Blocking of conditioned taste avoidance induced by wheel running

In Experiment 1, compared to non-reinforced presentation of a food stimulus (A → no US), the association of a food stimulus with wheel running (A → US) blocked subsequent avoidance of a distinctive flavor (X), when both the food and flavor were followed by wheel running (AX → US). Experiment 2 replicated and extended the blocking effect, demonstrating that the amount of avoidance of X after AX → wheel training depended on the correlation between A-alone trials and wheel running—the predictiveness of the A stimulus. The present study is the first to demonstrate associative blocking of conditioned taste avoidance (CTA) induced by wheel running and strongly implicates associative learning as the basis for this kind of avoidance.     

昂丹司琼联合泮托拉唑对宫颈癌同步放化疗所致恶心呕吐的临床疗效

摘要 目的：研究昂丹司琼联合泮托拉唑对宫颈癌同步放化疗所致恶心呕吐的临床疗效。方法：选择2018年1月～2020年1月我院收治的79例宫颈癌患者,均采取同步化疗,将其随机分为两组。对照组在当天化疗前30 min和随后的6 d连续静脉注射昂丹司琼,每次8 mg,1次/d;同时给予地塞米松磷酸钠注射液10 mg,1次/d。观察组在昂丹司琼的基础上静脉注射泮托拉唑,每次40 mg,1次/d,给药的时间与昂丹司琼相同。比较两组宫颈癌患者恶心呕吐的完全缓解率、癌因性疲乏评分和不良反应的发生情况。结果：两组化疗第1、2 d恶心呕吐的完全缓解率比较差异无明显统计学意义(P>0.05),观察组化疗第3、4、5、6 d恶心呕吐的完全缓解率分别为76.92 %、79.49 %、87.18 %、87.18 %,均明显高于对照组(P<0.05);观察组的癌因性疲乏评分为(45.39±7.29)分,明显低于对照组的(67.24±8.36)分(P<0.05);两组的乏力嗜睡、便秘、椎体外系反应、失眠/不安、腹泻、轻度头痛的发生率比较无明显统计学差异(P>0.05)。结论：昂丹司琼联合泮托拉唑对宫颈癌同步放化疗所致恶心呕吐的疗效显著优于单用昂丹司琼治疗,并能明显减轻癌因性疲乏,且安全性高。     

康莱特注射液联合放化疗治疗中晚期宫颈癌的临床研究

目的：探讨康莱特注射液联合放化疗对中晚期宫颈癌患者的疗效及对放化疗引起的毒副反应的影响。方法：选取2009年6月—2012年3月间笔者所在医院收治的经病理组织学确诊的62例局部晚期宫颈鳞癌患者,随机平均分成实验组（n=31）和对照组（n=31）,分别接受康莱特注射液+放化疗联用和单纯放化疗的治疗,考察两组受试者的临床有效率、生活质量及毒副反应。结果：实验组和对照组受试者的总有效率分别为93.6%和83.9%,无显著差异（P>0.05）;生活质量稳定和改善的比率分别为93.5%和71.0%,有显著差异（P<0.05）;实验组受试者的主要毒副反应发生率明显低于对照组（P<0.05）。结论：康莱特注射液联合放化疗能有效用于中晚期宫颈癌患者的治疗,并显著提高患者生活质量,明显减轻放化疗所致不良反应。     

重组人血管内皮抑素联合同步放化疗治疗晚期非小细胞肺癌临床研究

目的:探讨重组人血管内皮抑素联合同步化疗治疗晚期非小细胞肺癌(NSCLC)的临床疗效.方法:将我院收治的40例NSCLC患者随机分为治疗组和对照组,对照组患者采用紫杉醇化疗方案联合同步放射治疗,治疗组患者给予重组人血管内皮抑素联合同步放化疗进行治疗,治疗2个周期后对患者的近期疗效、毒副反应以及无肿瘤进展时间(TTP)等进行比较.结果:治疗组CR+PR的患者为15例,明显高于对照组的5例(P＜0.05);治疗组患者TTP为154±11d,中位生存时间为274d,而对照组TTP为108±8d,中位生存时间为179d,两组患者比较存在明显的差异性(P＜0.05);治疗组患者QOL评分明显优于对照组(P＜0.05),而两组患者毒副反应无明显的差异性(P＞0.05).结论:对晚期NSCLC患者采用重组人血管内皮抑素联合同步化疗进行治疗,可提高患者生存时间,且不会增加患者毒副反应的发生.     

放化疗对胃肠道的损伤以及微生态制剂防治的研究进展

肿瘤患者放化疗后不良反应较多,尤其是胃肠道反应.放化疗对胃肠道的损伤主要包括:严重损伤肠粘膜,造成肠黏膜免疫功能紊乱,以及肠道菌群失调,引发腹泻或便秘.研究发现,微生态制剂可用于防治放化疗对胃肠道的损伤,减少或避免不良反应的发生.     

