NG2-positive pericytes regulate homeostatic maintenance of slow-type skeletal muscle with rapid myonuclear turnover

BACKGROUND

Skeletal muscle comprises almost 40% of the human body and is essential for movement, structural support and metabolic homeostasis. Size of multinuclear skeletal muscle is stably maintained under steady conditions with the sporadic fusion of newly produced myocytes to compensate for the muscular turnover caused by daily wear and tear. It is becoming clear that microvascular pericytes (PCs) exhibit myogenic activity. However, whether PCs act as myogenic stem cells for the homeostatic maintenance of skeletal muscles during adulthood remains uncertain.

METHODS

We utilized PC-fused myofibers using PC-specific lineage tracing mouse (NG2-CreERT/Rosa-tdTomato) to observe whether muscle resident PCs have myogenic potential during daily life. Genetic PC deletion mouse model (NG2-CreERT/DTA) was used to test whether PC differentiates to myofibers for maintenance of muscle structure and function under homeostatic condition.

RESULTS

Under steady breeding conditions, tdTomato-expressing PCs were infused into myofibers, and subsequently, PC-derived nuclei were incorporated into myofibers. Especially in type-I slow-type myofibers such as the soleus, tdTomato+ myofibers were already observed 3 days after PC labeling; their ratio reached a peak (approximately 80%) within 1 month and was maintained for more than 1 year. Consistently, the NG2+ PC-specific deletion induced muscular atrophy in a slow-type myofiber-specific manner under steady breeding conditions. The number of myonucleus per volume of each myofiber was constant during observation period.

CONCLUSIONS

These findings demonstrate that the turnover of myonuclei in slow-type myofibers is relatively fast, with PCs acting as myogenic stem cells-the suppliers of new myonuclei under steady conditions-and play a vital role in the homeostatic maintenance of slow-type muscles.

SPRR1A is a key downstream effector of MiR-150 during both maladaptive cardiac remodeling in mice and human cardiac fibroblast activation

MicroRNA-150 (miR-150) is conserved between rodents and humans, is significantly downregulated during heart failure (HF), and correlates with patient outcomes. We previously reported that miR-150 is protective during myocardial infarction (MI) in part by decreasing cardiomyocyte (CM) apoptosis and that proapoptotic small proline-rich protein 1a (Sprr1a) is a direct CM target of miR-150. We also showed that Sprr1a knockdown in mice improves cardiac dysfunction and fibrosis post-MI and that Sprr1a is upregulated in pathological mouse cardiac fibroblasts (CFs) from ischemic myocardium. However, the direct functional relationship between miR-150 and SPRR1A during both post-MI remodeling in mice and human CF (HCF) activation was not established. Here, using a novel miR-150 knockout;Sprr1a-hypomorphic (Sprr1a^hypo/hypo) mouse model, we demonstrate that Sprr1a knockdown blunts adverse post-MI effects caused by miR-150 loss. Moreover, HCF studies reveal that SPRR1A is upregulated in hypoxia/reoxygenation-treated HCFs and is downregulated in HCFs exposed to the cardioprotective β-blocker carvedilol, which is inversely associated with miR-150 expression. Significantly, we show that the protective roles of miR-150 in HCFs are directly mediated by functional repression of profibrotic SPRR1A. These findings delineate a pivotal functional interaction between miR-150 and SPRR1A as a novel regulatory mechanism pertinent to CF activation and ischemic HF.

Noncoding RNAs as Key Regulators for Cardiac Development and Cardiovascular Diseases

Noncoding RNAs (ncRNAs) play fundamental roles in cardiac development and cardiovascular diseases (CVDs), which are a major cause of morbidity and mortality. With advances in RNA sequencing technology, the focus of recent research has transitioned from studies of specific candidates to whole transcriptome analyses. Thanks to these types of studies, new ncRNAs have been identified for their implication in cardiac development and CVDs. In this review, we briefly describe the classification of ncRNAs into microRNAs, long ncRNAs, and circular RNAs. We then discuss their critical roles in cardiac development and CVDs by citing the most up-to-date research articles. More specifically, we summarize the roles of ncRNAs in the formation of the heart tube and cardiac morphogenesis, cardiac mesoderm specification, and embryonic cardiomyocytes and cardiac progenitor cells. We also highlight ncRNAs that have recently emerged as key regulators in CVDs by focusing on six of them. We believe that this review concisely addresses perhaps not all but certainly the major aspects of current progress in ncRNA research in cardiac development and CVDs. Thus, this review would be beneficial for readers to obtain a recent picture of key ncRNAs and their mechanisms of action in cardiac development and CVDs.

Ninjurin1 deletion in neuron-glial antigen 2-positive pericytes prevents microvessel maturation and delays wound healing

The formation of mature vasculature through angiogenesis is essential for adequate wound healing, such that blood-borne cells, nutrients, and oxygen can be delivered to the remodeling skin area. Neovessel maturation is highly dependent on the coordinated functions of vascular endothelial cells and perivascular cells, namely pericytes (PCs). However, the underlying mechanism for vascular maturation has not been completely elucidated, and its role in wound healing remains unclear. In this study, we investigated the role of Ninjurin-1 (Ninj1), a new molecule mediating vascular maturation, in wound healing using an inducible PC-specific Ninj1 deletion mouse model. Ninj1 expression increased temporarily in NG2-positive PCs in response to skin injury. When tamoxifen treatment induced a decreased Ninj1 expression in PCs, the neovessels in the regenerating wound margins were structurally and functionally immature, but the total number of microvessels was unaltered. This phenotypic change is associated with a reduction in PC-associated microvessels. Wound healing was significantly delayed in the NG2-specific Ninj1 deletion mouse model. Finally, we showed that Ninj1 is a crucial molecule that mediates vascular maturation in injured skin tissue through the interaction of vascular endothelial cells and PCs, thereby inducing adequate and prompt wound healing.

