淡色库蚊对3种化学杀虫剂交互抗性的实验研究

目的 目的 了解淡色库蚊对常用化学杀虫剂的交互抗性, 为合理使用化学杀虫剂提供依据。方法 方法 采用WHO生物 测定方法, 检测淡色库蚊敏感品系和抗敌敌畏、 抗残杀威、 抗氯氰菊酯3种抗性品系IV龄幼虫分别对敌敌畏、 残杀威和氯 氰菊酯3种化学杀虫剂的抗性。 结果 结果 淡色库蚊抗敌敌畏品系对敌敌畏、 残杀威和氯氰菊酯3种化学杀虫剂的抗性系 数分别为14.47、 8.96和207.27, 抗残杀威品系对上述3种杀虫剂的抗性系数分别为3.27、 6.93和8.65, 抗氯氰菊酯品系对 3种杀虫剂的抗性系数分别为2.93、 1.61和501.11。 结论 结论 长期使用一种化学杀虫剂易产生抗性, 并对其他化学杀虫剂 产生不同程度的交互抗性。使用杀虫剂时应注意选择药物品种和剂量, 以避免和延缓蚊虫抗药性的产生。     

淡色库蚊对常用杀虫剂长期选育的抗性水平及交互抗性

目的了解淡色库蚊对3种常用化学杀虫剂长期选育的抗性状况及5种杀虫剂的交互抗性,为合理有效地进行蚊虫化学防治提供依据。方法采用WHO生物测定方法,测定淡色库蚊对3种杀虫剂长期选育的抗性水平。结果经过42代选育,淡色库蚊对敌敌畏（DDVP）、残杀威和氯氰菊酯的抗性指数分别最高达12．17、11．78和534．31倍。结论经过长期选育,发现淡色库蚊对3种常用化学杀虫剂均产生不同程度的抗药性及交互抗性,提示应采取适当措施克服或延缓蚊虫抗药性的产生和发展。     

5种杀虫剂配伍对淡色库蚊毒力的测定

目的：为了延缓和克服蚊虫抗性的发性和发展。方法：采用WHO生物测试法，测定了5种杀虫剂两两配伍对3种抗性品系淡色库蚊的增效效果。结果：对抗钱杀威品系蚊虫增效效果较明显的有：残杀威十三氯杀虫酯、残杀威＋氯氰菊酯、DDVP＋三氯杀虫酯3种配伍形式；对抗DDVP品系蚊虫增效效果较明显的配伍有：DDVP十三氯杀虫酯、DDVP＋氯氰菊酯、残杀威＋三氯杀虫酯、残杀威＋氯氰菊酯4种配伍形式；对抗氯氰菊酯品系蚊虫增效效果较明显的有：氯氰菊酯＋残杀威、氯氰菊酯＋DDVP、DDVP＋三氯杀虫酯、残杀威＋三氯杀虫酯4种配伍形式。结论：当淡色库蚊产生抗药性后，应用有机磷类或氨基甲酸酯类杀虫剂与拟除虫菊酯类或有机氯类杀虫剂混用，能取得较好的杀虫效果。     

5种杀虫剂配伍对淡色库蚊毒力的测定

目的为了延缓和克服蚊虫抗性的发生和发展。方法采用 WHO生物测试法 ,测定了 5种杀虫剂两两配伍对 3种抗性品系淡色库蚊的增效效果。结果对抗残杀威品系蚊虫增效效果较明显的有 :残杀威 +三氯杀虫酯、残杀威 +氯氰菊酯、DDVP+三氯杀虫酯 3种配伍形式 ;对抗 DDVP品系蚊虫增效效果较明显的配伍有 :DDVP+三氯杀虫酯、DDVP+氯氰菊酯、残杀威 +三氯杀虫酯、残杀威 +氯氰菊酯 4种配伍形式 ;对抗氯氰菊酯品系蚊虫增效效果较明显的有 :氯氰菊酯 +残杀威、氯氰菊酯 +DDVP、DDVP+三氯杀虫酯、残杀威 +三氯杀虫酯4种配伍形式。结论当淡色库蚊产生抗药性后 ,应用有机磷类或氨基甲酸酯类杀虫剂与拟除虫菊酯类或有机氯类杀虫剂混用 ,能取得较好的杀虫效果     

微板法测定抗药性酯酶检测淡色库蚊抗药性的研究

目的 研究简捷灵敏的蚊虫抗药性早期测报技术。方法 以β-乙酸萘酯为底物，坚固蓝B盐为显色剂，用酯酶微板法测定实验室和现场单个淡色库蚊体内非特异性酯酶活力。结果 实验室5个品系淡色库蚊以抗DDVP品系非特异性酯酶活力水平最高，其次为抗残杀威品系和抗DDVP降解品系，抗氯氰菊酯品系较低，与敏感品系相近；3个现场淡色库蚊种群对DDVP抗性为4．15～9．36倍，对残杀威抗性为1．02～3．8l倍，其非特异性酯酶活力水平均较高。结论 酯酶微板法测定非特异性酯酶能够检测蚊虫对有机磷和氨基甲酸酯类杀虫剂的抗性水平，能够早期预测抗性发展趋势，便于制订抗药性克服对策。     

