Postnatal Maturation of Membrane Potential Dynamics during in Vivo Hippocampal Ripples

Sharp-wave ripples (SWRs) are transient high-frequency oscillations of local field potentials (LFPs) in the hippocampus and play a critical role in memory consolidation. During SWRs, CA1 pyramidal cells exhibit rapid spike sequences that often replay the sequential activity that occurred during behavior. This temporally organized firing activity gradually emerges during 2 weeks after the eye opening; however, it remains unclear how the organized spikes during SWRs mature at the intracellular membrane potential (Vm) level. Here, we recorded Vm of CA1 pyramidal cells simultaneously with hippocampal LFPs from anesthetized immature mice of either sex after the developmental emergence of SWRs. On postnatal days 16 and 17, Vm dynamics around SWRs were premature, characterized by prolonged depolarizations without either pre- or post-SWR hyperpolarizations. The biphasic hyperpolarizations, features typical of adult SWR-relevant Vm, formed by approximately postnatal day 30. This Vm maturation was associated with an increase in SWR-associated inhibitory inputs to pyramidal cells. Thus, the development of SWR-relevant inhibition restricts the temporal windows for spikes of pyramidal cells and allows CA1 pyramidal cells to organize their spike sequences during SWRs.SIGNIFICANCE STATEMENT Sharp-wave ripples (SWRs) are prominent hippocampal oscillations and play a critical role in memory consolidation. During SWRs, hippocampal neurons synchronously emit spikes with organized temporal patterns. This temporal structure of spikes during SWRs develops during the third and fourth postnatal weeks, but the underlying mechanisms are not well understood. Here, we recorded in vivo membrane potentials from hippocampal neurons in premature mice and suggest that the maturation of SWR-associated inhibition enables hippocampal neurons to produce precisely controlled spike times during SWRs.

Machine learning-based segmentation of the rodent hippocampal CA2 area from Nissl-stained sections

The hippocampus is a center of learning, memory, and spatial navigation. This region is divided into the CA1, CA2, and CA3 areas, which are anatomically different from each other. Among these divisions, the CA2 area is unique in terms of functional relevance to sociality. The CA2 area is often manually detected based on the size, shape, and density of neurons in the hippocampal pyramidal cell layer, but this manual segmentation relying on cytoarchitecture is impractical to apply to a large number of samples and dependent on experimenters' proficiency. Moreover, the CA2 area has been defined based on expression pattern of molecular marker proteins, but it generally takes days to complete immunostaining for such proteins. Thus, we asked whether the CA2 area can be systematically segmented based on cytoarchitecture alone. Since the expression pattern of regulator of G-protein signaling 14 (RGS14) signifies the CA2 area, we visualized the CA2 area in the mouse hippocampus by RGS14-immunostaining and Nissl-counterstaining and manually delineated the CA2 area. We then established "CAseg," a machine learning-based automated algorithm to segment the CA2 area with the F1-score of approximately 0.8 solely from Nissl-counterstained images that visualized cytoarchitecture. CAseg was extended to the segmentation of the prairie vole CA2 area, which raises the possibility that the use of this algorithm can be expanded to other species. Thus, CAseg will be beneficial for investigating unique properties of the hippocampal CA2 area.

Theta oscillations represent collective dynamics of multineuronal membrane potentials of murine hippocampal pyramidal cells

Theta (θ) oscillations are one of the characteristic local field potentials (LFPs) in the hippocampus that emerge during spatial navigation, exploratory sniffing, and rapid eye movement sleep. LFPs are thought to summarize multineuronal events, including synaptic currents and action potentials. However, no in vivo study to date has directly interrelated θ oscillations with the membrane potentials (Vm) of multiple neurons, and it remains unclear whether LFPs can be predicted from multineuronal Vms. Here, we simultaneously patch-clamp up to three CA1 pyramidal neurons in awake or anesthetized mice and find that the temporal evolution of the power and frequency of θ oscillations in Vms (θ_Vms) are weakly but significantly correlate with LFP θ oscillations (θ_LFP) such that a deep neural network could predict the θ_LFP waveforms based on the θ_Vm traces of three neurons. Therefore, individual neurons are loosely interdependent to ensure freedom of activity, but they partially share information to collectively produce θ_LFP.

Inhibition allocates spikes during hippocampal ripples

Sets of spikes emitted sequentially across neurons constitute fundamental pulse packets in neural information processing, including offline memory replay during hippocampal sharp-wave ripples (SWRs). The relative timing of neuronal spikes is fine-tuned in each spike sequence but can vary between different sequences. However, the microcircuitry mechanism that enables such flexible spike sequencing remains unexplored. We recorded the membrane potentials of multiple hippocampal CA1 pyramidal cells in mice and found that the neurons were transiently hyperpolarized prior to SWRs. The pre-SWR hyperpolarizations were spatiotemporally heterogeneous, and larger hyperpolarizations were associated with later spikes during SWRs. Intracellular blockade of Cl--mediated inhibition reduced pre-SWR hyperpolarizations and advanced spike times. Single-unit recordings also revealed that the pre-SWR firing rates of inhibitory interneurons predicted the SWR-relevant spike times of pyramidal cells. Thus, pre-SWR inhibitory activity determines the sequential spike times of pyramidal cells and diversifies the repertoire of sequence patterns.

