Precision diagnosis and therapy of a case of brain abscesses associated with asymptomatic pulmonary arteriovenous fistulas.

BACKGROUND: Brain abscesses, a severe infectious disease of the CNS, are usually caused by a variety of different pathogens, which include Streptococcus intermedius (S. intermedius). Pulmonary arteriovenous fistulas (PAVFs), characterized by abnormal direct communication between pulmonary artery and vein, are a rare underlying cause of brain abscesses. CASE PRESENTATION: The patient was a previous healthy 55-year-old man who presented with 5 days of headache and fever. Cerebral magnetic resonance imaging (MRI) suggested a brain abscess. Thoracic CT scan and angiography demonstrated PAVFs. Aiding by metagenomic next-generation sequencing (mNGS) of the cerebrospinal fluid (CSF) sample which identified S. intermedius as the causative pathogen, the patient was switched to the single therapy of large dose of penicillin G and was cured precisely and economically. CONCLUSIONS: It is an alternative way to perform mNGS to identify causative pathogens in patients with brain abscesses especially when the results of traditional bacterial culture were negative. Further thoracic CT or pulmonary angiography should also be undertaken to rule out PAVFs as the potential cause of brain abscess if the patient without any known premorbid history.

[Effects of injecting heparin into the center of hematoma on peri-hematoma edema and hematoma volume in pigs with intracerebral hemorrhage].

OBJECTIVE: To investigate the safety and effect of injecting heparin into hematoma on peri-hematoma edema and hematoma volume in pigs with intracerebral hemorrhage (ICH). METHODS: Thirteen sucking pigs were divided randomly into two groups: hemorrhage group, in which 2.5 ml arterial blood was injected into the right frontal lobe and heparin group, in which 0.2 ml of heparin was injected into the hematoma produced by the injection of 2.3 ml of blood into the similar site. The hematoma volume and peri-hematoma edema were determined by the sequences of T2* weighted image (T2*WI), fluid-attenuated inversion- recovery (FLAIR) image and diffusion weighted image (DWI) by 1.5 T magnetic resonance image (MRI) from 30-60 minutes afterwards to 24 hours. The peri-hematoma apparent diffusion coefficient (ADC) was compared with that of contralateral hemisphere, and the corresponding histologic changes were studied. RESULTS: The average volume, shown by T2*WI at 24 hours, was significantly larger than that at 30-60 minutes after hematoma formation in hemorrhagic group [(5.29+/-0.98) cm3 vs. (3.09+/-0.38) cm3, P<0.01]. But there was no significant change in hematoma volume in hemorrhagic group from 30-60 minutes on to 24 hours [(2.21+/-0.28) cm3 vs. (2.33+/-0.30) cm3, P>0.05]. Both increased and decreased ADC were found around the hematoma in some animals of the heparin group compared with that of the contralateral hemisphere. On the other hand, in hemorrhagic group, only increased ADC could be found around the lesion, and there was no decreased ADC. CONCLUSION: Injection of heparin into an intracerebral hematoma leads to enlargement of the hematoma and more marked peri-lesion edema. On ADC maps, enlargement of hematoma is attributed to the edema around the lesion leading to injury to the brain tissue.

The effects of Shuxuetong on the pathology of cerebral ischemia-reperfusion injury and GABA and TNF-alpha expression in gerbil models.

Objective To study the protective effect and mechanism of Shuxuetong on gerbil brain tissue from the area of ischemia-reperfusion. Methods Cerebral ischemia-reperfusion animal model has made by transient clipping bilateral common carotid arteries in gerbils. Pathological changes in the hippocampal tissue were observed at different reperfusion time (12h, 3 d, 7 d). The expression levels of GABA and TNF-alpha in the hippocampal CA1 subfield were observed using immunohistochemitry at 12 h, 3 d after reperfusion. The difference of above indices among false operation group, ischemia-reperfusion group and treatment group were compared. Results The injuries of pathology to hippocampal area in ischemia reperfusion group were more serious than treatment group. The expression levels of GABA in treatment group were significantly increased compared with ischemia-reperfusion group, but the expression levels of TNF-alpha between the two groups have no difference. Conclusion Shuxuetong has protective effect on brain tissue of ischemia-reperfusion by enhancing the expression of GABA in the hippocampal tissue.