血吸虫对吡喹酮抗药性的研究XⅧ日本血吸虫吡喹酮抗性株与敏感株混合感染子代成虫对吡喹酮的敏感性

目的　测定实验诱导产生的日本血吸虫吡喹酮抗性株与实验室保种传代的日本血吸虫吡喹酮敏感株混合感染后产生的子代成虫对吡喹酮的敏感性。方法　取实验室诱导产生的日本血吸虫吡喹酮抗性株[吡喹酮半数有效剂量（ED50值）为277.4 mg/kg]尾蚴与实验室传代保种的日本血吸虫吡喹酮敏感株（吡喹酮ED50值为99.6 mg/kg）尾蚴,分别按1∶1和2∶1混合后感染小鼠。后在实验室经小鼠⁃钉螺循环8代后,取尾蚴感染小鼠。感染35 d后将小鼠分为对照组及5个给药组。5个给药组分别按37.5、75、150、300 mg/kg和600 mg/kg剂量一次性灌胃给予吡喹酮,对照组给予2.5%聚氧乙烯蓖麻油。给药14 d后解剖鼠并以静脉灌注法收集成虫,计算减虫率及吡喹酮对虫株的ED50值。取经12轮亚治疗剂量吡喹酮诱导筛选的日本血吸虫吡喹酮抗性株,置实验室经小鼠⁃钉螺循环常规传代,取子8代日本血吸虫尾蚴感染实验鼠,测定吡喹酮对此子代成虫的ED50值。结果　日本血吸虫吡喹酮抗性株与敏感株尾蚴按1∶1混合感染小鼠后,吡喹酮对子8代成虫ED50值为135.2 mg/kg;日本血吸虫吡喹酮抗性株与敏感株尾蚴按2∶1混合感染小鼠后,吡喹酮对子8代成虫ED50值为129.2 mg/kg;日本血吸虫吡喹酮抗性株未予吡喹酮压力传代,吡喹酮对子8代后成虫ED50值为208.4 mg/kg。 结论　与实验室诱导的抗性株相比,日本血吸虫吡喹酮抗性株与敏感株尾蚴混合感染同一宿主后所获的子代成虫对吡喹酮抗性有所降低。日本血吸虫吡喹酮抗性株不经药物压力传代,其子代成虫仍可能够维持对吡喹酮的抗性。     

吡喹酮对体外生活期曼氏血吸虫的作用

本文报道吡喹酮对曼氏血吸虫的虫卵孵化、毛蚴和尾蚴的作用。将感染曼氏血吸虫的小鼠粪便内的虫卵用沉淀法进行分离,并放在有光刺激和27℃的条件下孵出毛蚴,然后将毛蚴和从感染的扁卷螺内逸出的尾蚴培育在含有吡喹酮的药液中。实验在室温条件下进行。实验用雌性 CFI/W74株小鼠,在感染后7天或8周解剖动物,计数童虫和成虫数,与对照组相比较来评价药物的疗效。     

吡喹酮体外处理日本血吸虫卵对鼠肺肉芽肿形成的影响

我们曾用吡喹酮早期治疗感染日本血吸虫的小鼠后,可以抑制虫卵肝肉芽肿的形成。为探讨其抑制机理,我们应用鼠肺肉芽肿模型进行了进一步研究。观察体外用吡喹酮处理的日本血吸虫卵,在鼠体内形成肺肉芽肿的动态变化。材料和方法一、吡喹酮处理虫卵昆明远交鼠30只,雌雄不拘,每只小鼠经腹部皮肤人工感染日本血吸虫尾蚴80～100条。56d 后取肝脏,常规分离虫卵。分离纯卵用500μg/ml 浓度吡喹酮药液按1%(w/v)配成悬液,置4℃     

左旋吡喹酮对感染小鼠肝内日本血吸虫虫卵肉芽肿的影响

吡喹酮作为一种有效的抗血吸虫药物,其有效成分主要存在于左旋同分异构体中。此药不仅能杀死血吸虫成虫,还可以抑制宿主组织内的虫卵周围炎症反应。本实验应用小剂量的左旋吡喹酮治疗感染日本血吸虫小鼠,观察其对肝脏病变的影响。一、材料与方法体重20～22g 雄性小鼠120只经腹部皮肤感染40条日本血吸虫尾蚴。感染后30d,将小鼠随机分成3组:(1)左旋吡喹酮治疗组(简称 LPQ 组),以75mg/kg 左旋吡喹酮(LPQ)悬液灌胃给药;(2)消旋吡喹酮治疗组(简称 PZQ 组),以150mg/kg 消旋吡喹酮(PZQ)悬液灌胃给药;(3)对照组,不给药。每组分别在给药后3、7、14、21、     

