Oxytocin-induced increases in cytokines and clinical effect on the core social features of autism: Analyses of RCT datasets

Although oxytocin may provide a novel therapeutics for the core features of autism spectrum disorder (ASD), previous results regarding the efficacy of repeated or higher dose oxytocin are controversial, and the underlying mechanisms remain unclear. The current study is aimed to clarify whether repeated oxytocin alter plasma cytokine levels in relation to clinical changes of autism social core feature. Here we analyzed cytokine concentrations using comprehensive proteomics of plasmas of 207 adult males with high-functioning ASD collected from two independent multi-center large-scale randomized controlled trials (RCTs): Testing effects of 4-week intranasal administrations of TTA-121 (A novel oxytocin spray with enhanced bioavailability: 3U, 6U, 10U, or 20U/day) and placebo in the crossover discovery RCT; 48U/day Syntocinon or placebo in the parallel-group verification RCT. Among the successfully quantified 17 cytokines, 4 weeks TTA-121 6U (the peak dose for clinical effects) significantly elevated IL-7 (9.74, 95 % confidence interval [CI] 3.59 to 15.90, False discovery rate corrected P (PFDR) < 0.001), IL-9 (56.64, 20.46 to 92.82, PFDR < 0.001) and MIP-1b (18.27, 4.96 to 31.57, PFDR < 0.001) compared with placebo. Inverted U-shape dose-response relationships peaking at TTA-121 6U were consistently observed for all these cytokines (IL-7: P < 0.001; IL-9: P < 0.001; MIP-1b: P = 0.002). Increased IL-7 and IL-9 in participants with ASD after 4 weeks TTA-121 6U administration compared with placebo was verified in the confirmatory analyses in the dataset before crossover (PFDR < 0.001). Furthermore, the changes in all these cytokines during 4 weeks of TTA-121 10U administration revealed associations with changes in reciprocity score, the original primary outcome, observed during the same period (IL-7: Coefficient = -0.05, -0.10 to 0.003, P = 0.067; IL-9: -0.01, -0.02 to -0.003, P = 0.005; MIP-1b: -0.02, -0.04 to -0.007, P = 0.005). These findings provide the first evidence for a role of interaction between oxytocin and neuroinflammation in the change of ASD core social features, and support the potential role of this interaction as a novel therapeutic seed. Trial registration: UMIN000015264, NCT03466671/UMIN000031412.

Effects of volatile anesthetics on circadian rhythm in mice: a comparative study of sevoflurane, desflurane, and isoflurane

PURPOSE

Volatile anesthetics affect the circadian rhythm of mammals, although the effects of different types of anesthetics are unclear. Here, we anesthetized mice using several volatile anesthetics at two different times during the day. Our objective was to compare the effects of these anesthetics on circadian rhythm.

METHODS

Male adult C57BL/6 J mice were divided into eight groups (n = 8 each) based on the anesthetic (sevoflurane, desflurane, isoflurane, or no anesthesia) and anesthesia time (Zeitgeber time [ZT] 6-12 or ZT18-24). Mice were anesthetized for 6 h using a 0.5 minimum alveolar concentration (MAC) dose under constant dark conditions. The difference between the start of the active phase before and after anesthesia was measured as a phase shift. Clock genes were measured by polymerase chain reaction in suprachiasmatic nucleus (SCN) samples removed from mouse brain after anesthesia (n = 8-9 each).

RESULTS

Phase shift after anesthesia at ZT6-12 using sevoflurane (- 0.49 h) was smaller compared with desflurane (- 1.1 h) and isoflurane (- 1.4 h) (p < 0.05). Clock mRNA (ZT6-12, p < 0.05) and Per2 mRNA (ZT18-24, p < 0.05) expression were different between the groups after anesthesia.

CONCLUSION

0.5 MAC sevoflurane anesthesia administered during the late inactive to early active phase has less impact on the phase shift of circadian rhythm than desflurane and isoflurane. This may be due to differences in the effects of volatile anesthetics on the expression of clock genes in the SCN, the master clock of the circadian rhythm.

Is oral Streptococcus mutans with collagen-binding protein a risk factor for intracranial aneurysm rupture or formation?

OBJECTIVE

Streptococcus mutans (SM) with the collagen-binding protein Cnm is a unique member of the oral resident flora because it causes hemorrhagic vascular disorders. In the multicenter study, we examined the relationship between Cnm-positive SM (CP-SM) and intracranial aneurysm (IA) rupture, which remains unknown.

METHODS

Between May 2013 and June 2018, we collected whole saliva samples from 431 patients with ruptured IAs (RIAs) and 470 patients with unruptured IAs (UIAs). Data were collected on age, sex, smoking and drinking habits, family history of subarachnoid hemorrhage, aneurysm size, number of teeth, and comorbidities of lifestyle disease.

RESULTS

There was no difference in the positivity rate of patients with CP-SM between the patients with RIAs (17.2%) and those with UIAs (19.4%). The rate of positivity for CP-SM was significantly higher in all IAs <5 mm than in those ≥10 mm in diameter (P=0.0304). In the entire cohort, the rate of positivity for CP-SM was lower in larger aneurysms than in smaller aneurysms (P=0.0393).

CONCLUSIONS

The rate of positivity for CP-SM was lower among patients with large UIAs. These findings are consistent with the hypothesis that CP-SM plays a role in the formation of vulnerable IAs that tend to rupture before becoming larger.

Correction to "Fabrication of a Floatable Micron-Sized Enzyme Device Using Diatom Frustules"

[This corrects the article DOI: 10.1021/acsomega.3c02104.].

Fabrication of a Floatable Micron-Sized Enzyme Device Using Diatom Frustules

Immobilization of enzymes has been widely reported due to their reusability, thermal stability, better storage abilities, and so on. However, there are still problems that immobilized enzymes do not have free movements to react to substrates during enzyme reactions and their enzyme activity becomes weak. Moreover, when only the porosity of support materials is focused, some problems such as enzyme distortion can negatively affect the enzyme activity. Being a solution to these problems, a new function "floatability" of enzyme devices has been discussed. A "floatable" micron-sized enzyme device was fabricated to enhance the free movements of immobilized enzymes. Diatom frustules, natural nanoporous biosilica, were used to attach papain enzyme molecules. The floatability of the frustules, evaluated by macroscopic and microscopic methods, was significantly better than that of four other SiO2 materials, such as diatomaceous earth (DE), which have been widely used to fabricate micron-sized enzyme devices. The frustules were fully suspended at 30 °C for 1 h without stirring, although they settled at room temperature. When enzyme assays were performed at room temperature, 37, and 60 °C with or without external stirring, the proposed frustule device showed the highest enzyme activity under all conditions among papain devices similarly prepared using other SiO2 materials. It was confirmed by the free papain experiments that the frustule device was active enough for enzyme reactions. Our data indicated that the high floatability of the reusable frustule device, and its large surface area, is effective in maximizing enzyme activity due to the high probability to react to substrates.

Dietary Iron Restriction Protects against Aneurysm Rupture in a Mouse Model of Intracranial Aneurysm

INTRODUCTION

Iron accumulation in vessel walls induces oxidative stress and inflammation, which can cause cerebrovascular damage, vascular wall degeneration, and intracranial aneurysmal formation, growth, and rupture. Subarachnoid hemorrhage from intracranial aneurysm rupture results in significant morbidity and mortality. This study used a mouse model of intracranial aneurysm to evaluate the effect of dietary iron restriction on aneurysm formation and rupture.

METHODS

Intracranial aneurysms were induced using deoxycorticosterone acetate-salt-induced hypertension and a single injection of elastase into the cerebrospinal fluid of the basal cistern. Mice were fed an iron-restricted diet (n = 23) or a normal diet (n = 25). Aneurysm rupture was detected by neurological symptoms, while the presence of intracranial aneurysm with subarachnoid hemorrhage was confirmed by post-mortem examination.

