Influence of splenomegaly on aortic and liver parenchymal CT numbers during contrast-enhance CT in patients with cirrhosis

INTRODUCTION

To compare CT (computed tomography) values for enhancement of the abdominal aorta and liver parenchyma during dynamic contrast enhancement (CE) CT in cirrhotic patients with and without splenomegaly (SM).

METHODS

We considered 258 patients (83 males and 46 females for the splenomegaly group, and 83 males and 46 females for the control group) for this retrospective study. We measured CT values in the abdominal aorta and hepatic parenchyma during the hepatic arterial (HAP) and portal venous (PVP) phases. The aortic CE at HAP and the hepatic parenchymal CE at PVP were compared between the two groups. For success rate of scans, we also calculated the optimal CE rates (>280 HU in the abdominal aorta and >50 HU in the hepatic parenchyma) for each group.

RESULTS

In the SM group, the CE for abdominal aorta was decreased during the aortic phase for a dynamic CE-CT (p < 0.05). When evaluating the success rates, they were found to be 65.1 % and 58.9 % in the SM group and 81.4 % and 72.3 % in the non-SM group (p < 0.05).

CONCLUSION

The success rate of scans and CE for the abdominal aorta during the aortic phase exhibited a significant decrease during dynamic CE-CT scans on patients with SM. Patients with SM may have reduced diagnostic ability with typical contrast injection protocols.

IMPLICATIONS FOR PRACTICE

It may be necessary to change the injection rates and contrast medium volume during CE-CT depending on the presence or absence of SM.

A surge in respiratory syncytial virus infection-related hospitalizations associated with the COVID-19 pandemic: An observational study at pediatric emergency referral hospitals in Tokushima Prefecture

The outbreak of coronavirus disease (COVID-19) resulted in implementation of social distancing and other public health measures to control the spread of infection and improve prevention, resulting in a decrease in respiratory syncytial virus (RSV) and pediatric respiratory tract infection rates. However, there was a rapid and large re-emergence of RSV infection in Japan. Notably, we were faced with a difficult situation wherein there was a shortage of hospital beds. This study aimed to examine the epidemiological patterns of RSV-related hospitalizations among children before and after the COVID-19 pandemic onset at two pediatric emergency referral hospitals covering the entire Tokushima Prefecture. Data were extracted from electronic medical records of children hospitalized with RSV infection between January 1, 2018, and December 31, 2021. All patients meeting the eligibility criteria were included in this study. The rates of study outcomes were documented annually during 2018-2021 and compared between the 2018-2020 and 2021 periods. In 2020, there was no RSV infection outbreak. Hospitalizations at the peak week in 2021 were 2.2- and 2.8-fold higher than those in 2018 and 2019, respectively. Hospitalizations in 2021 were concentrated within a short period. In addition, there was a significant increase in hospitalizations among children aged 3-5 months and those older than 24 months. The high-flow nasal cannula (HFNC) use rate nearly doubled in 2021. A new pandemic in the future may cause an outbreak of RSV infection that can result in an intensive increase in the number of hospitalizations of pediatric patients requiring respiratory support, especially in infants aged <6 months. There is an urgent need to improve the preparedness of medical systems, particularly in terms of the number of inpatient beds and the immediate availability of HFNC.

A pediatric case of infliximab-resistant ulcerative colitis successfully treated using vedolizumab

Pediatric ulcerative colitis is likely to be more severe than adult ulcerative colitis. Failure to thrive should be considered during therapy. A 10-year-old boy was diagnosed with ulcerative colitis based on his clinical presentation and colonoscopy and biopsy results. The administration of 5-aminosalicylic acid and prednisolone resulted in remission ; however, the symptoms reappeared after the discontinuation of prednisolone. Then, infliximab was administered ; however, the patient was resistant to it and appeared to be dependent on prednisolone. Vedolizumab, a monoclonal antibody against ?4?7 integrin, was administered, which resulted in rapid remission. A steady decrease in prednisolone followed, and remission was maintained even after prednisolone discontinuation. Vedolizumab may be effective in pediatric patients with moderate-to-severe refractory ulcerative colitis. Vedolizumab prevents lymphocytes from binding to MAdCAM-1, which is selectively expressed in the gastrointestinal submucosa, leading to the mitigation of the systemic side effects of immunosuppression, such as infections. In Japan, vedolizumab use is not yet approved for use in children, but its effectiveness and safety in children is expected to be investigated in the future. J. Med. Invest. 70 : 294-297, February, 2023.