吡喹酮对曼氏血吸虫虫卵的作用及其控制脑型血吸虫病的可行性

吡喹酮对血吸虫成虫有很强的杀伤力,但对虫卵的作用尚未取得一致的意见。脑型血吸虫病,主要与虫卵毒素的分泌及虫卵肉芽肿的形成有关。为此,作者研究了吡喹酮不同疗程对曼氏血吸虫虫卵的影响,并探讨了吡喹酮用于脑型血吸虫病的可行性。实验用小鼠,每鼠感染曼氏血吸虫波多黎各株尾蚴200条,7周后,选择每克粪便虫卵在100个以上的阳性鼠作为观察对象。将感染度相似的动物分配在同一实验组内。实验一:共4组,每组10个鼠。1.吡喹酮60mg/kg     

吡喹酮是否具有免疫调节作用

血吸虫病是一种免疫性疾病，主要的致病机理是血吸虫卵在肝脏和肠组织的沉积，虫卵释放出可溶性抗原，引起一系列免疫反应，形成虫卵肉芽肿（Ⅳ型超敏反应），不断破坏肝脏和肠组织结构等。吡喹酮具有显著的杀血吸虫作用，但实验显示，吡喹酮不杀日本血吸虫成熟期卵及发育期卵，对虫卵的发育无明显影响。肖树华等以小鼠做实验，于感染血吸虫尾蚴后32d一次口服毗喹酮300mg／kg，于不同时间剖杀小鼠，取肝组织压片，作卵谱检查，并与未治疗感染鼠对照。结果，治后1～3d，肝组织的卵谱与对照组相似，给药后7～14d，Ⅰ期（初产卵与空泡发育期）、Ⅱ期（发育期）虫卵相继消失，而Ⅲ期（成熟期）、Ⅳ期（变性或死亡期）虫卵则增多；治后21～27d，除Ⅲ期虫卵增多外，其余各期虫卵均少。卵谱观察的结果表明，吡喹酮对日本血吸虫卵的发育无明显影响。     

血吸虫对吡喹酮抗药性的研究ⅩⅦ 日本血吸虫吡喹酮抗性株在小鼠体内的生物学特性

目的实验观察日本血吸虫吡喹酮抗性株在终宿主小鼠体内的生物学特性,探索日本血吸虫吡喹酮抗性株对终宿主的致病力及传播强度。方法分别采用日本血吸虫江苏吡喹酮敏感株和抗性株、湖南吡喹酮敏感株和抗性株尾蚴定量感染小鼠,建立小鼠-钉螺-小鼠生活史循环,观察比较各虫株的虫卵开放前期、产卵量及虫卵分布、对终宿主的易感性、虫体生长发育等生物学特性。结果日本血吸虫江苏吡喹酮敏感株和抗性株虫卵开放前期分别为36.1 d和36.8d(t=0.907,P=0.372),粪便中虫卵数分别为14.6只/100 mg和21.2只/100 mg(t=2.946,P=0.007),回收成虫数分别为20.5条/鼠和25.1条/鼠(t=2.128,P=0.042),组织中虫卵数分别为31 303只/对成虫和38 594只/对成虫(t=2.185,P=0.040)、肝脏虫卵数分别为14 810只/对成虫和19 715只/对成虫(t=2.934,P=0.007),肠组织中虫卵数分别为16 493只/对成虫和18 879只/对成虫(t=1.044,P=0.309);江苏敏感株和抗性株雌雄合抱虫体长度(t=0.328,P=0.744)、雌虫体长(t=0.386,P=0.701)及雄虫体长(t=0.332,P=0.741)差异均无统计学意义。日本血吸虫湖南吡喹酮敏感株和抗性株虫卵开放前期分别为35.5 d和35.6 d(t=0.169,P=0.867),粪便中虫卵数分别为13.3只/100 mg和18.9只/100 mg(t=3.622,P=0.001),回收成虫数分别为17.6条/鼠和25.1条/鼠(t=3.153,P=0.004),组织中虫卵数分别为30 932只/对成虫和53 903只/对成虫(t=3.865,P=0.001),肝脏虫卵数分别为12 307只/对成虫和26 363只/对成虫(t=4.388,P0.01),肠组织中虫卵数分别为18 625个/对成虫和27 541个/对成虫(t=2.679,P=0.012);湖南敏感株和抗性株雌雄合抱虫体长度(t=0.853,P=0.397)、雌虫体长(t=0.573,P=0.569)及雄虫体长(t=0.742,P=0.461)差异均无统计学意义。结论日本血吸虫吡喹酮抗性株产卵量和肝组织虫卵沉积量均明显高于敏感株,提示其对终宿主的致病性更强;抗性株感染鼠粪便中排出虫卵数明显多于敏感株,提示抗性株的传播能量高于敏感株。     

