Characteristics of estrogen-induced peroxidase in mouse uterine luminal fluid.

Peroxidase activity in the uterine luminal fluid of mice treated with diethylstilbestrol was measured by the guaiacol assay and also by the formation of 3H2O from [2-3H]estradiol. In the radiometric assay, the generation of 3H2O and 3H-labeled water-soluble products was dependent on H2O2 (25 to 100 microM), with higher concentrations being inhibitory. Tyrosine or 2,4-dichlorophenol strongly enhanced the reaction catalyzed either by the luminal fluid peroxidase or the enzyme in the CaCl2 extract of the uterus, but decreased the formation of 3H2O from [2-3H]estradiol by lactoperoxidase in the presence of H2O2 (80 microM). NADPH, ascorbate, and cytochrome c inhibited both luminal fluid and uterine tissue peroxidase activity to the same extent, while superoxide dismutase showed a marginal activating effect. Lactoferrin, a major protein component of uterine luminal fluid, was shown not to contribute to its peroxidative activity, and such an effect by prostaglandin synthase was also ruled out. However, it was not possible to exclude eosinophil peroxidase, brought to the uterus after estrogen stimulation, as being the source of peroxidase activity in uterine luminal fluid.     

Response of the mouse uterus to nafoxidine stimulation: agonism and antagonism

Nafoxidine (NAF) acts as an estrogen agonist or antagonist depending on the animal model used. In the CD-1 mouse uterus, a three-day uterine bioassay of NAF produced a bell-shaped dose response curve with a maximal uterine wet weight increase at 200 micrograms/kg; this dose produced only a fractional increase in uterine dry weight. Combination treatment with NAF and estradiol antagonized estradiol stimulation of both wet and dry weight parameters. The time course of uterine wet weight stimulation following a single injection of NAF had an early pattern (0-10 h) similar to that of estradiol. However, at later times after stimulation, the patterns changed dramatically: the low NAF dose (200 micrograms/kg) returned to control levels by 24 h; estradiol and the high dose NAF (1.7 mg/kg) showed sustained stimulation, which peaked at 36 h with NAF compared to 24 h for estradiol. Nuclear estrogen receptor (ER) levels were measured after a single injection of 1.7 mg/kg NAF and showed a bimodal pattern similar to that seen with estradiol, with increases at 1 h and 8 h, although the overall ER levels were elevated above those seen with estradiol. Cytosolic ER levels with NAF decreased by 1 h and remained low up to 48 h. NAF treatment did stimulate uterine DNA and RNA synthesis, with a delayed time course compared to estradiol. DNA synthesis following a single 1.7 mg/kg dose of NAF was 2.5 times higher than that produced by 20 micrograms/kg estradiol. NAF treatment resulted in hypertrophy and hyperplasia in the luminal epithelium but not in the glandular epithelium. Long-term exposure to estradiol for 5 wk resulted in development of uterine cystic glandular hyperplasia and increased secretory activity; long-term exposure to NAF produced a more significant tissue hyperplasia but no secretions. These studies show that NAF stimulates some of the receptor-mediated responses attributed to an estrogen agonist in the mouse uterus; but, when co-administered with estradiol, NAF antagonizes some aspects of estrogen action.     

The effect of grazing intensity on phosphorus spiralling in autotropic streams

The effect of grazing on primary productivity and phosphorus cycling in autotrophic streams was studied using the snail Goniobasis clavaeformes. Snails were added to each of three replicate laboratory stream channels, receiving once-through flow of groundwater, in densities of 2.1, 3.0, and 4.2 g ash free dry mass (AFDM)/m². A fourth channel received no snails and served as an ungrazed control. Presence of snail grazers resulted in a large reduction in aufwuchs biomass, primary productivity, and biotic phosphorus uptake; a modest reduction in fine particulate organic matter (FPOM); and an increase in the fraction of stream particulate organic matter (POM) exported as seston. Although primary production and aufwuchs biomass continued to decline with increasing snail density, phosphorus uptake increased. This increased phosphorus uptake is attributed to abiotic sorption to inorganic surfaces exposed as a result of efficient removal of aufwuchs at high snail densities. Although snail densities were chosen to bracket the density measured in a natural stream, the experimental densities may result in considerably higher grazing pressure on aufwuchs due to the absence of alternate food sources (e.g., coarse particulate organic matter) usually found in natural streams. Presence of snail grazers increased the spiralling length of phosphorus, primarily by reducing aufwuchs biomass and consequently reducing uptake of phosphorus from the water. Presence of snails also increased downstream transport velocity of phosphorus bound to organic particles. These results follow the patterns predicted in a previous theoretical analysis for mildly phosphorus-limited streams.     

