Differences in pathological changes between two rat models of severe traumatic brain injury

The rat high-impact free weight drop model mimics the diffuse axonal injury caused by severe traumatic brain injury in humans,while severe controlled cortical impact can produce a severe traumatic brain injury model using precise strike parameters.In this study,we compare the pathological mechanisms and pathological changes between two rat severe brain injury models to identify the similarities and differences.The severe controlled cortical impact model was produced by an electronic controlled cortical impact device,while the severe free weight drop model was produced by dropping a 500 g free weight from a height of 1.8 m through a plastic tube.Body temperature and mortality were recorded,and neurological deficits were assessed with the modified neurological severity score.Brain edema and bloodbrain barrier damage were evaluated by assessing brain water content and Evans blue extravasation.In addition,a cytokine array kit was used to detect inflammatory cytokines.Neuronal apoptosis in the brain and brainstem was quantified by immunofluorescence staining.Both the severe controlled cortical impact and severe free weight drop models exhibited significant neurological impairments and body temperature fluctuations.More severe motor dysfunction was observed in the severe controlled cortical impact model,while more severe cognitive dysfunction was observed in the severe free weight drop model.Brain edema,inflammatory cytokine changes and cortical neuronal apoptosis were more substantial and blood-brain barrier damage was more focal in the severe controlled cortical impact group compared with the severe free weight drop group.The severe free weight drop model presented with more significant apoptosis in the brainstem and diffused blood-brain barrier damage,with higher mortality and lower repeatability compared with the severe controlled cortical impact group.Severe brainstem damage was not found in the severe controlled cortical impact model.These results indicate that the severe controlled cortical impact model is relatively more stable,more reproducible,and shows obvious cerebral pathological changes at an earlier stage.Therefore,the severe controlled cortical impact model is likely more suitable for studies on severe focal traumatic brain injury,while the severe free weight drop model may be more apt for studies on diffuse axonal injury.All experimental procedures were approved by the Ethics Committee of Animal Experiments of Tianjin Medical University,China(approval No.IRB2012-028-02)in Febru ary 2012.

Pseudoileus caused by primary visceral myopathy in a Han Chinese patient with a rare MYH11 mutation:A case report

BACKGROUND Chronic intestinal pseudo-obstruction(CIPO)is a syndrome of intestinal motor dysfunction caused by intestinal nerve,muscle,and/or Cajal stromal cell lesions.CIPO is a serious category of gastrointestinal dynamic dysfunction,which can eventually lead to the death of patients with intestinal failure.Due to considerable phenotypic heterogeneity,the estimated incidence of CIPO is 1/476190 and 1/416666 in men and women,respectively.According to the etiology,CIPO can be divided into idiopathic and secondary,of which the latter is the most common,often secondary to tumor,virus infection,connective tissue disease,neurological diseases,and endocrine diseases.Idiopathic CIPO in the intestinal tract is divided into visceral myopathy,neuropathy,and stromal cell lesions according to the location.Surgery is usually not recommended for CIPO,because it often does not benefit patients with CIPO,and postoperative intestinal obstruction is likely to occur,which may even worsen the condition.CASE SUMMARY Here,we describe the case of a 43-year-old male Han Chinese patient with a 15-year history of recurrent abdominal distention with no clear cause.The results of physical,biochemical,and other relevant examinations showed no clear abnormalities.Contrast-enhanced computed tomography(CT)indicated a large duodenum,clear expansion of the intestinal lumen,and CIPO.Whole exome sequencing(WES)of the patient and his mother confirmed the diagnosis of primary familial visceral myopathy type 2 chronic pseudoileus with a rare heterozygous gene mutation in MYH11.This is the second reported case of CIPO with a heterozygous MYH11[NM_001040113.1:c.5819delC(p.Pro1940Hisfs*91)]mutation.CONCLUSION This case report indicates that physicians can perform routine clinical examinations,CT,and WES to achieve a diagnosis and treatment of CIPO in early disease stages.