Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Low plasma levels of B-type natriuretic peptide predict the insulin resistance and left ventricular concentric remodeling in subjects without heart diseases: the observational arita cohort study

Introduction

Although natriuretic peptides (NPs) are established as a biomarker of heart failure (HF), NPs have been attracting attention as a mediator in the metabolic sequences recently. On the other hand, metabolic disorders including insulin resistance have been suggested to be involved in left ventricular (LV) concentric remodeling, hinting us to the unexpected relationship among NPs, insulin resistance and LV concentric remodeling.

Purpose

To investigate whether the basal B-type natriuretic peptide (BNP) level is linked to insulin resistance or LV concentric remodeling in the participants independent of HF in the Japanese Arita-cho cohort study.

Methods

Among 1632 subjects who participated in annual health checks from 2005 to 2008 in Arita-cho, Saga, Japan as a cohort study, we studied 675 subjects without history of cardiovascular disease with LV ejection fraction≥50% and BNP level<35pg/ml (227 men; median 62 years old). Insulin resistance was assessed by homeostatic model assessment of insulin resistance (HOMA-IR) and LV geometry including LV concentric remodeling was classified based on relative wall thickness (RWT) and LV mass index from echocardiographic findings.

Results

The tertile levels of BNP were inversely associated with HOMA-IR (the 1st tertile 1.33 (0.76–1.74), the 2nd tertile 1.05 (0.72–1.59), the 3rd tertile 0.95 (0.66–1.58), p=0.005); in the logistic regression analysis, the lower BNP level was related to the prevalence of insulin resistance defined as HOMA-IR≥1.37 after full multivariate adjustment (1 SD increment of BNP: adjusted odds ratio [aOR] 0.740, 95% confidence interval 0.601–0.912, P=0.005. LV concentric remodeling (RWT >0.42 and LV mass index ≤115 g/m2 in men and ≤95 g/m2 in women) was observed in 170 (25%) subjects; both low BNP level and higher insulin resistance were independently linked with LV concentric remodeling after multivariate adjustment (1 SD increment of BNP: aOR 0.714, 95% CI 0.544–0.938, p=0.015, HOMA-IR≥1.37 vs. <1.37: aOR 1.694, 95% CI 1.004–2.857, p=0.048, respectively) (Figure).

Conclusions

In the cohort without HF, the low BNP level was linked to insulin resistance and LV concentric remodeling independently, suggesting that the subjects with low NPs levels may cause metabolic disorders and LV morphological abnormalities.

Funding Acknowledgement

Type of funding sources: None.

Frequency of consumption of balanced meals, bodyweight gain and incident risk of glucose intolerance in Japanese men and women: A cohort study

AIMS/INTRODUCTION

This cohort study assessed the risk for bodyweight gain and development of glucose intolerance based on the frequency of consumption of balanced meals including grain, fish or meat and vegetables.

MATERIALS AND METHODS

The participants (8,573 men, 3,327 women) were employees of a company in Japan. A self-administered questionnaire was used to evaluate the frequency of balanced meal consumption. Bodyweight changes and the incidence of glucose intolerance (glycated hemoglobin >6.0%) during the 3-year follow-up period were determined through annual health examinations.

RESULTS

The mean bodyweight change over a period of 3 years was 0.78 kg for men and 0.84 kg for women. A lower frequency of balanced meals was associated with a higher bodyweight gain for men (P for trend = 0.004), but not for women. During the study, 464 men and 115 women developed glucose intolerance. Overall, the frequency of balanced meals was not associated with the risk of glucose intolerance in either sex. However, the interaction between the frequency of balanced meals and degree of obesity had a significant effect on the incidence of glucose intolerance in men (P = 0.005), with less frequent consumption of balanced meals being associated with a higher risk for glucose intolerance among men with a BMI ≥25.0 kg/m2 (P for trend = 0.007).

CONCLUSIONS

A higher frequency of balanced meals, including grain, fish or meat and vegetable dishes - important components of healthy Japanese food - was associated with a lower risk of glucose intolerance in obese men, but not in non-obese men and women.

Prognostic differences between atrial functional mitral regurgitation and ventricular functional mitral regurgitation

Introduction

Atrial functional mitral regurgitation (A-FMR) has been under-recognized until recently as a cause of FMR, and the prognostic difference between A-FMR and ventricular FMR (V-FMR) has not been fully elucidated. As there has been different mechanisms of FMR suggested in A-FMR and V-FMR, we hypothesized that prognosis and prognostic predictors of A-FMR may differ from those of V-FMR.