The subiculum sensitizes retrosplenial cortex layer 2/3 pyramidal neurons

KEY POINTS

Neurons in the retrosplenial cortex (RSC), a cerebral region that connects synaptically with various brain regions, are known to increase neuronal activity in accordance with hippocampal sharp wave-ripples. Pyramidal cells in granular RSC (gRSC) layer 2/3, but not layer 5, exhibit slowly ramping depolarization and considerably delayed spikes in response to a step-pulse current injection. The latencies of delayed spikes in RSC layer 2/3 pyramidal neurons were shortened by a preceding current injection. This effect was mimicked by activation of axonal afferents from the subiculum, but not of neocortical afferents. The subiculum is likely to facilitate information processing and flow in the RSC.

ABSTRACT

The retrosplenial cortex (RSC), a cerebral region involved in diverse cognitive functions, is an anatomical hub that forms monosynaptic connections with various brain areas. Here, we report a unique form of short-term intrinsic plasticity in mouse granular RSC layer 2/3 pyramidal cells. These cells exhibited delayed spikes in response to somatic current injection, but the spike latencies were shortened by a preceding brief depolarization (priming). This priming-induced sensitization is distinct from desensitization, which is commonly observed in other cortical neurons. The facilitatory priming effect lasted for more than 3 s, providing a time window for increased sensitivity to RSC inputs. Based on in vitro and in vivo patch-clamp recordings following optogenetic stimulation of axonal fibres, we found that preactivation of subicular afferents replicated the facilitatory priming effect. The results suggest that subicular inputs to RSC layer 2/3 neurons may modulate subsequent information integration in the RSC layer 2/3 circuits.

Molecular Characterization of Superficial Layers of the Presubiculum During Development

The presubiculum, a subarea of the parahippocampal region, plays a critical role in spatial navigation and spatial representation. An outstanding aspect of presubicular spatial codes is head-direction selectivity of the firing of excitatory neurons, called head-direction cells. Head-direction selectivity emerges before eye-opening in rodents and is maintained in adulthood through neurophysiological interactions between excitatory and inhibitory neurons. Although the presubiculum has been physiologically profiled in terms of spatial representation during development, the histological characteristics of the developing presubiculum are poorly understood. We found that the expression of vesicular glutamate transporter 2 (VGluT2) could be used to delimit the superficial layers of the presubiculum, which was identified using an anterograde tracer injected into the anterior thalamic nucleus (ATN). Thus, we immunostained slices from mice ranging in age from neonates to adults using an antibody against VGluT2 to evaluate the VGluT2-positive area, which was identified as the superficial layers of the presubiculum, during development. We also immunostained the slices using antibodies against parvalbumin (PV) and somatostatin (SOM) and found that in the presubicular superficial layers, PV-positive neurons progressively increased in number during development, whereas SOM-positive neurons exhibited no increasing trend. In addition, we observed repeating patch structures in presubicular layer III from postnatal days 12. The abundant expression of VGluT2 suggests that the presubicular superficial layers are regulated primarily by VGluT2-mediated excitatory neurotransmission. Moreover, developmental changes in the densities of PV- and SOM-positive interneurons and the emergence of the VGluT2-positive patch structures during adolescence may be associated with the functional development of spatial codes in the superficial layers of the presubiculum.

In Vivo Whole-Cell Patch-Clamp Methods: Recent Technical Progress and Future Perspectives

Brain functions are fundamental for the survival of organisms, and they are supported by neural circuits consisting of a variety of neurons. To investigate the function of neurons at the single-cell level, researchers often use whole-cell patch-clamp recording techniques. These techniques enable us to record membrane potentials (including action potentials) of individual neurons of not only anesthetized but also actively behaving animals. This whole-cell recording method enables us to reveal how neuronal activities support brain function at the single-cell level. In this review, we introduce previous studies using in vivo patch-clamp recording techniques and recent findings primarily regarding neuronal activities in the hippocampus for behavioral function. We further discuss how we can bridge the gap between electrophysiology and biochemistry.

Early detection of Niemann-pick disease type C with cataplexy and orexin levels: continuous observation with and without Miglustat

Study objectives

Niemann-Pick type C (NPC) is an autosomal recessive and congenital neurological disorder characterized by the accumulation of cholesterol and glycosphingolipids. Symptoms include hepatosplenomegaly, vertical supranuclear saccadic palsy, ataxia, dystonia, and dementia. Some cases frequently display narcolepsy-like symptoms, including cataplexy which was reported in 26% of all NPC patients and was more often recorded among late-infantile onset (50%) and juvenile onset (38%) patients. In this current study, we examined CSF orexin levels in the 10 patients of NPC with and without cataplexy, which supports previous findings.

Methods

Ten patients with NPC were included in the study (5 males and 5 females). NPC diagnosis was biochemically confirmed in all 10 patients, from which 8 patients with NPC1 gene were identified. We compared CSF orexin levels among NPC, narcoleptic and idiopathic hypersomnia patients.

Results

Six NPC patients with cataplexy had low or intermediate orexin levels. In 4 cases without cataplexy, their orexin levels were normal. In 5 cases with Miglustat treatment, their symptoms stabilized or improved. For cases without Miglustat treatment, their conditions worsened generally. The CSF orexin levels of NPC patients were significantly higher than those of patients with narcolepsy-cataplexy and lower than those of patients with idiopathic hypersomnia, which was considered as the control group with normal CSF orexin levels.

Discussion

Our study indicates that orexin level measurements can be an early alert of potential NPC. Low or intermediate orexin levels could further decrease due to reduction in the neuronal function in the orexin system, accelerating the patients’ NPC pathophysiology. However with Miglustat treatment, the orexin levels stabilized or improved, along with other general symptoms. Although the circuitry is unclear, this supports that orexin system is indeed involved in narcolepsy-cataplexy in NPC patients.