Aerosol Loading and Radiation Budget Perturbations in Densely Populated and Highly Polluted Indo-Gangetic Plain by COVID-19: Influences on Cloud Properties and Air Temperature

Aerosols emitted in densely populated and industrialized Indo-Gangetic Plain, one of the most polluted regions in the world, modulate regional climate, monsoon, and Himalayan glacier retreat. Thus, this region is important for understanding aerosol perturbations and their resulting impacts on atmospheric changes during COVID-19 lockdown period, a natural experimental condition created by the pandemic. By analyzing 5 years (2016-2020) data of aerosols and performing a radiative transfer calculation, we found that columnar and near-surface aerosol loadings decreased, leading to reductions in radiative cooling at the surface and top of the atmosphere and atmospheric warming during lockdown period. Further, satellite data analyses showed increases in cloud optical thickness and cloud-particle effective radius and decrease in lower tropospheric air temperature during lockdown period. These results indicate critical influences of COVID-19 lockdown on regional climate and water cycle over Indo-Gangetic Plain, emphasizing need for further studies from modeling perspectives.

Sarcopenia-derived exosomal micro-RNA 16-5p disturbs cardio-repair via a pro-apoptotic mechanism in myocardial infarction in mice

Sarcopenia is a pathophysiological malfunction induced by skeletal muscle atrophy. Several studies reported an association between sarcopenia-induced cardiac cachexia and poor prognosis in heart disease. However, due to lack of an established animal models, the underlying mechanism of disturbed cardiac repair accompanied with sarcopenia remains poorly understood. Here, we developed a novel sarcopenia-induced cardiac repair disturbance mouse model induced by tail suspension (TS) after cardiac ischemia and reperfusion (I/R). Importantly, we identified a specific exosomal-microRNA marker, miR-16-5p, in the circulating exosomes of I/R-TS mice. Of note, sarcopenia after I/R disturbed cardiac repair and raised the level of circulating-exosomal-miR-16-5p secreting from both the atrophic limbs and heart of TS mice. Likewise, miR-16-5p mimic plasmid disturbed cardiac repair in I/R mice directly. Additionally, in neonatal rat ventricular myocytes (NRVMs) cultured in vitro under hypoxic conditions in the presence of a miR-16-5p mimic, we observed increased apoptosis through p53 and Caspase3 upregulation, and also clarified that autophagosomes were decreased in NRVMs via SESN1 transcript interference-mediated mTOR activation. In conclusion, we show the pro-apoptotic effect of sarcopenia-derived miR-16-5p, which may be behind the exacerbation of myocardial infarction. Therefore, miR-16-5p can be a novel therapeutic target in the context of cardiac repair disturbances in sarcopenia-cachexia.

Back somersault-induced atrioventricular nodal reentrant tachycardia - A case of a 15-year-old promising gymnast

A male 15-year-old promising gymnast suffered palpitations, which emerged only after landing a round-off back somersault. The performance induced an attack of regular narrow QRS complex tachycardia that was highly reproducible. Not a single element of the performance, but a whole sequence of round-off back somersault was required to induce the attack. An electrophysiologic study revealed an intra-nodal dual pathway causing atrioventricular nodal reentrant tachycardia (AVNRT). A complication of a tiny atrial septal defect (ASD) was incidentally detected, thus we initially suspected a causal relation of ASD as the platypnea-orthodeoxia syndrome. However, it was denied as the major mechanism of attack because of a very faint shunt flow and no-induction of hypoxemia during a round-off back somersault. The major triggering mechanisms of a whole sequence of round-off back somersaults were speculated to be related to transient atrial overload and autonomic imbalance induced by a swift postural-axial change together with an intense Valsalva maneuver with the maximal level of breath holding. The AVNRT attack was successfully treated by radiofrequency catheter ablation and has never recurred even by a whole sequence of round-off back somersaults. Currently he is a healthy and active gymnast with no symptoms. <Learning objective: The individual trigger of an atrioventricular nodal reentrant tachycardia (AVNRT) attack varies. The unique and sole trigger of the attack in the present gymnast case was a whole sequence of round-off back somersaults. A swift postural-axial change together with an intense Valsalva maneuver with the maximal level of breath holding increased the atrial overload with stretching the atrial wall, which might have induced atrial extrasystole and played a trigger role initiating the AVNRT attack.>.