Purpose

To investigate the prognosis and prognostic predictors of A-FMR in comparison with V-FMR.

Methods

Among 1312 consecutive patients with grade 3+ (moderate to severe) or 4+ (severe) MR, 378 consecutive FMR patients were identified by excluding patients with degenerative MR, previous cardiac surgery, or concomitant aortic valve disease and/or mitral stenosis. FMR with ejection fraction (EF) <40% or FMR due to regional wall motion abnormalities with leaflet tethering were classified as V-FMR (N=288), and FMR due to left atrial (LA) and/or annular dilatation with preserved or mid-range EF (≥40%) were classified as A-FMR (N=90). All-cause death and heart failure hospitalization were analyzed as cardiovascular (CV) events in this study. Surgical or percutaneous mitral valve intervention without CV events was handled as not reaching an endpoint and these cases were censored.

Results

A-FMR were significantly older (76 [69–82] vs. 70 [58–77] years), higher rates of female (64 vs. 35%) and atrial fibrillation (88 vs. 42%), and lower B-type natriuretic peptide (BNP) values (169 [101–318] vs. 447 [213–952] pg/ml) compared to V-FMR (all P<0.05). On echocardiography, LV end-diastolic and end-systolic dimensions (52 [48–57] vs. 64 [58–72] mm, 34 [31–37] vs. 55 [48–64] mm), respectively) were smaller, and EF (55 [50–60] vs. 28 [19–35] %) and LA volume (99 [73–137] vs. 73 [57–91] ml/m2) were larger in A-FMR (all P<0.05). Effective regurgitant orifice area (32 [26–40] vs. 31 [24–45] mm2) and regurgitant volume (50±15 vs. 52±16 ml) were similar (both n.s.). During a median follow up of 1407 days, 206 (54%) patients developed CV events. Kaplan-Meier analysis revealed that V-FMR had a significantly higher rates of CV events compared to A-FMR (Figure) with adjusted hazard ratio (HR) of 1.762 [1.168–2.660], P=0.007 after adjusted for variables including age, sex, New York Heart Association functional class, previous heart failure hospitalization, estimated glomerular filtration rate (eGFR) and BNP. Further, stepwise multivariate analysis showed that independent prognostic predictors of A-FMR were LA volume and eGFR, while those for V-FMR were LA volume, age, and LV end-systolic dimension.

Conclusions

A-FMR had relatively better prognosis compared to V-FMR, and there were different prognostic predictors between A-FMR and V-FMR. Our results suggest that different treatment strategies need to be considered between A-FMR and V-FMR.

The Kaplan-Meier life table

Funding Acknowledgement

Type of funding source: None

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

[A Nutritional Supplement with a High Blend Ratio of ω-3 Fatty Acids(Prosure®) Reduces Severe Oral Mucositis and Body Weight Loss for Head and Neck Cancer Patients Treated with Chemoradiotherapy]

BACKGROUND

Oral mucositis and body weight loss are the most critical conditions known to lead to the discontinuation of chemoradiotherapy for head and neck cancer. We investigated the effect of a nutritional supplement with a high blend ratio of w-3 fatty acids(Prosure®)on body weight loss, oral mucositis, and the completion rate of chemoradiotherapy in patients with oropharyngeal and hypopharyngeal cancer.

PATIENTS AND METHODS

The study group comprised patients with oropharyngeal and hypopharyngeal cancer who were treated with concomitant cisplatin and 70 Gy of radiotherapy. These patients received 2 packs of Prosure®per day during chemoradiotherapy.

RESULTS

A total of 17 patients were included in this study. The reduction in body weight was significantly improved compared with that in the historical control group that did not receive Prosure®(7.3% vs 10.3%, p<0.01), and the rate of Grade 3-4 oral mucositis was significantly reduced for the patient groups that received Prosure®(CTCAE v3.0 GradeB3; 24% vs 58%, p<0.05). The completion rate of chemoradiotherapy was not significantly different between both groups(77% vs 60%, NS).

CONCLUSIONS

A nutritional supplement with a high blend ratio of w-3 fatty acids(Prosure®)had effects on oral mucositis and body weight loss in head and neck cancer patients treated with chemoradiotherapy.

Serological surveillance for antibodies against Erysipelothrix species in wild boar and deer in Japan

We investigated the seroprevalence of antibodies against Erysipelothrix in wild animals in Japan. Serum samples were collected from 48 wild boar, 26 Yezo deer and 26 Japanese deer in Japan. Growth agglutination (GA) test was performed to estimate antibody titers. As a result, positive results were obtained from 32 (66.7%), 1 (3.6%) and 6 (23.1%) samples from wild boar, Yezo deer and Japanese deer, respectively. Our findings suggest that wild animals may be an important reservoir of Erysipelothrix.

