Measuring effective orifice area of bileaflet mechanical valves in patients after aortic valve replacement using phase-contrast cine MR imaging

POSTER PRESENTATION2011 SCMR/Euro CMR Joint Scientific Sessions / Nice, France / 3-6 February 201

Masked diabetes insipidus in pituitary metastasis from breast cancer after thalamic biopsy: a case report

Hashimoto H., Maruo T., Nakamura M., et al. Masked diabetes insipidus in pituitary metastasis from breast cancer after thalamic biopsy: a case report. Journal of Medical Case Reports 16, 12 (2022); https://doi.org/10.1186/s13256-021-03229-y.Background: Symptomatic pituitary metastasis is rare; furthermore, it can result in diabetes insipidus and panhypopituitarism. Since diabetes insipidus is masked by concurrent panhypopituitarism, it can impede the diagnosis of pituitary dysfunction. Case presentation: A 68-year-old Japanese female suffering from pituitary and thalamic metastases caused by untreated breast cancer, underwent a biopsy targeting the thalamus, not the pituitary. She lacked prebiopsy pituitary dysfunction symptoms; however, these symptoms unexpectedly occurred after biopsy. Diabetes insipidus was masked by corticosteroid insufficiency, and she showed normal urinary output and plasma sodium levels. Upon commencement of glucocorticoid replacement therapy, the symptoms of diabetes insipidus appeared. Conclusions: In this case, thalamic biopsy, as opposed to pituitary biopsy, was performed to preserve pituitary function. However, pituitary dysfunction could not be avoided. Caution is necessary for asymptomatic patients with pituitary metastases as invasive interventions, such as surgery, may induce pituitary dysfunction. Moreover, with respect to masked diabetes insipidus, there is a need to carefully consider pituitary dysfunction to avoid misdiagnosis and delayed treatment

Cerebral cortical processing time is elongated in human brain evolution

サルより遅いヒトの脳処理 --進化するほど脳の回転は遅くなる!?--. 京都大学プレスリリース. 2022-01-26.An increase in number of neurons is presumed to underlie the enhancement of cognitive abilities in brain evolution. The evolution of human cognition is then expected to have accompanied a prolongation of net neural-processing time due to the accumulation of processing time of individual neurons over an expanded number of neurons. Here, we confirmed this prediction and quantified the amount of prolongation in vivo, using noninvasive measurements of brain responses to sounds in unanesthetized human and nonhuman primates. Latencies of the N1 component of auditory-evoked potentials recorded from the scalp were approximately 40, 50, 60, and 100 ms for the common marmoset, rhesus monkey, chimpanzee, and human, respectively. Importantly, the prominent increase in human N1 latency could not be explained by the physical lengthening of the auditory pathway, and therefore reflected an extended dwell time for auditory cortical processing. A longer time window for auditory cortical processing is advantageous for analyzing time-varying acoustic stimuli, such as those important for speech perception. A novel hypothesis concerning human brain evolution then emerges: the increase in cortical neuronal number widened the timescale of sensory cortical processing, the benefits of which outweighed the disadvantage of slow cognition and reaction

Coupling between infraslow activities and high-frequency oscillations precedes seizure onset

Hashimoto H., Khoo H.M., Yanagisawa T., et al. Coupling between infraslow activities and high-frequency oscillations precedes seizure onset. Epilepsia Open 5, 501 (2020); https://doi.org/10.1002/epi4.12425.Infraslow activities and high-frequency oscillations (HFOs) are observed in seizure-onset zones. However, the relation between them remains unclear. In this study, we investigated phase-amplitude coupling between infraslow phase (0.016-1 Hz) and HFOs' amplitude of focal impaired awareness seizures followed by focal to bilateral tonic-clonic seizures, in a 28-year-old right-handed man with a dysembryoplastic neuroepithelial tumor. We recorded five habitual seizures. After the time of seizure onset, a significant increase in the power of HFOs was observed, and the power was significantly coupled with θ (4-8 Hz) phase. In contrast, coupling of infraslow activities and HFOs surged a few minutes before the seizure-onset time, and ictal HFOs discharged after that. Collectively, our results show that coupling of infraslow activities and HFOs precedes the seizure-onset time. We infer that such coupling may be a potential biomarker for seizure prediction