RESULTS

The aneurysmal rupture rate was significantly lower in iron-restricted diet mice (37%) compared with normal diet mice (76%; p < 0.05). Serum oxidative stress, iron accumulation, macrophage infiltration, and 8-hydroxy-2'-deoxyguanosine in the vascular wall were lower in iron-restricted diet mice (p < 0.01). The areas of iron positivity were similar to the areas of CD68 positivity and 8-hydroxy-2'-deoxyguanosine in both normal diet and iron-restricted diet mouse aneurysms.

CONCLUSIONS

These findings suggest that iron is involved in intracranial aneurysm rupture via vascular inflammation and oxidative stress. Dietary iron restriction may have a promising role in preventing intracranial aneurysm rupture.

Hybridization of papain molecules and DNA-wrapped single-walled carbon nanotubes evaluated by atomic force microscopy in fluids

Although various conjugates of single-walled carbon nanotubes (SWNTs) and biomolecules, such as nanobiosensors and nanobiodevices, have been reported, the conjugation of papain and SWNTs have not been reported because of the formation of unexpected aggregates. In this study, atomic force microscopy (AFM) in liquid was used to investigate the interactions between papain and DNA-wrapped SWNTs (DNA-SWNTs) at two different pH values (pH 3.0 and 10.5). The direct AFM observation of the mixture of papain and DNA-SWNTs confirmed the aggregation of papain molecules with DNA-SWNTs in the buffer solutions. The numerous and non-uniform adsorption of papain molecules onto DNA-SWNTs was more pronounced at pH 3.0 than that at pH 10.5. Furthermore, thick conjugates appeared when papain and DNA-SWNTs were simultaneously mixed. The near-infrared photoluminescence spectra of the SWNTs drastically changed when the papain molecules were injected into the DNA-SWNT suspension at pH 3.0. Thus, the regulation of electrostatic interactions is a key aspect in preparing optimal conjugates of papain and DNA-SWNTs. Furthermore, although previous papers reported AFM images of dried samples, this study demonstrates the potential of AFM in liquid in evaluating individual bioconjugates of SWNTs.

Efficacy and Safety of Prasugrel vs Clopidogrel in Thrombotic Stroke Patients With Risk Factors for Ischemic Stroke Recurrence: A Double-blind, Phase III Study (PRASTRO-III)

AIM

To examine the efficacy and safety of prasugrel vs clopidogrel in thrombotic stroke patients at risk of ischemic stroke.

METHODS

This multicenter, active-controlled, randomized, double-blind, double-dummy, parallel group study enrolled thrombotic stroke patients aged ≥ 50 years at risk of ischemic stroke. Patients received prasugrel (3.75 mg/day) or clopidogrel (75 or 50 mg/day) for 24-48 weeks; other antiplatelet drugs were prohibited. The primary efficacy endpoint was the composite incidence of ischemic stroke, myocardial infarction (MI), and death from other vascular causes from the start to 1 day after treatment completion or discontinuation. Secondary efficacy endpoints included the incidences of ischemic stroke, MI, death from other vascular causes, ischemic stroke and transient ischemic attack, and stroke. Safety endpoints included bleeding events and adverse events (AEs).

RESULTS

In the prasugrel (N=118) and clopidogrel (N=112; all received 75 mg) groups, the primary efficacy endpoint composite incidence (95% confidence interval) was 6.8% (3.0%-12.9%) and 7.1% (3.1%-13.6%), respectively. The risk ratio (prasugrel/clopidogrel) was 0.949 (0.369-2.443). Secondary efficacy endpoints followed a similar trend. The combined incidences of life-threatening, major, and clinically relevant bleeding were 5.0% and 3.5% in the prasugrel and clopidogrel groups, respectively. The incidences of all bleeding events and AEs were 19.2% and 24.6% and 76.7% and 82.5% in the prasugrel and clopidogrel groups, respectively. No serious AEs were causally related to prasugrel.

CONCLUSIONS

We observed a risk reduction of 5% with prasugrel vs clopidogrel, indicating comparable efficacy. There were no major safety issues for prasugrel.

Attachment of DNA-Wrapped Single-Walled Carbon Nanotubes (SWNTs) for a Micron-Sized Biosensor

We fabricated a micron-sized biodevice based on the near-infrared photoluminescence (PL) response of single-walled carbon nanotubes (SWNTs). Various biosensors using the unique optical responses of SWNTs have been proposed by many research groups. Most of these employed either colloidal suspensions of dispersed SWNTs or SWNT films on flat surfaces, such as electrodes. In this study, we attached DNA-wrapped SWNTs (DNA-SWNTs) to frustule (micron-sized nanoporous biosilica) surfaces, which were purified from cultured isolated diatoms. After the injection of an oxidant and a reductant, the SWNTs on the frustules showed prominent PL responses. This suggests that the biodevice functions as a micron-sized redox sensor. Frustules can be easily suspended in aqueous solutions because of their porous structures and can easily be collected as pellets by low-speed centrifugation. Thus, the removal of unbound SWNTs and the recovery of the fabricated DNA-SWNT frustules for reuse were achieved by gentle centrifugation. Our proposal for micron-sized SWNT biodevices would be helpful for various biological applications.

An Efficient Method of Observing Diatom Frustules via Digital Holographic Microscopy

Herein, we propose a convenient method to enable pretreatment of target objects using digital holographic microscopy (DHM). As a test sample, we used diatom frustules (Nitzschia sp.) as the target objects. In the generally used sample preparation method, the frustule suspension is added dropwise onto a glass substrate or into a glass chamber. While our work confirms good observation of purified frustules using the typical sample preparation method, we also demonstrate a new procedure to observe unseparated structures of frustules prepared by baking them on a mica surface. The baked frustules on the mica surface were transferred to a glass chamber with 1% sodium dodecyl sulfate solution. In this manner, the unseparated structures of the diatom frustules were clearly observed. Furthermore, metal-coated frustules prepared by sputtering onto them on a mica surface were also clearly observed using the same procedure. Our method can be applied for the observation of any target object that is pretreated on a solid surface. We expect our proposed method to be a basis for establishing DHM techniques for microscopic observations of biomaterials.

Distinguishing Antioxidant Molecules with Near-Infrared Photoluminescence of DNA-Wrapped Single-Walled Carbon Nanotubes

In this study, two biomolecule solutions were distinguished using the capacity difference in the near-infrared photoluminescence (PL) of single-walled carbon nanotubes (SWNTs). Biosensing techniques using sensitive responses of SWNTs have been intensively studied. When a small amount of an oxidant or reductant solution was injected into the SWNT suspensions, the PL intensity of the SWNTs is significantly changed. However, distinguishing between different molecules remains challenging. In this study, we comparably injected saponin and banana solutions, which are known antioxidant chemicals, into an SWNT suspension. The SWNTs were solubilized by wrapping them with DNA molecules. The results show that 69.1 and 155.2% increases of PL intensities of SWNTs were observed after injection of 20 and 59 μg/mL saponin solutions, respectively. Subsequently, the increase in PL was saturated. With the banana solution, 18.1 and 175.4% increases in PL intensities were observed with 20 and 59 μg/mL banana solutions, respectively. Based on these results, the two antioxidant molecules could be distinguished based on the different PL responses of the SWNTs. In addition, the much higher saturated PL intensities observed with the banana solution suggests that the banana solution increased the capacity of the PL increase for the same SWNT suspension. These results provide helpful information for establishing biosensing applications of SWNTs, particularly for distinguishing chemicals.

