Membrane backtracking at the maximum capacity of nondigestible antigen phagocytosis in macrophages.

The zipper model has been dominantly used to describe the driving mechanism of the engulfment process and its specific identification of antigens during phagocytosis in macrophages. However, the abilities and limitations of the zipper model, capturing the process as an irreversible reaction, have not been examined yet under the critical conditions of engulfment capacity. Here, we demonstrated the phagocytic behavior of macrophages after reaching the maximum engulfment capacity by tracking the progression of their membrane extension during engulfment using IgG-coated nondigestible polystyrene beads and glass microneedles. The results showed that, after macrophages reached their maximum engulfment capacity, they induced membrane backtracking (the reverse phenomenon of engulfment) in both polystyrene beads and glass microneedles, regardless of the difference in the shape of these antigens. We evaluated the correlation of engulfment in simultaneous stimulations of two IgG-coated microneedles and found that each microneedle was regurgitated by the macrophage independently of the advancement or backtracking of membranes on the other microneedle. Moreover, assessing the total engulfment capacity determined by the maximum amount the macrophage was capable of engulfing when imposing each antigen geometry showed that the capacity increased as the attached antigen areas increased. These results indicate that the mechanism of engulfment should imply the following: 1) macrophages have a backtracking function to recover their phagocytic activity after reaching maximal engulfment limit, 2) both phagocytosis and backtracking are local phenomena of the macrophage membrane that operates independently, and 3) the maximum engulfment capacity is determined not only by mere local cell membrane capacity but also by the whole-cell volume increase during simultaneous phagocytosis of multiple antigens by the single macrophages. Thus, the phagocytic activity may entail a hidden backtracking function, adding to the conventionally known irreversible zipper-like ligand-receptor binding mechanism during membrane progression to recover the macrophages that are saturated from engulfing targets beyond their capacity.

Grading of Atrophic Gastritis is Useful for Risk Stratification in Endoscopic Screening for Gastric Cancer.

OBJECTIVES: In order to screen for gastric cancer effectively, its interval should be set according to the risk. This study aimed to determine whether risk stratification is possible using the data obtained from medical examination or endoscopic findings. METHODS: First, subjects who underwent both cancer screening and medical examination from 2009 to 2015 and underwent cancer screening once more by 2016 were studied. Data such as the lipid profile and history of smoking obtained during the medical examination, and the grade of atrophy and presence of peptic ulcers were studied using multivariate analysis. Next, subjects who underwent cancer screening twice or more between 2009 and 2015 with or without medical examinations were studied to analyze any correlation between the grade of atrophy and cancer occurrence using univariate analysis. In both studies, the status of Helicobacter pylori (HP) infection was determined. RESULTS: In the multivariate analysis, 9378 subjects were included. Aging, advanced atrophy, presence of ulcers, and uric acid levels were identified as risk factors. Among subjects who underwent successful HP eradication therapy, advanced atrophy and aging were observed to be crucial risk factors. In the univariate analysis, there were 12,941 subjects. Gastric cancer occurred more frequently in the more severe atrophy group (P < 0.001). The annual rate of cancer occurrence in the most severe atrophy group was 0.31%, which was approximately thrice as that in the less atrophy group. CONCLUSIONS: Risk stratification was possible based on endoscopic examination alone. The interval should be set depending on each case.

[Infertility Due to Hyperprolactinemia in Empty Sella : A Case Report].

