Achalasia cardia is one of the common causes of motor dysphagia.Though the disease was first described more than 300 years ago,exact pathogenesis of this condition still remains enigmatic.Pathophysiologically,achalasi...Achalasia cardia is one of the common causes of motor dysphagia.Though the disease was first described more than 300 years ago,exact pathogenesis of this condition still remains enigmatic.Pathophysiologically,achalasia cardia is caused by loss of inhibitory ganglion in the myenteric plexus of the esophagus.In the initial stage,degeneration of inhibitory nerves in the esophagus results in unopposed action of excitatory neurotransmitters such as acetylcholine,resulting in high amplitude non-peristaltic contractions(vigorous achalasia);progressive loss of cholinergic neurons over time results in dilation and low amplitude simultaneous contractions in the esophageal body(classic achalasia).Since the initial description,several studies have attempted to explore initiating agents that may cause the disease,such as viral infection,other environmental factors,autoimmunity,and genetic factors.Though Chagas disease,which mimics achalasia,is caused by an infective agent,available evidence suggests that infection may not be an independent cause of primary achalasia.A genetic basis for achalasia is supported by reports showing occurrence of disease in monozygotic twins,siblings and other first-degree relatives and occurrence in association with other genetic diseases such as Down's syndrome and Parkinson's disease.Polymorphisms in genes encoding for nitric oxide synthase,receptors for vasoactive intestinal peptide,interleukin 23 and the ALADIN gene have been reported.However,studies on larger numbers of patients and controls from different ethnic groups are needed before definite conclusions can be obtained.Currently,the disease is believed to be multi-factorial,with autoimmune mechanisms triggered by infection in a genetically predisposed individual leading to degeneration of inhibitory ganglia in the wall of the esophagus.展开更多
目的总结国家标准GB/T31002.1的验证性实验研究过程,以指导国家标准的推广与应用。方法采用心理物理学法获取健康青年人不同提举高度、频率与水平距离下的最大可接受质量(Maximum acceptable weight of lift,MAWL),并分析MAWL与NIOSH手...目的总结国家标准GB/T31002.1的验证性实验研究过程,以指导国家标准的推广与应用。方法采用心理物理学法获取健康青年人不同提举高度、频率与水平距离下的最大可接受质量(Maximum acceptable weight of lift,MAWL),并分析MAWL与NIOSH手工提举方程质量推荐限值(RWL)间的差异。结果MAWL随三提举参数的增大呈显著降低趋势,多数RWL高于中国青年人的手工提举重物能力。结论国内青年人群应用NIOSH手工提举方程时,可通过调整提举高度系数与降低负荷常量予以修正。展开更多
Bloating is one of the most common and bothersome symptoms complained by a large proportion of patients. This symptom has been described with various definitions, such as sensation of a distended abdomen or an abdomin...Bloating is one of the most common and bothersome symptoms complained by a large proportion of patients. This symptom has been described with various definitions, such as sensation of a distended abdomen or an abdominal tension or even excessive gas in the abdomen, although bloating should probably be defined as the feeling (e.g. a subjective sensation) of increased pressure within the abdomen. It is usually associated with functional gastrointestinal disorders, like irritable bowel syndrome, but when bloating is not part of another functional bowel or gastrointestinal disorder it is included as an independent entity in Rome III criteria named functional bloating. In terms of diagnosis, major difficulties are due to the lack of measurable parameters to assess and grade this symptom. In addition, it is still unclear to what extent the individual patient complaint of subjective bloating correlates with the objective evidence of abdominal distension. In fact, despite its clinical, social and economic relevance, bloating lacks a clear pathophysiology explanation, and an effective management endorsement, turning this common symptom into a true challenge for both patients and clinicians. Different theories on bloating etiology call into questions an increased luminal contents (gas, stools, liquid or fat) and/or an impaired abdominal empting and/or an altered intra-abdominal volume displacement (abdomino-phrenic theory) and/or an increased perception of intestinal stimuli with a subsequent use of empirical treatments (diet modifications, antibiotics and/or probiotics, prokinetic drugs, antispasmodics, gas reducing agents and tricyclic antidepressants). In this review, our aim was to review the latest knowledge on bloating physiopathology and therapeutic options trying to shed lights on those processes where a clinician could intervene to modify disease course.展开更多
