Biological response and morphological assessment of individually dispersed multi-wall carbon nanotubes in the lung after intratracheal instillation in rats

Biological responses of multi-wall carbon nanotubes (MWCNTs) were assessed after a single intratracheal instillation in rats. The diameter and median length of the MWCNTs used in this study were approximately 60 nm and 1.5 μm, respectively. Groups of male Sprague–Dawley rats were intratracheally instilled with 0.04, 0.2, or 1 mg/kg of the individually dispersed MWCNT suspension. After instillation, the bronchoalveolar lavage fluid was assessed for inflammatory cells and markers, and the lung, liver, kidney, spleen, and cerebrum were histopathologically evaluated at 3-day, 1-week, 1-month, 3-month, and 6-month post-exposure. Transient pulmonary inflammatory responses were observed only in the lungs of the group of rats exposed to 1 mg/kg of MWCNTs. Morphology of the instilled MWCNTs in the lungs of rats was assessed using light microscopy and transmission electron microscopy (TEM). Light microscopy examination revealed that MWCNTs deposited in the lungs of the rats were typically phagocytosed by the alveolar macrophages and these macrophages were consequently accumulated in the alveoli until 6-month post-exposure. The 400 TEM images obtained showed that all MWCNTs were located in the alveolar macrophages or macrophages in the interstitial tissues, and MWCNTs were not located in the cells of the interstitial tissues. There was no evidence of chronic inflammation, such as angiogenesis or fibrosis, induced by MWCNT instillation. These results suggest that MWCNTs were being processed and cleared by alveolar macrophages.     

Two cases of mycosis fungoides treated by reduced-intensity cord blood transplantation

Mycosis fungoides is a cutaneous T-cell lymphoma, which is clinically divided into three stages: patch, plaque and tumor. Despite a variety of treatments the prognosis is poor in advanced mycosis fungoides. Recently, allogeneic hematopoietic stem cell transplantation has been successfully applied for such cases. We performed reduced-intensity umbilical cord blood transplantation for two advanced mycosis fungoides patients. Case 1 was a 56-year-old man and case 2 was a 30-year-old woman. Tumors of each case were refractory to conventional chemotherapy. Although radiation therapy was considerably effective, tumors relapsed after several months. Reduced-intensity umbilical cord blood transplantation was performed because case 1 had no human leukocyte antigen-identical siblings and the sibling of case 2 did not agree to be the donor. The male patient died of pulmonary failure 23 days after reduced-intensity umbilical cord blood transplantation. The case 2 patient succeeded in reduced-intensity umbilical cord blood transplantation and remained in complete/partial remission for 13 months. However, chemotherapy-resistant tumors relapsed, and allogeneic hematopoietic stem cell transplantation was performed at 17 months. She died of cerebral hemorrhage 23 days after the procedure. Reduced-intensity umbilical cord blood transplantation may be included in the treatments for advanced mycosis fungoides, where graft-versus-lymphoma effect seems to be a significant factor for the success of the treatment.     

Electromyographic activity of m. longissimus and the kinematics of the vertebral column during level and downslope treadmill walking in cats

Electromyographic (EMG) burst patterns of m. longissimus and the kinematics of the vertebral column were assessed in cats during treadmill walking for six downslope grades (5 degrees-30 degrees). The EMG bursts during downslope walking were weak between 5 degrees and 20 degrees. At steeper grades (>20 degrees), EMG bursts were large. Bursts at T10 facilitated inward movements, and those at L1 decreased forward movements, while those at L5 decreased backward movements during downslope walking at steeper grades.     

Symptomatic hypersomnia due to orexin deficiency in hypothalamic lesions

Narcolepsy is characterized by excessive daytime sleepiness (EDS), cataplexy and other abnormal manifestations of REM sleep. Recently, it was discovered that the pathophysiology of idiopathic narcolepsy-cataplexy is linked to orexin ligand deficiency in the brain and cerebrospinal fluid. Orexin neurons localize in the posterior hypothalamic area, which was previously described as "waking center" by von Economo in 1920s. Hypersomnia due to orexin ligand deficiency can also occur during the course of other neurological conditions, such as hypothalamic tumor, encephalopathy and demyelinating disorder (i.e. symptomatic hypersomnia). We experienced 8 pediatric cases with symptomatic hypersomnia. These cases were diagnosed as brain tumor (n = 2), head trauma (n = 1), encephalopathy (n = 1), demyelinating disorder (n = 3) and infarction (n = 1). Six pediatric cases with orexin measurements from the literatures were additionally included and total 14 cases were studied. Although it is difficult to rule out the comorbidity of idiopathic narcolepsy in some cases, a review of the case histories reveals numerous unquestionable cases of symptomatic hypersomnia. In these cases, the occurrences of the hypersomnia run parallel with the rise and fall of the causative diseases. Most of symptomatic hypersomnia cases show both extended nocturnal sleep time and EDS consisting of prolonged sleep episodes of NREM sleep. The features of nocturnal sleep and EDS in symptomatic hypersomnia are more similar to idiopathic hypersomnia than to narcolepsy.     