A 41-year-old male with the chief complaint of infertility was referred to our hospital. He presented withmild erectile dysfunction and reduced shaving frequency. Semen analysis indicated a decreased semen volume in addition to a low sperm count and motility. Hormone evaluation revealed the following details : follicle stimulating hormone (FSH) 1.7 mIU/ml (range 2.0-8.3 mIU/ml), luteinizing hormone (LH) 0.9 mIU/ml (range 0.8-5.7 mIU/ml), testosterone 86.6 ng/dl (range 225.0-1,039 ng/dl), and prolactin (PRL) 242.0 ng/ml (range 3.6-12.8 ng/ml). Magnetic resonance imaging (MRI) of the patient's head showed empty sella turcica. He was diagnosed with acquired hypogonadotropic hypogonadism due to hyperprolactinemia. We suspected that the hyperprolactinemia was due to the pituitary lesion, although the possibility of coexisting pituitary microadenoma could not be discarded. Based on the diagnosis, cabergoline therapy was started. Four months after initiation of cabergoline therapy, the patient's hormone levels and semen parameters normalized, followed by improvement in his clinical symptoms. Furthermore, his wife spontaneously conceived.

Integrate and fire model with refractory period for synchronization of two cardiomyocytes.

We investigate an integrate and fire model for two cardiomyocytes interacting with each other. A feature of the model is to incorporate the refractory periods of the cardiomyocytes as well as the influence of firing of adjacent cells. The present model predicts that, if refractory periods of the two cells are nearly equal, the beating rhythms of the two cells always synchronize and their beating rate is tuned to the faster rate between the two cells. On the other hand, if their refractory periods significantly differ, they exhibit various kinds of harmonious beating rhythms. These results successfully explain the well known characteristics of synchronized beating of cultured cardiomyocytes. We also discuss effects of a delay time of cell-to-cell interaction, that gives further complicated phase diagrams for the beating rhythms.

Optimal screening interval for men with low baseline prostate-specific antigen levels (≤1.0 ng/mL) in a prostate cancer screening program.

PURPOSE: To optimize the rescreening schedule for men with low baseline prostate-specific antigen (PSA) levels, we evaluated men with baseline PSA levels of ≤1.0 ng/mL in PSA-based population screening. METHODS: We enrolled 8086 men aged 55-69 years with baseline PSA levels of ≤1.0 ng/mL, who were screened annually. The relationships of baseline PSA and age with the cumulative risks and clinicopathological features of screening-detected cancer were investigated. RESULTS: Among the 8086 participants, 28 (0.35 %) and 18 (0.22 %) were diagnosed with prostate cancer and cancer with a Gleason score (GS) of ≥7 during the observation period, respectively. The cumulative probabilities of prostate cancer at 12 years were 0.42, 1.0, 3.4, and 4.3 % in men with baseline PSA levels of 0.0-0.4, 0.5-0.6, 0.7-0.8, and 0.9-1.0 ng/mL, respectively. Those with GS of ≥7 had cumulative probabilities of 0.42, 0.73, 2.8, and 1.9 %, respectively. The cumulative probabilities of prostate cancer were significantly lower when baseline PSA levels were 0.0-0.6 ng/mL compared with 0.7-1.0 ng/mL. Prostate cancer with a GS of ≥7 was not detected during the first 10 years of screening when baseline PSA levels were 0.0-0.6 ng/mL and was not detected during the first 2 years when baseline PSA levels were 0.7-1.0 ng/mL. CONCLUSIONS: Our study demonstrated that men with baseline PSA levels of 0.0-0.6 ng/mL might benefit from longer screening intervals than those recommended in the guidelines of the Japanese Urological Association. Further investigation is needed to confirm the optimal screening interval for men with low baseline PSA levels.

Interventricular dyssynchrony in a patient with a biventricular physiology and a systemic right ventricle.

We describe of a unique pattern of cardiac dyssynchrony in a patient with a biventricular physiology and systemic right ventricle (RV): the interventricular dyssynchrony due to a contraction delay between the left ventricle and RV. In the present case, the cineangiography and intracardiac electrocardiography of the RV did not reveal intraventricular dyssynchrony of the RV, but revealed interventricular dyssynchrony. In addition, the pressure curves of the ventricles exhibited time phase differences between the two ventricles. The cardiac resynchronization therapy determining the pacing lead positions based on the idea of interventricular dyssynchrony induced reverse cardiac remodeling in this patient with systemic RV dysfunction.