吡喹酮治疗血吸虫病肝纤维化的实验研究

目的观察吡喹酮对血吸虫病肝纤维化的治疗作用。方法将小鼠随机分为正常对照组、模型组、吡喹酮组。模型组、吡喹酮组小鼠经腹部皮肤感染日本血吸虫尾蚴诱导肝纤维化模型,吡喹酮组于感染8周后灌胃吡喹酮治疗2次。16周末测小鼠血清中ALT、AST;观察小鼠肝脏形态,HE染色观察肝纤维化病理组织变化,测定虫卵肉芽肿面积;免疫组化测定肝脏Ⅰ和Ⅲ型胶原表达。结果吡喹酮治疗可降低血吸虫病肝纤维化小鼠肝脏指数及血清ALT、AST,改善肝组织形态结构,降低肝脏Ⅰ和Ⅲ型胶原表达及虫卵肉芽肿面积。结论吡喹酮对血吸虫病肝纤维化有明显治疗作用。     

血吸虫对吡喹酮抗药性的研究Ⅵ吡喹酮对曼氏血吸虫吡喹酮抗性株和敏感株虫卵肉芽肿形成的影响

目的 体内比较吡喹酮对曼氏血吸虫吡喹酮抗性株与敏感株肝脏虫卵肉芽肿形成的影响。方法 用抗性株与敏感株尾蚴感染小鼠，在感染第58、59、60天每日以200mg／kg微粒化吡喹酮悬液灌胃治疗小鼠，治后35d剖杀小鼠取肝脏做石蜡切片，进行HE染色，显微镜下作病理学观察；以图像分析仪定量测定虫卵肉芽肿的面积。结果 敏感株未治疗组虫卵肉芽肿由大量炎性浸润细胞及少量间质成纤维细胞组成；治疗组则由少量炎性浸润细胞和大量间质成纤维细胞组成；未治疗组肉芽肿的面积明显大于治疗组，两者间差异具有非常显著性。但抗性株治疗组和未治疗组虫卵肉芽肿均由大量炎性浸润细胞和少量间质成纤维细胞组成，两组虫卵肉芽肿的面积间差异无显著性。结论鼠体内吡喹酮的治疗对曼氏血吸虫吡喹酮敏感株和抗性株肝脏虫卵肉芽肿的形成影响作用具有显著差异；在肝组织中，敏感株虫卵对吡喹酮的敏感性高于抗性株。     

日本血吸虫低感染度动物粪便排卵观察北大核心CSCD

目的观察低数量日本血吸虫尾蚴感染实验动物后在其体内存活和粪便排卵状况,为了解低水平流行态势下血吸虫低感染度动物传播能力奠定基础。方法取新鲜逸出的尾蚴2、4、6、8条,分别感染小鼠和家兔,饲养至感染后42d收集小鼠和家兔粪便,连续收集3d,利用浓集法镜检计数每克小鼠粪便虫卵数量(EPG),尼龙袋集卵孵化法观察家兔粪便毛蚴孵化率,以判定粪便中血吸虫卵排出情况。解剖全部实验小鼠与家兔,灌注法收集成虫,计算小鼠和家兔的感染率、体内合抱成虫检获率及虫负荷水平;同时观察小鼠和家兔肝脏表面虫卵结节,并收集家兔血清进行血吸虫抗体检测。结果小鼠感染尾蚴数量为2条时,其感染率、体内合抱成虫检获率、肝脏虫卵结节率和粪便排卵率分别为66.67%、58.33%、58.33%和58.33%,随感染尾蚴数量的增加四者趋于100%,但差异均无统计学意义(χ^(2)值分别为2.455,3.135,3.135和3.135,均P>0.05);小鼠体内平均虫荷和粪便平均EPG随感染尾蚴数量增加而增加(r值分别为0.588和0.533,均P<0.01)。家兔尾蚴感染数量为2条时,其感染率、体内合抱成虫检获率、肝脏虫卵结节率、血检阳性率和粪便孵化阳性率均为40%,除粪便孵化阳性率外(χ^(2)=0.003,P>0.05),其他指标均随感染尾蚴数量的增加趋于100%,差异均有统计学意义(χ^(2)值分别为4.473,4.473,4.473和6.758,P<0.05或P<0.01);随着感染尾蚴数量的增加,家兔体内虫荷增加(r=0.421,P<0.01)。结论感染一对日本血吸虫的小鼠和家兔即可检测到粪便排卵,提示小型适宜哺乳动物宿主传病能力强,应加强监测与控制,消除潜在的传染源隐患。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

MUTATION FREQUENCY IN NURSES AND PHARMACISTS WORKING WITH CYTOTOXIC DRUGS

Individuals occupationally exposed to cytotoxic drugs may be at risk owing to the effects of these agents on DNA. As an index of DNA damage, in vivo mutations were measured in lymphocytes from 24 oncology nurses or pharmacists and 24 matched controls. Mutation frequency was significantly increased in exposed individuals and appeared to be related to duration of exposure. However, the overall magnitude of the increase was small and its biological significance remains to be determined.