Beta-2-glycoprotein I and urinary trypsin inhibitor levels in the plasma of pregnant and postpartum women

Annexins (Anx) are a family of structurally related proteins that all bind to anionic phospholipids in a Ca(2+)-dependent manner. Some biological properties of beta-2-glycoprotein I (beta(2)-GPI) are similar to those of Anx IV and Anx V. Urinary trypsin inhibitor (UTI) helps to maintain normal pregnancy and prevent preterm delivery by inhibiting uterine contraction. However, plasma beta(2)-GPI and UTI levels have not been measured in normal pregnancy. The aim of this study is to clarify the levels of these parameters. Subjects were nonpregnant women (n=50), 120 pregnant women, and maternal subjects just after delivery (n=53) or postpartum (n=67). All of the subjects were healthy. Plasma levels of beta(2)-GPI, UTI, Anx IV, Anx V and other coagulation and fibrinolysis markers were measured by ELISA. The mean plasma level of beta(2)-GPI was significantly increased during the third trimester of pregnancy and 3 to 5 days after delivery. The mean plasma level of UTI was unchanged from the first trimester of pregnancy to the postpartum period. The mean plasma UTI level in vaginal delivery group was significantly higher than that in cesarean section group. beta(2)-GPI protein was expressed in some of the syncytiotrophoblasts. These data suggest that beta(2)-GPI might act to prevent blood clotting on the placental surfaces and also prevents disseminated intravascular coagulation in the microcirculation and maternal plasma. UTI levels might be kept constant by increased urinary excretion despite overproduction during pregnancy.     

De novo and salvage pathways of DNA synthesis in primary cultured neurall stem cells

We studied the de novo and salvage pathways of DNA synthesis in sphere-forming neural stem cells obtained from mouse embryos by a neurosphere method. The former pathway needs folic acid (FA) for nucleotide biosynthesis, while the latter requires deoxyribonucleosides (dNS). We examined the proliferative activity of sphere-forming cells in E14.5 embryos by counting the number of spheres formed in media that lacked FA and/or dNS. Proliferation failure and apoptosis occurred in a deficient medium lacking of both FA and dNS. Spheres formed in the deficient medium supplemented with dNS, without FA, did not produce neuron, but rather only seem to generate astrocytes and oligodendrocytes when plated under differentiation condition in culture. On the other hand, a subpopulation of cultured cells formed spheres in the deficient medium supplemented with FA alone in an appropriate concentration, and did possess the self-renewing and multipotential characteristics of neural stem cells. Spheres formed in the media containing low dose Azathioprine and methotrexate, inhibitors of de novo DNA synthesis, were selectively prevented from producing neurons even in the presence of FA. These results suggested that activating de novo DNA synthesis was needed for neural stem cells to proliferate with multipotentiality.     

Effects of an hERG Activator,ICA-105574, on Electrophysiological Properties of Canine Hearts

In short QT syndrome, inherited gain-of-function mutations in the human ether a-go-go-related gene (hERG) K⁺ channel have been associated with development of fatal arrhythmias. This implies that drugs that activate hERG as a side effect may likewise pose significant arrhythmia risk. hERG activators have been found to have diverse mechanisms of activation, which may reflect their distinct binding sites. Recently, the new hERG activator ICA-105574 was introduced, which disables inactivation of the hERG channel with very high potency. We explored characteristics of this new drug in several experimental models. Patch clamp experiments were used to verify activation of hERG channels by ICA-105574 in human embryonic kidney cells stably-expressing hERG channels. ICA-105574 significantly shortened QT and QTc intervals and monophasic action potential duration (MAP₉₀) in Langendorff-perfused guinea-pig hearts. We also administered ICA-105574 to anesthetized dogs while recording ECG and drug plasma concentrations. ICA-105574 (10 mg/kg) significantly shortened QT and QTc intervals, with a free plasma concentration of approximately 1.7 μM at the point of maximal effect. Our data showed that unbound ICA-105574 caused QT shortening in dogs at concentrations comparable to the half maximal effective concentration (EC₅₀, 0.42 μM) of hERG activation in the patch clamp studies.     

Molecular genetics of ependymomas and pediatric diffuse gliomas: a short review

Here, we review the recent literature on molecular discoveries in ependymomas and pediatric diffuse gliomas. Ependymomas can now be categorized into three location-related subgroups according to their biological profile: posterior fossa ependymomas, group A (PFA) and B (PFB), and supratentorial ependymomas. Although no recurrently mutated genes were found throughout these groups of ependymomas, PFA exhibited a CpG island methylator phenotype, PFB was associated with extensive chromosomal aberrations, and the C11orf95-RELA fusion gene was frequently observed in supratentorial ependymomas. Meanwhile, it has now become apparent that pediatric diffuse gliomas have a distinct genetic status from their adult counterparts, even though they share an indistinguishable histology. In pediatric low-grade diffuse gliomas, an intragenic duplication of the portion of FGFR1 encoding the tyrosine kinase domain (TKD) and rearrangements of MYB/MYBL1 were found recurrently and mutually exclusively. As for non-brainstem high-grade tumors, in addition to H3F3A, TP53, and ATRX mutations, which were frequently observed in older children, recurrent fusions involving NTRK1, NTRK2, and NTRK3 were reported in infants younger than 3 years of age. Moreover, in diffuse intrinsic pontine gliomas (DIPG), recurrent somatic mutations of ACVR1 were found in association with HIST1H3B mutations.