Algorithm for the precise detection of single and cluster cells in microfluidic applications.

Recent advances in imaging flow cytometry and microfluidic applications have led to the development of suitable mathematical algorithms capable of detecting and identifying targeted cells in images. In contrast to currently existing algorithms, we herein proposed the identification and reconstruction of cell edges based on original approaches that overcome frequent detection limitations such as halos, noise, and droplet boundaries in microfluidic applications. Reconstructed cells are then discriminated between single cells and clusters of round-shaped cells, and cell information such as the area and location of a cell in an image is output. Using this method, 76% of cells detected in an image had an error <5% of the cell area size and 41% of the image had an error <1% of the cell area size (n = 1,000). The method developed in the present study is the first image processing algorithm designed to be flexible in use (i.e. independent of the size of an image, using a microfluidic droplet system or not, and able to recognize cell clusters in an image) and provides the scientific community with a very accurate imaging algorithm in the field of microfluidic applications. © 2016 International Society for Advancement of Cytometry.

A distribution analysis of action potential parameters obtained from patch-clamped human stem cell-derived cardiomyocytes.

We investigated electrophysiological properties of human induced-pluripotent-stem-cell-derived and embryonic-stem-cell-derived cardiomyocytes, and analyzed action potential parameters by plotting their frequency distributions. In the both cell lines, the distribution analysis revealed that histograms of maximum upstroke velocity showed two subpopulations with similar intersection values. Sub-populations with faster maximum upstroke velocity showed significant prolongation of action potential durations by application of E-4031, whereas others did not, which may be partly due to shallower maximum diastolic potentials. We described electrophysiological and pharmacological properties of stem-cell-derived cardiomyocytes in the respective sub-populations, which provides a way to characterize diverse electrical properties of stem-cell-derived cardiomyocytes systematically.

Fatal pulmonary arterial hypertension in an infant girl with incontinentia pigmenti.

We report the case of an infant girl with incontinentia pigmenti (IP) complicated by fatal pulmonary arterial hypertension (PAH). She was diagnosed with IP, based on the presence of specific skin lesions, neonatal seizures, hypereosinophilia and a maternal family history of IP. At the age of 2 months, she was diagnosed with PAH on systolic heart murmur due to tricuspid valve regurgitation. Despite several treatments for PAH but not including epoprostenol, severe PAH persisted and she died of pulmonary hypertensive crisis at the age of 5 months. On postmortem histopathology the pulmonary artery had severe intimal thickening, with occlusion or stenosis of the vascular lumen of the small pulmonary arteries as well as partial plexiform lesions, all of which were compatible with PAH. Modulation of nuclear factor-κB signaling may be involved in the development of PAH in IP.

Displacement of the anterior leaflet of the tricuspid valve: Rare variant of Ebstein's anomaly.

In Ebstein's anomaly, the points of attachment, or hinges, of the septal and mural leaflets in the right ventricle are displaced away from the atrioventricular junction. In contrast, the junctional hinge of the anterior leaflet usually retains a normal position. Here, we report a case of giant right atrial aneurysm due to isolated displacement of the anterior leaflet of the tricuspid valve in an infant, a rare variant of Ebstein's anomaly. Enlargement of the right atrium, which was initially diagnosed during the fetal period, progressively and markedly dilated after birth and was successfully treated with surgical resection. Isolated displacement of the anterior leaflet should be recognized as a variant of Ebstein's anomaly.

The clinical characteristics of sudden cardiac arrest in asymptomatic patients with congenital heart disease.