文摘Achalasia cardia is one of the common causes of motor dysphagia.Though the disease was first described more than 300 years ago,exact pathogenesis of this condition still remains enigmatic.Pathophysiologically,achalasia cardia is caused by loss of inhibitory ganglion in the myenteric plexus of the esophagus.In the initial stage,degeneration of inhibitory nerves in the esophagus results in unopposed action of excitatory neurotransmitters such as acetylcholine,resulting in high amplitude non-peristaltic contractions(vigorous achalasia);progressive loss of cholinergic neurons over time results in dilation and low amplitude simultaneous contractions in the esophageal body(classic achalasia).Since the initial description,several studies have attempted to explore initiating agents that may cause the disease,such as viral infection,other environmental factors,autoimmunity,and genetic factors.Though Chagas disease,which mimics achalasia,is caused by an infective agent,available evidence suggests that infection may not be an independent cause of primary achalasia.A genetic basis for achalasia is supported by reports showing occurrence of disease in monozygotic twins,siblings and other first-degree relatives and occurrence in association with other genetic diseases such as Down's syndrome and Parkinson's disease.Polymorphisms in genes encoding for nitric oxide synthase,receptors for vasoactive intestinal peptide,interleukin 23 and the ALADIN gene have been reported.However,studies on larger numbers of patients and controls from different ethnic groups are needed before definite conclusions can be obtained.Currently,the disease is believed to be multi-factorial,with autoimmune mechanisms triggered by infection in a genetically predisposed individual leading to degeneration of inhibitory ganglia in the wall of the esophagus.
文摘目的总结国家标准GB/T31002.1的验证性实验研究过程,以指导国家标准的推广与应用。方法采用心理物理学法获取健康青年人不同提举高度、频率与水平距离下的最大可接受质量(Maximum acceptable weight of lift,MAWL),并分析MAWL与NIOSH手工提举方程质量推荐限值(RWL)间的差异。结果MAWL随三提举参数的增大呈显著降低趋势,多数RWL高于中国青年人的手工提举重物能力。结论国内青年人群应用NIOSH手工提举方程时,可通过调整提举高度系数与降低负荷常量予以修正。
文摘Bloating is one of the most common and bothersome symptoms complained by a large proportion of patients. This symptom has been described with various definitions, such as sensation of a distended abdomen or an abdominal tension or even excessive gas in the abdomen, although bloating should probably be defined as the feeling (e.g. a subjective sensation) of increased pressure within the abdomen. It is usually associated with functional gastrointestinal disorders, like irritable bowel syndrome, but when bloating is not part of another functional bowel or gastrointestinal disorder it is included as an independent entity in Rome III criteria named functional bloating. In terms of diagnosis, major difficulties are due to the lack of measurable parameters to assess and grade this symptom. In addition, it is still unclear to what extent the individual patient complaint of subjective bloating correlates with the objective evidence of abdominal distension. In fact, despite its clinical, social and economic relevance, bloating lacks a clear pathophysiology explanation, and an effective management endorsement, turning this common symptom into a true challenge for both patients and clinicians. Different theories on bloating etiology call into questions an increased luminal contents (gas, stools, liquid or fat) and/or an impaired abdominal empting and/or an altered intra-abdominal volume displacement (abdomino-phrenic theory) and/or an increased perception of intestinal stimuli with a subsequent use of empirical treatments (diet modifications, antibiotics and/or probiotics, prokinetic drugs, antispasmodics, gas reducing agents and tricyclic antidepressants). In this review, our aim was to review the latest knowledge on bloating physiopathology and therapeutic options trying to shed lights on those processes where a clinician could intervene to modify disease course.