Osteoarticular infections at a pediatric emergency core hospital in Japan

OBJECTIVES

Osteomyelitis (OM) and septic arthritis (SA) in childhood might cause complications, sequelae, or even death if diagnosis and treatment are delayed. Here, we examined the outcomes of OM/SA at a pediatric emergency core hospital in Japan.

METHODS

This was a single-center, retrospective, observational cohort study at a pediatric emergency core hospital in Japan. Pediatric outpatients who underwent magnetic resonance imaging at the hospital in the period 2012?2020 were recruited. Primary outcomes were sequelae, recurrent symptoms, chronicity, and death.

RESULTS

Fifteen OM/SA patients (9 OM, 4 SA, 2 OM+SA) were recruited. The identified major pathogens included methicillin-susceptible Staphylococcus aureus (40.0 %, n=6) and methicillin-resistant S. aureus (13.3 %, n=2). Mean time from onset to first hospital visit, hospitalization, and initiation of effective antibiotics was 2 days, 3.9?±?1.8 days, and 4.9±2.2 days, respectively. All OM/SA patients recovered without complications or sequelae.

CONCLUSIONS

In this study, all patients with OM/SA showed a good prognosis. Despite the small sample size, this pilot study suggests that the pediatric emergency core system in Japan provides early treatment and a good prognosis for patients diagnosed with OM/SA. J. Med. Invest. 70 : 236-240, February, 2023.

Applying patient characteristics, stent-graft selection, and pre-operative computed tomographic angiography data to a machine learning algorithm: Is endoleak prediction possible?

INTRODUCTION

This study aims to predict endoleak after endovascular aneurysm repair (EVAR) using machine learning (ML) integration of patient characteristics, stent-graft configuration, and a selection of vessel lengths, diameters and angles measured using pre-operative computed tomography angiography (CTA).

METHODS

We evaluated 1-year follow-up CT scans (arterial and delayed phases) in patients who underwent EVAR for the presence or absence of an endoleak. We also obtained data on the patient characteristics, stent-graft selection, and preoperative CT vessel morphology (diameter, length, and angle). The extreme gradient boosting (XGBoost) for the ML system was trained on 30 patients with endoleaks and 81 patients without. We evaluated 5217 items in 111 patients with abdominal aortic aneurysms, including the patient characteristics, stent-graft configuration and vascular morphology acquired using pre-EVAR abdominal CTA. We calculated the area under the curve (AUC) of our receiver operating characteristic analysis using the ML method.

RESULTS

The AUC, accuracy, 95% confidence interval (CI), sensitivity, and specificity were 0.88, 0.88, 0.79-0.97, 0.85, and 0.91 for ML applying XGBoost, respectively.

CONCLUSIONS

The diagnostic performance of the ML method was useful when factors such as the patient characteristics, stent-graft configuration and vessel length, diameter and angle of the vessels were considered from pre-EVAR CTA.

IMPLICATIONS FOR PRACTICE

Based on our findings, we suggest that this is a potential application of ML for the interpretation of abdominal CTA scans in patients with abdominal aortic aneurysms scheduled for EVAR.

Radiation dose reduction method combining the ECG-Edit function and high helical pitch in retrospectively-gated CT angiography

INTRODUCTION

The purpose of this study was to demonstrate that dose reduction does not compromise image quality when combining high helical pitch (HP) and the ECG-Edit function during low HP retrospectively gated computed tomography angiography (CTA).

METHODS

This study made use of a pulsating cardiac phantom (ALPHA 1 VTPC). The heart rate (HR) of the cardiac phantom was changed in five intervals, every 5 beats per minute (bpm), from 40 to 60 bpm. Evaluation of a range of HR was important because data loss might occur when combining a low HR and high HP. We performed retrospectively gated CTA scans five times using a low HP (0.16) and high HP (0.24), for each of the five HR intervals, using a 64-detector row CT scanner. The CT volume dose index (CTDI_vol) was recorded from the CT console of each scan. For the images with data loss, data were repaired using the ECG-Edit function. We compared the CTDI_vol, estimated cardiac phantom volume, and the visualization of the coronary ladder phantom between HP 0.16, with or without repaired HP 0.24, using the ECG-Edit function.

RESULTS

Data loss occurred with a HR of 40 bpm and 45 bpm when using HP 0.24. The CTDI_vol was reduced by approximately 33% with HP 0.24 when compared with HP 0.16. There were no significant differences in the mean cardiac motion phantom volume and visualization scores between HP 0.16 and with and without repaired HP 0.24 using the ECG-Edit function (p < 0.05).

CONCLUSION

The ECG-Edit function is potential useful for repairing the lost data in patients with a low HR, and when combined with a high HP, it is possible to reduce the radiation dose by approximately 33%.