Sudden cardiac arrest (SCA) is a major cause of death in patients with congenital heart disease (CHD). Systemic ventricular dysfunction is a reported risk factor for SCA. We retrospectively analyzed the medical records of 46 patients (age >6 years) who experienced SCA. The following underlying cardiac defects were observed: biventricular repair with affected subpulmonary right ventricle (n = 18, 39 %), biventricular repair with systemic right ventricle and Eisenmenger syndrome (n = 6 each, 13 %), Fontan circulation and unrepaired CHD (n = 5 each, 11 %), and others (n = 6, 13 %). Twenty-one patients (46 %) had no history of arrhythmias, and 21 of 43 (49 %) showed systemic ventricular ejection fraction >55 %. According to the New York Heart Association classification, 18 patients (39 %) were class I and 28 (61 %) were class II/III. SCA occurred at a younger age in class I (16 ± 5 years) than in the other classes (23 ± 10 years; P = 0.004). QRS duration was similar between the groups (136 ± 38 vs. 141 ± 50 ms; P not significant). Seven patients in class I (15 % of all SCAs) had no history of arrhythmias or features of hemodynamic abnormalities. The proportion of patients with biventricular repair and affected subpulmonary right ventricle was higher than that of patients with other defects, and the majority of SCA patients had more complicated defects than a simple repaired ventricular septal defect or an atrial septal defect. No symptoms of heart failure, history of arrhythmias, or features of hemodynamic abnormalities were observed in 15 % of the patients who experienced SCA. Prolonged QRS duration might be a predictor of SCA even in asymptomatic CHD patients. Prevention of SCA in CHD patients may require more detailed evaluation than is typically considered necessary.

DNA hybridization efficiency on concave surface nano-structure in hemispherical Janus nanocups.

We examined the effect of a concave structure on DNA hybridization efficiency using an inner surface of hemispherical Janus nanocups in the range from 140 to 800 nm. Target DNA was specifically immobilized onto the inner cup surface, hybridized with complementary DNA-attached 20 nm Au probes, and the number of the hybridized probes was counted by scanning electron microscopy. The hybridization density of the attached Au probes on 800 nm nanocups was 255 µm(-2), which was 0.57 times that on a flat surface, 449 µm(-2), and increased to 394 µm(-2) on a 140 nm cup, 0.88 times of a flat surface, as the cup size decreased. The local density of attached Au probes within the central 25% at the bottom of the 800 nm nanocups was 444 µm(-2), which was closer to that on a flat surface, and the tendency was the same for all sizes of cups, indicating that the size dependency of DNA hybridization efficiency on the concave structures were mostly affected by the lower efficiency of side wall hybridization.

Pleurodesis using OK-432 for persistent pleural effusion after cardiac surgery in the neonatal period or early infancy.

OBJECTIVE: To evaluate the efficacy of pleurodesis using OK-432 after cardiac surgery in the neonatal period or early infancy. METHODS: We retrospectively reviewed the data of 11 consecutive patients who underwent cardiac surgery in the neonatal period or early infancy and pleurodesis using OK-432 for persistent postoperative pleural effusion in two institutions. RESULTS: The median age at surgery was 8 days (interquartile range [IR], 2-18) with a body weight of 2.84 kg (IR, 2.30-3.07). The maximum amount of pleural drainage before pleurodesis was 94.7 (IR, 60.2-107.7) ml/kg/day. Pleurodesis was initiated at postoperative day 20 (IR, 17-22) and performed in bilateral pleural spaces in seven patients and unilateral in four. The median numbers of injection were 4 (IR, 3-6) times per patient and 3 (IR, 2-3) times per pleural space. In 10 patients, pleural effusion was decreased effectively, and drainage tubes were removed without reaccumulation within 15 (IR, 12-28) days after initial pleurodesis. However, in one patient, with severe lymphedema, pleural effusion was uncontrollable, resulting in death due to sepsis. Adverse events were observed in nine patients; temporal deterioration of lung compliance and arterial blood gas occurred in two, insufficient drainage requiring new chest tube(s) in five, temporal atrial tachyarrhythmia in one, and lymphedema in four. CONCLUSIONS: Pleurodesis using OK-432 is effective and reliable for persistent postoperative pleural effusion in neonates and early infants. Most of the complications, which derived from inflammatory reactions, were temporary and controllable. However, severe lymphedema is difficult to control.