Conclusion

The NPC patients with cataplexy had low or intermediate orexin levels. In the cases without cataplexy, their orexin levels were normal. Our study suggests that orexin measurements can serve as an early alert for potential NPC; furthermore, they could be a marker of therapy monitoring during a treatment.

Dissipation-Based Quantum Sensing of Magnons with a Superconducting Qubit

Hybrid quantum devices expand the tools and techniques available for quantum sensing in various fields. Here, we experimentally demonstrate quantum sensing of a steady-state magnon population in a magnetostatic mode of a ferrimagnetic crystal. Dispersively coupling the magnetostatic mode to a superconducting qubit allows for the detection of magnons using Ramsey interferometry with a sensitivity on the order of 10^{-3}  magnons/sqrt[Hz]. The protocol is based on dissipation as dephasing via fluctuations in the magnetostatic mode reduces the qubit coherence proportionally to the number of magnons.

Breaking the trade-off between fast control and long lifetime of a superconducting qubit

The rapid development in designs and fabrication techniques of superconducting qubits has made coherence times of qubits longer. In the future, however, the radiative decay of a qubit into its control line will be a fundamental limitation, imposing a trade-off between fast control and long lifetime of the qubit. Here, we break this trade-off by strongly coupling another superconducting qubit along the control line. This second qubit, which we call “Josephson quantum filter” (JQF), prevents the first qubit from emitting microwave photons and thus suppresses its relaxation, while transmitting large-amplitude control microwave pulses due to the saturation of the quantum filter, enabling fast qubit control. This device functions as an automatic decoupler between a qubit and its control line and could help in the realization of a large-scale superconducting quantum processor by reducing the heating of the qubit environment and the crosstalk between qubits.

The trade-off between long lifetime and inevitable radiative decay to a control line has become a key limitation for superconducting qubits. Here, the authors break the trade-off by coupling another qubit to the control line of the first one to suppress its relaxation, while enabling fast qubit control.

SAT0057 PREDICTING INADEQUATE RESPONSE TO JAK INHIBITORS BY CLUSTER ANALYSIS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Oral Janus kinase inhibitors (JAKi) have dramatically altered outcomes in patients with rheumatoid arthritis (RA). However, there remains some proportion of patients who respond to inadequately JAKi treatment (JAKi-IR) [1,2]. The characteristics in RA patients associated with JAKi-IR have not been fully demonstrated.

Objectives:

To clarify the characteristics of JAKi-IR in patients with RA by cluster analysis.

Methods:

This retrospective study comprised 120 RA patients who were treated with JAKi (Tofacitinib or Baricitinib) between July 2013 and September 2019 in five facilities. The disease status at the baseline, at 12 weeks after JAKi treatment and at the time point of withdrawing JAKi was assessed using the Disease Activity Score (DAS28) and the American College of Rheumatology (ACR) response criteria. JAKi-IR was defined as follows, primary non-response at 12 weeks after JAKi treatment: withdrawal of JAKi with ACR20 non-response or non-improvement in DAS28-CRP (ΔDAS28-CRP<1.2 from baseline), secondary non-response: withdrawal of JAKi without clinical remission after 12 weeks. Hierarchical cluster analysis was performed with the following variables: gender, age, disease duration, bone erosion, ACR functional classification (Class ≥3), comcomitant rheumatoid arthritis related interstitial lung disease (RA-ILD) or other autoimmune disease (AID), anti-citrullinated protein antibody (ACPA) positivity, rheumatoid factor (RF) at baseline, use/dose of methotrexate (MTX) and prednisolone (PSL), serum ESR/CRP, tender/swollen joint counts (TJC/SJC), visual analog scale by patients (VAS-Pt), and prior of biologic DMARDs.

Results:

The 120 enrolled patients were classified into 4 groups by cluster analysis(Figure1), The characteristics of each group are as follows, Group A(n=21): female + bone erosion + RF/ACPA positive + AID + MTX non-user, Group B(n=36): male + older age + RA-ILD + RF/ACPA positive + MTX non-user, Group C(n=35): RF/ACPA positive + absence of RA-ILD + MTX user, Group D (n=28): seronegative + MTX user + absence of RA-ILD + history of biologic DMARDs failure. The rate of JAKi-IR was A:9%, B:8%, C:20%, D:32%, and the significant difference between Group B and D was identified (p=0.02). In multiple comparison of 4 groups, no significant difference was identified (p=0.06) (Figure2).

Conclusion:

JAKi-IR would be more likely to be seronegative, MTX use, absence of RA-ILD and history of biologic DMARDs failure. Cluster analysis is an exploratory tool that aids in the analysis of huge amount of data.

References:

[1] Takeuchi T, Yamanaka H, Yamaoka K, Arai S, Toyoizumi S, DeMasi R, et al. Efficacy and safety of tofacitinib in Japanese patients with rheumatoid arthritis by background methotrexate dose: A post hoc analysis of clinical trial data. Mod Rheumatol. 2019;29(5):756-66.

[2] Tanaka Y, Atsumi T, Amano K, Harigai M, Ishii T, Kawaguchi O, et al. Efficacy and safety of baricitinib in Japanese patients with rheumatoid arthritis: Subgroup analyses of four multinational phase 3 randomized trials. Mod Rheumatol. 2018;28(4):583-91.

