RESUMEN
Medium exchange of particles/cells to a clean buffer with a low background is essential for biological, chemical, and clinical research, which has been conventionally conducted using centrifugation. However, owing to critical limitations, such as possible cell loss and physical stimulation of cells, microfluidic techniques have been adopted for medium exchange. This study demonstrates a continuous on-chip washing process in a co-flow system using viscoelastic and Newtonian fluids. The co-flow system was constructed by adding a small amount of biocompatible polymer (xanthan gum, XG) to a sample containing particles or cells and introducing Newtonian fluids as sheath flows. Polymer concentration-dependent and particle size-dependent lateral migration of particles in the co-flow system were examined, and then the optimal concentration and the critical particle size for medium exchange were determined at the fixed total flow rate of 100 µL/min. For clinical applications, the continuous on-chip washing of white blood cells (WBCs) in lysed blood samples was demonstrated, and the washing performance was evaluated using a scanning spectrophotometer.
RESUMEN
Treatment of paraclinoid aneurysms weather by surgery, or endovascular embolization has a risk of visual loss due to optic neuropathy, or diplopia due to cranial nerve palsies. Visual complications occur immediately after the clipping, whereas they can occur variable time after endovascular coiling. Recently, endovascular coiling for paraclinoid aneurysm is regarded as a safe and feasible treatment. But it still has risks of acute thromboembolic complication, or cranial nerve palsies. A 45-year-old woman was referred from local hospital to our hospital due to ruptured large ICA dorsal wall aneurysm. A total of 12 coils (195 cm) were used for obliteration of aneurysm. Postoperative diffusion weighted image showed no abnormal signal intensity lesion and magnetic resonance angiography demonstrated no sign of vasospasm, or vessel narrowing. But, she complained visual problem 23 days after coil embolization. Ophthalmologist confirmed the left optic disc atrophy on fundoscopy. Although steroid was started, but monocular blindness did not recover completely. The endovascular embolization of paraclinoid aneurysm, especially projecting superiorly with large irregular shape, has the risk of progressive visual loss because of the proximity to optic nerve.
RESUMEN
Pneumocephalus is commonly seen after craniofacial injury. The pathogenesis of pneumocephalus has been debated as to whether it was caused by ball valve effect or combined episodic increased pressure within the nasopharynx on coughing. Discontinuous exchange of air and cerebrospinal fluid due to "inverted bottle" effect is assumed to be the cause of it. Delayed tension pneumocephalus is not common, but it requires an active management in order to prevent serious complication. We represent a clinical case of a 57-year-old male patient who fell down from 3 m height, complicated by tension pneumocephalus on 5 months after trauma. We recommend a surgical intervention, but the patient did not want that so we observe the patient. The patient was underwent seizure and meningitis after 7 months after trauma, he came on emergency room on stupor mentality. Tension pneumocephalus may result in a neurologic disturbance due to continued air entrainment and it significantly the likelihood of intracranial infection caused by continued open channel. Tension pneumocephalus threat a life, so need a neurosurgical emergency surgical intervention.