Ultrafast high-endurance memory based on sliding ferroelectrics.

The persistence of voltage-switchable collective electronic phenomena down to the atomic scale has extensive implications for area- and energy-efficient electronics, especially in emerging nonvolatile memory technology. We investigate the performance of a ferroelectric field-effect transistor (FeFET) based on sliding ferroelectricity in bilayer boron nitride at room temperature. Sliding ferroelectricity represents a different form of atomically thin two-dimensional (2D) ferroelectrics, characterized by the switching of out-of-plane polarization through interlayer sliding motion. We examined the FeFET device employing monolayer graphene as the channel layer, which demonstrated ultrafast switching speeds on the nanosecond scale and high endurance exceeding 1011 switching cycles, comparable to state-of-the-art FeFET devices. These characteristics highlight the potential of 2D sliding ferroelectrics for inspiring next-generation nonvolatile memory technology.

Cardiopulmonary variables during exercise predict pregnancy outcome in women with congenital heart disease.

BACKGROUND: Maternal New York Heart Association (NYHA) class is associated with pregnancy outcome in women with congenital heart disease (WCHD), but objective predictive criteria of exercise capacity have not been established. METHODS AND RESULTS: A total of 33 WCHD (age, 28 ± 5 years; NYHA class, 1.3 ± 0.6) who had undergone cardiopulmonary exercise testing (CPX) 1.8 ± 2.2 years before their delivery were retrospectively identified. Maternal, cardiac, and neonatal events occurred in 8 (24%), 12 (36%), and 14 (42%), respectively. All CPX parameters correlated with neonatal birth weight (P<0.05-0.001). Exercise time, peak heart rate (HR), peak systolic blood pressure, and peak oxygen uptake (VO(2)) were associated with cardiac events (P<0.05-0.01), and exercise time and peak VO(2) were also associated with neonatal events (P<0.05). Exercise time, peak HR, and peak VO(2) were associated with at least 1 of the 3 events (P<0.05-0.01). Receiver operating characteristic analysis showed that peak HR <150 beats/min and/or peak VO(2) <22.0 ml · kg(-1) · min(-1), peak VO(2) <26.2 ml · kg(-1) · min(-1), and peak HR <150 beats/min and/or peak VO(2) <25.3 ml · kg(-1) · min(-1) predicted a high probability of maternal cardiac, neonatal, and maternal cardiac and/or neonatal event, respectively. CONCLUSIONS: CPX parameters predict pregnancy outcome and peak HR ≥ 150 beats/min and/or peak VO(2) ≥ 25 ml · kg(-1) · min(-1) may be reference value(s) for a safer pregnancy outcome in WCHD.

Microtechnologies to fuel neurobiological research with nanometer precision.

The interface between engineering and molecular life sciences has been fertile ground for advancing our understanding of complex biological systems. Engineered microstructures offer a diverse toolbox for cellular and molecular biologists to direct the placement of cells and small organisms, and to recreate biological functions in vitro: cells can be positioned and connected in a designed fashion, and connectivity and community effects of cells studied. Because of the highly polar morphology and finely compartmentalized functions of neurons, microfabricated cell culture systems and related on-chip technologies have become an important enabling platform for studying development, function and degeneration of the nervous system at the molecular and cellular level. Here we review some of the compartmentalization techniques developed so far to highlight how high-precision control of neuronal connectivity allows new approaches for studying axonal and synaptic biology.

Early quality of life outcomes in patients with prostate cancer managed by high-dose-rate brachytherapy as monotherapy.

