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试述旋毛虫对人的致病过程及主要症状。

答案

参考答案:

根据旋毛虫的生活史,将其对人的致病过程分为三期:

1、侵入期脱囊的幼虫和成虫侵入肠粘膜,引起炎症、充血、水肿甚至溃疡。持续约1周。

2、幼虫移行期发生在感染后2-6周,幼虫经血液循环移行全身各器官及侵入横纹肌,而导致严重的危害:①幼虫在血管内移行引起血管炎,这是由于幼虫的机械刺激及分泌物毒性作用引起所经过之处组织的炎症反应,病人可出现全身中毒症状、高热、眼睑及面部浮肿,血中嗜酸性粒细胞升高。②幼虫移行至全身肌肉,引起肌炎和肌纤维肿胀、排列紊乱、横纹消失,甚至肌细胞坏死崩解。病人突出而多发的症状为全身肌肉疼痛,尤以腓肠肌、肱二头肌明显。③幼虫移行到肺,损伤肺毛细血管,产生局灶或广泛性肺出血、肺水肿。④幼虫侵犯心肌引起心肌炎,可导致心衰,为旋毛虫病死亡的主要原因之一。

3、成囊期在感染后1个月,虫体周围形成梭形囊包,轻症患者急性症状消退,但肌痛可持续数月之久。严重患者出现恶病质、水肿、虚脱、毒血症和心肌炎等,甚至死亡。

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Social-networking sites offer users easy ways to present idealized images of themselves, even if those ideals don’t always square with their real-world personalities. Psychology researcher Soraya Mehdizadeh has discovered a way to poke through the offline-online curtain: she has used Faeebook to predict a person’s level of narcissism and self-esteem.

Mehdizadeh, who conducted the study as an undergraduate at Toronto’s York University, gained access to the Faeebook accounts of 100 college students and measured activities like photo sharing, wall postings and status updates; she also studied how frequently users logged on and how often they remained online during each session. Her findings were published recently in Cyberpsyehology, Behavior and Social Networking.

After measuring each subject using the Narcissism Personality Inventory and Rosenberg Self-Esteem Scale, Mehdizadeh, who graduated from York this past spring, discovered narcissists and people with lower self-esteem were more likely to spend more than an hour a day on Facebook and were more prone to post self-promo-tional photos ( striking a pose or using Photoshop, for example). Narcissists were also more likely to showcase themselves through status updates (using phrases like "I’m so glamorous I bleed glitter") and wall activity (posting self-serving links like " My Celebrity Look-alikes" ).

Self-esteem and narcissism are often interrelated but don’t always go hand in hand. Some psychologists believe that narcissists--those who have a pervasive pattern of grandiosity, a need for admiration, as well as a lack of sympathy--unconsciously inflate their sense of self-importance as a defense against feeling inadequate. Not enough empirical research has been produced to confirm that link, although Mehdizadeh’s study seems to support it. Because narcissists have less capacity to sustain intimate or long-term relationships, Mehdizadeh thinks that they would be more drawn to the online world of virtual friends and emotionally detached communication.

Although it seems that Facebook can be used by narcissists to fuel their inflated egos, Mehdizadeh stops short of proclaiming that excessive time spent on Faeebook can turn regular users into narcissists. She also notes that social-networking sites might ultimately be found to have positive effects when used by people with low self-esteem or depression. "If individuals with lower self-esteem are more prone to using Facebook," she says, "the question becomes, ’ Can Facebook help raise self- esteem by allowing patients to talk to each other and help each other in a socially interactive environment’ I don’t think it’s necessarily a bad thing that people with low self-esteem use Facebook.

Mehdizadeh may think that()

A.Facebook will make people abnormal

B. people with low self-esteem could increase their confidence by Facebook

C. Facebook is socially interactive environment

D. narcissists with lower self-esteem don’t like to communicate mood