Recovery of corneal irregular astigmatism, ocular higher-order aberrations, and contrast sensitivity after discontinuation of overnight orthokeratology

AIMS

To examine prospectively the recovery of various parameters after discontinuation of overnight orthokeratology.

METHODS

Seventeen subjects undergoing orthokeratology for 12 months were examined. Refraction, corneal topography, wavefront aberrometry, a visual acuity test and a contrast sensitivity test were performed at baseline, 12 months after commencement of the procedure, and 1 week and 1 month after discontinuation of the treatment. Asymmetry and higher-order irregularity components were calculated using a Fourier analysis of the corneal topography data. Contrast sensitivity was assessed at four spatial frequencies, and the area under the log contrast sensitivity function (AULCSF) was calculated.

RESULTS

Orthokeratology significantly reduced manifest refraction (p<0.0001, Dunnett test) and significantly improved uncorrected visual acuity (UCVA) at 12 months after commencement of the procedure (p<0.0001). Asymmetry and higher-order irregularity components increased significantly (p<0.0001, p = 0.0032, respectively), and third- and fourth-order aberrations also increased significantly (p<0.0001). The treatment resulted in significant decreases in AULCSF (p = 0.0004). After discontinuing lens wear, all parameters, such as refraction, UCVA, asymmetry, higher-order irregularity, third-order aberration, fourth-order aberration and AULCSF, returned to the baseline level at 1 week.

CONCLUSION

This study confirmed that the effect of orthokeratology is completely reversible in light of optical quality of the eye and quality of vision as well as refraction and visual acuity.

Higher-order wavefront aberration and letter-contrast sensitivity in keratoconus

AIMS

To evaluate the relation between higher-order aberration of the eye and contrast sensitivity function in eyes with keratoconus.

METHODS

In 22 eyes of 14 patients with keratoconus (age 30.5+/-8.4 years, means+/-SD) and 26 eyes of 13 normal controls (age 29.2+/-6.7 years), ocular higher-order wavefront aberration for a 6-mm pupil was measured with the Hartmann-Schack aberrometer (KR-9000 PW, Topcon). The root mean square (RMS) of third- and fourth-order Zernike coefficients was used to represent higher-order aberrations. The letter-contrast sensitivity was examined using the CSV-1000LV contrast chart (Vector Vision).

RESULTS

In the keratoconus group, the letter-contrast sensitivity showed significant correlation with third-order (Spearman's correlation coefficient r=-0.736, P<0.001) and fourth-order aberrations (r=-0.464, P<0.05). There was borderline correlation between log MAR BSCVA and third-order (r=0.413, P=0.070) and fourth-order aberrations (r=0.394, P=0.086). In the normal group, the letter-contrast sensitivity had no significant correlation with third-order (r=-0.170, P=0.411) and fourth-order aberrations (r=-0.088, P=0.673), and log MAR best spectacle-corrected visual acuity (BSCVA) showed no correlation with third-order (r=0.063, P=0.762) and fourth-order aberrations (r=-0.282, P=0.165).

CONCLUSIONS

In eyes with keratoconus, there is significant correlation between contrast sensitivity and ocular higher-order wavefront aberrations.

Influence of tilt and decentration of scleral-sutured intraocular lens on ocular higher-order wavefront aberration

AIM

To investigate the influence of tilt and decentration of scleral-sutured intraocular lenses (IOLs) on ocular higher-order wavefront aberrations.

METHODS

In 45 eyes of 36 patients who had undergone scleral suture fixation of posterior chamber IOL, tilt and decentration of IOLs were determined by Scheimpflug videophotography, and higher-order aberration for a 4-mm pupil was measured using the Hartmann-Shack aberrometer. In another 100 eyes of 100 patients after standard cataract surgery with posterior chamber IOL implantation, ocular higher-order aberration was measured.

