New protocol for contrast media reduction in atrial fibrillation ablation-planning CT with dual region of interest.

INTRODUCTION: Many patients with atrial fibrillation have impaired renal function, and therefore pre-operative CT for radiofrequency catheter ablation should minimize the use of contrast media. This study describes a dual-region-of-interest (D-ROI) protocol for the scanning of pulmonary veins and left atrium (PVs-LA) with less contrast media and optimized scan timing compared to the single-region-of-interest (S-ROI) protocol, without compromising image quality. METHODS: This study retrospectively included 100 patients who underwent PVs-LA CT between July 2019 and February 2022. The participants were divided into two groups: Those scanned using the S-ROI method (Group A, n = 50), and those scanned using the D-ROI method (Group B, n = 50). Descriptive statistical analysis of the contrast effect and scan timing was performed using quantitative and qualitative data collected from both groups of images. RESULTS: The contrast media dose was larger in group A than in group B (63.6 ± 10.1 mL vs. 45.6 ± 6.9 mL; p < 0.001). The CT values of the PVs-LA did not differ significantly between groups A and B [434.2 ± 77.0 Hounsfield units (HU) and 428.8 ± 77.2 HU, respectively; p = 0.73]. Two evaluators determined appropriate scan timing (when PVs-LA reached a relatively sufficient contrast effect for diagnosis) in 23 (46%) and 45 (90%) patients from groups A and B, respectively (p < 0.001). CONCLUSIONS: Although the radiation dose is slightly increased compared with the S-ROI method, the D-ROI method provides improved scan timing and images with similar contrast enhancement while reducing the amount of contrast medium administered. IMPLICATIONS FOR PRACTICE: The novel D-ROI bolus tracking technique can reduce the contrast medium dose while optimizing scan timing.

A dusty compact object bridging galaxies and quasars at cosmic dawn.

Understanding how super-massive black holes form and grow in the early Universe has become a major challenge1,2 since it was discovered that luminous quasars existed only 700 million years after the Big Bang3,4. Simulations indicate an evolutionary sequence of dust-reddened quasars emerging from heavily dust-obscured starbursts that then transition to unobscured luminous quasars by expelling gas and dust5. Although the last phase has been identified out to a redshift of 7.6 (ref. 6), a transitioning quasar has not been found at similar redshifts owing to their faintness at optical and near-infrared wavelengths. Here we report observations of an ultraviolet compact object, GNz7q, associated with a dust-enshrouded starburst at a redshift of 7.1899 ± 0.0005. The host galaxy is more luminous in dust emission than any other known object at this epoch, forming 1,600 solar masses of stars per year within a central radius of 480 parsec. A red point source in the far-ultraviolet is identified in deep, high-resolution imaging and slitless spectroscopy. GNz7q is extremely faint in X-rays, which indicates the emergence of a uniquely ultraviolet compact star-forming region or a Compton-thick super-Eddington black-hole accretion disk at the dusty starburst core. In the latter case, the observed properties are consistent with predictions from cosmological simulations7 and suggest that GNz7q is an antecedent to unobscured luminous quasars at later epochs.

Effect of proton pump inhibitors on the development of hypomagnesemia induced by panitumumab.

Panitumumab, a therapeutic agent for unresectable advanced/recurrent colorectal cancer, is a human IgG2 monoclonal antibody that binds to and inhibits the activity of the epidermal growth factor receptor (EGFR). The onset of hypomagnesemia is a known side effect of anti-EGFR inhibitors, including panitumumab, and it is thought that inhibition of reabsorption of Mg in renal tubules is one of the causes. In addition, recent reports have shown that long-term administration of proton pump inhibitors (PPIs) reduces serum magnesium levels. Therefore, in this study, 102 patients who received oral PPIs treated with panitumumab were classified into a PPI combination group and a PPI non-combination group, and the effect of PPIs on the development of grade 2 or higher hypomagnesemia was investigated. The incidence of hypomagnesemia in the PPI combination group (46.9%, 15/32) was higher than that in the PPI non-combination group (25.7%, 18/70). A comparison of the backgrounds of the two groups of patients showed a significant difference in serum albumin levels. PPI administration was significantly associated with panitumumab-induced hypomagnesemia development when adjusted for known risk factors, serum albumin level, renal function, and oral magnesium oxide tablets in Cox proportional hazards regression analysis (hazard ratio 2.09; 95% confidence interval 1.03-4.22; P =0.040). These results indicate that detailed monitoring of serum magnesium levels is recommended for patients treated with panitumumab and co-administration of PPIs.