A recessive mutation causing imperforate vagina in mice

A recessive mutation (ipv) causing imperforate vagina was discovered in a line of mice selected for low lean tissue mass as a proportion of body weight. Two full sisters were found to have marked swelling of the perineum and complete closure of the vagina. Crosses of heterozygotes identified by progeny testing produced a female progeny ratio not different from the 3 normal: 1 affected (chi 2 = 0.695; p less than .3) expected on the basis of a recessive allele at a single autosomal locus. As a consequence of the imperforate vagina, the uterus and vagina were greatly distended by fluid. The uterus of affected females displayed a swollen uterine lumen and thin endometrial stroma and muscularis. Ovarian tissue of affected females was similar to that of normal mice, and affected females produced ova that were normal in appearance. The mutation causing an imperforate vagina may present a useful model for studying the basis of abnormal vaginal development in other species and increasing the understanding of normal vaginal development in the mouse.     

Immature mouse uterine tissue in organ culture: Estrogen-induced growth,morphology and biochemical parameters

Summary Although estrogens have been shown to stimulate a variety of morphologic and biochemical changes in the uterus in vivo, no clear consistent demonstration of similar responses in vitro have been made; thus, a defined organ culture system using the immature mouse uterus was established to study the possibility of demonstrating estrogenic responses in vitro. Uterine tissue from immature outbred mice (17 to 24 days of age) were cut crosswise in 1-mm³ coins and cultured in a defined medium in the absence of serum, phenol red, or growth factor supplements. Diethylstilbestrol (DES), a synthetic estrogen, was added to the media at doses ranging from 1 to 100 ng/ml. The effect of DES on uterine cell proliferation was assessed by morphologic changes in uterine epithelial and stromal cells, increase in number of epithelial cells per unit basement membrane, increase in height of luminal epithelial cells, and [³H]thymidine incorporation. Functional changes were determined by measuring the amounts of the estrogen-inducible uterine protein, lactoferrin, that was localized in the epithelial cells and secreted into the media, and the localization of the estrogen receptor in the cultured tissues. Results indicate that under the described conditions of culture, estrogens like DES can induce morphologic and biochemical responses in the uterus that are similar to those seen in vivo. This organ culture system will aid in the investigation of various mechanisms involved in the hormonal regulation of growth and differentiation of estrogen target tissues.     

Properties of ionophore-resistant Bacteroides ruminicola enriched by cultivation in the presence of tetronasin.

Bacteroides ruminicola M384 was grown in the presence of increasing concentrations of tetronasin, an ionophore that has been developed as a feed additive for ruminants. The resulting culture, B. ruminicola M384/TnR, was then maintained in medium containing 0.1 microgram tetronasin/ml. Growth of the parent strain was eliminated by the addition of 0.1 micrograms tetronasin/ml, but the growth rate of B. ruminicola M384/TnR, which grew more slowly than the parent strain, was unaffected by adding tetronasin. Bacteroides ruminicola M384/TnR retained its resistance to tetronasin even after repeated subculture in the absence of the ionophore, suggesting that a mutation had occurred. The absence of plasmids in individual colonies of B. ruminicola M384/TnR implied that the mutation was chromosomal. Bacteroides ruminicola M384/TnR was also more resistant to the ionophores monensin and lasalocid and, to a lesser degree, to the antibiotic avoparcin than B. ruminicola M384. Binding of [14C]tetronasin to B. ruminicola M384/TnR was lower than binding of the ionophore to the parent stain, and this difference was eliminated by washing cells with EDTA. The peptidolytic activity of B. ruminicola M384 towards triphenylalanine (Mr = 460) was unaffected in B. ruminicola M384/TnR, but the rate of breakdown tetraphenylalanine (Mr = 607) was decreased. This difference was also abolished by EDTA. It was concluded that growth of B. ruminicola in the presence of tetronasin resulted in a mutation affecting the permeability of the cell envelope, such that permeation of tetronasin and molecules of a similar size (Mr = 628) was decreased.     

Characterization of murine cell lines from Diethylstilbestrol-Induced uterine endometrial Adenocarcinomas

Neonatal treatment with estrogens is associated with development of uterine adenocarcinomas in CD-1 mice. Treatment with the synthetic estrogen diethylstilbestrol (DES) on Days 1 to 5 after birth results in 90% incidence of these hormonedependent lesions in 18-mo.-old mice. Three cell lines were established from these DES-associated tumors. Each of these cell lines exhibited morphologic and ultrastructural characteristics of transformed epithelial cells, including an increased nuclear:ytoplasmic ratio, enlarged and irregular nuclei with multiple nucleoli and areas of chromatin condensation, positive staining for cytokeratin, desmosomes, and microvilli. After subcutaneous injection into nude mice, all three cell lines formed solid tumors within 4 wk. Although the primary uterine tumors and tumor transplants in nude mice had been shown to be estrogen-dependent and estrogen-receptor positive, neither the monolayer growth nor the tumorigenicity of any of the three cell lines in this study was enhanced by or dependent on estrogen. Estrogen receptor levels were low in early and intermediate passage cells. Allele-specific oligonucleotide hybridization analysis of PCR-amplified cell line DNA revealed no point mutations in the 12th, 13th, or 61st codons of the K-ras or H-ras protooncogenes. Southern analysis revealed no changes in genomic organization of the putative tumor suppressor gene DCC, but demonstrated a three-to four-fold amplification of the c-myc gene in one cell line. Expression of c-myc RNA was concomitantly increased in the same cell line. These three transformed cell lines represent the end point in the process of hormone-associated tumorigenesis and as such should prove useful in investigating the molecular changes and the mechanisms involved in hormonal carcinogenesis.     

