Immunoreactivity profiling of Anti-Chinese hamster ovarian host cell protein antibodies by isobaric labeled affinity purification-mass spectrometry reveals low-recovery proteins.

We evaluated the immunoreactivity profiles of eight commercial anti-host cell protein (anti-HCP) antibodies from different host animals and their antigens used for immunization by an isobaric labeled affinity purification-mass spectrometry (AP-MS) method. As a result, 34 proteins with high abundance but low recovery from harvest cell culture fluid were identified. Since they are likely to be underestimated in biopharmaceutical quality assessment, the features common to these proteins were investigated. Compared to other immunoprecipitated HCP proteins, proteins exhibiting lower molecular weight (ΔMW = -14600), lower isoelectric point (ΔpI = -0.86), and lower hydrophobicity (ΔGRAVY = -0.13) were enriched. This AP-MS method provides important information for HCP control strategies using immunological methods and is expected to contribute to the development of safe biopharmaceutics.

Heat shock response enhanced by cell culture treatment in mouse embryonic stem cell-derived proliferating neural stem cells.

Cells have a regulatory mechanism known as heat shock (HS) response, which induces the expression of HS genes and proteins in response to heat and other cellular stresses. Exposure to moderate HS results in beneficial effects, such as thermotolerance and promotes survival, whereas excessive HS causes cell death. The effect of HS on cells depends on both exogenous factors, including the temperature and duration of heat application, and endogenous factors, such as the degree of cell differentiation. Neural stem cells (NSCs) can self-renew and differentiate into neurons and glial cells, but the changes in the HS response of symmetrically proliferating NSCs in culture are unclear. We evaluated the HS response of homogeneous proliferating NSCs derived from mouse embryonic stem cells during the proliferative phase and its effect on survival and cell death in vitro. The number of adherent cells and the expression ratios of HS protein (Hsp)40 and Hsp70 genes after exposure to HS for 20 min at temperatures above 43°C significantly increased with the extension of the culture period before exposure to HS. In contrast, caspase activity was significantly decreased by extension of the culture period before exposure to HS and suppressed the decrease in cell viability. These results suggest that the culture period before HS remarkably affects the HS response, influencing the expression of HS genes and cell survival of proliferating NSCs in culture.

Investigation on the optimal implantation site and setting of Reveal LINQ® avoiding interference with performance of transthoracic echocardiography.

BACKGROUND: The optimal implantation site of a new implantable cardiac monitor (ICM) named Reveal LINQ® may be limited based on a sufficient amplitude of R wave potential (AEP) acquisition because it is the same anatomic area used for transthoracic echocardiography (TTE). METHODS: Among 18 healthy volunteers, we assessed AEPs in 3 combinations through parasternal placement of 2 electrodes, (i) in the 4th intercostal space (ICS; site A/setting a; A/a), (ii) the same setting in the 5th ICS (site B/setting a; B/a), and (iii) in a sagittal plane relative to the left sternal border at the 4th ICS (site A/setting b; A/b), and further measured AFPs in several body positions in all site-setting combinations: supine, left and right lateral decubitus, sitting, and standing. The degree of interference with TTE performance was assessed by placement of an imitation ICM in setting a at both sites A and B. RESULTS: Only the AEPs in A/a and B/a met the criteria (AEP ≥ 0.3 mV) in all positions. The AEPs in the supine position with all combinations were higher than those achieved in other positions (P < .001). The imitation interfered with TTE performance at site A among 78% of subjects, but only 17% at site B (P = .0006). The end-diastolic dimension of the left ventricle at site A was decreased after the imitation placement (P = .028). At site B, all female subjects complained of discomfort because their brassieres overlaid the imitation. CONCLUSION: The B/a combination is optimal; however, the personal discomfort related to brassieres should be considered.

Mechanism of injury to the corpus callosum, with particular reference to the anatomical relationship between site of injury and adjacent brain structures.

The location of corpus callosum injury was investigated using magnetic resonance imaging in 92 patients. The anatomical relationships in the region around the corpus callosum were also evaluated to clarify involvement in the mechanism of corpus callosum injury in 20 normal volunteers. Lesions in the posterior half of the corpus callosum accounted for 80% of corpus callosum injuries. The falx was increasingly elongated toward the posterior portion of the corpus callosum and the corpus callosum was thinnest at the body-splenium junction in the normal volunteers. The mechanism of corpus callosum injury apparently involves the following factors. The posterior half of the falx is closer to the corpus callosum than the anterior half. Therefore, the anterior part of the corpus callosum easily moves with lateral movement of the cerebral hemispheres, and the strain is likely to be concentrated in the posterior half of the corpus callosum, because the falx greatly limits lateral movement of the hemisphere in the posterior region. The corpus callosum is easily distorted at the thinnest part of the body-splenium junction. Therefore, corpus callosum injury predominantly occurs in the posterior half of the corpus callosum.