Hopelessness and Depression Predict Sarcopenia in Advanced CKD and Dialysis: A Multicenter Cohort Study.

BACKGROUND/OBJECTIVES: Depression and hopelessness are frequently experienced in chronic kidney disease (CKD) and are generally associated with lessened physical activity. The aim of this study was to quantify the associations between sarcopenia as determined by SARC-F with both depression and hopelessness. DESIGN AND SETTING: This multicenter cohort study involving cross-sectional and longitudinal analyses was conducted in a university hospital and four general hospitals, each with a nephrology center, in Japan. PARTICIPANTS: Participants consisted of 314 CKD patients (mean age 67.6), some of whom were receiving dialysis (228, 73%). MEASUREMENTS: The main exposures were depression, measured using the Center for Epidemiologic Studies Depression (CES-D) questionnaire, and hopelessness, measured using a recently developed 18-item health-related hope scale (HR-Hope). The outcomes were sarcopenia at baseline and one year after, measured using the SARC-F questionnaire. Logistic regression models were applied. RESULTS: The cross-sectional and longitudinal analyses included 314 and 180 patients, respectively. Eighty-nine (28.3%) patients experienced sarcopenia at baseline, and 44 (24.4%) had sarcopenia at the one-year follow-up. More hopelessness (per 10-point lower, adjusted odds ratio [AOR]: 1.33, 95% confidence interval [95% CI] 1.12-1.58), depression (AOR: 1.87, 95% CI 1.003-3.49), age (per 10-year higher, AOR: 1.70, 95% CI 1.29-2.25), being female (AOR: 2.67, 95% CI 1.43-4.98), and undergoing hemodialysis (AOR, 2.92; 95% CI, 1.41-6.05) were associated with a higher likelihood of having baseline sarcopenia. More hopelessness (per 10-point lower, AOR: 1.69, 95% CI 1.14-2.51) and depression (AOR: 4.64, 95% CI: 1.33-16.2) were associated with a higher likelihood of having sarcopenia after one year. CONCLUSIONS: Among patients with different stages of CKD, both hopelessness and depression predicted sarcopenia. Provision of antidepressant therapies or goal-oriented educational programs to alleviate depression or hopelessness can be useful options to prevent sarcopenia.

Reproductive interference in live-bearing fish: the male guppy is a potential biological agent for eradicating invasive mosquitofish.

The eradication of invasive exotic species is desirable but often infeasible. Here, we show that male guppies are a potential biological agent for eradicating invasive mosquitofish through the mechanism of reproductive interference, which is defined as any sexual behavior erratically directed at a different species that damages female and/or male fitness. Together with decades of data on species distribution, our field surveys suggest that mosquitofish initially became established on Okinawa Island before being replaced by the more recently introduced guppies. More importantly, our laboratory experiments suggest that reproductive interference was one of the mechanisms underlying this species exclusion, and that in this case, the negative effects were asymmetric, i.e., they only impacted mosquitofish. Reproductive interference may offer a safer and more convenient method of biological control than the traditional sterile male release method because radiation is not necessary.

Prediction model for glucose metabolism based on lipid metabolism.