IMPLICATIONS FOR PRACTICE

The ECG-Edit function and high HP may be a viable option in pediatric CTA studies.

Temporal changes in transcripts of miniature inverted-repeat transposable elements during rice endosperm development

The repression of transcription from transposable elements (TEs) by DNA methylation is necessary to maintain genome integrity and prevent harmful mutations. However, under certain circumstances, TEs may escape from the host defense system and reactivate their transcription. In Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), DNA demethylases target the sequences derived from TEs in the central cell, the progenitor cell for the endosperm in the female gametophyte. Genome-wide DNA demethylation is also observed in the endosperm after fertilization. In the present study, we used a custom microarray to survey the transcripts generated from TEs during rice endosperm development and at selected time points in the embryo as a control. The expression patterns of TE transcripts are dynamically up- and downregulated during endosperm development, especially those of miniature inverted-repeat TEs (MITEs). Some TE transcripts were directionally controlled, whereas the other DNA transposons and retrotransposons were not. We also discovered the NUCLEAR FACTOR Y binding motif, CCAAT, in the region near the 5' terminal inverted repeat of Youren, one of the transcribed MITEs in the endosperm. Our results uncover dynamic changes in TE activity during endosperm development in rice.

Preparation of aluminosilicate and hydroxyapatite/aluminosilicate composite films with the sputtering technique and their adsorption capacity with cesium and strontium

BACKGROUND

Removal of radioactive substances, such as cesium (Cs) and strontium (Sr), has become an emerging issue after the Fukushima Daiichi nuclear power plant disaster. It has been reported that hydroxyapatite (HA) and aluminosilicate composite powders can be used to remove Cs and Sr. However, the film type of these materials for the removal of Cs and Sr has not been reported.

OBJECTIVE

The aim of this study was to assess the possibility of using HA, aluminosilicate, and aluminosilicate/HA composites for the removal of Cs and Sr radioactive substances.

METHODS

Aluminosilicate films and HA films were fabricated using a sputtering technique with diatomaceous earth and HA targets, respectively. The aluminosilicate film was observed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). A comb-shaped HA/aluminosilicate composite film was prepared to take advantage of the adsorption properties of the HA and the aluminosilicate films. The Cs and Sr adsorption on these films were also evaluated.

RESULTS

In the XRD patterns, the film sputtered from a diatomaceous earth target under 5.0 Pa of Ar pressure showed aluminosilicate peaks (Na1.82(Al2Si3O10) and Al2SiO5) after 8 h of vapor-phase hydrothermal treatment. The film showed higher adsorption of Cs than Sr in Cs and Sr solutions, while the HA film adsorbed far more Sr than Cs. A HA/aluminosilicate composite film was successfully fabricated, and the SEM images showed that the width of the HA region was 230-260 μm, and that of the aluminosilicate region was 170-200 μm. The HA/aluminosilicate composite film showed 84.8 ± 11.5% Cs adsorption and 28.3 ± 1.4% Sr adsorption in a mixed solution of Cs and Sr.

CONCLUSION

This study shows the feasibility of using HA films, aluminosilicate films, and HA/aluminosilicate composite films for the removal of radioactive substances such as Cs and Sr.

Epigenetics and plant reproduction: Multiple steps for responsibly handling succession

Although flowering plants and mammals have distinct life cycles and developmental programs, epigenetic information in both plant and mammalian cells is faithfully inherited across mitotic cell division. In mammals, epigenetic reprograming is a prominent process that is re-established in the zygote and germ line during early development. By contrast, plants do not produce germ cells until later in development. This difference, along with the many examples of the transmission of stable epialleles in plants, suggests that epigenetic reprograming in plants and mammals occurs via distinct mechanisms. In this review, we highlight recent advances in genome-wide epigenetic analyses in plants. These analyses provide insight into dynamic epigenetic regulation in plants and reveal unique processes that maintain genome integrity during plant sexual reproduction.

Escherichia coli pyomyositis in a patient with Down syndrome: A case report

Pyomyositis is an infection of the skeletal muscle that involves intramuscular abscess formation. It is typically caused by gram-positive bacteria, especially Staphylococcus aureus. Few cases of Escherichia coli pyomyositis have been reported in immunocompromised adult patients, while none have been reported in children.