Pericyte-specific deletion of ninjurin-1 induces fragile vasa vasorum formation and enhances intimal hyperplasia of injured vasculature

Adventitial abnormalities including enhanced vasa vasorum malformation are associated with development and vulnerability of atherosclerotic plaque. However, the mechanisms of vasa vasorum malformation and its role in vascular remodeling have not been fully clarified. We recently reported that ninjurin-1 (Ninj1) is a crucial adhesion molecule for pericytes to form matured neovessels. The purpose is to examine if Ninj1 regulates adventitial angiogenesis and affects the vascular remodeling of injured vessels using pericyte-specific Ninj1 deletion mouse model. Mouse femoral arteries were injured by insertion of coiled wire. Four weeks after vascular injury, fixed arteries were decolorized. Vascular remodeling, including intimal hyperplasia and adventitial microvessel formation were estimated in a three-dimensional view. Vascular fragility, including blood leakiness was estimated by extravasation of fluorescein isothiocyanate (FITC)-lectin or FITC-dextran from microvessels. Ninj1 expression was increased in pericytes in response to vascular injury. NG2-CreER/Ninj1^loxp mice were treated with tamoxifen (Tam) to induce deletion of Ninj1 in pericyte (Ninj1 KO). Tam-treated NG2-CreER or Tam-nontreated NG2-CreER/Ninj1^loxp mice were used as controls. Intimal hyperplasia was significantly enhanced in Ninj1 KO compared with controls. Vascular leakiness was significantly enhanced in Ninj1 KO. In Ninj1 KO, the number of infiltrated macrophages in adventitia was increased, along with the expression of inflammatory cytokines. In conclusion, deletion of Ninj1 in pericytes induces the immature vasa vasorum formation of injured vasculature and exacerbates adventitial inflammation and intimal hyperplasia. Thus, Ninj1 contributes to the vasa vasorum maturation in response to vascular injury and to reduction of vascular remodeling.NEW & NOTEWORTHY Although abnormalities of adventitial vasa vasorum are associated with vascular remodeling such as atherosclerosis, the mechanisms of vasa vasorum malformation and its role in vascular remodeling have not been fully clarified. The present study provides a line of novel evidence that ninjurin-1 contributes to adventitial microvascular maturation during vascular injury and regulates vascular remodeling.

Comparison between unattended automated office blood pressure and conventional office blood pressure under the environment of health checkup among Japanese general population

Unattended automated office blood pressure (AOBP) measurement has been endorsed as the preferred in-office measurement modality in recent Canadian and American clinical practice guidelines. However, the difference between AOBP and conventional office blood pressure (CBP) under the environment of a health checkup remains unclear. We aimed to identify the clinical significance of AOBP as compared to CBP under the environment of a health checkup. There were 491 participants (333 females, mean age of 62.5 years) who were at least 20 years old, including 179 participants who were previously diagnosed with hypertension. Mean AOBPs were 131.8 ± 20.9/76.6 ± 11.7 mm Hg, and CBPs were 135.6 ± 21.6/77.3 ± 11.5 mm Hg. There was a difference of 3.9 mm Hg in systolic blood pressure (SBP) and 0.8 mm Hg in diastolic BP between AOBP and CBP. In all participants, SBP and pulse pressure, as well as the white coat effect (WCE), increased with age. The cutoff value used was 140/90 mm Hg for CBP and 135/85 mm Hg for AOBP, and the prevalence of WCE and masked hypertension effect (MHE) was 12.4% and 14.1%, respectively. Even in a health checkup environment of the general population, there was a difference between the AOBP and CBP, and the WCE was observed more strongly in the elderly with a history of hypertension, suggesting that a combination of AOBP with CBP may be useful in detecting WCE and MHE in all clinical scenarios including health checkups, and help solve the "hypertension paradox" not only in Japan but in all over the world.

Sarcopenia-derived exosomal micro-RNA 16-5p exerts the cardio-repair disturbance via pro-apoptotic mechanism in myocardial infarction of mice

Background

Sarcopenia is a pathophysiological malfunction induced by skeletal muscle atrophy, and several studies reported an association between sarcopenia-induced cardiac cachexia and poor prognosis in heart disease. Since only a few established animal models are recently available, the underlying mechanism of disturbed cardiac repair accompanied with sarcopenia remains poorly understood.

Purpose

We hypothesized that specific microRNAs in sarcopenia-derived exosomes play crucial roles in disturbed cardiac repair with sarcopenia, and these microRNAs directly exacerbate cardiomyocyte injury following cardiac ischemia and reperfusion.

Methods

We developed a novel sarcopenia-induced cardiac repair disturbance mouse model that is induced by tail suspension (TS) 7 days after a 45-min coronary occlusion of cardiac ischemia and reperfusion (I/R). The reduction of the left ventricular ejection fraction (LVEF) after I/R was compared in mice with TS [I/R-TS(+), n=14] and without [I/R-TS(−), n=12] by echocardiography. To investigate the exosomal mechanism of cardiac repair disturbance, a comprehensive analysis of extracted exosomal microRNAs from mice serum was performed in the 2 groups at day 8. Then, we investigated the impact of the identified candidate microRNA in neonatal rat cardiomyocytes (NRVMs). After 4 days in primary culture, candidate microRNA was transfected into NRVMs under hypoxic culture conditions. TUNEL analysis and quantitative PCR analysis of apoptosis-related genes were performed on the NRVMs.