OBJECTIVES: We developed a robust, long-term clinical prediction model to predict conditions leading to early diabetes using laboratory values other than blood glucose and insulin levels. Our model protects against missing data and noise that occur during long-term analysis. METHODS: RESULTS of a 75-g oral glucose tolerance test (OGTT) were divided into three groups: diabetes, impaired glucose tolerance (IGT), and normal (n = 114, 235, and 325, respectively). For glucose metabolic and lipid metabolic parameters, near 30-day mean values and 10-year integrated values were compared. The relation between high-density lipoprotein cholesterol (HDL-C) and variations in HbA1c was analyzed in 158 patients. We also constructed a state space model consisting of an observation model (HDL-C and HbA1c) and an internal model (disorders of lipid metabolism and glucose metabolism) and applied this model to 116 cases. RESULTS: The root mean square error between the observed HbA1c and predicted HbA1c was 0.25. CONCLUSIONS: In the observation model, HDL-C levels were useful for prediction of increases in HbA1c. Even with numerous missing values over time, as occurs in clinical practice, clinically valid predictions can be made using this state space model.

Hepatocyte destruction with enhanced collagen synthesis: characteristic feature of chronic hepatitis C patients on haemodialysis.

Hepatitis C virus (HCV) infection is frequent among patients with end-stage renal disease on haemodialysis and is considered to be an independent risk factor for mortality in this setting. However, only a few of these patients are treated with anti-hepatitis virus treatment before the development of end-stage renal disease. Recent guidelines recommend identification of patients with good prognoses who are in need of interferon treatment, but we know little of patients who must be treated urgently. Ninety-eight patients on haemodialysis (48 anti-HCV-positive and 50 anti-HCV-negative patients) were enrolled in this study; HCV RNA was detected in 43 anti-HCV-positive patients. Univariate analysis and multivariate regression analysis were applied to identify variables independently associated with persistent HCV infection. Seven variables were proven to be associated with persistent HCV infection. Among them, type IV collagen 7S and N-terminal propeptide of type III procollagen (P-III-P) were defined as independent variables useful in distinguishing HCV RNA-positive patients from HCV RNA-negative patients with 0.91 sensitivity, 0.91 specificity, 0.89 positive predictive value and 0.93 negative predictive value. Our observations suggest that hepatocyte destruction with enhanced liver fibrosis is a characteristic clinical feature of persistent HCV infection. Type IV collagen 7S of ≥ 5 ng/mL and/or P-III-P of ≥ 5 U/mL would be useful markers to identify patients in need of interferon treatment, which supports the idea of the Kidney Disease: Improving Global Outcomes guidelines that a good prognosis in patients with HCV infection on haemodialysis should prompt consideration for IFN treatment when applicable.

Nafamostat mesilate, a noncalcium compound, as an anticoagulant, induces calcium-dependent haemolysis when infused with packed erythrocytes.

BACKGROUND: Nafamostat mesilate (NM), a protease inhibitor, is available for acute pancreatitis and disseminated intravascular coagulopathy and is used as an anticoagulant for haemodialysis in Japan. Co-infusion of red cell concentrates (RCC) and intravenous drugs is usually contraindicated. Because of limited venous access, adherence to the guidelines may be compromised in some clinical settings. Therefore, we investigated the influence of co-infusion of RCC and various anticoagulants on haemolysis in vitro. METHODS: We investigated the effect of co-incubation of RCC and various anticoagulant drugs [NM, gabexate mesilate (GM), heparin] in packed erythrocytes. We evaluated haemolysis using lactate dehydrogenase and free haemoglobin. In addition, we also evaluated the influence of co-incubation on phosphatidylserine (PS) expression on the erythrocyte membrane. RESULTS: GM and NM induced haemolysis in a dose-dependent manner, which was inhibited by removal of citrate and pretreatment with the calcium chelator, ethylenediaminetetraacetic acid. In a dynamic experiment using an infusion pump, NM not only induced haemolysis during co-infusion with RCC but also elevated PS expression dependent on extracellular calcium. CONCLUSION: NM and GM induce haemolysis in packed erythrocytes in the presence of citrate that is dependent on extracellular calcium.