Phase-amplitude coupling between infraslow and high-frequency activities well discriminates between the preictal and interictal states

Hashimoto H., Khoo H.M., Yanagisawa T., et al. Phase-amplitude coupling between infraslow and high-frequency activities well discriminates between the preictal and interictal states. Scientific Reports 11, 17405 (2021); https://doi.org/10.1038/s41598-021-96479-1.Infraslow activity (ISA) and high-frequency activity (HFA) are key biomarkers for studying epileptic seizures. We aimed to elucidate the relationship between ISA and HFA around seizure onset. We enrolled seven patients with drug-resistant focal epilepsy who underwent intracranial electrode placement. We comparatively analyzed the ISA, HFA, and ISA-HFA phase-amplitude coupling (PAC) in the seizure onset zone (SOZ) or non-SOZ (nSOZ) in the interictal, preictal, and ictal states. We recorded 15 seizures. HFA and ISA were larger in the ictal states than in the interictal or preictal state. During seizures, the HFA and ISA of the SOZ were larger and occurred earlier than those of nSOZ. In the preictal state, the ISA-HFA PAC of the SOZ was larger than that of the interictal state, and it began increasing at approximately 87 s before the seizure onset. The receiver-operating characteristic curve revealed that the ISA-HFA PAC of the SOZ showed the highest discrimination performance in the preictal and interictal states, with an area under the curve of 0.926. This study demonstrated the novel insight that ISA-HFA PAC increases before the onset of seizures. Our findings indicate that ISA-HFA PAC could be a useful biomarker for discriminating between the preictal and interictal states

Phase-amplitude coupling of ripple activities during seizure evolution with theta phase

Hashimoto H., Khoo H.M., Yanagisawa T., et al. Phase-amplitude coupling of ripple activities during seizure evolution with theta phase. Clinical Neurophysiology 132, 1243 (2021); https://doi.org/10.1016/j.clinph.2021.03.007.Objective: High-frequency activities (HFAs) and phase-amplitude coupling (PAC) are key neurophysiological biomarkers for studying human epilepsy. We aimed to clarify and visualize how HFAs are modulated by the phase of low-frequency bands during seizures. Methods: We used intracranial electrodes to record seizures of focal epilepsy (12 focal-to-bilateral tonic-clonic seizures and three focal-aware seizures in seven patients). The synchronization index, representing PAC, was used to analyze the coupling between the amplitude of ripples (80–250 Hz) and the phase of lower frequencies. We created a video in which the intracranial electrode contacts were scaled linearly to the power changes of ripple. Results: The main low frequency band modulating ictal-ripple activities was the θ band (4–8 Hz), and after completion of ictal-ripple burst, δ (1–4 Hz)-ripple PAC occurred. The ripple power increased simultaneously with rhythmic fluctuations from the seizure onset zone, and spread to other regions. Conclusions: Ripple activities during seizure evolution were modulated by the θ phase. The PAC phenomenon was visualized as rhythmic fluctuations. Significance: Ripple power associated with seizure evolution increased and spread with fluctuations. The θ oscillations related to the fluctuations might represent the common neurophysiological processing involved in seizure generation

Frequency band coupling with high-frequency activities in tonic-clonic seizures shifts from θ to δ band

Hashimoto H., Khoo H.M., Yanagisawa T., et al. Frequency band coupling with high-frequency activities in tonic-clonic seizures shifts from θ to δ band. Clinical Neurophysiology 137, 122 (2022); https://doi.org/10.1016/j.clinph.2022.02.015.Objective: To clarify variations in the relationship between high-frequency activities (HFAs) and low-frequency bands from the tonic to the clonic phase in focal to bilateral tonic-clonic seizures (FBTCS), using phase-amplitude coupling. Methods: This retrospective study enrolled six patients with drug-resistant focal epilepsy who underwent intracranial electrode placement at Osaka University Hospital (July 2018–July 2019). We recorded 11 FBTCS. The synchronization index (SI) and receiver-operating characteristic (ROC) analysis were used to analyze the coupling between HFA amplitude (80–250 Hz) and lower frequencies phase. Results: In the tonic phase, the θ (4–8 Hz)-HFA coupling peaked, and the HFA power occurred at baseline (0 μV) of θ oscillations. In contrast, in the clonic phase, the δ (2–4 Hz)-HFA coupling peaked, and the HFA power occurred at the trough of δ oscillations. ROC analysis indicated that the δ-HFA SI discriminated well the clonic from the tonic phase. Conclusions: The main low-frequency band modulating the HFA shifted from the θ band in the tonic phase to the δ band in the clonic phase. Significance: Neurophysiological key frequency bands were implied to be the θ band and δ band in tonic and clonic seizures, respectively, which improves our understanding of FBTCS