Results

At day 8 after I/R, the LVEF of I/R-TS(+) was not significantly ameliorated compared to that of I/R-TS(−) (ΔLVEF; 1.59±6.92 vs. 8.04±7.71% p=0.034). Four candidate microRNAs obtained from I/R mice serum were identified in the microRNA array analysis. The re-analysis of these candidate micro-RNAs using all I/R mice demonstrated that the level of mir-16-5p in I/R-TS(+) was raised by approximately nine-fold than that in I/R-TS(−) (9.67±13.35 vs. 0.99±1.41, p&lt;0.05). Next, an in vitro experimental model using a microRNA mimic revealed that apoptosis in NRVMs was greatly enhanced by the transfection of a mir-16-5p mimic in hypoxic culture conditions (mir-16-5p vs. control = 5.77±2.84 vs. 1.72±0.55%, p&lt;0.01). Furthermore, by qRT-PCR analysis, the expression of CASP3 and TRP53 were upregulated in NRVMs treated with a mir-16-5p mimic than in control NRVMs.

Conclusion

Myocardial I/R injury in sarcopenia ended in cardiac repair disturbance accompanying with the enhanced expression of exosomal-mir-16-5p. A pro-apoptotic effect of mir-16-5p may exacerbate myocardial I/R injury and thus can be a novel therapeutic target for cardiac repair disturbance in sarcopenia.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science

EphA7+ perivascular cells as myogenic and angiogenic precursors improving skeletal muscle regeneration in a muscular dystrophic mouse model

Skeletal muscle has a capacity for muscular regeneration mediated by satellite cells (SCs) and non-SCs. Although it is proposed that non-SCs are attractive therapeutic targets for dystrophies, the biological properties of these cells remain unclear. We have recently identified novel multipotent pericytes (PCs), capillary stem cells (CapSCs) derived from the microvasculature. In the present study, we determined if CapSCs contributed to myogenic regeneration using muscular dystrophy mouse model. CapSCs were isolated as EphA7+NG2+PCs from the subcutaneous adipose tissues of GFP-transgenic mice. Co-culture with C2C12 myoblast cells showed that CapSCs effectively enhanced myogenesis as compared to controls including EphA7- PCs and adipose stromal cells (ASCs). CapSCs transplanted in cardiotoxin-injured gastrocnemius muscles were well differentiated into both muscle fibers and microvessels, as compared to controls. At three weeks after cell-transplantation into the limbs of the mdx/utrn-/-mouse, CapSCs increased the number of GFP+myofibers along with dystrophin expression and the area size of myofibers, and also enhanced the muscular mass and its performance, assessed by treadmill test as compared to controls. In conclusion, CapSCs have potent myogenic regeneration capacity and improved the pathological condition in a muscular dystrophy mouse. Thus, CapSCs are an attractive cellular source in regenerative therapy for muscular dystrophy.

Anti-signal Recognition Particle Antibody-positive Necrotizing Myopathy with Secondary Cardiomyopathy: The First Myocardial Biopsy- and Multimodal Imaging-proven Case

A 69-year-old Japanese woman was admitted to our hospital with progressive muscle weakness and dysphagia. She was taking pitavastatin for dyslipidemia. Her serum creatine kinase was 6,300 U/L. Pitavastatin was stopped, but her symptoms deteriorated, and cardiac congestion appeared. A muscle biopsy showed necrotizing myopathy (NM), and anti-signal recognition particle (SRP) antibody was positive. ¹⁸F-fluorodeoxyglucose-positron emission tomography showed an abnormal uptake, and magnetic resonance imaging showed abnormal gadolinium enhancement in the left ventricular wall. An endomyocardial biopsy revealed inflammatory cardiomyopathy. Steroid, tacrolimus, and intravenous immunoglobulins were effective against the symptoms. This is the first case of biopsy-proven secondary cardiomyopathy due to anti-SRP-positive NM.

P4144Pericyte-specific deletion of ninjurin1 induces abnormal vasa vasorum formation and persistent inflammation and enhances intimal hyperplasia of injured vasculature

Introduction

Atherosclerosis is fundamental pathological condition inducing severe ischemic diseases such as ischemic heart disease and stroke. New concept has been proposed that adventitial abnormalities including enhanced malformation of adventitial microvessel, vasa vasorum are associated with development and vulnerability of atherosclerotic plaque. However, the role of vasa vasorum malformation in vascular remodelling has not been fully clarified. We recently reported that Ninjurin1 (Ninj1) is critical adhesion molecule to associate pericytes (PCs) with endothelial (EC) tubes to form stabilized mature neovessels. The purpose of this study is to examine if formation of adventitial microvessels affects the vascular remodelling of injured vessels using PCs-specific Ninj1 deletion mouse model.

Methods and results

Deletion of Ninj1 gene in NG2-positive PCs was induced by tamoxifen (Tam)-treated NG2-CreER/Ninj1loxp mice (Ninj1KO, n=9). Tam-treated-NG2-CreER (n=4) or Tam-nontreated NG2-CreER/Ninj1loxp (n=5) mice were used as Control (Ct1 and Ct2 respectively). Femoral arteries were injured by insertion of coiled wire. After 4 weeks of surgery, blood vessels were stained by venous injection of FITC-lectin. Isolated femoral arteries were fixed with paraformaldehyde and decolorized with CUBIC reagent. Wire-mediated vessel injury induced intimal hyperplasia, as assessed by intima/media (I/M) ratio and accordingly grew microvessels in adventitia. Intimal hyperplasia in Ninj1KO were significantly enhanced compared to Controls. Although there was no significant difference in total length of adventitial microvessels among three groups, extravasation of FITC-lectin from adventitial microvessels were significantly enhanced in Ninj1KO. The number of infiltrated macrophages in adventitia were increased in Ninj1KO.