Successful lactation in Plgrkt-deficient female mice caused by a 1-bp deletion of exon4

Plasminogen (Pg) activation on the cell surface is important for various (patho)physiologic conditions, and Plg-RKT is a cell membrane protein that binds to Pg and promotes its activation. To evaluate the role of Plg-RKT in atherosclerosis, Plgrkt gene in Ldlr-/-/Apobec1-/- was modified using in vivo CRISPR/Cas9. Synthetic RNA for Plgrkt and Cas9 complex was electroporated into the fertilized eggs in the oviducts. Plgrkt deficient mice were established through a 1-bp deletion, and in this research communication we report their lactational ability. In contrast to Plgrkt-/- mice developed by a conventional method, these newly developed mice did not suffer lactation failure and could maintain their pups until weaning. The major obvious difference between these lines is the area of gene modification. The conventionally developed mouse possesses about 10 kb deletion of Plgrkt, which might relate to the lactation failure. Lactation failure is a lethal phenotype in mammals, and analyses of causative genes are especially important for dairy industries. Further genome-wide analyses with both Plgrkt-/- mice may help to establish causative genes for lactation failure.

Abstract TP256: The Role Of Dietary Iron Restriction In The Pathophysiology Of Intracranial Aneurysm Rupture

Background: Iron is an essential element for maintaining vascular wall, however iron depositions in vascular wall cause tissue damage by oxidative stress via Fenton/Haber-Weiss reaction. We hypothesized that iron promotes intracranial aneurysmal formation and rupture through oxidative stress and vascular inflammation. Using a mouse model of intracranial aneurysm, we examined whether iron restriction reduces aneurysm formation and rupture.

Methods: To induce aneurysm, we combined induced systemic hypertension (deoxycorticosterone acetate-salt hypertension) and a single injection of elastase (35mU) into the cerebrospinal fluid at the right basal cistern. The mice were divided into two groups and fed with iron restricted diet (IRD) (0.32mg/100g) or normal diet (ND) (600mg/100g) for 5 weeks.

Results: IRD significantly reduced the aneurysmal rupture compared to ND (ND versus IRD: 76% versus 37%; P < 0.05). Whereas, there was no significant difference in the overall incidence of aneurysms between the ND and IRD groups (ND versus IRD: 68% versus 69%; P =1.00).

Conclusion: Our data demonstrate that iron restriction reduces intracranial aneurysm rupture.

In vitro analysis of mechanism of pulsed-laser thrombolysis

Thrombolytic therapy in the treatment of cardiogenic acute cerebral embolism caused by coagulated blood carries the risk of hemorrhagic complications, and there is a need to develop safer and more reliable treatment methods. Laser thrombolysis therapy, which utilizes the difference in energy absorption between the thrombus and the arterial wall, has shown promise as a new treatment method because it can selectively act only on the thrombus. It has not been applied clinically, however, and one of the main reasons for this is that its underlying mechanism has not been elucidated. We developed a pulse laser thrombolysis system for treating cerebral blood vessels that consists of a diode-pumped solid-state neodymium-yttrium aluminum garnet laser, which has excellent stability and maintainability and is suitable for clinical applications coupled to a small-diameter optical fiber. Moreover, we analyzed the mechanisms that occur during pulsed laser irradiation of transparent glass tubes and gelatin phantoms. We found that bubbles form as a thermal effect in addition to ablation of the pulsed laser irradiation. Furthermore, we detected no shock waves or water jets associated with the bubbles. We analyzed the bubbles’ dynamics and growth rate, and their effect on a rabbit blood clot phantom. We concluded that the bubbles generated by the laser irradiation physically cut the thrombus and thereby had a thrombectomy effect. We believe that this study will clarify the mechanism of laser thrombolysis therapy and contribute greatly to the realization of its clinical application.

Effect of a novel nasal oxytocin spray with enhanced bioavailability on autism: a randomized trial

Although intranasal oxytocin is expected to be a novel therapy for the core symptoms of autism spectrum disorder, which has currently no approved medication, the efficacy of repeated administrations was inconsistent, suggesting that the optimal dose for a single administration of oxytocin is not optimal for repeated administration.

The current double-blind, placebo-controlled, multicentre, crossover trial (ClinicalTrials.gov Identifier: NCT03466671) was aimed to test the effect of TTA-121, a new formulation of intranasal oxytocin spray with an enhanced bioavailability (3.6 times higher than Syntocinon® spray, as assessed by area under the concentration–time curve in rabbit brains), which enabled us to test a wide range of multiple doses, on autism spectrum disorder core symptoms and to determine the dose–response relationship. Four-week administrations of TTA-121, at low dose once per day (3 U/day), low dose twice per day (6 U/day), high dose once per day (10 U/day), or high dose twice per day (20 U/day), and 4-week placebo were administered in a crossover manner. The primary outcome was the mean difference in the reciprocity score (range: 0–14, higher values represent worse outcomes) on the Autism Diagnostic Observation Schedule between the baseline and end point of each administration period. This trial with two administration periods and eight groups was conducted at seven university hospitals in Japan, enrolling adult males with high-functioning autism spectrum disorder. Enrolment began from June 2018 and ended December 2019. Follow-up ended March 2020.

Of 109 males with high-functioning autism spectrum disorder who were randomized, 103 completed the trial. The smallest P-value, judged as the dose–response relationship, was the contrast with the peak at TTA-121 6 U/day, with inverted U-shape for both the full analysis set (P = 0.182) and per protocol set (P = 0.073). The Autism Diagnostic Observation Schedule reciprocity score, the primary outcome, was reduced in the TTA-121 6 U/day administration period compared with the placebo (full analysis set: P = 0.118, mean difference = −0.5; 95% CI: −1.1 to 0.1; per protocol set: P = 0.012, mean difference = −0.8; 95% CI: −1.3 to −0.2). The per protocol set was the analysis target population, consisting of all full analysis set participants except those who deviated from the protocol. Most dropouts from the full analysis set to the per protocol set occurred because of poor adherence to the test drug (9 of 12 in the first period and 8 of 15 in the second period). None of the secondary clinical and behavioural outcomes were significantly improved with the TTA-121 compared with the placebo in the full analysis set.

A novel intranasal spray of oxytocin with enhanced bioavailability enabled us to test a wide range of multiple doses, revealing an inverted U-shape dose–response curve, with the peak at a dose that was lower than expected from previous studies. The efficacy of TTA-121 shown in the current exploratory study should be verified in a future large-scale, parallel-group trial.

Numerical Simulation: Fluctuation in Background Synaptic Activity Regulates Synaptic Plasticity

Synaptic plasticity is vital for learning and memory in the brain. It consists of long-term potentiation (LTP) and long-term depression (LTD). Spike frequency is one of the major components of synaptic plasticity in the brain, a noisy environment. Recently, we mathematically analyzed the frequency-dependent synaptic plasticity (FDP) in vivo and found that LTP is more likely to occur with an increase in the frequency of background synaptic activity. Meanwhile, previous studies suggest statistical fluctuation in the amplitude of background synaptic activity. Little is understood, however, about its contribution to synaptic plasticity. To address this issue, we performed numerical simulations of a calcium-based synapse model. Then, we found attenuation of the tendency to become LTD due to an increase in the fluctuation of background synaptic activity, leading to an enhancement of synaptic weight. Our result suggests that the fluctuation affects synaptic plasticity in the brain.