We present a case of a 4-year-old boy with Down syndrome who developed Escherichia coli pyomyositis. The patient presented to our hospital with a fever and right forearm swelling. The magnetic resonance imaging findings suggested pyomyositis of the right forearm muscle and osteomyelitis of the distal radius. Both the blood and puncture fluid cultures were negative. Cefazolin and vancomycin were administered, and his blood examination results and right forearm swelling improved; however, a slight fever persisted. The multiplex polymerase chain reaction isolated the chuA gene but not the YjaA gene; thus the patient was diagnosed with pyomyositis and osteomyelitis caused by Escherichia coli group D. The cefazolin was substituted with meropenem, and the vancomycin was discontinued. Thereafter, his fever promptly improved, which indicated that the cause of persistent fever was vancomycin drug fever. The patient was discharged after receiving 3 weeks of intravenous antimicrobial therapy, and recovered fully with no long-term sequelae.

To the best of our knowledge, this is the first reported case of Escherichia coli pyomyositis in a child. The findings in this case suggest that Escherichia coli should be considered when choosing initial empiric therapy for pyomyositis, especially in children with underlying conditions.

Mutation of the imprinted gene OsEMF2a induces autonomous endosperm development and delayed cellularization in rice

In angiosperms, endosperm development comprises a series of developmental transitions controlled by genetic and epigenetic mechanisms that are initiated after double fertilization. Polycomb repressive complex 2 (PRC2) is a key component of these mechanisms that mediate histone H3 lysine 27 trimethylation (H3K27me3); the action of PRC2 is well described in Arabidopsis thaliana but remains uncertain in cereals. In this study, we demonstrate that mutation of the rice (Oryza sativa) gene EMBRYONIC FLOWER2a (OsEMF2a), encoding a zinc-finger containing component of PRC2, causes an autonomous endosperm phenotype involving proliferation of the central cell nuclei with separate cytoplasmic domains, even in the absence of fertilization. Detailed cytological and transcriptomic analyses revealed that the autonomous endosperm can produce storage compounds, starch granules, and protein bodies specific to the endosperm. These events have not been reported in Arabidopsis. After fertilization, we observed an abnormally delayed developmental transition in the endosperm. Transcriptome and H3K27me3 ChIP-seq analyses using endosperm from the emf2a mutant identified downstream targets of PRC2. These included >100 transcription factor genes such as type-I MADS-box genes, which are likely required for endosperm development. Our results demonstrate that OsEMF2a-containing PRC2 controls endosperm developmental programs before and after fertilization.

Next-generation sequencing for the diagnosis of patients with congenital multiple anomalies and / or intellectual disabilities

Background : In clinical practice, a large proportion of patients with multiple congenital anomalies and/or intellectual disabilities (MCA / ID) lacks a specific diagnosis. Recently, next-generation sequencing (NGS) has become an efficient strategy for genetic diagnosis of patients with MCA/ID.

OBJECTIVE

To review the utility of NGS for the diagnosis of patients with MCA / ID.

METHOD

Patients with MCA/ID were recruited between 2013 and 2017. Molecular diagnosis was performed using NGS-based targeted panel sequencing for 4,813 genes. Promising causative variants underwent confirmation by Sanger sequencing or chromosomal microarray.

RESULTS

Eighteen patients with MCA/ID were enrolled in this study. Of them, 8 cases (44%) were diagnosed by targeted panel sequencing. Most of diagnosed patients were able to receive better counseling and more appropriate medical management.

CONCLUSION

NGS-based targeted panel sequencing seems to be an effective testing strategy for diagnosis of patients with MCA/ID. J. Med. Invest. 67 : 246-249, August, 2020.

Molecular diagnosis of an infant with TSC2/PKD1 contiguous gene syndrome

A 1-month-old Japanese infant with cardiac rhabdomyoma was diagnosed with TSC2/PKD1 contiguous gene syndrome by targeted panel sequencing with subsequent quantitative polymerase chain reaction that revealed gross monoallelic deletion, including parts of two genes: exons 19-42 of TSC2 and exons 2-46 of PKD1. Early molecular diagnosis can help to detect bilateral renal cyst formation and multidisciplinary follow-up of this multisystem disease.

Assessment of right ventricular function by isovolumic acceleration of pulmonary and tricuspid annulus in surgically repaired tetralogy of Fallot