Conclusion

Deletion of Ninj1 in PCs contributes to formation of immature microvessels in adventitia of injured vasculature and to adventitial microbleeding, and subsequently enhances intimal hyperplasia. Ninj1 is an attractive target to normalize microvessels for anti-atherosclerotic therapy.

Capillary-resident EphA7+ pericytes are multipotent cells with anti-ischemic effects through capillary formation

The presence of pericytes (PCs) with multipotency and broad distribution along capillary suggests that microvasculature plays a role not only as a duct for blood fluid transport but also as a stem cell niche that contributes to tissue maintenance and regeneration. The lack of an appropriate marker for multipotent PCs still limits our understanding of their pathophysiological roles. We identified the novel marker EphA7 to detect multipotent PCs using microarray analysis of an immortalized PC library. PCs were isolated from microvessels of mouse subcutaneous adipose tissues, then EphA7⁺ PCs called capillary stem cells (CapSCs) were separated from EphA7⁻ control PCs (ctPCs) using fluorescence‐activated cell sorting system. CapSCs had highly multipotency that enabled them to differentiate into mesenchymal and neuronal lineages compared with ctPCs. CapSCs also differentiated into endothelial cells and PCs to form capillary‐like structures by themselves. Transplantation of CapSCs into ischemic tissues significantly improved blood flow recovery in hind limb ischemia mouse model due to vascular formation compared with that of ctPCs and adipose stromal cells. These data demonstrate that EphA7 identifies a subpopulation of multipotent PCs that have high angiogenesis and regenerative potency and are an attractive target for regenerative therapies.

Pericyte-Specific Ninjurin1 Deletion Attenuates Vessel Maturation and Blood Flow Recovery in Hind Limb Ischemia

Supplemental Digital Content is available in the text.

Objective—

Angiogenesis, entire step from endothelial cells (ECs) sprouts to vascular maturation, is a critical response to ischemia. To form functional mature vessels, interactions between ECs and pericytes are essential. Ninj1 (ninjurin1) is an adhesion molecule that contributes to the pathogenesis of neuroinflammation. We recently demonstrated that Ninj1 is expressed in pericytes during angiogenesis. However, the role of Ninj1 in angiogenesis under pathophysiological ischemic conditions has not yet been elucidated.

Approach and Results—

Ninj1 was detected in microvessels, and its expression was enhanced in ischemic tissues after mouse hindlimb ischemia. Knockdown of Ninj1 was performed by injection of biodegradable microspheres releasing Ninj1-small interfering RNA into muscle tissues. Alternatively, pericyte-specific Ninj1 knockout was induced by tamoxifen treatment of NG2-CreERT/Ninj1-flox mice. Ninj1 knockdown/knockout reduced the formation of blood-circulating functional vessels among total CD31⁺ microvessels within ischemic tissues and subsequently attenuated color Doppler–assessed blood flow recovery. Ninj1 overexpression enhanced expression of Anpt (angiopoietin) 1, whereas Ninj1 knockdown enhanced the endogenous Anpt1 antagonist, Anpt2 expression in pericytes and inhibited the association of pericytes with ECs and subsequent formation of capillary-like structure, that is, EC tube surrounded with pericytes in 3-dimensional gel culture.

Conclusions—

Our data demonstrate that Ninj1 is involved in the formation of functional matured vessels through the association between pericytes and ECs, resulting in blood flow recovery from ischemia. These findings further the current our understanding of vascular maturation and may support the development of therapeutics for ischemic diseases.

Development of Algorithm for Discriminating Hydrometeor Particle Types with a Synergistic Use of CloudSat and CALIPSO

We developed a method for classifying hydrometeor particle types, including cloud and precipitation phase and ice crystal habit, by a synergistic use of CloudSat/Cloud Profiling Radar (CPR) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)/Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP). We investigated how the cloud phase and ice crystal habit characterized by CALIOP globally relate with radar reflectivity and temperature. The global relationship thus identified was employed to develop an algorithm for hydrometeor type classification with CPR alone. The CPR-based type classification was then combined with CALIPSO-based type characterization to give CPR-CALIOP synergy classification. A unique aspect of this algorithm is to exploit and combine the lidar's sensitivity to thin ice clouds and the radar's ability to penetrate light precipitation to offer more complete picture of vertically resolved hydrometeor type classification than has been provided by previous studies. Given the complementary nature of radar and lidar detections of hydrometeors, our algorithm delivers thirteen hydrometeor types: warm water, supercooled water, randomly-oriented ice crystal (3D-ice), horizontally-oriented plate (2D-plate), 3D-ice+2D-plate, liquid drizzle, mixed-phase drizzle, rain, snow, mixed-phase cloud, water+liquid drizzle, water+rain and unknown. The global statistics of three-dimensional occurrence frequency of each hydrometeor type revealed that 3D-ice contributes the most to the total cloud occurrence frequency (53.8%), followed by supercooled water (14.3%), 2D-plate (9.2%), rain (5.9%), warm water (5.7%), snow (4.8%), mixed-phase drizzle (2.3%), and the remaining types (4.0%). This hydrometeor type classification provides useful observation-based information for climate model diagnostics in representation of cloud phase and their microphysical characteristics.