Plasminogen Deficiency Significantly Reduces Vascular Wall Disease in a Murine Model of Type IIa Hypercholesterolemia

The fibrinolytic system has been implicated in the genesis and progression of atherosclerosis. It has been reported that a plasminogen (Pg) deficiency (Plg^−/−) exacerbates the progression of atherosclerosis in Apoe^−/− mice. However, the manner in which Plg functions in a low-density lipoprotein-cholesterol (LDL-C)-driven model has not been evaluated. To characterize the effect of Pg in an LDL-C-driven model, mice with a triple deficiency of the LDL-receptor (LDLr), along with the active component (apobec1) of the apolipoprotein B editosome complex, and Pg (L^−/−/A^−/−/Plg^−/−), were generated. Atherosclerotic plaque formation was severely retarded in the absence of Pg. In vitro studies demonstrated that LDL uptake by macrophages was enhanced by plasmin (Pm), whereas circulating levels of LDL were enhanced, relative to L^−/−/A^−/− mice, and VLDL synthesis was suppressed. These results indicated that clearance of lipoproteins in the absence of LDLr may be regulated by Pg/Pm. Conclusions: The results from this study indicate that Pg exacerbates atherosclerosis in an LDL-C model of atherosclerosis and also plays a role in lipoprotein modification and clearance. Therefore, controlling the Pg system on macrophages to prevent foam cell formation would be a novel therapeutic approach.

Fibrin-mediated growth restriction of early-stage human trophoblasts is switched to growth promotion through fibrinolysis

STUDY QUESTION

Does fibrin promote trophoblast growth in human and mouse blastocysts during early embryo implantation?

SUMMARY ANSWER

Mouse blastocysts were unaffected by fibrin; however, human blastocysts were significantly suppressed by fibrin in trophoblast growth and then switched to growth promotion through increased fibrinolysis with urokinase-type plasminogen activator (uPA) activity.

WHAT IS KNOWN ALREADY

Fibrin(ogen) plays an important role in various physiological processes and is also critical for maintaining feto-maternal attachment during pregnancy. The addition of fibrin to embryo transfer media has been used to increase implantation rates in human ART; however, its mechanism of action' in vitro has not yet been characterized.

STUDY DESIGN, SIZE, DURATION

Vitrified mouse and human blastocysts were warmed and individually cultured in vitro for up to 120 and 168 h, respectively, on a fibrin substrate. Blastocysts were cultured at 37°C in 6% CO2, 5% O2 and 89% N2. Blastocyst development and related fibrinolytic factors were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ICR strain mouse embryos were purchased from a commercial supplier. Human blastocysts were donated with informed consent from two fertility centers. Mouse and human blastocysts cultured on fibrin-coated plates were compared to those on non-coated and collagen-coated plates in vitro. Trophoblast growth and fibrin degradation were assessed based on the cell area and fibrin-free area, respectively. Fibrinolytic factors were detected in supernatants using plasminogen-casein zymography. The fibrinolytic activity of blastocysts was investigated using a selective uPA inhibitor, exogenous uPA, plasminogen activator inhibitor-1 (PAI-1) inhibitor and fibrin degradation products (FDPs). Fibrinolysis-related mRNA expression level was detected using quantitative real-time PCR.

MAIN RESULTS AND THE ROLE OF CHANCE

Fibrin did not affect the developmental speed or morphology of mouse blastocysts, and a large fibrin-degrading region was observed in the attachment stage. In contrast, fibrin significantly suppressed the outgrowth of trophoblasts in human blastocysts, and trophoblasts grew after the appearance of small fibrin-degrading regions. uPA was identified as a fibrinolytic factor in the conditioned medium, and uPA activity was significantly weaker in human blastocysts than in mouse blastocysts. The inhibition of uPA significantly reduced the outgrowth of trophoblasts in mouse and human blastocysts. Human blastocysts expressed PLAU (uPA), PLAUR (uPA receptor), SERPINE1 (PAI-1) and SERPINB2 (PAI-2), whereas mouse blastocysts were limited to Plau, Plaur and Serpine1. In a subsequent experiment on human blastocysts, the addition of exogenous uPA and the PAI-1 inhibitor promoted trophoblast growth in the presence of fibrin, as did the addition of FDPs.

LIMITATIONS, REASONS FOR CAUTION

This model excludes maternal factors and may not be fully reproduced in vivo. Donated human embryos are surplus embryos that may inherently exhibit reduced embryonic development. In addition, donated ART-derived embryos may exhibit weak uPA activity, because women with sufficient uPA-active embryos may not originally require ART. The present study used orthodox culture methods, and results may change with the application of recently developed protocols for culture blastocysts beyond the implantation stage.

WIDER IMPLICATIONS OF THE FINDINGS

The present results suggest that the distinct features of trophoblast outgrowth in human blastocysts observed in the presence of fibrin are regulated by a phenotypic conversion induced by contact with fibrin and FDPs. Mouse embryos did not exhibit the human phenomenon, indicating that the present results may be limited to humans.

STUDY FUNDING/COMPETING INTEREST(S)

The present study was supported by the Department of Obstetrics and Gynecology at the Hamamatsu University School of Medicine and Kishokai Medical Corporation. None of the authors have any conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Stable Near-Infrared Photoluminescence of Single-Walled Carbon Nanotubes Dispersed Using a Coconut-Based Natural Detergent

We prepared single-walled carbon nanotube (SWNT) suspensions in phosphate buffer solutions containing 1% of a coconut-based natural detergent (COCO) or 1% of sodium dodecyl sulfate (SDS). The suspensions exhibited strong photoluminescence (PL) in the near-infrared region, suggesting that the SWNTs, such as those with (9, 4) and (7, 6) chiralities, were monodispersed. Upon diluting the suspensions with a detergent-free phosphate buffer solution, the PL intensity of the SDS-containing SWNT suspension was significantly lower than that of the COCO-containing SWNT suspension. The COCO-containing SWNT suspension was more stable than the SDS-containing SWNT suspension. The SWNT concentration of the suspensions prepared via bath-type sonication was lower than that of the suspensions prepared via probe-type sonication. However, near-infrared (NIR) PL intensity of the SWNT suspensions prepared via bath-type sonication was much higher than that of the SWNT suspensions prepared via probe-type sonication regardless of the detergent. This suggested that the fraction of monodispersed SWNTs of the suspensions prepared via bath-type sonication was larger than that of the suspensions prepared via probe-type sonication, although the SWNT concentration was low. Our results indicated that COCO favored the fabrication of SWNT suspensions with stable and strong NIR PL, which are useful for various biological applications.

A Dose-Confirmation Phase 1 Study to Evaluate the Safety and Pharmacology of Glucarpidase in Healthy Volunteers

Glucarpidase rapidly decomposes methotrexate. A phase 1 study of glucarpidase in an open‐label, randomized parallel group was conducted to evaluate the safety, pharmacokinetics, and other pharmacologic effects in Japanese healthy volunteers without methotrexate treatment. A dose of 50 U/kg (n = 8) or 20 U/kg (n = 8) of glucarpidase was administered as an intravenous injection, with 1 repeated dose at 48 hours after the first dose. No dose‐limiting toxicities, no significant clinical examination findings, and no clinically relevant differences between dose levels were observed. The pharmacokinetic parameters at a first dose of 20 or 50 U/kg were similar to those at a second dose and were as follows: half‐life, 7.45 and 7.25 hours; area under the plasma concentration–time curve from time 0 to infinity, 8.25 and 19.05 μg·h/mL; total clearance, 4.85 and 5.47 mL/min; and volume of distribution during the elimination phase, 3.12 and 3.41 L, respectively. The area under the plasma concentration–time curve increased in a generally linear dose‐proportional manner. An ethnicity specificity in the pharmacokinetic profile was not observed in Japanese volunteers. The serum folate concentration decreased after glucarpidase administration in all the volunteers. The production of anti‐glucarpidase antibody was observed in many cases in both cohorts. Although the long‐term effect of anti‐glucarpidase antibody will need to be investigated in the future, the effects produced by the anti‐glucarpidase antibody were not influenced by the pharmacokinetics of glucarpidase within 96 hours after the first dose. The observed safety and tolerability, pharmacokinetics, and pharmacodynamics support the continued evaluation of glucarpidase in the patients with lethal methotrexate toxicities.