Disclosure of Interests:

Masanari Sugawara: None declared, Yuichiro Fujieda: None declared, Atsushi Noguchi: None declared, Shun Tanimura: None declared, Yuka Shimizu: None declared, Ikuma Nakagawa: None declared, Michihito Kono: None declared, Masaru Kato: None declared, Kenji Oku: None declared, Tatsuya Atsumi Grant/research support from: Eli Lily Japan K.K., Alexion Pharmaceuticals, Inc., Bristol-Myers Squibb Co., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Astellas Pharma Inc., Consultant of: Gilead Sciences, Inc., Eli Lilly Japan K.K., UCB Japan Co. Ltd., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Speakers bureau: Eli Lilly Japan K.K., UCB Japan Co. Ltd., Bristol-Myers Squibb Co., AbbVie Inc., Eisai Co. Ltd., Otsuka Pharmaceutical Co., Ltd., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Takeda Pharmaceutical Co., Ltd., Astellas Pharma Inc.

Helicity-Changing Brillouin Light Scattering by Magnons in a Ferromagnetic Crystal

Brillouin light scattering in ferromagnetic materials usually involves one magnon and two photons and their total angular momentum is conserved. Here, we experimentally demonstrate the presence of a helicity-changing two-magnon Brillouin light scattering in a ferromagnetic crystal, which can be viewed as a four-wave mixing process involving two magnons and two photons. Moreover, we observe an unconventional helicity-changing one-magnon Brillouin light scattering, which apparently infringes the conservation law of the angular momentum. We show that the crystal angular momentum intervenes to compensate the missing angular momentum in the latter scattering process.

Heterogeneous expression patterns of fibronectin in the mouse subiculum

The subiculum displays as much anatomical and physiological heterogeneity as the hippocampus. Recent studies suggest that the subiculum is also diverse in terms of gene expression. However, few studies have investigated the heterogeneity of the entire subiculum. To address this issue, we focused on fibronectin because its mRNA (FN1 mRNA) is expressed in the dorsal and ventral subiculum. We immunohistochemically characterized the intracellular expression of fibronectin in the entire subiculum along three axes (i.e., the dorsoventral, proximodistal, and superficial-deep axes). We first confirmed that FN1 mRNA is translated into protein inside cells. Moreover, we found that fibronectin was expressed evenly in the pyramidal cell layer of the dorsal subiculum, whereas in the ventral subicular pyramidal field, fibronectin was most concentrated in the superficial, distal corner. These results suggest that excitatory neurons labeled by fibronectin are more localized in the ventral subiculum than in the dorsal subiculum. Therefore, fibronectin may be useful as an indicator for studying the heterogeneity of principal cells in the subiculum.

Whisker electromyograms signify awake and anesthetized states in mice

The behavioral state of animals is essential information for functional recordings of neuronal activity; practically, the exact timing when animals recover from anesthesia is important information. Recordings of cortical local field potentials and dorsal neck electromyograms (EMGs), a widely used method to identify behavioral states, requires at least two recording electrodes, one of which also requires a craniotomy procedure. In the present study, recordings of whisker EMGs alone are sufficient to detect the state switch from anesthesia to awakening in head-fixed mice. This method uses a single electrode and thus is technically simple and demands a less physical burden to animals. Moreover, whisker EMGs recorded under anesthesia reflect respiratory rhythms.

Simultaneous monitoring of mouse respiratory and cardiac rates through a single precordial electrode

Normal respiratory and circulatory functions are crucial for survival. However, conventional methods of monitoring respiration, some of which use sensors inserted into the nasal cavity, may interfere with naïve respiratory rates. In this study, we conducted a single-point measurement of electrocardiograms (ECGs) from the pectoral muscles of anesthetized and waking mice and found low-frequency oscillations in the ECG baseline. Using the fast Fourier transform of simultaneously recorded respiratory signals, we demonstrated that the low-frequency oscillations corresponded to respiratory rhythms. Moreover, the baseline oscillations changed in parallel with the respiratory rhythm when the latter was altered by pharmacological manipulation. We also demonstrated that this method could be combined with in vivo whole-cell patch-clamp recordings from the hippocampus. Thus, we developed a non-invasive form of respirometry in mice. Our recording method using a simple derivation algorithm is applicable to a variety of physiological and pharmacological experiments, providing an experimental platform in studying the mechanisms underlying the interaction of the central nervous system and the peripheral functions.

Brillouin Light Scattering by Magnetic Quasivortices in Cavity Optomagnonics

A ferromagnetic sphere can support optical vortices in the form of whispering gallery modes and magnetic quasivortices in the form of magnetostatic modes with nontrivial spin textures. These vortices can be characterized by their orbital angular momenta. We experimentally investigate Brillouin scattering of photons in the whispering gallery modes by magnons in the magnetostatic modes, zeroing in on the exchange of the orbital angular momenta between the optical vortices and magnetic quasivortices. We find that the conservation of the orbital angular momentum results in different nonreciprocal behavior in the Brillouin light scattering. New avenues for chiral optics and optospintronics can be opened up by taking the orbital angular momenta as a new degree of freedom for cavity optomagnonics.

Information-to-work conversion by Maxwell's demon in a superconducting circuit quantum electrodynamical system

Information thermodynamics bridges information theory and statistical physics by connecting information content and entropy production through measurement and feedback control. Maxwell’s demon is a hypothetical character that uses information about a system to reduce its entropy. Here we realize a Maxwell’s demon acting on a superconducting quantum circuit. We implement quantum non-demolition projective measurement and feedback operation of a qubit and verify the generalized integral fluctuation theorem. We also evaluate the conversion efficiency from information gain to work in the feedback protocol. Our experiment constitutes a step toward experimental studies of quantum information thermodynamics in artificially made quantum machines.

Maxwell’s demon is a hypothetical character that uses information about a system to reduce its entropy, highlighting the link between information and thermodynamic entropies. Here the authors experimentally realise a Maxwell's demon controlling a quantum system and explore how it affects thermodynamic laws.

