A study of the relationship between metabolism using1H-MRS and function using several neuropsychological tests in temporal lobe epilepsy

AbstractSeveral investigators have reported on the relationship between metabolism, using magnetic resonance spectroscopy (MRS), and function, using neuropsychological tests in temporal lobe epilepsy (TLE) patients , but the opinions regarding the results remain in contention. The aim of this study is to examine the relationship between metabolism, using proton MRS (1H-MRS), and function using several neuropsychological tests in the temporal lobes of TLE patients. We studied 29 TLE patients at our hospital using1H-MRS and neuropsychological tests. We used a clinical 1.5 T MR unit. We conducted five neuropsychological tests to examine the function of the left or right temporal lobe. There were significant correlations between the N-acetylaspartate/creatine + phosphocreatine (NAA/Cr) ratios and the scores of almost all of the neuropsychological tests for the temporal lobe function ipsilateral to the spike focus. However, in two Wechsler Memory Scale-Revised (WMS-R) subtests we found no significant correlation in the ipsilateral side. These findings suggest that the NAA/Cr ratios, which reflect neural metabolism, are closely related to function in the temporal lobes of TLE patients . The disparity between the results in two subtests of WMS-R show that several tests may be necessary in order to assess temporal lobe function

Autistic Traits and Brain Activation during Face-to-Face Conversations in Typically Developed Adults

BACKGROUND: Autism spectrum disorders (ASD) are characterized by impaired social interaction and communication, restricted interests, and repetitive behaviours. The severity of these characteristics is posited to lie on a continuum that extends into the general population. Brain substrates underlying ASD have been investigated through functional neuroimaging studies using functional magnetic resonance imaging (fMRI). However, fMRI has methodological constraints for studying brain mechanisms during social interactions (for example, noise, lying on a gantry during the procedure, etc.). In this study, we investigated whether variations in autism spectrum traits are associated with changes in patterns of brain activation in typically developed adults. We used near-infrared spectroscopy (NIRS), a recently developed functional neuroimaging technique that uses near-infrared light, to monitor brain activation in a natural setting that is suitable for studying brain functions during social interactions. METHODOLOGY: We monitored regional cerebral blood volume changes using a 52-channel NIRS apparatus over the prefrontal cortex (PFC) and superior temporal sulcus (STS), 2 areas implicated in social cognition and the pathology of ASD, in 28 typically developed participants (14 male and 14 female) during face-to-face conversations. This task was designed to resemble a realistic social situation. We examined the correlations of these changes with autistic traits assessed using the Autism-Spectrum Quotient (AQ). PRINCIPAL FINDINGS: Both the PFC and STS were significantly activated during face-to-face conversations. AQ scores were negatively correlated with regional cerebral blood volume increases in the left STS during face-to-face conversations, especially in males. CONCLUSIONS: Our results demonstrate successful monitoring of brain function during realistic social interactions by NIRS as well as lesser brain activation in the left STS during face-to-face conversations in typically developed participants with higher levels of autistic traits

Extracellular Vesicles from Vascular Endothelial Cells Promote Survival, Proliferation and Motility of Oligodendrocyte Precursor Cells.

We previously examined the effect of brain microvascular endothelial cell (MVEC) transplantation on rat white matter infarction, and found that MVEC transplantation promoted remyelination of demyelinated axons in the infarct region and reduced apoptotic death of oligodendrocyte precursor cells (OPCs). We also found that the conditioned medium (CM) from cultured MVECs inhibited apoptosis of cultured OPCs. In this study, we examined contribution of extracellular vesicles (EVs) contained in the CM to its inhibitory effect on OPC apoptosis. Removal of EVs from the CM by ultracentrifugation reduced its inhibitory effect on OPC apoptosis. To confirm whether EVs derived from MVECs are taken up by cultured OPCs, we labeled EVs with PKH67, a fluorescent dye, and added them to OPC cultures. Many vesicular structures labeled with PKH67 were found within OPCs immediately after their addition. Next we examined the effect of MVEC-derived EVs on OPC behaviors. After 2 days in culture with EVs, there was significantly less pyknotic and more BrdU-positive OPCs when compared to control. We also examined the effect of EVs on motility of OPCs. OPCs migrated longer in the presence of EVs when compared to control. To examine whether these effects on cultured OPCs are shared by EVs from endothelial cells, we prepared EVs from conditioned media of several types of endothelial cells, and tested their effects on cultured OPCs. EVs from all types of endothelial cells we examined reduced apoptosis of OPCs and promoted their motility. Identification of the molecules contained in EVs from endothelial cells may prove helpful for establishment of effective therapies for demyelinating diseases

精神疾患の客観的診断バイオマーカーの探索 －山の向こうに山あり，山また山－

客観的な診断バイオマーカーがなく, 問診だけで診断している精神科医療における喫緊の課題は各精神疾患の診断バイオマーカーを獲得することである. しかし, 世界中でたくさんの研究者が遺伝子解析やMRI などの画像を用いた臨床マーカーの研究に凌ぎを削っているが, 他の研究者によって再確認されることがほとんどなく, 臨床的に有用な知見は得られていない.この小論ではがんのバイオマーカー研究で始まり, 精神疾患のバイオマーカーの研究に従事し, 技術革新を目指してきた, 小生の研究の旅路を紹介する. 近赤外線スペクトロスコピーが種々の精神疾患のうつ症状の補助的診断法として厚生省から先進医療に承認されたことは大きな一歩であったが, 精神疾患患者の治療に本質的にかかわる分子マーカーの探索が必須である.（Kitakanto Med J 2014；64：117～124）A central problem in clinical psychiatry is that in the absence of objective diagnostic biomarkers for mental disorders, psychiatrists depend on subjective examinations in order to properly diagnose their patients. Many researchers have studied genetics and investigated objective tools such as magnetic resonance imaging for use as diagnostic markers to aid subjective examinations. None of these findings, however, have been replicated consistently enough to merit widespread clinical use. In this article, I would like to describe briefly the trajectory of my life’s work from cancer research to biomarker research for mental disorders, seeking for developing technical innovation in the practice of medical psychiatry. It was the excellent advance in psychiatric practice that a Near Infrared Spectroscopy(NIRS)technique has been exclusively approved by the Ministry of Health,Labour and Welfare as one of dozens of the Advanced Medical Technology to assist in the differential diagnoses of depressive states. However, a search for more essential biomarkers should be continued, to offer better care to people with mental-health problems.（Kitakanto Med J 2014；64：117～124

MVEC-EVs promoted OPC survival, proliferation, and motility in a dose-dependent manner.