OBJECTIVES: To evaluate the early quality of life outcomes in prostate cancer patients managed by high-dose-rate brachytherapy as monotherapy. METHODS: A total of 51 patients with cT1c-T3aN0M0 prostate cancer treated between July 2007 and January 2010 were included in this study. The average age was 69 years, and the average initial serum prostate-specific antigen was 10.98 ng/mL. A total of 25, 18 and eight patients were considered to be low, intermediate and high risk, respectively. All patients received one implant of Ir-192 and seven fractions of 6.5 Gy within 3.5 days for a total prescribed dose of 45.5 Gy. For high-risk prostate cancer, neoadjuvant androgen deprivation therapy was carried out for at least 6 months, and continued after high-dose-rate brachytherapy. Quality of life outcomes were measured by using the International Prostate Symptom Score, the Functional Assessment of Cancer Therapy-Prostate and the International Index of Erectile Function Questionnaire. The oncological outcome was assessed by serum prostate-specific antigen and diagnostic imaging. Adverse events were also recorded. RESULTS: The Functional Assessment of Cancer Therapy-Prostate scores decreased for a few months after high-dose-rate brachytherapy, and recovered to pretreatment condition thereafter. The International Prostate Symptom Score significantly increased 2 weeks after treatment for each of its items and their sum, and it returned to baseline after 12 weeks. Sexual function decreased at 2 and 4 weeks, and recovered after 12 weeks. Severe complications were rare. Within a median follow up of 17.2 months, two patients showed a prostate-specific antigen recurrence. CONCLUSIONS: High-dose-rate brachytherapy for prostate cancer is a feasible treatment modality with acceptable toxicity and only a limited impact on the quality of life.

On-Chip Free-Flow Measurement Revealed Possible Depletion of Macrophages by Indigestible PM2.5 within a Few Hours by the Fastest Intervals of Serial Phagocytosis.

To understand the influence of indigestible particles like particulate matter 2.5 (PM2.5) on macrophages, we examined the time course of the series phagocytosis of indigestible 2 µm polystyrene spheres (PS). Five kinds of antigens were used as samples for phagocytosis; Zymosan, non-coated 2 µm PS, bovine serum albumin (BSA)-coated PS (BSA-PS), IgG-coated PS (IgG-PS), and IgG-BSA-coated PS (IgG/BSA-PS). To keep the surrounding concentration of antigens against single macrophages constant, antigens flowed at a continuous rate of 0.55 µm/s within a culture dish as a free-flow measurement assay (on-chip free-flow method). The interval of series phagocytosis for IgG/BSA-PS was the shortest among five samples; it was six times faster than Zymosan in terms of engulfment frequency, and up to 50 particles were engulfed within two hours, maintaining constant intervals until reaching the maximum number. The rate of increase in the total number of phagocytozed IgG/BSA-PS over time was constant, at 1.5 particles/min, in series phagocytosis with a 33-cell population, indicating that the phagocytosis rate constant remained constant independent of the number of phagocytoses. Reaction model fitting of the results showed that IgG/BSA-PS had the highest efficiency in terms of the phagocytosis rate constant, 2.3 × 10-2 particles/min, whereas those of IgG-PS, BSA-PS, PS, and Zymosan were 1.4 × 10-2, 1.1 × 10-2, 4.2 × 10-3, and 3.6 × 10-3 particles/min, respectively. One-by-one feeding of IgG/BSA-PS with optical tweezers was examined to confirm the phagocytosis intervals, and we found that the intervals remained constant until several times before the maximum number of antigens for engulfment, also indicating no change in the phagocytosis rate constant regardless of the history of former phagocytosis and phagocytosis number. Simultaneous phagocytosis of two IgG-BSA-decorated microneedle engulfments also showed that the initiation and progress of two simultaneous engulfments on the two different places on a cell were independent and had the same elongation velocity. Therefore, each phagocytosis of indigestible antigens does not affect both in series or in simultaneous subsequent phagocytosis until reaching the maximum capacity of the phagocytosis number. The results suggest (1) no change in the phagocytosis rate constant regardless of the history of phagocytosis numbers and attachment timing and positions, and (2) IgG-BSA decoration of indigestible microparticles in blood accelerates their engulfment faster, resulting in a severe shortage of macrophages within the shortest time.