Juvenile Hippocampal CA2 Region Expresses Aggrecan

Perineuronal nets (PNNs) are distributed primarily around inhibitory interneurons in the hippocampus, such as parvalbumin-positive interneurons. PNNs are also present around excitatory neurons in some brain regions and prevent plasticity in these neurons. A recent study demonstrated that PNNs also exist around mouse hippocampal pyramidal cells, which are the principle type of excitatory neurons, in the CA2 subregion and modulate the excitability and plasticity of these neurons. However, the development of PNNs in the CA2 region during postnatal maturation was not fully investigated. This study found that a main component of PNNs, aggrecan, existed in the pyramidal cell layer of the putative CA2 subarea prior to the appearance of the CA2 region, which was defined by the CA2 marker protein regulator of G protein signaling 14 (RGS14). We also found that aggrecan immunoreactivity was more evident in the anterior sections of the CA2 area than the posterior sections, which suggests that the function of CA2 PNNs varies along the anterior-posterior axis.

Antiviral Effect of Interferon Therapy for Patients with Chronic Hepatitis C

Thirty-two patients with chronic hepatitis who were positive for hepatitis C virus (HCV) RNA by polymerase chain reaction and had antibody to HCV (anti-HCV), were enrolled in this study. Twenty of them were also positive for antibody to the GOR epitope (anti-GOR). Sixteen of the enrolled patients were treated with human lymphoblastoid interferon for six months. Treatment was initiated with 3 million units of interferon daily for 2 weeks, followed by 3 million units three times a week for 6 weeks and 1.5 million units three times a week for 16 weeks. The efficacy of therapy was assessed by comparison with the results in 16 untreated patients. Aminotransferase values, titre of anti-HCV and anti-GOR antibodies showed significant decreases throughout the therapy compared with baseline levels and the untreated patients. After a 3 month follow-up, nine treated patients (56.3%) had normal aminotransferase activities and six of them eliminated HCV RNA from their sera (37.5%). Three of these six patients became negative for both anti-HCV and anti-GOR antibodies (18.8%). None of the untreated control patients had normal aminotransferase activities or became negative for HCV markers. The present study suggests that human lymphoblastoid interferon can control the disease activity and eliminate hepatitis C virus from patients with chronic hepatitis C.

Cavity Optomagnonics with Spin-Orbit Coupled Photons

We experimentally implement a system of cavity optomagnonics, where a sphere of ferromagnetic material supports whispering gallery modes (WGMs) for photons and the magnetostatic mode for magnons. We observe pronounced nonreciprocity and asymmetry in the sideband signals generated by the magnon-induced Brillouin scattering of light. The spin-orbit coupled nature of the WGM photons, their geometrical birefringence, and the time-reversal symmetry breaking in the magnon dynamics impose the angular-momentum selection rules in the scattering process and account for the observed phenomena. The unique features of the system may find interesting applications at the crossroad between quantum optics and spintronics.

Phenotypic changes associated with exogenous expression of p16INK4a in human glioma cells

The tumor suppressor p16/CDKN2A/INK4a gene is frequently mutated, mostly by homozygous deletions in high-grade gliomas. Although the p16 protein suppresses cell proliferation primarily through inhibition of cell-cycle progression at the G1 phase, other phenotypic changes in glioma cells associated with p16INK4a alterations have not been fully described. To determine the roles of p16 alterations in glioma formation, we have established ecdysone-driven inducible p16 expression in the human glioblastoma cell line CL-4, which were derived from p16-null U87MG cells. Here we show that exogenous p16 expression in CL-4 cells results in morphological changes, with large and flattened cytoplasm, which are associated with increased formation of cytoplasmic actin-stress fibers and vinculin accumulation in the focal adhesion contacts. Adhesion of CL-4 cells to extracellular matrix proteins, such as laminin, fibronectin, and type IV collagen, significantly increased upon exogenous p16 expression, which correlated with increased expression of integrin alpha5 and alphav. Expression of a small GTP-binding protein, Rac, also decreased. Following epidermal growth factor stimulation, phosphorylation of MAP kinases ERK1 and 2 and induction of an early immediate gene product, c-Fos, were significantly reduced in CL-4 cells with p16 expression. These results suggest that the tumor suppressor p16 may exert its antitumor effects through modulation of multiple aspects of glioblastoma phenotypes, including proliferation, invasiveness, and responsiveness to extracellular growth stimuli.

Itinerant electron magnetism in CaRu(1-x)Mn(x)O(3) (0 ≤ x ≤ 0.5)

The effect of Mn substitution in paramagnetic metal CaRuO(3) was studied by magnetization and neutron diffraction measurements. Development of ferromagnetic order is observed for x≥0.2 in CaRu(1-x)Mn(x)O(3). For the sample with x = 0.4, the Curie temperature of ∼160 K is obtained from the Arrott plot and the ratio of effective moment and saturation moment P(eff)/M(0) is estimated to be ∼4.8. We further found that the magnetization is significantly suppressed with decreasing temperature T below ∼90 K. In the neutron diffraction experiment at T = 15 K, we observed the evolution of a magnetic Bragg peak originating from the G-type antiferromagnetic order as well as the ferromagnetic one. This strongly suggests that both ferromagnetic and antiferromagnetic states are coexistent with each other at low temperatures. In the M(T)(0)(2) against T(2) plot (here, M(T)(0) is a spontaneous magnetization estimated from the Arrott plot), M(T)(0)(2) linearly increases with decreasing T(2) in the ferromagnetic region between ∼90 and 160 K. The ferromagnetic properties of the CaRu(1-x)Mn(x)O(3) system (x≤0.5) are well explained in terms of spin fluctuation theory based on the itinerant electron model rather than the localized spin model.

