The isotropic-liquid crystal (cholesteric) phase boundary concentrations for aqueous solutions of xanthan, an ionic double-helical polysaccharide, were determined as functions of the molecular weight of xanthan and the added sodium chloride concentration. The phase boundary concentrations increased sharply with decreasing molecular weight at low molecular weights, as in the case of neutral stiff polymer solutions, and depended strongly on the added salt concentration. The latter dependence demonstrates the importance of the electrostatic interaction between polymers in the isotropic-liquid crystal phase equilibrium. These experimental results were compared with two theories: the Onsager theory extended by Odijk to semiflexible polyelectrolyte solutions and a perturbation theory proposed by us (Sato, T.; Teramoto, A. Physica A 1991, 176,72). The latter theory succeeded in almost quantitative prediction of the experimental phase boundary concentrations for xanthan. The same comparison was performed on two other rigid polyion systems: tobacco mosaic virus and DNA.
Apraxia of eyelid opening (AEO) has been associated with levodopa. It has also been linked to impaired function of the frontal lobe, with the dopaminergic neuron projected to the frontal lobe. However, dopaminergic treatment for AEO is still controversial. Here we describe two patients with both Parkinson's disease (PD) and AEO, who responded differently to a continuous intrajejunal levodopa-carbidopa intestinal gel (LCIG) infusion. One of the patients manifested a deterioration of AEO after LCIG infusion, and off-periods were shortened by the decrease in the severity of dyskinesia. After discontinuing the use of LCIG, there was an improvement in the patient's ability to open her eyelids. The other patient had AEO prior to LCIG treatment, and this treatment spontaneously elevated her eyelids. These two PD patients raised the concern as to whether AEO may be a critical symptom for the indication of LCIG treatment. The different responses to LCIG might have been due to the fluctuation in brain dopamine levels during LCIG treatment.
Background Cerebral arterial air embolism is often associated with an invasive iatrogenic etiology and a high rate of convulsive seizures. There are only a few descriptions of electroencephalogram findings in convulsive seizures due to cerebral arterial air embolism of noniatrogenic etiology. Herein, we describe the case of a patient with lung cancer and convulsive seizures with abnormalities detected on electroencephalogram caused by cerebral arterial air embolism of noniatrogenic etiology. Case presentation A 55-year-old Japanese man underwent radiotherapy and chemotherapy for cancer in the hilum of the left lung that was diagnosed after hemoptysis. One year after the diagnosis, he developed fever and chest pain that required hospitalization. At admission, he was in shock, and chest computed tomography revealed invasion of the left atrium and left main bronchus by the hilar cancer. Chest and abdominal computed tomography revealed small low-density areas within the tumor and around the intestinal membrane, which were interpreted as the presence of air due to invasion of the lung cancer. He was diagnosed with septic shock due to necrotic infection secondary to cancer invasion into the left atrium. The following day, he complained of difficulty in speaking and weakness in the left side of his body. A head computed tomography scan revealed multiple small low-density areas in the right cortex and bilateral subcortex, which were interpreted as air emboli. On day 3, he experienced generalized tonic–clonic seizures for approximately 1 minute, followed by myoclonus-like convulsions in the left lower limb and a right-sided gaze. The electroencephalogram findings after the convulsive seizures revealed partial epilepsy-like waves with intermittent spikes in the bilateral cerebral hemispheres and a diffuse slow wave in the left frontal lobe. He recovered from sepsis without recurrence of convulsive seizures; however, he died of hemoptysis on day 50 after discharge. Conclusions Electroencephalogram findings of focal spike activities and diffuse slow waves were detected in early seizures due to cerebral arterial air embolism of noniatrogenic etiology associated with lung cancer. Additional case descriptions are warranted to establish patterns in electroencephalogram findings specific to cerebral arterial air embolism.
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