吉林省农安县乡镇饮水型氟中毒改水降氟效果动态分析

目的掌握农安县饮水型氟中毒病区改水后水、尿氟含量的变化及儿童氟斑牙的流行趋势,评估饮水型氟中毒防治效果。方法于2009-2011年每年4、8月,采用离子选择电极法,对华家乡松柏村和万顺乡光辉村两个监测点水氟和8～12岁儿童尿氟含量进行测定;用Dean’s法对8～12岁儿童进行氟斑牙检查;与2008年常规监测结果比较。结果华家乡松柏村水氟含量由改水前的13.00 mg/L降至1.03 mg/L,氟斑牙患病率由98.18%降至71.82%;万顺乡光辉村水氟含量由改水前的9.08 mg/L降至1.01 mg/L,氟斑牙患病率由50.12%降至42.93%。随着改水时间的延长,水、尿氟含量呈逐年下降的趋势,尿氟含量与氟斑牙患病率之间相关系数显著性检验r=0.867,P〈0.05,二者呈显著正相关关系,有统计学意义。结论改水降氟能够有效控制饮水型氟中毒的流行。     

催化-臭氧在游泳池水质处理的应用

目的:建立一种用催化-臭氧方法氧化游泳池水中尿素,以使得游泳池水中的尿素、细菌总数、大肠菌群指标符合国家标准。方法:用不同的方法,如改性沸石过滤试验;加氯试验;臭氧氧化试验;臭氧加入催化剂(催化剂为硫酸铜或五氧化二矾)等试验观察尿素的去除效果。结果:催化-臭氧方法去除尿素效果最好,臭氧加入以硫酸铜为催化剂的催化方法尿素去除率为76.3%,臭氧加入以五氧化二矾为催化剂的催化方法尿素去除率为76.8%,高浓度氯(有效氯含量5.0 mg/L)消毒剂效果次之,去除率为46.1%。结论:理想的去除游泳池水尿素及杀灭细菌的有效方法为臭氧发生器连接游泳池本身的循环水处理系统。     

深圳市6家医院集中空调冷却水军团菌污染状况及其管理对策

目的了解深圳市福田区医院集中空调冷却水军团菌污染现况,为医院集中空调管理提供依据。方法根据《公共场所集中空调通风系统卫生规范》,采集辖区内6家医院16个大型空调冷却塔共32份冷却塔水进行军团菌检测。结果所调查的医院空调冷却塔水中军团菌检出率为50.0%,共分离出16株军团菌,均为LPl型嗜肺军团菌。结论军团菌广泛存在于医院空调冷却塔水中,对医院内的易感人群的健康造成潜在威胁,对这一潜在传染来源应采取有效防范措施。     

北京市政供水中三氯甲烷和四氯化碳含量分析及健康风险评估

目的 了解南水北调之后北京市市政水中三氯甲烷和四氯化碳的浓度水平,评估其对人体健康的潜在风险.方法 收集了 2015-2019年北京市出厂水、末梢水和二次供水中三氯甲烷和四氯化碳的监测数据,利用美国环保局(USEPA)推荐的健康风险评价四步法模型对其进行健康风险评估.结果 4 292件监测水样中,三氯甲烷平均浓度为0....     

牧区生活饮用水贾第鞭毛虫和隐孢子虫的调查

目的了解牧区生活饮用水贾第鞭毛虫和隐孢子虫的污染状况。方法于2014年6—7月,采集随机抽取的赤峰市翁牛特旗8所幼儿园和18户家庭的生活饮用水水样以及辖区内的2条河流和1个水库的环境水样,检测贾第鞭毛虫、隐孢子虫、浑浊度、色度、p H值、总大肠菌群和耐热大肠菌群。结果幼儿园水样中贾第鞭毛虫的检出率为62.5%,均未超标;隐孢子虫的检出率为62.5%,超标率为12.5%。家庭水样中贾第鞭毛虫的检出率为50%,均未超标;隐孢子虫的检出率为27.8%,均未超标。26份饮用水样中浑浊度、色度和总大肠菌群的超标率分别为23.08%,26.92%和19.23%,耐热大肠菌群无超标。3份环境水样均检出贾第鞭毛虫、隐孢子虫和总大肠菌群。水中贾第鞭毛虫、总大肠菌群均与隐孢子虫呈显著正相关(rs分别为0.682、0.495,均P0.01);水中贾第鞭毛虫、隐孢子虫均与耐热大肠菌呈显著正相关(rs分别为0.441、0.463,均P0.05)。结论本次调查牧区的生活饮用水和环境水体均存在原虫污染,可能与粪便污染有关。     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: PHYSIOLOGICAL ACTIONS OF ANGIOTENSIN II MEDIATED BY AT1 AND AT2 RECEPTORS IN THE BRAIN

• 1 Autoradiographic binding studies have shown that the AT₁ receptor is the predominant angiotensin II (AngII) receptor subtype in the central nervous system (CNS). Major sites of AT₁ receptors are the lamina terminalis, hypothalamic paraventricular nucleus, the lateral parabrachial nucleus, rostral and caudal ventrolateral medulla, nucleus of the solitary tract and the intermediolateral cell column of the thoraco-lumbar spinal cord.
• 2 While there are differences between species, AT₂ receptors are found mainly in the cerebellum, inferior olive and locus coeruleus of the rat.
• 3 Circulating AngII acts on AT₁ receptors in the subfornical organ and organum vasculosum of the lamina terminalis (OVLT) to stimulate neurons that may have a role in initiating water drinking.
• 4 Centrally administered AngII may act on AT₁ receptors in the median preoptic nucleus and elsewhere to induce drinking, sodium appetite, a sympathetic vasoconstrictor response and vasopressin secretion.
• 5 Recent evidence shows that centrally administered AT₁ antagonists inhibit dipsogenic, natriuretic, pressor and vasopressin secretory responses to intracerebroventricular infusion of hypertonic saline. This suggests that an angiotensinergic neural pathway has a role in osmoregulatory responses.
• 6 Central angiotensinergic pathways which include neural inputs to the rostral ventrolateral medulla may use AT₁ receptors and play a role in the function of sympathetic pathways maintaining arterial pressure.