Zoledronate facilitates large-scale ex vivo expansion of functional gammadelta T cells from cancer patients for use in adoptive immunotherapy

BACKGROUND

Human gammadelta T cells can be activated by phospho-antigens and aminobisphosphonates such as zoledronate. Because they can kill tumor cells in a major histocompatibility complex (MHC)-unrestricted manner, adoptive transfer of activated gammadelta T cells may represent a novel cancer immunotherapy. We tested whether gammadelta T cells from advanced cancer patients can be expanded by zoledronate.

METHODS

Peripheral blood mononuclear cells from healthy donors and patients with advanced non-small cell lung cancer, bone metastatic breast or prostate cancer, or lung metastatic colorectal cancer, were stimulated with zoledronate (5 microM) and interleukin (IL)-2 (1000 IU/mL) for 14 days. The phenotype and function of the expanded gammadelta T-cell populations from healthy donors and cancer patients were compared.

RESULTS

Gammadelta T cells from cancer patients and healthy donors responded to zoledronate equally well in terms of both phenotype and function. gammadelta T cells grew rapidly in vitro and expression of effector molecules, such as interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, perforin, granzyme B, FasL and TRAIL, increased over time. Cytotoxicity peaked on days 12-14, and proliferation continued up to 14 days, during which time>1x10(9) gammadelta T cells could be obtained from a starting sample of 45-70 mL peripheral blood.

DISCUSSION

Using the agent zoledronate, already widely used in the clinic, we have established that efficient large-scale ex vivo expansion of gammadelta T cells from cancer patients is possible. These cells exert potent cytotoxicity and may be used for autologous cellular immunotherapy of cancer.

Keratan sulphate levels in mucopolysaccharidoses and mucolipidoses

The mucopolysaccharidoses (MPS) is characterized by accumulation of glycosaminoglycans (GAGs), and mucolipidosis (ML) by accumulation of GAGs and sphingolipids. Each type of MPS accumulates specific GAGs. The lysosomal enzymes N-acetylgalactosamine-6-sulphate sulphatase and beta-galactosidase involve the stepwise degradation of keratan sulphate (KS). Deficiency of these enzymes results in elevation of KS levels in the body fluids and in tissues, leading to MPS IV disease. In this study, we evaluated blood and urine KS levels in types of MPS and ML other than MPS IV. Eighty-five plasma samples came from MPS I (n = 18), MPS II (n = 28), MPS III (n = 20), MPS VI (n = 3), MPS VII (n = 5) and ML (n = 11) patients while 127 urine samples came from MPS I (n = 34), MPS II (n = 34), MPS III (n = 32), MPS VI (n = 7), MPS VII (n = 9) and ML (n = 11) patients. KS levels were determined using the ELISA method. Plasma KS levels varied with age in both control and patient populations. In all age groups, the mean values of plasma KS in MPS and ML patients were significantly higher than those in the age-matched controls. Plasma KS values in four newborn patients were above the mean + 2SD of the age-matched controls (mean, 41 ng/ml). Overall, 85.9% of individual values in non-type IV MPS and ML patients were above the mean + 2SD of the age-matched controls. For urine KS levels, 24.4% of individual values in patients were above the mean + 2SD of the age-matched controls. In conclusion, KS in blood is elevated in each type of non-type IV MPS examined, in contrast to the conventional understanding. This finding suggests that measurement of KS level provides a new diagnostic biomarker in a wide variety of mucopolysaccharidoses and mucolipidoses in addition to MPS IV.

Heparan sulfate levels in mucopolysaccharidoses and mucolipidoses

Glycosaminoglycans are accumulated in both mucopolysaccharidoses (MPS) and mucolipidoses (ML). MPS I, II, III and VII and ML II and ML III patients cannot properly degrade heparan sulphate (HS). In spite of the importance of HS storage in the metabolic pathway in these diseases, blood and urine HS levels have not been determined systematically using a simple and economical method. Using a new ELISA method using anti-HS antibodies, HS concentrations in blood and urine were determined in MPS and ML II and ML III patients. HS concentrations were determined in 156 plasma samples from MPS I (n = 23), MPS II (n = 26), MPS III (n = 24), MPS IV (n = 62), MPS VI (n = 5), MPS VII (n = 5), ML II (n = 8) and ML III (n = 3), and 205 urine samples from MPS I (n = 33), MPS II (n = 33), MPS III (n = 30), MPS IV (n = 82), MPS VI (n = 7), MPS VII (n = 9), ML II (n = 8) and ML III (n = 3). The ELISA method used monoclonal antibodies against HS. MPS I, II, III and VII and ML II and III patients had significant elevation in plasma HS, compared to the age-matched controls (p < 0.0001). Eighty-three out of 89 (93.3%) of individual values in the above MPS types and ML were above the mean +2SD of the controls. In urine samples, 75% of individual values in patients with those types were above the mean +2SD of the controls. In contrast to the previous understanding of the HS metabolic pathway, plasma HS levels in all five MPS VI and 15% of MPS IV patients were elevated above the mean +2SD of the controls. These findings suggest that HS concentration determined by ELISA, especially in plasma, could be a helpful marker for detection of the most severe MPS I, II, III, VI and VII and ML II, distinguishing them from normal populations.