人体动脉血气波浪式变化特点的实验证据—同时间动、静脉血波浪式变化幅度的不同*

目的: 人动脉血来源是右心系统并在肺脏进行气体交换的静脉血,右心系统的静脉血是否存在波浪式信号目前尚没有证据支持,本研究旨在对比同时间动、静脉血中信号的连续变化特点。方法: 选择心功能正常,需要连续监测动脉血流动力学变化的患者6 例,4男2女,年龄（59.00±16.64） 岁,体质量（71.67±10.37）kg,左心射血分数（LVEF）（61.33±2.16)%。患者签署知情同意书后,选择心功能正常需要监测动、静脉血流动力学变化的患者6 例,连续同时桡动脉、颈内静脉逐搏取血,测定PaO₂。选取2个典型呼吸周期,用于分析同时段动、静脉血气的波浪式变化。分别比较患者血氧分压最高和最低值,以验证同时段动、静脉血气是否都存在周期性波浪式信号变化。此外,将患者动脉、静脉血气周期性波浪式信号的变化幅度进行统计学t 检验分析,比较有无差异。结果: 共6例患者,抽取动、静脉血液充满肝素化细长塑化管需要15~16次心跳,即取血需要15~16次心跳,全部覆盖超过2个呼吸周期。所有患者动脉血气中PaO₂均呈现明显的波浪式变化（P<0.05）,幅度是（9.96±5.18）mmHg,是均值的（8.09±2.43）%。患者静脉血气中PaO₂波动幅度并不明显,为（1.63±0.41）mmHg,是均值的（3.91±1.22）%,与动脉血气组相比有明显统计学差异（P<0.05）。结论: 采用同时连续逐搏动、静脉取血血气分析法证实,患者自主呼吸时动脉血气有明显的周期性波浪式变化信号,而静脉血气几乎没有周期性波浪式变化信号（很弱）,说明动脉血气波浪式信号主要是由于肺通气过程中吸气和呼气期产生肺泡中氧分压规律性上升和下降,通过离开肺毛细血管与肺泡氧气压力平衡的动脉化血液,经过左心室搏血进入动脉血管系统所致。     

新生儿首次呼吸前后脐带动静脉血液氧和二氧化碳变化探索呼吸调控机制的初步报告II—同一个新生儿同一时间的脐带动静脉血液氧和二氧化碳分压差值个体化分析*

目的: 为探讨新生儿自主呼吸产生机制,前文已对新生儿出生后自主呼吸开始前脐带动静脉氧气和二氧化碳差值进行了人群组间分析;而本部分则对相关信息进行个体化分析。方法: 在产前经所有胎儿父母签署知情同意书,新生儿出生后还没有呼吸之前在脐带动脉和脐带静脉分别连续逐搏取血,仅有3例同时采集到Pua和Puv血液样本进行血气分析测定,计算分析脐带静脉和脐带动脉的异同和动态变化。结果: 虽然准备了数十产妇,但仅有3例同时采集到Pua和Puv血液样本,同一时间的PuvO₂显著高于PuaO₂（P均<0.01）,平均相差（24.17±7.09） mmHg;而PuvCO₂显著低于PuaCO₂（P均<0.01）,平均相差（-7.67±3.70） mmHg。在同一时间的Puv-uaO₂显著高于Puv-uaCO₂（P<0.05）。结论: 新生儿出生后自主呼吸前,全部氧气供应由脐带静脉运输,只要胎盘开始剥离则新生儿的PuaO₂随时间（心跳次数）逐渐降低,当PuaO₂达到触发呼吸阈值（最低值）诱发第一次吸气开始其自主呼吸。     

Alteration of surfactant protein A expression in renal cell carcinoma

Surfactant protein-A (SP-A) belongs to a family of collagen-containing C-type lectins called collectins. SP-A is expressed by renal tubule epithelial cells. We investigated the distribution of SP-A in renal cell carcinomas (RCC) using immunohistochemical techniques and western blotting. We used 35 formalin fixed, paraffin embedded (FFPE) RCC tissue samples. We compared results with clinico-pathological parameters of RCC including age, sex, Fuhrman grade, tumor volume, tumor node metastasis (TNM) and clinical stage. SP-A was localized in the glomerulus and renal tubule epithelium in nontumor tissue and strong SP-A immunoreactivity was observed in tumor tissue. SP-A was expressed in the RCC tumor cells (64%) and nontumor cells (34%) in males and RCC tumor cells (90%) and nontumor cells (30%) in females. There was a significant correlation between SP-A immunoreactivity in tumor cells and gender, age, tumor diameter, Fuhrman grade and tumor diameter. Western blot analysis supported the immunohistochemical findings. We present evidence for involvement of SP-A in RCC and suggest that increased SP-A expression in RCC is associated with favorable prognosis.