Dual Therapy with Vonoprazan and Amoxicillin Is as Effective as Triple Therapy with Vonoprazan, Amoxicillin and Clarithromycin for Eradication of Helicobacter pylori

BACKGROUNDS/AIMS

Vonoprazan (VPZ) is the first clinically available potassium competitive acid blocker. This class of agents provides faster and more potent acid inhibition than proton pump inhibitors. Most strains of Helicobacter pylori are sensitive to amoxicillin. We hypothesized that dual therapy with VPZ and amoxicillin would provide the sufficient eradication rate for H. pylori infection. To evaluate this, we compared the eradication rate by the dual VPZ/amoxicillin therapy with that by the standard triple VPZ/amoxicillin/clarithromycin therapy.

METHODS

Non-inferiority of the eradication rate of H. pylori by the dual therapy with VPZ 20 mg twice daily (bid) and amoxicillin 500 mg 3 times daily (tid) for 1 week to that by the triple therapy with VPZ 20 mg bid, amoxicillin 750 mg bid and clarithromycin 200 mg bid for 1 week was retrospectively studied. Propensity score matching was performed to improve comparability between 2 regimen groups. Successful eradication was diagnosed using the [13C]-urea breath test at 1-2 months after the end of eradication therapy.

RESULTS

The intention-to-treat analysis demonstrated that the eradication rate by the dual therapy (92.9%; 95% CI 82.7-98.0%, 52/56) was not inferior to that of the triple therapy (91.9%; 95% CI 80.4-97.0%, 51/56; OR 1.275, 95% CI 0.324-5.017%, p = 0.728). There were no statistically significant differences in incidences of adverse events between 2 regimens.

CONCLUSION

VPZ-based dual therapy (VPZ 20 mg bid and amoxicillin 500 mg tid for 1 week) provides an acceptable eradication rate of H. pylori infection without the need for second antimicrobial agents, such as clarithromycin.

Sinking of Four Species of Living Diatom Cells Directly Observed by a "Tumbled" Optical Microscope

The study of the sinking phenomenon of diatom cells, which have a slightly larger specific gravity (~1.3) compared to that of water, is an important research topic for understanding photosynthetic efficiency. In this study, we successfully demonstrated the observation of the sinking behaviors of four different species of diatom using a homemade “tumbled” optical microscope. A homemade 1 mm3 microchamber was employed to decrease the effects of convection currents. In the microchamber, diatom cells were basically settled in a linear manner without floating, although some of the cells were rotated during their sinking. Sinking speeds of the four species of diatom cells, Nitzschia sp., Pheodactylum tricornutum, Navicula sp., and Odontella aurita, were 0.81 ± 5.56, 3.03 ± 10.17, 3.29 ± 7.39, and 11.22 ± 21.42 μm/s, respectively, based on the automatic tracking analysis of the centroids of each cell. Manual analysis of a vector between two longitudinal ends of the cells (two-point analysis) was effective for quantitatively characterizing the rotation phenomenon; therefore, angles and angular velocities of rotating cells were well determined as a function of time. The effects of the cell shapes on sinking velocity could be explained by simulation analysis using the modified Stokes’ law proposed by Miklasz et al.

Hyperfunctioning Papillary Thyroid Carcinoma with a BRAF Mutation: The First Case Report and a Literature Review

INTRODUCTION

Hyperfunctioning papillary thyroid carcinoma (PTC) is rare and consequently, little information on its molecular etiology is available. Although BRAF V600E (BRAF c.1799T>A, p.V600E) is a prominent oncogene in PTC, its mutation has not yet been reported in hyperfunctioning PTC.

CASE PRESENTATION

Ultrasonography detected a 26-mm nodule in the right lobe of the thyroid gland of a 48-year-old man. Thyroid function tests indicated that he was hyperthyroid with a TSH level of 0.01 mIU/L (reference range: 0.05-5.00) and a free thyroxine level of 23.2 pmol/L (reference range: 11.6-21.9). TSHR autoantibodies were <0.8 IU/L (reference value: <2.0 IU/L). The ^99mTc thyroid scintigram revealed a round, right-sided focus of tracer uptake by the nodule with a decreased uptake in the remainder of the gland. The patient underwent total thyroidectomy because fine-needle aspiration cytology revealed a malignancy. The histopathological diagnosis was conventional PTC. Subsequent mutational analysis of BRAF (exon 15), TSHR (exons 1-10), GNAS (exons 7-10), EZH1 (exon 16), KRAS, NRAS, HRAS (codons 12, 13, and 61), and TERT promoter (C250T and C228T) identified a heterozygous point mutation in BRAF V600E in a tumor tissue sample. In addition, we identified a TSHR D727E polymorphism (TSHR c.2181C>G, p.D727E) in both the tumor and the surrounding normal thyroid tissue.

DISCUSSION AND CONCLUSIONS

We report a case of hyperfunctioning PTC with a BRAF V600E mutation for the first time. Our literature search yielded 16 cases of hyperfunctioning thyroid carcinoma in which a mutational analysis was conducted. We identified TSHR mutations in 13 of these cases. One case revealed a combination of TSHR and KRAS mutations; the other case revealed a TSHR mutation with a PAX8/PPARG rearrangement. These findings suggest that the concomitant activation of oncogenes (in addition to constitutive activation of the TSHR-cyclic AMP cascade) are associated with the malignant phenotype in hyperfunctioning thyroid nodules.

Repair of brain damage size and recovery of neurological dysfunction after ischemic stroke are different between strains in mice: evaluation using a novel ischemic stroke model

In the current study, we established a novel murine ischemic brain damage model using a photochemical reaction to evaluate the recovery of neurological dysfunction and brain repair reactions. In this model, reproducible damage was induced in the frontal lobe of the cortex, which was accompanied by neurological dysfunction. Sequential changes in damage size, microglial accumulation, astrocyte activation, and neurological dysfunction were studied in C57BL/6J and BALB/c mouse strains. Although the initial size of damage was comparable in both strains, the extent of damage was later reduced to a greater extent in C57BL/6J mice than that in BALB/c mice. In addition, C57BL/6J mice showed later edema clearance until day 7, less microglial accumulation, and relatively more astrocyte activation on day 7. Neurologic dysfunction was evaluated by three behavioral tests: the von Frey test, the balance beam test, and the tail suspension test. The behavioral abnormalities evaluated by these tests were remarkable following the induction of damage and recovered by day 21 in both strains. However, the abnormalities were more prominent and the recovery was later in C57BL/6J mice. These findings demonstrate that our novel ischemic stroke model is useful for evaluating brain repair reactions and the recovery of neurological dysfunction in mice with different genetic backgrounds. In addition, we found that both the brain repair reactions and the recovery of neurological dysfunction after comparable ischemic brain damage varied between strains; in that, they both occurred later in C57BL/6J mice.

Optical Response Characteristics of Single-Walled Carbon Nanotube Chirality Exposed to Oxidants with Different Oxidizing Power

Semiconductor single-walled carbon nanotubes (SWNTs) have unique characteristics owing to differences in the three-dimensional structure (chirality) expressed by the chiral index (n,m), and many studies on the redox characteristics of chirality have been reported. In this study, we investigated the relationship between the chirality of SWNTs and the oxidizing power of oxidants by measuring the near-infrared (NIR) absorption spectra of two double-stranded DNA-SWNT complexes with the addition of three oxidants with different oxidizing powers. A dispersion was prepared by mixing 0.5 mg of SWNT powder with 1 mg/mL of DNA solution. Different concentrations of hydrogen peroxide (H₂O₂), potassium hexachloroidylate (IV) (K₂IrCl₆), or potassium permanganate (KMnO₄) were added to the dispersion to induce oxidation. Thereafter, a catechin solution was added to observe if the absorbance of the oxidized dispersion was restored by the reducing action of the catechin. We found that the difference in the oxidizing power had a significant effect on the detection sensitivity of the chiralities of the SWNTs. Furthermore, we revealed a detectable range of oxidants with different oxidizing powers for each chirality.