Assessment of right ventricular (RV) function is quite important in patients with surgically corrected tetralogy of Fallot (TOF). However, quantitative assessment of RV function remains challenging, mainly because of the complex RV geometry. This prospective study investigated isovolumic acceleration (IVA), a parameter of myocardial systolic function not influenced by either preload or afterload, using tissue Doppler imaging. We evaluated IVA measured on pulmonary annulus (PA-IVA) and tricuspid annulus (TA-IVA), because we considered that PA-IVA and TA-IVA correspond with systolic function of the RV outflow tract (RVOT) and RV basal function, respectively. Thirty-nine patients with surgically repaired TOF (TOF group) and 40 age-matched healthy children (control group) were enrolled in this study. No significant difference was seen between TA-IVA (2.5 ± 0.8 m/s2) and PA-IVA (2.4 ± 0.8 m/s2) in the control group. In the TOF group, PA-IVA (1.0 ± 0.5 m/s2) was significantly lower than TA-IVA (1.3 ± 0.6 m/s2, p < 0.05). Both TA-IVA and PA-IVA were significantly lower in the TOF group than in the control group (p < 0.05 each). We concluded that PA-IVA offers a useful index to assess RVOT function in TOF patients. J. Med. Invest. 67 : 145-150, February, 2020.

Surface Enhanced Visible Absorption of Dye Molecules in the Near-Field of Gold Nanoparticles

Surface enhanced absorption is a plasmonic effect parenting to surface enhanced fluorescence and Raman scattering, and it was clearly reported to occur in the infrared region of the spectrum of light. In this paper, we unambiguously show that it also occurs in the visible region of the spectrum by using a dye; i.e. an azo-dye, which exhibits a good light absorption in that region, and gold nanoparticles, which act as plasmonic nanoantennas that capture and re-radiate light, when the azo-dyes and the nanoparticles are incorporated in the bulk of solid films of polymer. In such a configuration, it is possible to use a dye concentration much larger than that of the nanoparticles and absorption path lengths much larger than those of the molecularly thin layers used in surface enhanced effects studies. In addition, the dye undergoes shape and orientation change; i.e. isomerization and reorientation, upon polarized light absorption; and the observation of surface enhanced visible absorption is done by two separate experiments; i.e. UV-visible absorption spectroscopy and photo-induced birefringence, since the signals detected from both experiments are directly proportional to the extinction coefficient of the dye. Both the dye's absorption and photoorientation are enhanced by the presence of the nanoparticles.

Precision Analysis of the ^{136}Xe Two-Neutrino ββ Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements

We present a precision analysis of the ^{136}Xe two-neutrino ββ electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino ββ rate allows us to measure the ratio of the leading and subleading 2νββ nuclear matrix elements (NMEs), ξ_{31}^{2ν}=-0.26_{-0.25}^{+0.31}. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ξ_{31}^{2ν} range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ξ_{31}^{2ν} values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless ββ decay, ξ_{31}^{2ν} provides new insights toward reliable neutrinoless ββ NMEs.

Manifestation of intraoperative anaphylactic shock along with latex allergy:a pediatric case report

Natural rubber latex (NRL) allergy is one of the most important causes of severe anaphylaxis during medical intervention. We report a pediatric case of latex allergy with multiple surgical histories. A 12-year-old girl developed anaphylactic shock during the pyeloplasty for ureteropelvic junction restenosis. Latex gloves or medications used during the surgery were suspected to be the cause of anaphylactic shock. We diagnosed her latex allergy on the basis of the results that serum latex-specific IgE, skin prick tests of extract from NRL gloves and recombinant Hev b 6.02 solution were positive. Basophil activation test of NRL gloves was also positive, supporting the diagnosis of immediate allergic reactions caused by NRL. It was speculated that a history of multiple surgeries in infancy became a trigger of sensitization to latex in this patient. Reoperation after the diagnosis of NRL allergy was carried out in a latex-free environment and completed without any allergic symptoms. It would be necessary to perform the pre-screening of latex allergy to prevent the onset of latex allergy especially in the patients with multiple surgical histories. J. Med. Invest. 65:292-295, August, 2018.

Analysis of Right Ventricular Myocardial Stiffness and Relaxation Components in Children and Adolescents With Pulmonary Arterial Hypertension

Background

The rate of left ventricular pressure decrease during isovolumic relaxation is traditionally assessed algebraically via 2 empirical indices: the monoexponential and logistic time constants (τ_E and τ_L). Since the pattern of right ventricular (RV) pressure decrease is quite different from that of the left ventricular, we hypothesized that novel kinematic model parameters are more appropriate and useful to evaluate RV diastolic dysfunction.