Painless acute aortic dissection with a left hemiparesis.

BACKGROUND: Patients who present with only neurological symptoms and no pain challenge the recognition of acute aortic dissection. RESULTS: We report three patients with completely painless acute aortic dissection who presented with left hemiparesis. All patients presented with a left-sided weakness of sudden onset. We suspected an ischemic stroke but diagnosed acute aortic dissection (DeBakey Type II, Stanford Type A). We suspect that the innominate artery is occluded when the blood flow of the false lumen is dominant. In our cases, surgical and autopsy findings showed dissection of the innominate artery. CONCLUSIONS: Highly unusual presentations of aortic dissection with acute ischemic stroke exist. A wide mediastinum on plain chest X-ray was present in all cases.

MRI tracer study of the cerebrospinal fluid drainage pathway in normal and hydrocephalic guinea pig brain.

OBJECTIVE: Using magnetic resonance imaging (MRI), sequential information regarding the dynamic movement of the cerebrospinal fluid (CSF) from the subarachnoid space and the ventricles to the drainage pathway in response to the CSF pressure was obtained in guinea pigs. In this study, a new mechanical hydrocephalus model in a guinea pig was developed to investigate the CSF kinetics in an acute hydrocephalic brain. MATERIALS AND METHODS: A total of 18 adult male guinea pigs were studied. In the ventricular injection group, The CSF in the lateral and third ventricles was isolated by inserting a polyethylene tube with a cotton ball into the aqueduct of Sylvius. By infusing artificial CSF through this tubing acute ventriculomegaly was created. In the subarachnoid injection group, a polyethylene tube was placed at the cisterna magna. Using MRI with gadoteridol as a tracer, the movement of CSF from the subarachnoid space and dilated ventricles was monitored at various pressures. The CSF drainage pathway from the subarachnoid space in the hydrocephalic condition was examined and compared with the CSF drainage pathway in normal condition. RESULTS: Gadoteridol cleared from the lateral and third ventricles and reached the nasal mucosa via brain parenchyma; the movement was proportional to the CSF pressure. Gadoteridol from the subarachnoid space also reached the nasal mucosa and periorbital region in a similar manner. However, it was not observed to reach either over the convexity of the brain or adjacent to the superior sagittal sinus.

Painless acute aortic dissection with a left hemiparesis: a case report.

We report a patient with completely painless acute aortic dissection who presented with transient left hemiparesis. A 59-year-old male presented to our Emergency Department with left-sided weakness of sudden onset. We therefore suspected cerebrovascular accident. A computed tomography scan of the head did not show any abnormal findings; however, the patient's neurologic symptoms disappeared suddenly, and he recovered fully. We therefore considered the diagnosis of transient ischemic attack. However, immediately thereafter, the patient's neurologic symptoms returned. The cycle of symptom appearance and recovery recurred 3 times over a period of a few minutes. The final diagnosis was acute aortic dissection (DeBakey type II Stanford type A). Completely painless acute aortic dissection who presented with only neurologic symptoms, which made the diagnosis of acute aortic dissection extremely difficult.

[The usefulness of MRI around the tentorial incisura for determining the mechanism of brain stem injury: a case report].

We report a case of isolated brain stem injury caused by the tentorium cerebelli. A 17-year-old male was admitted to our hospital. Thirty minutes before admission, he was struck by another motorcycle while driving his own motorcycle. The Glasgow Coma Scale (GCS) was 10. He had no extremity weakness and his pupils were normal. CT scan showed no evidence of intracranial lesions except for facial bone fractures. His consciousness level improved to GCS 13 at 6 hours after admission. Follow-up CT scan was normal, however MRI 3 days after admission showed a contusion at the left lateral midbrain. He was discharged without any neurological deficits on 6 days after admission. Analysis of the distance between the brain stem and the tentorial margin using MR cisternography showed that the left side was shorter than the right side. We presumed that an isolated lateral brain stem injury was caused by the direct impact of the tentorium cerebelli. Typically the location of this type of lesion is present in the same side as that of impact. However in this case the orientation was opposite to that. We considered that the distance between the brain stem and the tentorial margin affected the mechanism of this lesion.