Superconductivity induced by longitudinal ferromagnetic fluctuations in UCoGe.

From detailed angle-resolved NMR and Meissner measurements on a ferromagnetic (FM) superconductor UCoGe (T(Curie)∼2.5 K and T(SC)∼0.6 K), we show that superconductivity in UCoGe is tightly coupled with longitudinal FM spin fluctuations along the c axis. We found that magnetic fields along the c axis (H∥c) strongly suppress the FM fluctuations and that the superconductivity is observed in the limited magnetic-field region where the longitudinal FM spin fluctuations are active. These results, combined with model calculations, strongly suggest that the longitudinal FM spin fluctuations tuned by H∥c induce the unique spin-triplet superconductivity in UCoGe. This is the first clear example that FM fluctuations are intimately related with superconductivity.

Making sense of postoperative CT imaging following laparoscopic partial nephrectomy.

The increasing popularity of laparoscopic partial nephrectomy (LPN) necessitates radiologists to become familiar with the operative techniques as well as normal and abnormal postoperative findings. Due to the varying presentation of abnormal changes following LPN and their similarities with other disease entities, radiologists should be cognizant of common pitfalls to avoid inadvertent misdiagnosis. A few common pitfalls discussed in this paper are the identification of laparoscopic port placement issues, recognizing a myriad of post-surgical materials, differentiating haemostatic materials from postoperative abscess and infection, non-absorbable suture material mimicking rim calcifications, as well as hints for differentiating exuberant granulation tissue from tumour recurrence.

Loss of multidrug and toxin extrusion 1 (MATE1) is associated with metformin-induced lactic acidosis.

BACKGROUNDS AND PURPOSE: Lactic acidosis is a fatal adverse effect of metformin, but the risk factor remains unclear. Multidrug and toxin extrusion 1 (MATE1) is expressed in the luminal membrane of the kidney and liver. MATE1 was revealed to be responsible for the tubular and biliary secretion of metformin. Therefore, some MATE polymorphisms, that cause it to function abnormally, are hypothesized to induce lactic acidosis. The purpose of this study is to clarify the association between MATE dysfunction and metformin-induced lactic acidosis. EXPERIMENTAL APPROACH: Blood lactate, pH and bicarbonate ion (HCO(3) (-) ) levels were evaluated during continuous administration of 3 mg·mL(-1) metformin in drinking water using Mate1 knockout (-/-), heterozygous (+/-) and wild-type (+/+) mice. To determine the tissue accumulation of metformin, mice were given 400 mg·kg(-1) metformin orally. Furthermore, blood lactate data were obtained from diabetic patients given metformin. KEY RESULTS: Seven days after metformin administration in drinking water, significantly higher blood lactate, lower pH and HCO(3) (-) levels were observed in Mate1(-/-) mice, but not in Mate1(+/-) mice. The blood lactate levels were not affected in patients with the heterozygous MATE variant (MATE1-L125F, MATE1-G64D, MATE2-K-G211V). Sixty minutes after metformin administration (400 mg·kg(-1) , p.o.) the hepatic concentration of metformin was markedly higher in Mate1(-/-) mice than in Mate1(+/+) mice. CONCLUSION AND IMPLICATIONS: MATE1 dysfunction caused a marked elevation in the metformin concentration in the liver and led to lactic acidosis, suggesting that the homozygous MATE1 variant could be one of the risk factors for metformin-induced lactic acidosis.

SU-E-T-557: A Planning Strategy of Volumetric Modulated Arc Therapy with Simultaneous Integrated Boost for Intracranial Stereotactic Radiotherapy.