Methods and Results

Eight patients with pulmonary arterial hypertension (age 12.5±4.8 years) and 20 normal subjects (control group; age 12.3±4.4 years) were enrolled. The kinematic model was parametrized by stiffness/restoring Ek and damping/relaxation μ. The model predicts isovolumic relaxation pressure as a function of time as the solution of d²P/dt²+(1/μ)dP/dt+EkP=0, based on the theory that the pressure decay is determined by the interplay of inertial, stiffness/restoring, and damping/relaxation forces. In the assessment of RV diastolic function, τ_E and τ_L did not show significant differences between the pulmonary arterial hypertension and control groups (46.8±15.5 ms versus 32.5±14.6 ms, and 19.6±5.9 ms versus 14.5±7.2 ms, respectively). The pulmonary arterial hypertension group had a significantly higher Ek than the control group (915.9±84.2 s⁻² versus 487.0±99.6 s⁻², P<0.0001) and a significantly lower μ than the control group (16.5±4.3 ms versus 41.1±10.4 ms, P<0.0001). These results show that the RV has higher stiffness/elastic recoil and lower cross‐bridge relaxation in pulmonary arterial hypertension.

Conclusions

The present findings indicate the feasibility and utility of kinematic model parameters for assessing RV diastolic function.

Massage therapy for home care patients using the health insurance system in Japan

OBJECTIVES

To clarify the status of home care massage services provided to patients. This will help in understanding how many patients utilize this service and the circumstances under which treatment is provided.

DESIGN

A retrospective study.

SETTING

Fifty-four acupuncture, moxibustion, and massage clinics. Participants were patients who had received home care massage for six months or more. We collected a total of 1587 responses from these 54 massage clinics; of these, 1415 responses (mean age = 79.1 ± 11.5 years) were valid (valid response rate 89.2%).

MAIN OUTCOME MEASURES

Actual patients and actual care services.

RESULTS

The most common disorder observed among patients who utilized home care massage services was cerebrovascular disease (at approximately 36%), while the second most common were arthropathy-related disorders (16.3%). Although most patients received massage, approximately 30% received manual therapy (e.g. manual correction) and hot fomentation as part of thermotherapy. Notably, only around 10% of patients received massage alone; the majority received treatment in combination with range of motion and muscle-strengthening exercises.

CONCLUSIONS

This study helped to clarify the actual state of patients receiving home care massage and the details of the massage services provided. This study clearly showed the treatment effectiveness of massage, which can be used by home medical care stakeholders to develop more effective interventions.

Overcoming the species hybridization barrier by ploidy manipulation in the genus Oryza

In most eudicot and monocot species, interspecific and interploidy crosses generally display abnormalities in the endosperm that are the major cause of a post-zygotic hybridization barrier. In some eudicot species, however, this type of hybridization barrier can be overcome by the manipulation of ploidy levels of one parental species, suggesting that the molecular mechanisms underlying the species hybridization barrier can be circumvented by genome dosage. We previously demonstrated that endosperm barriers in interspecific and interploidy crosses in the genus Oryza involve overlapping but different mechanisms. This result contrasts with those in the genus Arabidopsis, which shows similar outcomes in both interploidy and interspecific crosses. Therefore, we postulated that an exploration of pathways for overcoming the species hybridization barrier in Oryza endosperm, by manipulating the ploidy levels in one parental species, might provide novel insights into molecular mechanisms. We showed that fertile hybrid seeds could be produced by an interspecific cross of female tetraploid Oryza sativa and male diploid Oryza longistaminata. Although the rate of nuclear divisions did not return to normal levels in the hybrid endosperm, the timing of cellularization, nucellus degeneration and the accumulation of storage products were close to normal levels. In addition, the expression patterns of the imprinted gene MADS87 and YUCCA11 were changed when the species barrier was overcome. These results suggest that the regulatory machinery for developmental transitions and imprinted gene expression are likely to play a central role in overcoming species hybridization barriers by genome dosage in the genus Oryza.

Pulmonary annular motion velocity reflects right ventricular outflow tract function in children with surgically repaired congenital heart disease

Right ventricular (RV) dysfunction is generally evaluated using analyses of tricuspid annular motion. However, it represents only one aspect of RV performance. Whether measuring pulmonary annular motion velocity could serve as a novel way to evaluate global RV and/or RV outflow tract (RVOT) performance in pediatric congenital heart disease (CHD) patients with surgically repaired RVOT was evaluated. In this prospective study, tissue Doppler-derived pulmonary annular motion velocity was measured in children (aged 2-5 years) with RVOT reconstruction (RVOTR group, n = 48) and age-matched healthy children (Control, n = 60). The types of RVOTR procedures were as follows: pulmonary valve-sparing procedure (PVS, n = 7); transannular patch with monocusp valve reconstruction (TAP, n = 29); and RV-to-PA conduit reconstruction using a pericardial valve with expanded polytetrafluoroethylene conduit (Rastelli, n = 12). Pulmonary annular motion velocity waveforms comprised systolic bimodal (s1' and s2') and diastolic e' and a' waves in all participants. The peak velocities of s1', s2', e', and a' were significantly lower in the RVOTR group than in the control group (all p < 0.0001). Furthermore, these parameters depended significantly on the type of surgical procedure. The peak velocities of s1', s2', and e' had significant correlations with RVOT ejection fraction (RVOT-EF) (r = 0.56, 0.49, and 0.34, respectively), and RVOT fractional shortening (RVOT-FS) (r = 0.72, 0.55, and 0.41, respectively), although there were no significant correlations between pulmonary annular motion and global RV function, including RV ejection fraction (RVEF) and RV fractional area change (RVFAC) in the assessment of all RVOTR group patients. The pulmonary annular motion parameters in the PVS group had significant correlations with both global RV and RVOT performance. The TAP group showed significant correlations between RVOT function and pulmonary annular motion. The Rastelli group showed almost no significant correlations between RV/RVOT function and tissue Doppler parameters. Pulmonary annular motion velocity is a simple, rapid, reproducible, and useful method of assessing RVOT function in children with surgically repaired CHD.