Desflurane anesthesia shifts the circadian rhythm phase depending on the time of day of anesthesia

Desflurane is one of the most frequently used inhalational anesthetics in clinical practice. A circadian rhythm phase-shift after general anesthesia with sevoflurane or isoflurane has been reported in mice, but few studies have reported this effect with desflurane. In the present study, we examined the rest/activity rhythm of mice by counting the number of running wheel rotations, and we found that desflurane anesthesia caused a phase shift in the circadian rhythm that was dependent on the time of day of anesthesia. We also found that desflurane anesthesia altered the relative mRNA expression of four major clock genes (Per2, Bmal, Clock, and Cry1) in the suprachiasmatic nucleus (SCN). These results are important for elucidating the effects of desflurane on the SCN, which is the master clock for the mammalian circadian rhythm. Further studies on the relationship between anesthesia and circadian rhythm may lead to the prevention and treatment of postoperative complications related to circadian rhythms.

An efficient method to quantitatively detect competitive adsorption of DNA on single-walled carbon nanotube surfaces

In this study, we quantitatively detected adsorption and desorption of DNA molecules that competed with sodium cholate (SC) molecules on single-walled carbon nanotubes (SWNTs) by fluorescence spectroscopy. In previous studies, competitive adsorption and/or replacement were studied based on techniques such as near-infrared (NIR) absorbance and photoluminescence (PL) spectroscopy of SWNTs. In those studies, adsorption of organic molecules was detected as spectral changes in SWNTs, but not in organic molecules. In this study, we employed fluorescent-labeled DNA (Fc-DNA) to detect competitive adsorption through quenching of fluorescent dyes that were attached to DNA molecules. Through this approach, the adsorption behaviors of DNA molecules could be directly determined. Hence, we found that Fc-DNA molecules adsorbed on SWNT surfaces that were pre-wrapped with SC when the SC concentration was reduced. However, when SC concentrations recovered after three days of incubation, detachment of Fc-DNA molecules was observed. In addition, our method could be applied to evaluate the adsorption of fluorescent dyes on SWNT surfaces instead of DNA molecules. Hence, our method is effective in studying competitive adsorption of organic molecules on SWNT surfaces. The obtained information is complementary to that obtained from NIR spectroscopy of SWNTs.

Label-free imaging and analysis of subcellular parts of a living diatom cylindrotheca sp. using optical diffraction tomography

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Subcellular parts of a living diatom cell was well visualized by digital holographic microscope.

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Subcellular parts could be identified as differences of refractive indexes.

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The observation was achieved without any pre-treatment of the living cell.

Optical diffraction tomography is an emerging label-free microscopic technique with its capability of label-free, quantitative, and rapid imaging of biological samples. In this work, we present the imaging and analysis of a living diatom Cylindrotheca sp. in seawater without using any pretreatment such as fluorescence staining. The 3D refractive index (RI) of a living diatom cell was measured, to which quantitative image analysis was perform to investigate subcellular parts of the diatom. Each part of the cell was well distinguished as RI values and distributions. From the analysis, RI values of frustules, protoplasm, vacuole, and chloroplast were estimated to be in the range of 1.352−1.388, 1.363−1.381, 1.388−1.395, and 1.403−1.436, respectively. Our results suggest that the present method will be a powerful tool not only for observing diatom cells but also for studying various cells and mesoscopic materials.•

Subcellular parts of a living diatom cell was well visualized by digital holographic microscope.

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Subcellular parts could be identified as differences of refractive indexes.

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The observation was achieved without any pre-treatment of the living cell.

Different exercises can modulate the differentiation/maturation of neural stem/progenitor cells after photochemically induced focal cerebral infarction

INTRODUCTION

Exercise therapies during rehabilitation significantly promote recovery from various deficits after cerebral infarction, which is mediated by neuronal plasticity with distinct inputs. Although adult neurogenesis can also be modulated by neuronal activity before synaptogenesis, how distinct exercises contribute to the neurological reorganization of the injured cerebral cortex remains unclear. In the present study, we aimed to elucidate the effects of different exercise therapies on motor recovery and neuronal reorganization after photochemically induced focal cerebral infarction.

METHODS

Here, we examined the effects of three different exercises-(a) forced lower-intensity and (b) higher-intensity treadmill exercises, and (c) voluntary exercise with wheel running-on motor recovery and adult neurogenesis in a rat model of focal cerebral infarction. Photochemically induced thrombosis (PIT) was used to generate focal infarction in rats that was mostly confined to their motor cortices.

RESULTS

Beam walking tests showed that recovery after PIT-induced cortical infarction differed in acute and chronic stages and was influenced by the type of exercise. Furthermore, forced low-intensity training had more positive effects on functional recovery than other exercises or control. To evaluate the production of newly generated cells including de novo neurogenesis, we performed lineage analysis with BrdU labeling and immunofluorescence experiments. Lower-intensity treadmill exercise increased the number of BrdU/NeuN colabeled cells, but not total BrdU-retaining or BrdU/Sox2-colabeled cells, in the peri-infarct region of the ipsilateral cortex. In contrast, high-intensity treadmill or voluntary exercises had the opposite effects.

CONCLUSIONS

These results suggest that neuronal maturation can be differently modulated by distinct exercises and that low-intensity treadmill exercise could result in more potent generation of mature neurons. This also suggests the possibility that the generation of neural stem/progenitor cells and differentiation might be modulated by rehabilitation-mediated neural plasticity.

Decomposition of amyloid fibrils by NIR-active upconversion nanoparticles

We demonstrate amyloid fibril (AF) decomposition induced by NIR-active upconversion nanoparticles complexed with photosensitisers. The process is triggered by upconversion, which initiates a photochemical reaction cascade that culminates in the generation of the highly reactive singlet-oxygen product 1O2 close to the amyloid superstructures, resulting in AF decomposition.

A Review of Applications Using Mixed Materials of Cellulose, Nanocellulose and Carbon Nanotubes

Carbon nanotubes (CNTs) have been extensively studied as one of the most interesting nanomaterials for over 25 years because they exhibit excellent mechanical, electrical, thermal, optical, and electrical properties. In the past decade, the number of publications and patents on cellulose and nanocellulose (NC) increased tenfold. Research on NC with excellent mechanical properties, flexibility, and transparency is accelerating due to the growing environmental problems surrounding us such as CO2 emissions, the accumulation of large amounts of plastic, and the depletion of energy resources such as oil. Research on mixed materials of cellulose, NC, and CNTs has been expanding because these materials exhibit various characteristics that can be controlled by varying the combination of cellulose, NC to CNTs while also being biodegradable and recyclable. An understanding of these mixed materials is required because these characteristics are diverse and are expected to solve various environmental problems. Thus far, many review papers on cellulose, NC or CNTs have been published. Although guidance for the suitable application of these mixed materials is necessary, there are few reviews summarizing them. Therefore, this review introduces the application and feature on mixed materials of cellulose, NC and CNTs.

Fabrication of Microscope Stage for Vertical Observation with Temperature Control Function

Samples are usually placed onto a horizontal microscope stage for microscopic observation. However, to observe the influence of gravity on a sample or study afloat behavior, it is necessary to make the microscope stage vertical. To accomplish this, a sideways inverted microscope tilted by 90° has been devised. To observe samples with this microscope, sample containers such as Petri dishes or glass slides must be secured to the stage vertically. A device that can secure sample containers in place on a vertical microscope stage has been developed and is described here. Attachment of this device to the stage allows observation of sample dynamics in the vertical plane. The ability to regulate temperature using a silicone rubber heater also permits observation of temperature-dependent sample behaviors. Furthermore, the temperature data is transferred to an internet server. Temperature settings and log monitoring can be controlled remotely from a PC or smartphone.