Confocal and probe microscopy to study gene transfection mediated by cationic liposomes with a cationic cholesterol derivative

A novel cationic cholesterol derivative with a hydroxyethyl amino head group (I) has been synthesized and used for liposome-mediated gene transfection. Cationic liposomes with derivative (I) greatly facilitated gene transfection into various cultured cells. The efficiency of transfection by liposomes with derivative (I) was much higher than that using liposomes with DC-chol (II) or lipofectine. Atomic force microscopy and confocal laser scanning microscopy revealed the molecular mechanism of gene transfection by cationic liposomes. The results showed that at least two steps were involved in gene transfection mediated by cationic liposomes. One was endocytosis, where the liposome-DNA complex was internalized into target cells, and the other was membrane fusion between the liposome vectors and endosomes, where DNA transferred from the liposome to the nucleus. In addition we found that microtubules were involved in the intracellular dynamics of gene transfection.

Evaluating the performance of a hybrid artificial liver support system with a recoverable hepatic failure rat model

To evaluate the performance of an artificial liver, we created a recoverable hepatic failure rat model. This involves a 30-60 minute warm ischemia, via clamping, of one-third of the liver with a partial (two-thirds) hepatectomy. Variations on this method provide for the possibility of several modes of hepatic failure. Survival time of the rats was prolonged (35%) by applying our hybrid artificial liver. However, the extracorporeal circulation is a considerable burden to the rat. Therefore, we need to apply the hybrid artificial liver intermittently and repeatedly.

Sustained release of basic fibroblast growth factor and angiogenesis in a novel covalently crosslinked gel of heparin and alginate

The construction of organs by tissue engineering and regenerative engineering, using an artificial extracellular matrix, is an innovative method that is expected to replace artificial organs and organ transplantation. We have produced an artificial extracellular matrix of alginate and demonstrated that the matrix stimulated the regeneration of skin, nerve, and bone. In this report, the new matrix, which consists of heparin and alginate covalently crosslinked with ethylenediamine, was produced to stabilize and control the release of growth factors. Heparin content of the new matrix was confirmed by toluidine blue absorption, elementary analysis, and Fourier transform infrared spectrum. In vitro experiments showed that the new matrix significantly suppressed the initial burst of basic fibroblast growth factor, which is a representative member of heparin-binding growth factors, and released biologically active basic fibroblast growth factor for 1 month under physiological conditions. Obvious cellular infiltration and angiogenesis were shown to occur in the new matrix which was implanted subcutaneously in the dorsal area of rat with 1 microg of basic fibroblast growth factor for 2 weeks. This new matrix may be useful for not only the construction of transplantable blood vessels of small diameter, but also the induction of angiogenesis in regenerated skin constructed by tissue engineering.

Inhibitory effects of sodium butyrate on proliferation and invasiveness of human glioma cells

OBJECTIVE

Sodium butyrate (SB), a differentiation-inducing agent, has been demonstrated to inhibit cellular proliferation in a number of human cell lines. Its precise mechanisms remain to be clarified, however. We investigated molecular mechanisms of SB-induced growth suppression as well as the effects of SB on the invasiveness of human glioma cells.

METHODS

Human glioma U87MG and U251MG cells were treated with 1 or 2 mmol/L SB for 48 hours, and the inhibition of cell growth was assessed by spectrophotometric analysis. Cell cycle analysis was carried out by the 5-bromo-2'-deoxyuridine incorporation method, and expression of cell cycle-regulatory proteins was determined by immunoblotting. In addition, invasiveness was assessed using a Transwell chamber (Iwaki, Tokyo, Japan) with extracellular matrix substrate fibronectin or laminin (Iwaki).

RESULTS

SB treatment resulted in significantly suppressed proliferation of both U87MG and U251MG cells in a dose-dependent manner. It inhibited the G1-S transition, which was associated with increased expression of p21 and cyclin D1 and reduced pRb phosphorylation. Treatment with antisense oligonucleotide for Rb abrogated SB-induced G1 arrest. p21 up-regulation was independent of the p53 status of the glioma cells. SB treatment also inhibited invasiveness on fibronectin and laminin.

CONCLUSION

Our results indicate that SB may suppress the growth of human glioma cells through modulation of cell cycle progression and also may affect their invasiveness on extracellular matrix substrates, which suggests that SB may be a useful therapeutic agent in treating multiple aspects of malignant gliomas.

[Primary squamous cell carcinoma of the prostate forming a rectourethral fistula: a case report]

Eleven cases of squamous cell carcinoma of the prostate have been previously reported in the Japanese medical literature. Patients with this type of carcinoma have dismal prognoses. Herein, we report a case in a 61-year-old man who was admitted to our hospital and whose chief complaints were dysuria and high fever. Pyuria, bacteriuria, and the results of a digital rectal examination suggested acute prostatitis. Despite the administration of antibiotics, the dysuria did not improve. A transrectal needle biopsy was performed, and histology of the tissue showed squamous cell carcinoma. After chemotherapy using methotrexate, pirarubicin, and cisplatin, total pelvic excentration was performed. At 12 months after the operation, the patient is alive with no evidence of the disease.

[A case of traumatic priapism]

We report a case of high flow priapism secondary to arteriovenous fistula produced by perineal trauma in a 43-year-old patient. Diagnosis was based on the result of gasometry in cavernous blood and color doppler sonography. Superselective embolization of the deep artery of the penis was performed with good results. After 6 months of treatment, erection and sexual function were normal. Our case demonstrates that this procedure is a safe and effective therapy for high flow priapism.