Assessment of pulmonary arterial compliance evaluated using harmonic oscillator kinematics

We hypothesized that K_PA, a harmonic oscillator kinematics-derived spring constant parameter of the pulmonary artery pressure (PAP) profile, reflects PA compliance in pediatric patients. In this prospective study of 33 children (age range = 0.5–20 years) with various cardiac diseases, we assessed the novel parameter designated as K_PA calculated using the pressure phase plane and the equation K_PA = (dP/dt_max)²/([Pmax – Pmin])/2)², where dP/dt_max is the peak derivative of PAP, and Pmax – Pmin is the difference between the minimum and maximum PAP. PA compliance was also calculated using two conventional methods: systolic PA compliance (sPAC) was expressed as the stroke volume/Pmax – Pmin; and diastolic PA compliance (dPAC) was determined according to a two-element Windkessel model of PA diastolic pressure decay. In addition, data were recorded during abdominal compression to determine the influence of preload on K_PA. A significant correlation was observed between K_PA and sPAC (r = 0.52, P = 0.0018), but not dPAC. Significant correlations were also seen with the time constant (τ) of diastolic PAP (r = −0.51, P = 0.0026) and the pulmonary vascular resistance index (r = −0.39, P = 0.0242). No significant difference in K_PA was seen between before and after abdominal compression. K_PA had a higher intraclass correlation coefficient than other compliance and resistance parameters for both intra-observer and inter-observer variability (0.998 and 0.997, respectively). These results suggest that K_PA can provide insight into the underlying mechanisms and facilitate the quantification of PA compliance.

Long-term Results After Open Mitral Commissurotomy for a One-Month-Old Infant With Mitral Stenosis

The strategy for an infant with congenital mitral stenosis should be determined by three important factors: left ventricular volume, the degree of the systemic outflow tract obstruction, and the type of mitral valve dysfunction. A successful staged biventricular repair in early infancy for a patient who had congenital mitral stenosis with short chordae, hypoplastic left ventricle and coarctation of the aorta, and the long-term results are described. There were the following important hemodynamic factors that led to the successful biventricular repair in the patient. Total systemic output was barely supplied through the hypoplastic left ventricle after closure of the ductus arteriosus on admission. The neonate underwent repair of coarctation of the aorta alone as the initial stage at 9 days after birth. Also, spontaneous closure of the foramen ovale following repair of coarctation of the aorta accelerated the progressive left ventricular growth. Open mitral commissurotomy with an interatrial fenestration using the modified Brawley's approach was performed for a 40-day-old infant. Good left ventricular growth and good mitral valve function have been observed for 18 years after open mitral commissurotomy. Appropriate early augmentation of left ventricular inflow through the mitral valve might be effective for growth of a hypoplastic left ventricle. J. Med. Invest. 64: 187-191, February, 2017.

Bactericidal and antimicrobial effects of pure titanium and titanium alloy treated with short-term, low-energy UV irradiation

Objectives

The surface of pure titanium (Ti) shows decreased histocompatibility over time; this phenomenon is known as biological ageing. UV irradiation enables the reversal of biological ageing through photofunctionalisation, a physicochemical alteration of the titanium surface. Ti implants are sterilised by UV irradiation in dental surgery. However, orthopaedic biomaterials are usually composed of the alloy Ti6Al4V, for which the antibacterial effects of UV irradiation are unconfirmed. Here we evaluated the bactericidal and antimicrobial effects of treating Ti and Ti6Al4V with UV irradiation of a lower and briefer dose than previously reported, for applications in implant surgery.