Conifer-Derived Monoterpenes and Forest Walking

Conifer and broadleaf trees emit volatile organic compounds in the summer. The major components of these emissions are volatile monoterpenes. Using solid phase microextraction fiber as the adsorbant, monoterpenes were successfully detected and identified in forest air samples. Gas chromatography/mass chromatogram of monoterpenes in the atmosphere of a conifer forest and that of serum from subjects who were walking in a forest were found to be similar each other. The amounts of α-pinene in the subjects became several folds higher after forest walking. The results indicate that monoterpenes in the atmosphere of conifer forests are transferred to and accumulate in subjects by inhalation while they are exposed to this type of environment.

Imaging mass spectrometry revealed the production of lyso-phosphatidylcholine in the injured ischemic rat brain

To develop an effective neuroprotective strategy against ischemic injury, it is important to identify the key molecules involved in the progression of injury. Direct molecular analysis of tissue using mass spectrometry (MS) is a subject of much interest in the field of metabolomics. Most notably, imaging mass spectrometry (IMS) allows visualization of molecular distributions on the tissue surface. To understand lipid dynamics during ischemic injury, we performed IMS analysis on rat brain tissue sections with focal cerebral ischemia. Sprague-Dawley rats were sacrificed at 24 h after middle cerebral artery occlusion, and brain sections were prepared. IMS analyses were conducted using matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) in positive ion mode. To determine the molecular structures, the detected ions were subjected to tandem MS. The intensity counts of the ion signals of m/z 798.5 and m/z 760.5 that are revealed to be a phosphatidylcholine, PC (16:0/18:1) are reduced in the area of focal cerebral ischemia as compared to the normal cerebral area. In contrast, the signal of m/z 496.3, identified as a lyso-phosphatidylcholine, LPC (16:0), was clearly increased in the area of focal cerebral ischemia. In IMS analyses, changes of PC (16:0/18:1) and LPC (16:0) are observed beyond the border of the injured area. Together with previous reports--that PCs are hydrolyzed by phospholipase A(2) (PLA(2)) and produce LPCs,--our present results suggest that LPC (16:0) is generated during the injury process after cerebral ischemia, presumably via PLA(2) activation, and that PC (16:0/18:1) is one of its precursor molecules.

The role of silicon in preventing appressorial penetration by the rice blast fungus

To test the hypothesis that silicon (Si) confers resistance against appressorial penetration of the rice blast fungus, the proportion of appressorial penetration into the leaf epidermis to total appressoria formed was compared among rice plants amended with various rates of silica gel to those plants nonamended. The amounts of Si in the youngest leaves were consistent with the amounts of silica gel applied to the rice plants. Relative Si levels on the adaxial surface of leaves as detected by energy dispersive X-ray analysis also increased with the amounts of silica gel applied. Based on light microscopic observation of the adaxial surface of rice leaves, the proportion of appressorial penetration was reduced by increasing amounts of silica gel applied and increased with the length of period after spray inoculation. Consequently, these results strongly support the hypothesis and suggest that Si in the leaf epidermis may confer resistance against appressorial penetration. Meanwhile, the number of lesions per leaf also decreased with the amount of Si applied, while only a certain part of penetrated appressoria could become sporulating susceptible lesions. This suggests that Si also confers physiological resistance against blast infection after the penetration.

Development of a wearable computer system with a hands-free operation interface for the use of home health caregiver

We previously developed a network-based medical care support system called the Hyper Hospital, a computer network with an interface that is dedicated to patient care. In this study, we developed a wearable information system that is designed so that a caregiver can obtain information and control various support devices within the home-care environment. In our system, the wearable computer itself consists of a computer network built into a jacket. Each required function is implemented by a dedicated small computer connected to the in-jacket network. A new function may easily be added to the system by connecting additional computers. A network comprising such a set of single-function computers becomes a highly efficient information system when applied to health care support.

Upper bound of the expected training error of neural network regression for a Gaussian noise sequence

In neural network regression problems, often referred to as additive noise models, NIC (Network Information Criterion) has been proposed as a general model selection criterion to determine the optimal network size with high generalization performance. Although NIC has been derived using asymptotic expansion, it has been pointed out that this technique cannot be applied under the assumption that a target function is in a family of assumed networks and the family is not minimal for representing the target true function, i.e. the overrealizable case, in which NIC reduces to the well-known AIC (Akaike Information Criterion) and others depending on a loss function. Because NIC is the unbiased estimator of generalization error based on training error, it is required to derive the expectations of errors for neural networks for such cases. This paper gives upper bounds of the expectations of training errors with respect to the distribution of training data, which we call the expected training error, for some types of networks under the squared error loss. In the overrealizable case, because the errors are determined by fitting properties of networks to noise components, including in data, the target set of data is taken to be a Gaussian noise sequence. For radial basis function networks and 3-layered neural networks with bell shaped activation function in the hidden layer, the expected training error is bounded above by sigma2* - 2nsigma2*logT/T, where sigma2* is the variance of noise, n is the number of basis functions or the number of hidden units and T is the number of data. Furthermore, for 3-layered neural networks with sigmoidal activation function in the hidden layer, we obtained the upper bound of sigma2* - O(log T/T) when n > 2. If the number of data is large enough, these bounds of the expected training error are smaller than sigma2* - N(n)sigma2*/T as evaluated in NIC, where N(n) is the number of all network parameters.