Quantitative Detection of the Disappearance of the Antioxidant Ability of Catechin by Near-Infrared Absorption and Near-Infrared Photoluminescence Spectra of Single-Walled Carbon Nanotubes

We succeeded in quantitatively detecting the disappearance of catechin antioxidant ability as a function of time using near-infrared (NIR) absorbance and NIR photoluminescence (PL) spectra of single-walled carbon nanotubes (SWNTs) wrapped with DNA molecules (DNA-SWNT hybrids). When 15 μg/mL of catechin was added to the oxidized hybrid suspension, the absorbance of SWNTs increased, according to the antioxidant ability of catechin, and the effect was maintained at least for 30 min. When catechin concentrations were less than 0.3 μg/mL, SWNT absorbance gradually decreased, although it increased when catechin is added. The results revealed that disappearance of the catechin effects could be quantitatively detected by NIR absorbance spectra. When NIR PL was employed, the disappearance of PL intensity was also observed in the case of low catechin concentrations. However, time-lapse measurement of the disappearance was difficult because the PL intensity was rapidly quenched. In addition, the optical responses were different due to different chirality of SWNTs. Our results suggested that both NIR absorbance and PL can detect disappearance of catechin antioxidant effects; in particular, slow response of NIR absorbance was effective to detect time dependence of the disappearance of the catechin effects. Contrarily, PL revealed huge and rapid responses in contrast to NIR absorbance. PL might be effective for reversible use of DNA-SWNT hybrids as a nanobiosensor.

Fabrication of an Optical Cell Dryer for the Spectroscopic Analysis Cells

Optical cells, which are experimental instruments, are small, square tubes sealed on one side. A sample is placed in this tube, and a measurement is performed with a spectroscope. The materials used for optical cells generally include quartz glass or plastic, but expensive quartz glass is reused by removing substances, other than liquids, to be analyzed that adhere to the interior of the container. In such a case, the optical cells are washed with water or ethanol and dried. Then, the next sample is added and measured. Optical cells are dried naturally or with a manual hairdryer. However, drying takes time, which makes it one of the factors that increase the experiment time. In this study, the objective is to drastically reduce the drying time with a dedicated automatic dryer that can dry multiple optical cells at once. To realize this, a circuit was designed for a microcomputer, and the hardware using it was independently designed and manufactured.

Enhancement by Ticlopidine of the Inhibitory Effect on In Vitro Platelet Aggregation of the Glycoprotein IIb/IIIa Inhibitor Tirofiban

We determined the effects of combining the glycoprotein IIb/IIIa inhibitor tirofiban (MK-383, Aggrastat) and ticlopidine on inhibition of ADP-induced platelet aggregation, inhibition of collagen-induced platelet aggregation, and prolongation of bleeding time in 5 healthy male volunteers. The study consisted of 2 periods. In period 1, tirofiban was administered intravenously as a bolus injection at a dose of 5.0 µg/kg for 5 min, then as a continuous infusion at a rate of 0.05 µg/kg/min for 5 h 55 min. In period 2, ticlopidine was given orally at a dose of 200 mg once daily for 4 days, after which tirofiban was administered in the same manner as in period 1, starting 2 h after the last dose of ticlopidine. The percent inhibition of platelet aggregation induced by ADP 5 µM at the end of tirofiban infusion in periods 1 and 2 was 73.6 ± 2.6 and 87.1 ± 5.7% (mean ± SD), respectively. The corresponding values for inhibition of platelet aggregation induced by collagen 2 µg/ml were 45.4 ± 36.1 and 82.8 ± 27.0%, respectively. In contrast, the percent inhibition of platelet aggregation induced by ADP and collagen after treatment with ticlopidine alone was 15.8 ± 20.2 and p ± 4.8%, respectively. Compared with tirofiban alone, the combination of tirofiban and ticlopidine significantly enhanced inhibition of platelet aggregation induced by both ADP and collagen (p <0.02 and p <0.012, respectively). The inhibitory effects of ticlopidine alone were not statistically significant. Tirofiban prolonged bleeding time both in period 1 and in period 2. However, tirofiban and ticlopidine combined did not affect bleeding time. Ticlopidine administration did not alter the pharmacokinetics of tirofiban. In conclusion, at the doses of tirofiban and ticlopidine used in this study, the combination of the two drugs enhanced inhibition of platelet aggregation but did not prolong bleeding time, suggesting that appropriate doses of tirofiban can be used concomitantly with ticlopidine with no further safety concerns but with potential additional clinical effects.

Inhibitory Effect of a Novel Orally Active GP IIb/IIIa Inhibitor, SC-54684A on Intimal Thickening in the Guinea Pig Femoral Artery

The inhibitory effect of a novel orally active platelet membrane glycoprotein receptor complex IIb/IIIa (GP IIb/IIIa) inhibitor, SC-54684A is studied on intimal thickening in the guinea pig femoral artery. A segment of the femoral artery was occluded by a platelet-rich thrombus induced by photochemical reaction between systemically administered Rose Bengal and transluminal green light which causes endothelial injury followed by platelet adhesion and aggregation at the site of photochemical reaction. Three weeks after successful thrombolysis by tissue-type plasminogen activator, intimal thickening occurred at the irradiated site. SC-54684A (30 mg/kg), administered 2 h before photochemical reaction, significantly (P <0.05) prolonged the time to occlusion of the femoral artery; in this respect aspirin (100 mg/kg) was ineffective. A combination of SC-54684A and recombinant tissue-type plasminogen activator (rt-PA) increased the frequency of reopening and significantly (P <0.05) prolonged the duration of reflow compared with rt-PA alone. Further, SC-54684A administered orally twice a day for 3 weeks significantly (P <0.05) inhibited intimal thickening but aspirin, administered orally once a day for 3 weeks, was ineffective. Scanning electron microscopy revealed extensive platelet adhesion and aggregation on the denuded vessel walls in the untreated group 24 h after successful thrombolysis. In separate experiments, SC-54684A markedly inhibited platelet aggregation ex-vivo. Inhibition of platelet adhesion and aggregation at the site of endothelial injury by SC-54684A (via GPIIb/IIIa inhibition) may account for its inhibitory effect on intimal thickening

Vessel Wall Injury and Arterial Thrombosis Induced by a Photochemical Reaction

Arterial thrombosis may be initiated in an experimental animal by a photochemical reaction between transmural green light and i.v. administered Rose Bengal, a photosensitizer dye. In this study, scanning electron microscopy has been used to reveal the nature of vessel injury and the cellular composition of the photochemically induced thrombus. A 5 mm segment of the guinea pig femoral artery was occluded by a thrombus about 10 min after irradiation with green light in the presence of systemically administered Rose Bengal. Electron microscopy revealed that following photochemical reaction, endothelial cells first contract and, with further irradiation, become detached from the vessel wall, with their cell membrane being destroyed at the irradiated site where an occlusive platelet-rich thrombus was formed. Endothelial cell injury and vessel occlusion could be completely inhibited by the aminothiol, DL-cysteine administered i.v. 1 min after Rose Bengal. The mechanism of endothelial injury in this model appears to be by singlet molecular oxygen, 1O2 formed by energy transfer from the photo-excited dye to O2.

Scanning Techniques for Nanobioconjugates of Carbon Nanotubes

Nanobioconjugates using carbon nanotubes (CNTs) are attractive and promising hybrid materials. Various biological applications using the CNT nanobioconjugates, for example, drug delivery systems and nanobiosensors, have been proposed by many authors. Scanning techniques such as scanning electron microscopy (SEM) and scanning probe microscopy (SPM) have advantages to characterize the CNT nanobioconjugates under various conditions, for example, isolated conjugates, conjugates in thin films, and conjugates in living cells. In this review article, almost 300 papers are categorized based on types of CNT applications, and various scanning data are introduced to illuminate merits of scanning techniques.