淡色库蚊敌敌畏抗性和氯氰菊酯抗性品系对常用化学杀虫剂的交互抗性

目的了解淡色库蚊对6种常用化学杀虫剂的交互抗性,为科学使用化学杀虫剂提供依据。方法采用WHO生物测定方法检测淡色库蚊敏感品系、敌敌畏抗性品系和氯氰菊酯抗性品系Ⅳ龄幼虫对三氯杀虫酯、敌敌畏、马拉硫磷、残杀威、氯氰菊酯和溴氰菊酯等6种常用化学杀虫剂的敏感性,每次测定设置7个浓度,每个浓度设2组,每组25个幼虫,24h后统计幼虫死亡数据,计算致死中浓度(median lethal concentration,LC_(50))、回归方程和抗性指数。结果淡色库蚊敌敌畏抗性品系对三氯杀虫酯、敌敌畏、马拉硫磷、残杀威、氯氰菊酯和溴氰菊醑的LC_(50)分别为1.9623mg/L、1.1607mg/L、0.7359mmg/L、0.9002mg/L、0.0220mg/L和0.000 1 mg/L,回归方程分别为Y=3.5287+5.0254X、Y=4.6962+4.693 7X、Y=5.5051+3.853 6X、Y=5.2350+5.1476X、Y=10.4995+3.3184X和Y=13.2977+2.1683X,抗性指数分别为9.25、12.17、9.14、7.93、183.47和0.71;淡色库蚊氯氰菊酯抗性品系对三氯杀虫酯、敌敌畏、马拉硫磷、残杀威、氯氰菊酯和溴氰菊酯的LC_(50)分别为5.572 8mg/L、0.2464mg/L、0.0892mg/L、0.202 7mg/L、0.064 1 mg/L和0.008 5mg/L,回归方程分别为Y=2.7728+2.9852X、Y=7.2054+3.6260X、Y=9.475 1+4.2635X、Y=6.8106+2.6125X、Y=8.7404+3.1352X和Y=14.6951+4.6853X,抗性指数分别为26.27、2.58、1.10、1.79、534.31和40.60。结论长期使用一种化学杀虫剂会导致蚊虫产生抗药性,并对其他化学杀虫剂产生不同的交互抗性,应采取合理选择杀虫剂品种和确定使用剂量等有效措施以避免蚊虫抗药性的产生。     

微板法测定淡色库蚊体内非特异性酯酶检测其对杀虫剂抗性的研究

目的　探讨简捷灵敏的蚊虫抗药性早期测报技术。方法　以 β -乙酸萘酯为底物 ,坚固蓝B盐为显色剂 ,用微板法测定实验室和现场单个淡色库蚊体内非特异性酯酶活力。结果　实验室五个品系淡色库蚊以抗DDVP品系非特异性酯酶活力水平最高 ,其次为抗残杀威品系和抗DDVP降解品系 ,抗氯氰菊酯品系较低 ,与敏感品系相近 ;三个现场淡色库蚊种群对DDVP抗性为 4 15～ 9 36倍 ,对残杀威抗性为 1 0 2～ 3 81倍 ,其非特异性酯酶活力水平均较高。结论　微板法测定非特异性酯酶能够检测蚊虫对有机磷和氨基甲酸酯类杀虫剂的抗性水平。方法简便快速 ,结果客观准确 ,可重复性强 ;可测出抗性频率 ,早期发现抗性的存在 ;可测知抗性机制 ,便于制订抗药性克服对策     

非特异性酯酶在淡色库蚊对不同杀虫剂抗性中的作用研究

目的　探讨非特异性酯酶（Non-specific esterase,NSE）在淡色库蚊对不同杀虫剂抗性中的作用。方法　以β-乙酸萘酯为底物,坚固蓝B盐为显色剂,测定室内5个品系淡色库蚊的NSE活力。结果　5个品系淡色库蚊中以抗DDVP品系NSE活力水平最高,其次为抗DDVP降解品系和抗残杀威品系。抗氯氰菊酯品系较低,与敏感品系相近。结论　NSE在淡色库蚊对有机磷类杀虫剂的抗性中起重要作用,也是对氨基甲酸酯类杀虫剂产生抗性的机制之一,与对拟除虫菊酯类杀虫剂的抗性关系不大。     

非特异性酯酶在淡色库蚊对不同杀虫剂抗性中的作用研究

目的：探讨非特异性酯酶（Non-specific esterase,NSE)在谈色库蚊对不同杀虫剂抗性中的作用。方法：以β－乙酸萘酯为底物,坚固蓝B盐为显色剂,测定室内5个品系淡色库蚊的NSE活力。结果：5个品系淡色库蚊中以抗DDVP品系NSE活力水平最高,其次为抗DDVP降解品系和抗残杀威品系,抗氯氰菊酯品系较低,与敏感品系相近。结论：NSE在淡色库蚊对有机磷类杀虫剂的抗性中起重要作用,也是对氨基甲酸酯类杀虫剂产生的机制之一,与对拟除虫菊类杀虫剂的抗性关系不大。     

淡色库蚊抗性品系生态习性的探讨

实验观察淡色库蚊敏感品系的化蛹率显著高于抗DDVP品系及抗氯氰菊酯系 (χ2值为25.98和20.64,P＜0.05),而抗性品系幼虫历期略短于敏感品系;亚致死剂量氯氰菊酯对抗氯氰菊酯品系及敏感品系的Ⅲ～Ⅳ龄淡色库蚊幼虫化蛹有显著影响,抗性品系蚊虫寿命略有延长.表明长期使用单一的杀虫剂蚊虫易产生抗性.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.