Ranitidine clearance during hemodialysis with high-flux membrane: comparison of polysulfone and cellulose acetate hemodialyzers

OBJECTIVE

To compare the effect of hemodialysis using two different types of dialyzer membranes, polysulfone (PS), a high-flux membrane, and cuprophane (CP), a conventional membrane, on blood ranitidine concentration.

BACKGROUND

Recent advances in hemodialyzer membranes have improved the removal of small and middle size uremic toxins, while little is known about the change of drug removal by new membranes.

METHODS

Eight patients with chronic renal failure who received ranitidine (150 mg/day) on a chronic basis were included. During the dialysis, blood samples were obtained from both the arterial and venous sides (before and after, respectively) of the dialyzer.

RESULTS

Serum concentration of ranitidine decreased more on PS [54 +/- 3% (+/- SEM) reduction after 3 h] than on CP (35 +/- 4%). The dialyzer clearance of ranitidine on PS membrane (67.2 +/- 4.4 ml/min/m2) was significantly higher than that on CP (43.1 +/- 3.8 ml/min/m2, P < 0.001). Elimination fraction (EF) of the drug during the dialysis with PS was also significantly higher than that with CP (72 +/- 2% versus 44 +/- 3%). Apparent half-life of ranitidine during dialysis with PS (2.9 +/- 0.4 h) was shorter than that with CP (5.1 +/- 0.7 h). However, the amount of ranitidine removed by a single dialysis with PS membrane was less than 20 mg.

CONCLUSION

Ranitidine clearance by hemodialysis is significantly higher with PS than with CP. Although additional dose adjustment may not be needed for ranitidine, the type of dialyzer membrane can affect drug elimination and should be taken into account for consideration of drug removal by hemodialysis.

Optical properties and size distribution of aerosols derived from simultaneous measurements with lidar, a sunphotometer, and an aureolemeter

A new method is proposed to derive the optical properties and size distribution of aerosol in an air column from simultaneous measurements of the backscattering coefficient, the optical thickness, and the solar aureole intensity with lidar, a sunphotometer, and an aureolemeter. Inasmuch as the backscattering properties and the optical thickness depend on both the complex refractive index and the size distribution, whereas the forward-scattering properties depend mainly on the size distribution, real and imaginary indices of refraction and size distributions of aerosol are retrieved from these measurements. The real and the imaginary parts of the complex refractive index of an aerosol at a wavelength of 500 nm during the period from November 1991 to March 1992 obtained in Tsukuba, Japan, were estimated to be 1.46-1.48 and 0.005-0.014, respectively. It is inferred from the size distribution and an optical thickness fraction of stratospheric aerosols in the total columnar aerosols that these results reflect the influences of stratospheric aerosols that originated from the Mt. Pinatubo eruption.

Stratification and Size Distribution of Aerosols Retrieved from Simultaneous Measurements with Lidar, a SunPhotometer, and an Aureolemeter

Vertical profiles of backscattering coefficients, optical thicknesses, and columnar size distributions of aerosols were obtained by simultaneous measurements with lidar, a sunphotometer, and an aureolemeter in Tsukuba, Japan, from November 1991 to December 1992. Several conspicuous characteristics were found in the relationship between aerosol size distribution and stratification. In summer an accumulation mode is dominant, and aerosols were heavily loaded in the planetary boundary layer. Turbid atmospheres with an abundance of large particles are observed in the middle troposphere in the spring. In autumn and winter the troposphere is clear so that columnar aerosol size distributions reflect stratospheric aerosols. During the observation period, volcanic aerosols that are due to the Mt. Pinatubo eruption were being loaded in the stratosphere. The mode radius in the volume size distribution of the stratospheric aerosol was observed to increase from 0.45 mum in November 1991 to 0.6 mum in October 1992, and decreased after October 1992. Total aerosol loading in the stratosphere was estimated to be maximum in the spring of 1992, minimum in the autumn of 1992, and increased again after the autumn of 1992.

Simultaneous determination of the aerosol complex index of refraction and size distribution from scattering measurements of polarized light

In this study we attempt to determine the aerosol complex index of refraction and size distribution from scattering measurements of polarized light. We illustrate that the scattering matrix elements M(2)(100 degrees ) and D(21) (150 degrees ) can be selected as an optimum set of matrix elements for determination of the complex index of refraction. We also illustrate that errors increase if we include insensitive scattering matrix elements in the determination of the complex index of refraction. A method is developed for the simultaneous determination of the complex index of refraction and the size distribution. In our method, we selected two sets of matrix elements, M (2) (100 degrees ) and D (21) (150 degrees ), for the determination of the complex index of refraction and others, which are much less sensitive to the complex index of refraction than M(2) (100 degrees ) and D(21) (150 degrees ), for the determination of the size distribution, based on their sensitivity analyses. A modified inversion library algorithm is adopted to solve the coupled system. Numerical experiments show that both the complex index of refraction and the size distribution can be determined with reasonable accuracy when we apply our method to scattering measurements of polarized light.