RESULTS

In eyes with scleral-sutured IOL, the mean (SD) tilt angle and decentration were 4.43 degrees (3.02 degrees ) and 0.279 (0.162) mm, respectively. Ocular coma-like aberration in the sutured IOL group was 0.324 (0.170) microm, which was significantly greater than that of the standard cataract surgery group (0.169 (0.061) microm, p<0.001, Student's t test). No significant difference was found in ocular spherical-like aberration between the sutured IOL group (0.142 (0.065) microm) and standard surgery group (0.126 (0.033) microm; p = 0.254). In the sutured IOL group, IOL tilt significantly correlated with ocular coma-like aberration (Pearson's correlation coefficient r = 0.628, p<0.001), but no significant correlation was found between IOL tilt and ocular spherical-like aberration (r = 0.222, p = 0.175). The IOL tilt did not correlate with corneal coma-like (r = 0.289, p = 0.171) and spherical-like (r = 0.150, p = 0.356) aberrations. The IOL decentration did not correlate with any higher-order aberrations.

CONCLUSION

In eyes with scleral-sutured posterior chamber IOL, tilting of the lens induces considerable amount of ocular coma-like aberrations.

Legal medical record redefinition in a multimedia environment

As health information expands beyond the traditional paper-based medical record, HIM professionals need to confront the issues related to defining the medical record. The author provides a detailed assessment guide to the redefinition process.

[Amrinone reverses cardiac depression by enflurane in the dog]

To evaluate the interaction of amrinone with inhalational anesthetics, cardiovascular effects of amrinone were investigated in nine mongrel dogs anesthetized with enflurane. Each dog received enflurane and amrinone in the following sequence: 1) 2% enflurane alone, 2) continuous infusion of 20 micrograms.kg-1.min-1 during enflurane, 3) 40 micrograms.kg-1.min-1 infusion during enflurane. Amrinone 40 micrograms.kg-1.min-1 during enflurane anesthesia improved the maximum left ventricular dP/dt, stroke volume and decreased effective arterial elastance (Ea) without changes in left ventricular end-diastolic pressure and heart rate. Left ventricular pressure (LVP) and systolic femoral arterial pressure were stable, but diastolic femoral arterial pressure decreased significantly from enflurane anesthesia alone. These parameters at 20 micrograms.kg-1.min-1 of amrinone infusion during enflurane showed the same tendency with 40 micrograms.kg-1.min-1 infusion but not significantly different from enflurane alone. This result suggests that amrinone may be beneficial in the patients with depression of cardiac performance during anesthesia.

Membrane and protein recycling associated with gastric HCl secretion

Stimulation of the gastric parietal cell requires massive membrane transformations as H(+)-pumps from the domain of cytoplasmic tubulovesicles are recruited into the apical plasma membrane domain. The recycling of membrane pools, through fusion and fission processes that accompany stimulation and inhibition of HCl secretion, also involves highly selective events of protein incorporation and segregation. This manuscript describes several proteins that have been identified with the apical plasma membrane from maximally stimulated parietal cells, and broadly characterizes them either as permanent resident proteins of the apical membrane, or transient proteins that move into and out of the apical membrane as the cell progresses through the secretory cycle. A typical example of transient association with the apical membrane concerns the pump proteins, including the 94 kDa catalytic alpha-subunit of the H+K(+)-ATPase and its newly discovered beta-subunit glycoprotein, which move between tubulovesicles. Proteins that remain associated with the apical plasma membrane during rest and secretion include actin, and an 80-kDa phosphoprotein, which has been variously called 80 K, ezrin, p81 and cytovillin, and whose phosphorylation is increased by the histamine/cAMP pathway of parietal cell stimulation. An example of a cytosolic protein that becomes associated with the apical plasma membrane after stimulation is a 120-kDa protein, which appears to have protein kinase activity. Note that the identification, localization and characterization of the K+ and Cl- transport proteins, which participate in net HCl secretion, are of immediate importance.

Effect of ethanol on acid secretion by isolated gastric glands from rabbit

Isolated gastric glands from rabbit, as well as basolateral and microsomal membranes derived therefrom, were used to examine the effect of ethanol on several parameters related to acid secretion. Low concentrations of ethanol, 0.2%-5% (vol/vol), had no effect on basal aminopyrine accumulation by isolated gastric glands but significantly potentiated aminopyrine accumulation stimulated by histamine. In contrast, this dose range of ethanol inhibited aminopyrine accumulation stimulated by forskolin or dibutyryl-cyclic adenosine monophosphate. This dose range of ethanol produced a similar effect on adenylate cyclase activity of basolateral membranes from isolated gastric glands, with potentiation of histamine stimulation and inhibition of forskolin stimulation. Low-dose ethanol was found to produce increased proton permeability of the apical membrane of the parietal cell but had no effect on hydrogen-potassium-stimulated adenosine triphosphatase activity. Ethanol (10%) significantly inhibited all parameters of acid secretion studied. Ethanol has a biphasic effect on acid secretion with potentiation of histamine-stimulated aminopyrine accumulation and adenylate cyclase activity at low doses and inhibition of all parameters of acid secretion at high doses.