Four-alternative choice violates the constant-ratio rule

Six pigeons responded on a four-key concurrent variable-interval schedule in which a 27:9:3:1 distribution of reinforcers between the keys changed every 10 reinforcers. Their behaviour quickly came under the control of this changing four-way reinforcer ratio. However, preference between a pair of keys depended not only on the relative reinforcer rates on those keys, but also on the absolute levels of those rates. This contradicts the constant-ratio rule that underpins the matching approach to choice, but is predicted by a contingency-discriminability model that assumes that organisms may occasionally misattribute reinforcers to a response that did not produce them. Reinforcers produced strong preference pulses, or transient increases in responding on the just-reinforced key. Despite accurate tracking of the reinforcer ratio, reinforcers obtained late in components and from leaner keys still produced strong pulses, suggesting both extended and local control of behaviour. Patterns of switching between keys were graded and similarly controlled by the reinforcer rates on each key. Whether considered in terms of switching, local preference pulses, or extended preference, behaviour was controlled by a rapidly changing four-way reinforcer ratio in a graduated, continuous manner that is unlikely to be explained by a simple heuristic such as fix-and-sample.     

Experimental concurrent infection of Afar breed goats with Oestrus ovis (L1) and Haemonchus contortus (L3): interaction between parasite populations, changes in parasitological and basic haematological parameters

The study was conducted to examine the occurrence and interaction between Oestrus ovis and Haemonchus contortus in experimentally infected Ethiopian Afar breed of goats. Twenty goats were divided into four groups (O, OH, H, and C) of five animals each. Each animal of groups O and OH received weekly infections for 5 weeks with 66 first instar larvae (L₁) of O. ovis. Then animals of groups OH and H were infected with a single dose of 5000 third stage larvae (L₃) of H. contortus. Goats of group C were kept free of any infection as non-infected control. Faecal egg count (FEC), blood cell count, total serum protein level and body weight were recorded weekly throughout the study period. At necropsy worm burden, female worm length, fecundity and larval burden of O. ovis in the nasal-sinus cavities of infected animals were assessed. The results showed that the presence of H. contortus in the abomasum of goats of group OH had no influence on the development of O. ovis. On the contrary, a significant reduction (P < 0.05) in FEC, worm burden, fecundity and female worm length was revealed in group OH animals compared to the mono-infected animals (group H). This was associated with eosinophilia and reduced packed cell volume.     

Discrete-trial vs. continuous free-operant procedures in assessing whether reinforcement context affects reinforcement value

Pigeons were trained to respond to two alternating concurrent reinforcement schedules. The reinforcement probabilities were .05 and .10 in one component, and .10 and .20 in the other. In one condition, the pigeons received training on a discrete-trial procedure in which the keylights remained illuminated for 5s or until a response occurred. In another condition, pigeons received training on a procedure in which the reinforcement contingencies were the same as in the discrete-trial procedure, but the stimuli were not turned off after 5s or after a response. Following training in each condition, probe tests were presented. In both conditions, the .20 alternative was, overall, preferred to the .05 alternative during probe tests. Following discrete-trial training, there was no reliable preference between the two .10 alternatives. However, when the stimuli remained illuminated during the intertrial interval periods during training, probe tests results showed preference for the .10 alternative that had been presented in the leaner context during training. The pattern of results is consistent with the notion that probe preference can be influenced both by the absolute reinforcement schedules associated with each alternative, as well as changeover behavior developed during training.     

A two-stage model for concurrent sequences

Schneider and Davison [Schneider, S.M., Davison, M., 2005. Demarcated response sequences and the generalised matching law. Behav. Proc. 70, 51–61] showed that the generalised matching law applied to concurrent free-operant two-response sequences. When sufficient temporal spacing is required between the responses, however, neither the response-level nor the sequence-level forms of the generalised matching law provide good fits. An alternative “two-stage sensitivity” model with fewer free parameters features two types of sensitivity to the reinforcement contingencies on sequences. When temporal spacing between the responses is long, the “response distribution sensitivity” parameter describes sensitivity only of the individual responses to the sequence-level contingencies. At a threshold level, this sensitivity reaches a maximum. When spacing is shorter than threshold, the “response order sensitivity” parameter reflects a new sensitivity to the order of the responses within sequences. As this sensitivity approaches its maximum, sequence matching is achieved. For both stages, a changeover parameter describes bias against sequences that require changeovers between the two responses. The model fit data ranging from near-response matching with long minimum inter-response times (IRTs) to sequence matching with no minimum IRTs, using two species and a variety of sequence reinforcer distributions. Rats differed from pigeons in achieving sequence matching only at a nonzero minimum IRT. In a comparison based on pigeon data with no minimum IRT, the two-stage sensitivity model was more efficient than the generalised matching law according to the Akaike criterion. The logic of the model suggests a new way of understanding the mechanisms underlying behavioural units.