<p>EVs isolated from MVEC-CM were suspended in fresh serum-free medium at 0, 3, 12.5, 50, and 200 μg/ml proteins and added to OPC culture, which were maintained for 2 days (or overnight for cell motility assay). (A) The proportion of pyknotic nuclei decreased at doses ≥ 50 μg/ml. Results are shown as mean ± SE (N = 8 in each condition). **p<0.01 and ***p<0.001. (B) The proportion of BrdU-positive cells increased at doses ≥ 50 μg/ml. Results are shown as mean ± SE (N = 8 in each condition).***p<0.001. (C) The distance of OPC migration gradually increased in a dose-dependent manner. Results are shown as mean ± SE (N = 4 in each condition). **p<0.01 and ***p<0.001. These experiments were repeated three times, and similar results were obtained each time. Typical experiments are shown here.</p

Cultured OPCs incorporated isolated MVEC-EVs.

<p>Presence of exosomal markers (CD63 and CD9), and actin, a cytoskeletal protein, in isolated MVEC-EVs was confirmed by Western blot (A). MVEC-EVs were labeled with fluorescent dye PKH67, and added to OPC culture. PKH67-labeled EVs were immediately taken up by OPCs, and many small vesicles (green) were found in OPCs (B). Scale bar: 20 μm.</p

Removal of EVs from MVEC-CM reduced its effects on cultured OPCs.

<p>OPCs were cultured in MVEC-CM or EV-dep-MVEC-CM for 3 days (or overnight for cell motility assay). As control, OPCs were cultured in fresh serum-free medium. (A) Phase contrast images. Scale bar, 50 μm. (B) OPCs were stained with Hoechst 33342, and the nuclear morphology was observed. The number of pyknotic nuclei (red arrowheads) in MVEC-CM was smaller when compared to that of EV-dep-MVEC-CM. Scale bar, 50 μm. (C) After labeling with 10 μM BrdU for the last 4 h of culture, cells were fixed and stained with an anti-BrdU antibody. Cell nuclei were stained with propidium iodide (PI, red). Many BrdU-positive cells (green) were observed in MVEC-CM. Scale bar, 50 μm. (D) Phase contrast images of OPC migration 16 h after plating (<i>Insets</i>: OPC aggregates 1 h after plating). Scale bar, 200 μm. (E) All nuclei (pyknotic or non-pyknotic) were counted in a field of microscope and the fraction of pyknotic nuclei was determined, and results are shown as mean ± SE (N = 8 in each condition). Treatment with MVEC-CM significantly inhibited apoptotic cell death of OPCs. ***p<0.001 against control. #p<0.05 against EV-dep-MVEC-CM. (F) All cells were counted in a field of microscope and the fraction of BrdU-positive cells was determined, and results are shown as mean ± SE (N = 8 in each condition). The proportion of BrdU-positive cells in MVEC-CM was significantly larger when compared to EV-dep-MVEC-CM. *p<0.05 against control and MVEC-CM. (G) The distance of OPC migration in MVEC-CM was significantly larger when compared to EV-dep-MVEC-CM. Results are shown as mean ± SE (N = 4 in each condition). ***p<0.001 against control. ###p<0.001 against EV-dep-MVEC-CM. These experiments were repeated three times, and similar results were obtained each time. Typical experiments are shown here.</p

MVEC-EVs promoted OPC survival, proliferation and motility.

<p>EVs isolated from MVEC-CM were suspended in fresh serum-free medium at 50 μg/ml of proteins and added to OPC culture, which were maintained for 2 days (or overnight for cell motility assay). As control, OPCs were cultured in fresh serum-free medium without EVs. (A) Phase contrast images. Scale bar, 50 μm. (B) OPCs were stained with Hoechst 33342, and the nuclear morphology was observed. The proportion of pyknotic nuclei (red arrowheads) in OPCs with MVEC-EVs was smaller when compared to control. Scale bar, 50 μm. (C) After labeling with BrdU for the last 4 h of culture, cells were fixed and stained with an anti-BrdU antibody. Cell nuclei were stained with propidium iodide (PI, red). Many BrdU-positive cells (green) were observed in the presence of MVEC-EVs. Scale bar, 50 μm. (D) Phase contrast images of OPC migration 16 h after plating (<i>Insets</i>: OPC aggregates at 1 h after plating). Scale bar, 200 μm. (E) The proportion of pyknotic nuclei in the presence of MVEC-EVs was significantly smaller when compared to control. Results are shown as mean ± SE (N = 8 in each condition). ***p<0.001. (F) The proportion of BrdU-positive cells in the presence of MVEC-EVs was significantly larger when compared to control. Results are shown as mean ± SE (N = 8 in each condition). ***p<0.001. (G) The distance of OPC migration in the presence of MVEC-EVs was significantly larger when compared to control. Results are shown as mean ± SE (N = 4 in each condition). ***p<0.001. These experiments were repeated three times, and similar results were obtained each time. Typical experiments are shown here.</p