Effects of beta-adrenergic blocking agents on specific binding of [3H]D-Ala2-Met5-enkephalinamide and [3H]naloxone.

To gain further insight into the central nervous system (CNS)-action of beta-adrenergic blocking agents (beta-blockers), we examined the effects of various kinds of beta-blockers on opioid receptors (Op-Rs) using radiolabeled receptor assay (RRA). We demonstrated that beta-blockers are competitively bound to Op-Rs in the CNS. Sodium index of beta-blockers in [3H]naloxone binding study indicated that beta-blockers had the mixed agonist-antagonist activity of opiates. The relative potency of beta-blockers in opioid RRA was negatively correlated with their membrane stabilizing activity. Neither beta-blocking activity nor intrinsic sympathomimetic activity was correlated with IC50 values of beta-blockers in opioid RRA. While it is widely accepted that beta-blockers have a tranquilizing activity, a part of the tranquilizing action of beta-blockers may be mediated through Op-Rs in the CNS. Although beta-blockers may have effects on their own receptors (beta-receptors) in the CNS, the more precise mechanisms of central action of these drugs must be further investigated.</p

A Swallowing Decoder Based on Deep Transfer Learning: AlexNet Classification of the Intracranial Electrocorticogram

Electronic version of an article published as International Journal of Neural Systems, 31(11), 2021, 2050056. https://doi.org/10.1142/S0129065720500562 © 2021 World Scientific Publishing Company. https://www.worldscientific.com/worldscinet/ijnsTo realize a brain-machine interface to assist swallowing, neural signal decoding is indispensable. Eight participants with temporal-lobe intracranial electrode implants for epilepsy were asked to swallow during electrocorticogram (ECoG) recording. Raw ECoG signals or certain frequency bands of the ECoG power were converted into images whose vertical axis was electrode number and whose horizontal axis was time in milliseconds, which were used as training data. These data were classified with four labels (Rest, Mouth open, Water injection, and Swallowing). Deep transfer learning was carried out using AlexNet, and power in the high-γ band (75-150Hz) was the training set. Accuracy reached 74.01%, sensitivity reached 82.51%, and specificity reached 95.38%. However, using the raw ECoG signals, the accuracy obtained was 76.95%, comparable to that of the high-γ power. We demonstrated that a version of AlexNet pre-trained with visually meaningful images can be used for transfer learning of visually meaningless images made up of ECoG signals. Moreover, we could achieve high decoding accuracy using the raw ECoG signals, allowing us to dispense with the conventional extraction of high-γ power. Thus, the images derived from the raw ECoG signals were equivalent to those derived from the high-γ band for transfer deep learning

Anti-fibrotic Effects of ONO-EF-345, a Specific Phosphodiesterase IV inhibitor, on Lung Fibroblasts

Phosphodiesterase (PDE) IV inhibitors have been shown to inhibit various inflammatory reactions in pulmonary diseases such as bronchial asthma and chronic obstructive lung diseases (COPD). However, there have been no studies evaluating the effect of PDE IV inhibitors on airway fibrosis, which is a critical feature of airway remodeling in asthma and COPD. We therefore examined whether ONO-EF-345 (ONO), a PDE IV inhibitor, affected the function of lung fibroblasts. ONO suppressed TGF-ß-induced type I collagen (COL1) mRNA expression in lung fibroblasts and also inhibited TGF-ß-induced a- smooth muscle actin (SMA) protein expression. ONO did not affect Smad2 phosphorylation or Smad7 expression. However, ONO reduced JNK and p38 activation, which regulates TGF-ß-induced COL1 expression. These results indicate that PDE IV inhibitors exert anti-fibrotic effects through the JNK and/or p38 pathways