Materials and Methods

Ti and Ti6Al4V disks were prepared. To evaluate the bactericidal effect of UV irradiation, Staphylococcus aureus 834 suspension was seeded onto the disks, which were then exposed to UV light for 15 minutes at a dose of 9 J/cm². To evaluate the antimicrobial activity of UV irradiation, bacterial suspensions were seeded onto the disks 0, 0.5, one, six, 24 and 48 hours, and three and seven days after UV irradiation as described above. In both experiments, the bacteria were then harvested, cultured, and the number of colonies were counted.

Results

No colonies were observed when UV irradiation was performed after the bacteria were added to the disks. When the bacteria were seeded after UV irradiation, the amount of surviving bacteria on the Ti and Ti6Al4V disks decreased at 0 hours and then gradually increased. However, the antimicrobial activity was maintained for seven days after UV irradiation.

Conclusion

Antimicrobial activity was induced for seven days after UV irradiation on both types of disk. Irradiated Ti6Al4V and Ti had similar antimicrobial properties.

Cite this article: T. Itabashi, K. Narita, A. Ono, K. Wada, T. Tanaka, G. Kumagai, R. Yamauchi, A. Nakane, Y. Ishibashi. Bactericidal and antimicrobial effects of pure titanium and titanium alloy treated with short-term, low-energy UV irradiation. Bone Joint Res 2017;6:108–112. DOI: 10.1302/2046-3758.62.2000619.

A new device to select carriers for biomass immobilization and application in an aerobic/anaerobic fixed-bed sequencing batch biofilm reactor for nitrogen removal

This study proposes a new approach to selecting a biofilm carrier for immobilization using dissolved oxygen (DO) microsensors to measure the thickness of aerobic and anaerobic layers in biofilm. The biofilm carriers tested were polyurethane foam, mineral coal (MC), basaltic gravel, and low-density polyethylene. Development of layers in the biofilm carrier surface was evaluated using a flow cell device, and DO profiles were conducted to determine the size of the layers (aerobic and anaerobic). MC was the biofilm carrier selected due to allowing the development of larger aerobic and anaerobic layers in the biofilm (896 and 1,058 μm, respectively). This ability is supposed to improve simultaneous nitrogen removal by nitrification and denitrification biological processes. Thus, as a biofilm carrier, MC was used in a fixed-bed sequencing batch biofilm reactor (FB-SBBR) for treatment of wastewater with a high ammonia concentration (100-400 mgNH₄⁺-N L^-1). The FB-SBBR (15.0 L) was filled with matrices of the carrier and operated under alternating aeration and non-aeration periods of 6 h each. At a mean nitrogen loading rate of 0.55 ± 0.10 kgNH₄⁺-N m^-3 d^-1, the reactor attained a mean nitrification efficiency of 95 ± 9% with nitrite as the main product (aerobic period). Mean denitrification efficiency during the anoxic period was 72 ± 13%.

Noninvasive assessment of pulmonary arterial capacitance by pulmonary annular motion velocity in children with ventricular septal defect

Background

We hypothesized that longitudinal pulmonary arterial deformation during the cardiac cycle reflects pulmonary arterial capacitance. To examine this hypothesis, we assessed whether tissue Doppler-derived pulmonary annular motion could serve as a novel way to evaluate pulmonary arterial capacitance in pediatric patients with ventricular septal defect (VSD).

Methods

In this prospective study, pulmonary annular velocity was measured in children (age, 6 months–5 years) with a preoperative VSD (VSD group, n = 35) and age-matched healthy children (Control group, n = 23). Pulmonary artery capacitance was calculated by two methods. Systolic pulmonary arterial capacitance (sPAC) was expressed as the stroke volume/pulmonary arterial pulse pressure. Diastolic pulmonary arterial capacitance (dPAC) was determined according to a two-element windkessel model of the pulmonary arterial diastolic pressure profile.

Results

Pulmonary annular velocity waveforms comprised systolic bimodal (s1′ and s2′) and diastolic e’ and a’ waves in all participants. The peak velocities of s1′, s2′, and e’ were significantly lower in the VSD group than in the Control group. On multiple regression analysis, sPAC was an independent variable affecting the peak velocities of the s1′, s2′, and e’ waves (β = 0.41, 0.62, and 0.35, respectively). The dPAC affected the s1′ wave peak velocity (β = 0.34). The time durations of the s1′ and e’ waves were independently determined by the sPAC (β = 0.49 and 0.27).

Conclusion

Pulmonary annular motion velocity evaluated using tissue Doppler is a promising method of assessing pulmonary arterial capacitance in children with VSD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-016-0081-4) contains supplementary material, which is available to authorized users.