Increase in blood-brain barrier permeability does not directly induce neuronal death but may accelerate ischemic neuronal damage

It is observed that the increase in blood-brain barrier (BBB) permeability (BBBP) is associated with ischemic stroke and thought to trigger neuronal damage and deteriorate ischemic infarction, even though there is no experimental proof. Here, we investigated the effect of BBBP increase on brain damage, using a combination of photochemically-induced thrombotic brain damage (PIT-BD) model, a focal brain ischemic model, and transient bilateral carotid artery occlusion model (CAO, a whole brain ischemic model), in mice. In PIT-BD, BBBP increased in the region surrounding the ischemic damage from 4 h till 24 h with a peak at 8 h. On day 4, the damaged did not expand to the region with BBBP increase in mice with PIT-BD alone or with 30 min CAO at 1 h before PIT-BD, but expanded in mice with 30 min CAO at 3.5 h after PIT-BD. This expansion was paralleled with the increase in the number of apoptotic cells. These findings indicate that increase in BBBP does not cause direct neuronal death, but it facilitates ischemic neuronal loss, which was attributed, at least partially, to acceleration of apoptotic cell death.

A convenient method of attaching fluorescent dyes on single-walled carbon nanotubes pre-wrapped with DNA molecules

We demonstrated the attachment of different kinds of dyes, Uranine, Rhodamime 800 (R800), and Indocyanine green (ICG), to single-walled carbon nanotubes pre-wrapped with single-stranded DNAs (ssDNA-SWCNTs). A new but simple method was employed, in which a dye solution was added to ssDNA-SWCNTs that had been prepared beforehand in the conventional way. Resulting conjugates of dyes, DNA, and SWCNTs were precisely evaluated by ultraviolet to near-infrared fluorescence/absorbance spectrometry and atomic force microscopy. In particular, simultaneous measurements of fluorescence and absorbance spectroscopy enabled us to find differences in the behaviors of the dyes on SWCNT surfaces. As a result, the fluorescence/absorbance spectra of dyes showed significant changes upon adsorption on SWCNTs. The fluorescence/absorbance peaks of Uranine, R800, and ICG were quenched by 41.3/2.8%, 72.3/48.9%, and 88.3/45.0%, respectively, in the presence of 11.5 μg/mL SWCNTs. We concluded firstly that by pre-wrapping SWCNTs with ssDNA, stable hybrids with these components were obtained even if the dyes used were relatively hydrophobic and secondly that Uranine retained light absorption on the surface of SWCNT while R800 and ICG did not.

Prevention Effect of Antiplatelets on Aneurysm Rupture in a Mouse Intracranial Aneurysm Model

Background and Purpose: Subarachnoid hemorrhage (SAH) from intracranial aneurysm rupture results in significant morbidity and mortality. In the present study, we examined the effect of most widely used antiplatelet drugs, aspirin and cilostazol, on aneurysm rupture prevention using a mouse intracranial aneurysm model. Materials and Methods: Intracranial aneurysms were induced by a combination of deoxycorticosterone acetate-salt and a single injection of elastase into the cerebrospinal fluid in mice. Treatment with aspirin or cilostazol was started 1 day after aneurysm induction. Aneurysm rupture was detected by neurological symptoms and the presence of intracranial aneurysm with SAH was confirmed by post-mortem examination. Results: Aspirin (10 mg/kg) significantly reduced aneurysm rupture (control:aspirin = 80%:31%, p < 0.05) without affecting the overall incidence of aneurysm formation (60%:62%). Cilostazol (3 mg/kg, 30 mg/kg) did not reduce both rupture rate (control:3 mg/kg:30 mg/kg = 81%:67%:77%) and the overall incidence of aneurysm formation (control:3 mg/kg:30 mg/kg = 72%:71%:76%). Tail vein bleeding time prolonged significantly in both aspirin and cilostazol groups (p < 0.01). Conclusion: Aspirin prevented aneurysm rupture in a mouse intracranial aneurysm model, while cilostazol did not. Aspirin, the most frequently used drug for patients with ischemic myocardial and cerebral diseases, is also effective in preventing cerebral aneurysmal rupture.

Differences in dynamic behavior of single diatom cells caused by changing wavelengths

We investigate a motion of diatom cells stimulated by a halogen lamp irradiation. Diatom cells are single-celled organisms which have chloroplast. Chloroplast contains photosynthetic pigment which absorbs blue light (wave length of the light is 400 nm-450 nm) and red one (650 nm-700 nm). Light intensity of the halogen lamp is fixed about 500 Lx during the experiment. We used colored films to cut the blue or red light and observed motion of diatom cells by using the optical microscope. We found that the speed of diatom cells decreases when the colored film is inserted, and it increases after ejecting the film. It is noted that the light intensity is constant during the experiment, which means that we change wave length of the irradiated light. Our results show that the average speed of diatom cells is influenced by not the light intensity but the wave length of the light.

A Potential New Risk Factor for Stroke: Streptococcus Mutans With Collagen-Binding Protein

BACKGROUND

Among human oral bacteria, particular kinds of Streptococcus mutans (SM) known as dental caries pathogens contain a collagen-binding protein, Cnm, and show platelet aggregation inhibition and matrix metalloproteinase-9 activation. We have previously reported that these strains may be a risk factor for intracerebral hemorrhage. As a major sample-providing hospital, we report the clinical details, including intracranial aneurysms and ischemic stroke.

METHODS

After the study received approval from the Ethical Committee, 429 samples of whole saliva were obtained from patients who were admitted to or visited our hospital between February 16, 2010, and February 28, 2011. The study cohort comprised 48 patients with cardioembolic stroke (CES), 151 with non-CES infarct, 54 with intracerebral hemorrhage (ICH), 43 with ruptured intracranial aneurysm (RIA), and 97 with unruptured intracranial aneurysm (UIA). Cultured SM was identified as Cnm-positive when the corresponding gene was positive. The results were compared with those from 79 healthy volunteers. Relationships between Cnm-positive SM and known risk factors, including hypertension, diabetes, hyperlipidemia, smoking, and alcohol consumption, were analyzed.

RESULTS

A statistically significant high Cnm-positive rate was observed in patients with CES, non-CES infarct, ICH, and RIA (P = 0.002, 0.039, 0.013, and 0.009, respectively). There were no relationships between Cnm-positive SM and known risk factors.

CONCLUSIONS

Specific types of oral SM can be a risk factor for cardioembolic infarct, intracerebral hemorrhage, and intracranial aneurysm rupture. Further study is needed.

Suppression of Intimal Hyperplasia by a 5-lipoxygenase Inhibitor, MK-886: Studies with a Photochemical Model of Endothelial Injury

Intimal thickening is a major complication following percutaneous transluminal coronary angioplasty, which leads to restenosis and requires reoperation. We have investigated the effect of a 5-lipoxygenase inhibitor, MK-886, a leukotriene B4 (LTB4) receptor antagonist, ONO-4057 or a LTC4 and LTD4 receptor antagonist, ONO-1078, on intimal thickening. Photochemical reaction between green light and systemically administered Rose Bengal produced intimal thickening in the rat femoral artery. Each drug was administered orally, once a day for 7 days, starting just after the endothelial injury. Both MK-886 administration, 10 mg/kg, and ONO-4057 administration, 100 mg/kg, suppressed intimal thickening level examined three weeks after endothelial injury, while similarly administered ONO-1078 did not. In cultured rat-derived smooth muscle cells, LTB4, an active metabolite of 5-lipoxygenase whose biosynthesis in air pouch exudate was suppressed by MK-886, stimulated cell migration. Based on these observations, the 5-lipoxygenase may have a key role in intimal thickening via its metabolites such as LTB4.