A case of black dot ringworm with a review of Japanese cases

Black dot ringworm (BDR), caused by Trichophyton violaceum var. glabrum (T. glabrum), was observed in a 28-year-old Japanese female who had been treated with prednisolone (22.5 mg/day) for systemic lupus erythematosus. It was successfully treated with oral terbinafine (125 mg/day) for 12 weeks. The causative fungus was identified by molecular analysis as well as morphological and biochemical examination. The chitin synthase 1 (CHS1) gene cleavage pattern of the clinical isolate with restricted enzyme HinfI was identical to that of T. violaceum. We reviewed previous reports of BDR to determine the historical trend of this infection in Japan. Since 1974, 93 Japanese cases have been reported. The age distribution was bi-modal: the higher peak consisted of children (aged 0-15 years), and the lower peak was composed of the elderly (aged 60-75 years). In the elderly group, females were predominant (M:F=1:22, p<0.001). T. violaceum, including T. glabrum, was identified as the most common causative fungus of BDR (75.3%). Sixty percent of cases showed slight erythema. In 8 families, 16 cases were found to be intrafamilial infections. A history of previous steroid treatment was described in about 40%.

A cluster of lysinuric protein intolerance (LPI) patients in a northern part of Iwate, Japan due to a founder effect. The Mass Screening Group

Lysinuric protein intolerance is an autosomal recessive disease characterized by defective transport of the dibasic aminoacids. Mutational analysis of LPI patients in the northern part of Japan revealed that six were homozygous for the R410X mutation and two others were compound heterozygotes of R410X and other unknown mutations. In the population epidemiology study in a local cluster in the northern part of Iwate, ten heterozygotes were found in 1190 newborn babies leading to an estimated LPI incidence of 1/57,000. Polymorphism analysis revealed two major alleles, A and B, in intron 8. While the population frequency of allele A was 0.9 and that of allele B was 0.1 in the northern part of Japan the R410X mutations were exclusively on allele B in 31 chromosomes suggesting a founder effect. Genetic analysis in patients revealed strong linkage disequilibrium with D14S283 and TCRA indicating that the R410X mutation occurred before at least 130 generations ago (about 2600 years). The R410X mutation was shown to be useful as a molecular marker for screening LPI patients in the northern part of Japan.

Production of male cloned mice from fresh, cultured, and cryopreserved immature Sertoli cells

Although it is generally accepted that relatively high efficiencies of somatic cell cloning in mammals can be achieved by using donor cells from the female reproductive system (e.g., cumulus/granulosa, oviduct, and mammary gland cells), there is little information on the possibility of using male-specific somatic cells as donor cells. In this study we injected the nucleus of immature mouse Sertoli cells isolated from the testes of newborn (Days 3-10) males into enucleated mature oocytes in order to examine the ability of their nuclei to support embryonic development. After activation of the oocytes that had received the freshly recovered immature Sertoli cells, some developed into the morula/blastocyst stage, depending on the age of the donor cells (22.0-37.4%). When transferred into pseudopregnant females, 7 (3.3%, 7 of 215) developed into normal pups at term. Nuclear transfer of immature Sertoli cells after 1 wk in culture also produced normal pups after embryo transfer (3.1%, 2 of 65). Even after cryopreservation in a conventional cryoprotectant solution, their ability as donor cells was maintained, as demonstrated by the birth of cloned young (6.7%, 7 of 105). Immature Sertoli cells transfected with green fluorescent protein gene also supported embryo development into morulae/blastocysts, which showed specific fluorescence. This study demonstrates that immature Sertoli cells, male-specific somatic cells, are potential donors for somatic cell cloning.

SLC7A7 genomic structure and novel variants in three Japanese lysinuric protein intolerance families

Lysinuric protein intolerance (LPI) is a rare inherited disease caused by defective transport of the dibasic amino acids at the basolateral membranes of epithelial cells in the renal tubules and small intestine. The metabolic defect leads to brain dysfunction caused by hyperammonemia with a functional impairment of the urea cycle. Recently, mutations in the human SLC7A7 cDNA coding for y(+)LAT-1, which express dibasic amino acid transport activity, were reported to be responsible for LPI. In the present study, we examined the genomic structure of SLC7A7 by DNA sequencing of PCR products, and determined that the gene had 11 exons and 10 introns spanning about 18 kb of genomic DNA. We also identified an alternative RNA splicing at the 5' untranslated region of the SLC7A7 mRNA in human peripheral blood leukocytes, cultured lymphoblasts, and fibroblasts. As a result of mutational analysis of SLC7A7 in three Japanese LPI families, we found a nonsense mutation (R410X), a splicing mutation(911+1G>A) in intron 4, and four silent polymorphisms (201C/T, 445A/G, 784C/T, 946T/C). Identification of the genomic structure of SLC7A7 may provide a molecular basis for a genetic survey for LPI.

Two peptides from CD23, including the inverse RGD sequence and its related peptide, interact with the MHC class II molecule

The human CD23 molecule (low affinity receptor for IgE) has a C-type lectin domain, a reversed Arg-Gly-Asp (RGD) sequence near the C-terminus, and an "RGD-binding inhibitory peptide" at the root of the N-sugar chain. Three peptides were synthesized to determine their functions, i.e., #1, including an inverse RGD sequence near the C-terminus; #2, RGD-binding inhibitory peptides in the gpIIIa chain of platelet integrin gpIIb/IIIa; and #3, the inverse sequence located at the root of the N-sugar chain of CD23 which has homology to peptide 2. Among the three peptide, only peptide 3 inhibited aggregation of L-KT9 cells. Isotope-labeled peptides 1 and 3 bound to MHC class II molecules but peptide 1 did not bind to CD23 molecules. Peptide 3 showed a higher affinity to MHC class II than did peptide 1. Both peptides in CD23, therefore, seem to have interesting and important functions in relation to MHC class II molecules and also to CD23 molecules when CD23 on EBV-transformed B cells acts as a lectin in homotypic cell aggregation. The physiological function of CD23 was discussed from an evolutional point of view.