响其治疗预后的因素,为合理制定个体化的综合治疗方案提供参考。方法:回顾分析近年来NSCLC治疗的研究报道,分析如病理分期、实验室检查结果(VEGF、WBC、Hg等)影响治疗预后的因素,建议相应的治疗对策。结果:1.Ⅰ期、Ⅱ期及部分Ⅲa期NSCLC的患者治疗措施首先以手术治疗为主,同步放化疗比单纯放、化疗及序贯放化疗更能有效改善晚期NSCLC的预后;2.个体相关因素、肿瘤相关因素和治疗相关因素影响NSCLC治疗预后。结论:同步放化疗在晚期NSCLC的治疗中有重要作用,肿瘤的病理分期、血浆VEGF浓度是影响NSCLC预后的独立因素。