PURPOSE: The purpose of this planning study was to evaluate the dosimetric effect of dose escalation for intracranial stereotactic radiotherapy by volumetric modulated arc therapy (RapidArc) with simultaneous integrated boost (SIB-VMAT). METHODS: Dynamic conformal arc therapy (DCA), VMAT, and SIB-VMAT plans using Novalis Tx (Varian/BrainLAB) were performed for twenty target volumes in patients with intracranial metastases with median PTV of 16.0 cm3 (range 2.4-35.2 cm3 ). PTV was created with 2 mm expansion from GTV. All plans were generated with a prescribed dose of 35 Gy in 5 fractions to the PTV (D95 = 95%), and dose escalation up to 40 Gy (SIB-VMAT40) and 45 Gy (SIB-VMAT45) was performed only to the PTV-boost (PTV shrunk by 5 mm) for SIB-VMAT. Each plan was compared using conformity parameters. RESULTS: The average Paddick conformity index (CI) was 0.78, 0.90, 0.91, and 0.89 for DCA, VMAT, SIB-VMAT40, and SIB-VMAT45, respectively. The average healthy tissue overdosage factor (HTOF), suggested by SALT was 0.118, 0.006, 0.007, and 0.011 for DCA, VMAT, SIB-VMAT40, and SIB-VMAT45, respectively. The average V30, V20, and V10 of normal brain for VMAT and SIB-VMAT decreased by 3.0 cm3 (range 0.1-8.2 cm3 ), 3.0 cm3 (range 0.1-8.7 cm@@@3@@), and 7.5 cm@@@3@@ (range 0.3-26.2 cm@@@3@@), respectively, compared to DCA depending on the target volume. CONCLUSIONS: SIB-VMAT improved dose conformity to the PTV for intracranial stereotactic radiotherapy, and decreased high and low dose volume of normal brain compared to DCA. SIB-VMAT offers the ability of dose escalation due to high conformity of high dose regions inside the target volume.

Spermatogenic function in cats.

There are limited data on feline sperm production. We exhausted epididymal spermatozoa (i.e. the number of ejaculated spermatozoa <5 × 10(6)) by frequent semen collections using the artificial vagina method in five tomcats and determined the number of spermatozoa stored in the epididymis. We investigated the time (days) required for the number of epididymal spermatozoa to return to the pre-exhaustion level and determined the number of spermatozoa produced per day. After spermatozoa were exhausted by frequent semen collection, 6 or more days were required to return to the pre-exhaustion level. Based on the duration of resting (days) and total number of spermatozoa, the mean number of spermatozoa produced per day was 30 × 10(6).

Metformin suppresses hepatic gluconeogenesis and lowers fasting blood glucose levels through reactive nitrogen species in mice.

AIMS/HYPOTHESIS: Metformin, the major target of which is liver, is commonly used to treat type 2 diabetes. Although metformin activates AMP-activated protein kinase (AMPK) in hepatocytes, the mechanism of activation is still not well known. To investigate AMPK activation by metformin in liver, we examined the role of reactive nitrogen species (RNS) in suppression of hepatic gluconeogenesis. METHODS: To determine RNS, we performed fluorescence examination and immunocytochemical staining in mouse hepatocytes. Since metformin is a mild mitochondrial complex I inhibitor, we compared its effects on suppression of gluconeogenesis, AMPK activation and generation of the RNS peroxynitrite (ONOO(-)) with those of rotenone, a representative complex I inhibitor. To determine whether endogenous nitric oxide production is required for ONOO(-) generation and metformin action, we used mice lacking endothelial nitric oxide synthase (eNOS). RESULTS: Metformin and rotenone significantly decreased gluconeogenesis and increased phosphorylation of AMPK in wild-type mouse hepatocytes. However, unlike rotenone, metformin did not increase the AMP/ATP ratio. It did, however, increase ONOO(-) generation, whereas rotenone did not. Exposure of eNOS-deficient hepatocytes to metformin did not suppress gluconeogenesis, activate AMPK or increase ONOO(-) generation. Furthermore, metformin lowered fasting blood glucose levels in wild-type diabetic mice, but not in eNOS-deficient diabetic mice. CONCLUSIONS/INTERPRETATION: Activation of AMPK by metformin is dependent on ONOO(-). For metformin action in liver, intra-hepatocellular eNOS is required.