     

Does Fluid Flow Across the Intestinal Mucosa Affect Quantitative Oral Drug Absorption? Is It Time for a Reevaluation?

Purpose. Hydrophilic and charged solutes have a lower membrane permeability which is due to a lower partition into the lipid membrane (low solubility in the membrane phase) and/or a slower transcellular diffusion coefficient. They are therefore anticipated to be absorbed through the paracellular route, which is a consequence of diffusion and a convective volume flow through the water-filled intercellular space. Methods. Two approaches have been used to investigate the mechanisms underlying the paracellular drug transport across the intestinal mucosa: (a) including water transport by exposing the apical side of the epithelium with a hypotonic solution, and (b) stimulated paracellular transport by widening of tight junction and increased water absorption as a consequence of the sodium-coupled transport of nutrients. Results. Among the first studies that recognized this fluid flux dependent transmucosal transport of drugs, was one published by Oschenfahrt & Winne in 1973 and the one by Kitazawa et al. in 1975. During the last two decades the importance of this paracellular route for drug delivery have been explored in vitro and in situ. Conclusions. The limits concerning molecular weight, shape, ionization and the effect of physiological stimulants, such as luminal concentrations of nutrients, osmolality and motility, are currently under investigation. However, recently published in vivo human data by ourselves and others indicate that the promising results obtained in vitro and in situ for various hydrophilic compounds might not be valid in quantitative aspects in humans, especially not for drugs with a molecular weight over 200.     

明党参根中维生素及其水煎膏中无机元素的分析

目的:考察明党参根中营养元素的种类及含量,探讨其补益功效的物质基础.方法:采用高效液相色谱法、荧光分光光度法及扫描电子微量分析法,测定明党参根中维生素的含量和水煎膏中无机元素的含量.结果:明党参根含脂溶性维生素E、K分别为259.2、64.1μg/kg,水溶性维生素C、B1、B2分别为78.5、0.6、0.7 mg/kg.明党参水煎膏中含丰富的钾和钙离子.结论:明党参富含人体必需的有益元素,作为食用中药是有其物质基础的.     

滨州市部分地面水体细菌耐药性分析

目的 为了了解滨州市内地面水体中细菌的耐药性,并探讨其与耐药质粒谱之间的关系.方法 采集滨州市内4个地面水体的水样,分别检测水样菌落形成单位(colony-forming unit,CFU)以及氨苄青霉素耐药率,用K-B法对氨苄青霉素耐药菌株分别做7种不同抗生素的药敏试验,然后提取这些菌株的质粒,用EcorI酶切质粒电泳后分析酶切质粒谱.结果 样本氨苄青霉素耐药率达11.7%～49.8%.氨苄青霉素耐药菌株对其他3种不同的抗生素分别有12.5%～25%不等的耐药性,未找到耐西拉司丁钠的菌株.耐氨苄青霉素以及一种非β内酰胺类抗生素的菌株占32.5%,耐氨苄青霉素以及两种或者以上的非β内酰胺类抗生素的菌株占20%.酶切质粒谱共找到从815 bp～12.2 kb的63种大小不等的酶切片断.结论 滨州市地面水体中细菌耐药性普遍存在,且多重耐药性明显;对细菌耐药性的监测是十分有意义而且有必要的.     

Genetic deletion of melanin‐concentrating hormone neurons impairs hippocampal short‐term synaptic plasticity and hippocampal‐dependent forms of short‐term memory

The cognitive role of melanin‐concentrating hormone (MCH) neurons, a neuronal population located in the mammalian postero‐lateral hypothalamus sending projections to all cortical areas, remains poorly understood. Mainly activated during paradoxical sleep (PS), MCH neurons have been implicated in sleep regulation. The genetic deletion of the only known MCH receptor in rodent leads to an impairment of hippocampal dependent forms of memory and to an alteration of hippocampal long‐term synaptic plasticity. By using MCH/ataxin3 mice, a genetic model characterized by a selective deletion of MCH neurons in the adult, we investigated the role of MCH neurons in hippocampal synaptic plasticity and hippocampal‐dependent forms of memory. MCH/ataxin3 mice exhibited a deficit in the early part of both long‐term potentiation and depression in the CA1 area of the hippocampus. Post‐tetanic potentiation (PTP) was diminished while synaptic depression induced by repetitive stimulation was enhanced suggesting an alteration of pre‐synaptic forms of short‐term plasticity in these mice. Behaviorally, MCH/ataxin3 mice spent more time and showed a higher level of hesitation as compared to their controls in performing a short‐term memory T‐maze task, displayed retardation in acquiring a reference memory task in a Morris water maze, and showed a habituation deficit in an open field task. Deletion of MCH neurons could thus alter spatial short‐term memory by impairing short‐term plasticity in the hippocampus. Altogether, these findings could provide a cellular mechanism by which PS may facilitate memory encoding. Via MCH neuron activation, PS could prepare the day's learning by increasing and modulating short‐term synaptic plasticity in the hippocampus. © 2015 Wiley Periodicals, Inc.