The teleost cone cytoskeleton. Localization of actin, microtubules, and intermediate filaments

This laboratory has been using the teleost retinal cone as a model for studying the mechanisms and regulation of retinal cell motility. In previous inhibitor studies, the authors have shown that dark-induced cone elongation requires microtubules, whereas light-induced contraction requires actin filaments. This study examines the distributions of actin filaments, microtubules, and intermediate filaments in the cone cytoskeleton. Actin filaments have been localized in isolated cones by labeling with fluorescent derivatives of phalloidin; microtubules were localized by immunofluorescent labeling with anti-tubulin. Actin, microtubule, and intermediate filament distributions have also been examined in detergent-lysed motile cell models of cones fixed with a new method that enhances preservation of the cytoskeleton. Longitudinal bundles of actin filaments extend from the cone's calycal processes through the ellipsoid and into the myoid. No actin filaments are detectable in the perinuclear region and axon, but filaments are present in both pre- and post-synaptic components of the synapse. Intermediate filaments are numerous in the perinuclear region and cone axon but relatively sparse in the myoid. In contrast, microtubule distribution is more uniform: numerous longitudinally oriented microtubules are present throughout the length of the cell. Thus the cone cytoskeleton reflects the highly polarized shape and function of the cell, with actin filaments localized to the distal movable part of the cell and intermediate filaments localized to the proximal part of the cell, which is anchored in the retina.

Actin and associated proteins in gastric epithelial cells

A quantitative assessment of the distribution and state of microfilament-related proteins in the heterocellular fundic gastric epithelium was carried out. Actin content, as determined by the DNAase inhibition assay, ranged from 29 to 42 micrograms/mg of tissue protein, depending upon the tissue source. About 60% of the total actin existed in fresh tissue in the polymeric form (F-actin). The distribution of fluorescent-labelled phallicidin demonstrated that F-actin was concentrated predominantly in the acid-secreting oxyntic cells. The patterns of distribution corresponded to the location of the numerous elongated apical surface microvilli seen within oxyntic cell canaliculi. In the isolated apical membrane, actin represented about 10% of the total protein and was present entirely as F-actin. After mild treatment of membranes with Triton X-100, filaments could be readily visualized by negative staining. More extensive Triton X-100 extraction solubilized intrinsic membrane protein and yielded an insoluble residue highly enriched in actin and containing several additional polypeptides. Homogenization and fractionation of the gastric epithelium in low ionic strength media led to the depolymerization of a significant proportion of the tissue actin which was recovered in the homogenate supernatant. When purified by DNAase affinity chromatography, this gastric actin displayed structural and functional properties similar to muscle actin. Incubation of the homogenate supernatant in KCl-Mg2+ induced the formation of actin-rich gels. The gels contained myosin as well as several other peptides that may be actin-binding proteins.

Correlation of parietal cell structure and function

The apical surface of the gastric parietal cell is greatly expanded (5-10-fold) during maximal HCl secretion, as compared to the resting cell. The membrane recycling hypothesis has been proposed to account for the extensive, functionally related, rearrangement of cell membranes. Cytoplasmic membranes within the resting cell, the tubulovesicles, contain the H+/K+-ATPase. Fusion of tubulovesicles with the apical plasma membrane occurs when the cells are stimulated, thus providing the increased surface area and proper disposition of the H+ pump enzyme. Microfilaments, composed of actin and other regulatory proteins, serve to direct the reordering of the apical surface during stages of the secretory cycle. Cell fractionation of resting oxyntic mucosa reveals that virtually all of the H+/K+-ATPase activity is associated with light microsomal membrane vesicles, presumably derived from tubulovesicles. Although the enzyme from resting tissue is fully competent (e.g. ATP-driving pump, H+-K+ exchange), the microsomal vesicles lack an endogenous pathway to provide rapid access for K+ to its intravesicular activity site. In stimulated stomach, there is a redistribution of H+/K+-ATPase to a larger, denser membrane fraction, the so-called stimulation-associated vesicles. Morphological features and chemical content (e.g. microfilament proteins) suggest that the stimulation-associated vesicles are derived from the expanded apical surface of the stimulated oxyntic cell. A KCl cotransport system has been identified in the stimulation-associated membranes, which operates in parallel with the ATP-driven H+-K+ exchange pump. These two transport systems operate in concert within the apical membrane to provide the machinery for net HCl transport by the parietal cell.