Sexual reproduction in the cork oak (Quercus suber L). II. Crossing intra- and interspecific barriers

Intraspecific barriers promote outcrossing while interspecific mechanisms may contribute to the isolation of species; both control the exchange of genes between plants. In this paper we establish that post-pollination mechanisms promote outcross and act at different temporal and spatial levels to control seed set and quality in Quercus species. Controlled pollinations were performed to investigate intraspecific crossing barriers in Q. suber and pollen-pistil interactions following interspecific pollinations with some simpatric Quercus species. Cytological data of intraspecific crosses in Q. suber and Q. ilex have shown different kinetics on pollen tube growth after self and outcross pollination, but pollen tubes were able to reach the base of the styles in both species and seed set was successful. Although some pre-zygotic interaction is occurring at the style, the most important interaction takes place at ovary. The cross between Q. ilex and Q. suber is possible only in one direction, revealing a case of unilateral incongruity. We show that the lack of seed set observed in the cross Q. suber×Q. ilex is due to the inability of pollen tubes to penetrate the transmitting tissue after germination. With Q. suber mainly as female parent, pollinations with other simpatric Quercus species have shown different levels of constraint on pollen tube progression at stigma and style levels. Eventual hybridisation between Quercus species will depend on the compatibility of pollen-pistil interactions, on the competitive ability of pollen genotypes, and, most important, on the overlapping of geographical, phenological and ecological factors. Differences in seed set and seed allocation was evident in all crosses, and was particularly outstanding in interspecific and in self intraspecific crosses, determining the ultimate level of seed production and quality in Quercus species. Received: 4 April 2001 / Accepted: 8 May 2001     

Effect of beraprost sodium (BPS) in a new rat partial unilateral ureteral obstruction model

Unilateral ureteral obstruction (UUO) is a representative model for investigating the common mechanism of decreasing renal function in chronic renal failure. In this study, we present a new partial UUO model in adult rats and evaluated the effect of beraprost sodium (BPS: stable prostaglandin I₂ (PGI₂) analog). We could make reproductive and uniform partial UUO by ligating the left ureter together with a 0.5 mm diameter stainless steel wire with nylon thread, and withdrawing the stainless wire. One week later, the ureteral obstruction was released. After 3 weeks from the release of UUO, all animals of control group, without BPS administration, developed basophilic degeneration of tubular epithelium, tubular dilatation and interstitial fibrosis. The areas of tubular degeneration and fibrosis were significantly reduced in the BPS group, orally administered BPS 300 μg/kg twice a day from the next day of the release of obstruction, than in control group.In conclusion, we can established the adult rat partial UUO-release model and revealed that BPS can inhibit renal tubular damage and tubulointerstitial fibrosis.     

经单侧经皮椎体成形术小剂量与常规剂量骨水泥灌注治疗骨质疏松性椎体压缩骨折的疗效对比研究

摘要 目的：探讨经单侧经皮椎体成形术（PVP）小剂量与常规剂量骨水泥灌注治疗骨质疏松性椎体压缩骨折（OVCF）的疗效。方法：回顾性分析2017年3月~2019年2月期间我院收治的OVCF患者92例,均采用经单侧PVP治疗,根据骨水泥灌注剂量将患者分为A组46例和B组46例,A组给予常规剂量（2.6～3.5 mL）骨水泥灌注,B组给予小剂量（1.5～2.5 mL）骨水泥灌注。对比两组围术期指标、视觉模拟评分表（VAS）和Oswestry功能障碍指数（ODI）评分、Cobb 角和伤椎椎体前缘高度比、骨水泥渗漏情况及其他并发症发生情况。结果：两组术中出血量、手术时间对比无统计学差异（P>0.05）。对比两组术后1个月、术后6个月VAS、ODI评分无差异（P>0.05）,两组术前、术后1个月、术后6个月VAS、ODI评分呈下降趋势（P<0.05）。两组术后1个月、术后6个月Cobb角均较术前减小（P<0.05）。B组术后1个月、术后6个月伤椎椎体前缘高度比较A组更低（P<0.05）。B组渗漏总发生率较A组更低（P<0.05）。对比两组其他并发症无差异（P>0.05）。结论：经单侧PVP小剂量与常规剂量骨水泥灌注治疗OVCF,均可有效改善患者临床症状,减轻疼痛,促进运动功能恢复,但常规剂量骨水泥灌注治疗患者伤椎椎体前缘高度比改善更佳,而小剂量骨水泥灌注渗漏总发生率较低。     

脊柱双通道内镜治疗青少年腰椎间盘突出症的临床研究

摘要 目的：探讨使用单侧双通道脊柱内镜技术（unilateral biportal endoscopy,UBE）在青少年腰椎间盘突出症患者中的优势及安全性。方法：采用回顾性分析的方法,对符合纳入及排除标准的共计96例患者进行分析和比较,根据手术方式的不同,分为UBE组（52例）和单通道孔镜患者组（44例）。评价围手术期,手术前后疼痛、功能变化及影像学资料。结果：两组患者均无严重并发症。两组患者术后VAS评分及ODI评分较术前有显著改善 （P<0.05）,但从远期来看,UBE组优于PELD组。在术中透视次数、复发等指标中,UBE组显著优于PELD组。影像学指标中,UBE组在椎管面积,术后残留等指标中有显著优势（P<0.05）。结论：单侧双通道脊柱内镜技术在青年椎间盘突出症的治疗中是一种理想且安全的治疗方式。     

Inhibition of cellular autophagy in kidney tubular cells stimulated to grow by unilateral nephrectomy

Cytoplasmic growth (hypertrophy) presupposes a positive metabolic balance brought about by increased anabolic and/or decreased catabolic processes. Degradation of cytoplasmic components takes place in autophagic vacuoles (AVs) whose volume fraction may be taken as a measure of the relative rate of degradation of cytoplasmic components. Male adult Sprague-Dawley rats (n = 80) were unilaterally nephrectomized (n = 40) or sham-operated (n = 40) and were killed 3.5-57.5 h p.o. The volume density of AVs in parenchymal cells of renal cortical convoluted tubules was determined morphometrically by systematic evaluation of large test fields in the electron microscope. During compensatory renal growth, the volume densities of autophagic vacuoles were reduced at day 0 (3.5-8 h p.o.), day 1 (20.5-33.5 h p.o.) and day 2 (44.5-57.5 h p.o.) by 49% (p less than 0.01), 43% (p less than 0.05), and 19% (n.s.), respectively, when compared with sham-operated controls. No decrease, and even an increase, in the AV-volume fraction was found in liver parenchymal cells of the unilaterally nephrectomized animals. This indicates that inhibition of autophagy is not a general response after unilateral nephrectomy, but is confined to the growing kidney, where it may represent a significant factor in the increase of cytoplasmic mass.