Daily chewing gum exercise for stabilizing the vertical occlusion.

We investigated the effects of a chewing gum exercise program on occlusal conditions and evaluated compliance of subjects. Thirty-five healthy adult volunteers (26 males and nine females) were asked to chew gum for 10-15 min before or after three meals daily for four weeks. Occlusal conditions were recorded as occlusal parameters, such as occlusal contact area, occlusal contact force, and pressure using dental prescale films. These parameters were evaluated by an Occluzer before the exercise period commenced, after four weeks of exercise, and then one month after the end of the exercise period. These parameters were statistically compared using one-way ANOVA. We found that: (i) after four weeks of exercise, anterior and posterior occlusal contact areas and forces were significantly (P < 0.05) increased and the increments were significantly (P < 0.05) higher in the anterior occlusal contact area and force than in the posterior occlusal contact area and force, (ii) the anteroposterior ratio of occlusal contact area and force increased, but not markedly, (iii) increased parameters had significantly (P < 0.05) decreased within one month after the end of the four-week exercise period, (iv) most participants did not complain for discomfort or stress during the exercise. The chewing gum exercise program could increase occlusal contact area and force and also move the anteroposterior occlusal balance forward. Patient compliance with the exercise is likely high enough to keep them exercising.

Amphiregulin induces proliferative activities in osseous dysplasia.

Human osseous dysplasia (OD) is a benign fibro-osseous neoplasm of periodontal ligament origin in which normal bone is replaced with fibrous connective tissue containing abnormal bone or cementum. However, cellular differentiation and proliferation in OD have not been fully elucidated. In vitro culture systems have distinct advantages for analytical studies. Therefore, we established immortalized cell lines (OD-1) from OD lesions of the jaw from an individual with gnathodiaphyseal dysplasia (GDD). We hypothesized that OD-1 had a characteristic growth mechanism different from that of mineralized-associated cells such as osteoblasts. To clarify the difference of gene expression patterns between OD-1 and osteoblasts, we compared the profiles of genes expressed in the 2 cell types by microarray analysis. We identified amphiregulin to be highly expressed in OD-1 compared with osteoblasts and gingival fibroblasts. OD-1 showed proliferative activities regulated in an autocrine manner by amphiregulin, and amphiregulin may play a significant role in the proliferation of OD.

Depressed recovery of subendocardial perfusion in persistent heart failure after complete revascularisation in diabetic patients with hibernating myocardium.

OBJECTIVES: To investigate the relation between myocardial perfusion and heart failure (HF) status after revascularisation in patients with HF due to hibernating myocardium (HM) in diabetic and non-diabetic subjects. METHODS: 31 diabetic and 33 non-diabetic subjects with HF due to HM, who were already scheduled for complete revascularisation, were studied. Before and after revascularisation, left ventricular function and regional perfusion in subendocardial and subepicardial portions of the left ventricular wall were evaluated. RESULTS: Before revascularisation, left ventricular function and regional perfusion were similar in diabetic and non-diabetic subjects. At 6 months after revascularisation, subepicardial perfusion was markedly improved both in diabetic and non-diabetic subjects. However, subendocardial perfusion was markedly improved only in non-diabetic subjects and was little changed in diabetic patients. Thus, subendocardial perfusion was much lower in diabetic than non-diabetic subjects. Left ventricular function was improved more in non-diabetic than in diabetic subjects. Persistent HF was found much more often in diabetic than non-diabetic subjects. At multivariate analysis, subendocardial perfusion at 6 months independently contributed to persistent HF. CONCLUSIONS: This study describes the intramural heterogeneity of recovery of myocardial perfusion with depressed improvement in the subendocardial portion and its relation with persistent HF after complete revascularisation in diabetic patients with HF due to HM.