[MR venography using 3D-fast STIR sequence for lower extremities]

Venography of the lower extremities performed by injecting iodinated contrast material requires a complicated technique. Veins of lower-flow-speed such as varices are scarcely outlined by using the time-of-flight MR angiography technique. On the other hand, the 2D fast SE technique has proven itself unsuccessful when used with medium magnetic field MRI equipment in which a very long TR is unavailable. We obtained images of lower extremity veins by using the 3D fast STIR technique and medium magnetic field MRI equipment of 0.5 Tesla. The results were crisp angiographic images of lower-flow-speed veins including varices.

Tropospheric aerosol optical properties derived from lidar, sun photometer, and optical particle counter measurements

Tropospheric aerosols have been observed for the period from November 1990 to April 1992 with a lidar, a sun photometer, and an optical particle counter. Variations of aerosol optical thickness derived from the lidar and the sun photometer data and measurements are presented. The simultaneous measurements of these instruments also allowed us to estimate the extinction-to-backscatter ratio (S(1)), which ranged from 20 to 70. Comparison of optical thicknesses derived from both instruments clearly shows the effect of Mt. Pinatubo's eruption and the temporal variation of optical thickness in the stratosphere over 12 km. The possible range of the complex refractive index for the columnar mean aerosols can be deduced from the probable range of S(1) derived by the use of an S(1) diagram as a function of complex refractive index (m). The imaginary part of m can be estimated provided that the real part of m is known.

Serum interleukin-2 receptor and interferon-alpha levels in a patient with allergic granulomatous angiitis (Churg-Strauss)

A patient with allergic granulomatous angiitis accompanied by increases in serum interleukin-2 receptor (IL-2R) and interferon-alpha (IFN-alpha) levels is reported. Laboratory findings revealed leukocytosis with eosinophilia and increased serum IgE and IgG. The serum IL-2R and IFN-alpha were increased. The serum immune complex, interferon-beta, -gamma and complements remained at normal levels. The serum IgE, IgG, IL-2R and IFN-alpha correlated with disease activity. Immunofluorescent studies using frozen sections obtained from the dermal lesion showed no immunoglobulin or complement deposits on vascular walls. Measurements of serum IL-2R and IFN-alpha might be considered reliable serologic indicators of disease activity.

[A carcinoma of the cecum arising from the orifice of the appendix: a case report]

Reported is the case of a 50-year-old man who was admitted to hospital because of an abdominal pain. A barium enema revealed the shade of a distended, unfilled appendix that had reversed itself on the cecum and the ascending colon, the latter showing compression from the exterior. Further, a colonoscopic examination uncovered a flat, nodular tumor of the cecum that had elevated at the orifice of the vermiform appendix, and 67Ga scintigraphy indicated the uptake at the lower right abdomen. A resected specimen of the tumor showed proliferation in the cecal mucosa at the orifice of the appendix, causing an appendiceal abscess, and the histopathological findings revealed an adenocarcinoma of the cecal mucosa but no malignant transformation of the appendiceal mucosa.

[Diffuse abdominal uptake of 67Ga-citrate; report of three cases]

Three cases, two peritoneal lymphomatosis and one tuberculous peritonitis, which showed diffuse abdominal uptake of 67Ga-citrate, were reported. 67Ga scan should be indicated for patients suspected of malignancy or inflammation with a lack of localized symptoms and signs in the abdomen. 67Ga-citrate scan also can give notable information on the evaluation of therapeutic response in those patients.

[Malignant lymphoma of the ileum]

A 53-year-old man with malignant lymphoma of the ileum is reported. He was admitted to our hospital because of lower abdominal discomfort. 67Ga citrate radionuclide imaging revealed an abnormal round uptake in his lower abdomen. CT scans showed an abnormal soft tissue density mass and a remarkably dilated small intestine in the pelvis. X-ray studies of the small intestine revealed a giant diverticulum-like lesion. Angiograms showed a hypovascular tumor with irregularity of the small vessels. A resected specimen revealed non-Hodgkin's malignant lymphoma, diffuse large-cell type. 67Ga citrate radionuclide imaging was useful in screening for neoplastic lesions in the small intestine because of its easiness and safety.

[A case report of early rectal carcinoma, IIa + IIc type, with no invasion of the submucosa]

A 66-year-old woman was admitted to the Hakodate Chuo Hospital because of abdominal discomfort. A barium enema study revealed a deformity of the middle Houston's valve of the rectum and granular lesions at the Rb region of the rectum. A colonoscopic examination showed the IIa + IIc type of early rectal carcinoma. A resected specimen also revealed IIa + IIc type early rectal carcinoma, 8 X 13 mm in diameter, and well-differentiated adenocarcinoma with no invasion of the submucosa. Infiltration into the lymphatic vessels and regional lymph node metastasis were not encountered. The deformity of the rectal Houston's valve was checked by a barium enema study. It should be emphasized that early detection of colorectal carcinoma with no invasion of the submucosa, requires careful barium enema studies and colonoscopic examination.