Electron Bulk Acceleration and Thermalization at Earth's Quasiperpendicular Bow Shock

Electron heating at Earth's quasiperpendicular bow shock has been surmised to be due to the combined effects of a quasistatic electric potential and scattering through wave-particle interaction. Here we report the observation of electron distribution functions indicating a new electron heating process occurring at the leading edge of the shock front. Incident solar wind electrons are accelerated parallel to the magnetic field toward downstream, reaching an electron-ion relative drift speed exceeding the electron thermal speed. The bulk acceleration is associated with an electric field pulse embedded in a whistler-mode wave. The high electron-ion relative drift is relaxed primarily through a nonlinear current-driven instability. The relaxed distributions contain a beam traveling toward the shock as a remnant of the accelerated electrons. Similar distribution functions prevail throughout the shock transition layer, suggesting that the observed acceleration and thermalization is essential to the cross-shock electron heating.

Efficacy of radioiodine therapy for treating 20 patients with pulmonary metastases from differentiated thyroid cancer and a meta-analysis of the current literature

Background

Radioiodine therapy (RAI) after total or near-total thyroidectomy is a recommended treatment for patients with pulmonary metastasis from differentiated thyroid cancer (DTC). However, the total effective rate of iodine-131 therapy remains controversial. This study aimed to determine the efficacy of RAI for treating patients with pulmonary metastasis from DTC, and to identify independent predictors of its efficacy.

Methods

We conducted a retrospective study to evaluate 20 patients with pulmonary metastasis from DTC who underwent RAI at our center at first and performed a meta-analysis to evaluate relevant literature regarding the overall efficacy of RAI and subgroup-specific efficacies subsequently.

Results

The efficacy rate at our center was 40%, and no significant differences were observed according to sex, age, pathological type, metastasis state, or interval between the initial RAI and final surgery. The meta-analysis revealed that the pooled overall efficacy rate was 58%, and significant differences were observed when we compared pulmonary metastasis versus pulmonary and other distant metastasis, age of < 40 years versus age of ≥ 40 years, papillary thyroid cancer versus follicular thyroid cancer and male patients versus female patients.

Conclusions

These results suggest that RAI is an effective treatment for patients with pulmonary metastasis from DTC after surgical treatment. The efficacy of RAI was significantly predicted by the presence of papillary thyroid cancer, age of < 40 years, the absence of non-lung distant metastasis and female patients.

Effects of risk factors on periodontal disease defined by calibrated community periodontal index and loss of attachment scores

OBJECTIVES

We evaluated whether and how the effects of risk factors on periodontal disease (PD) were modified by measurement errors using community periodontal index (CPI) and loss attachment (LA) in the community-based survey.

METHODS

A pilot validation study was performed to estimate the rates of false negative and false positive for both CPI and LA in 31 subjects from different regions using measurements from 12 well-trained dentists and a senior periodontist as a gold standard. Afterward, a Taiwanese nationwide survey was conducted by enrolling 3,860 participants to estimate the effect of each risk factor on PD calibrated with both sensitivity and specificity of two indices.

RESULTS

The values obtained for the sensitivity to false-positive ratio for CPI ranged widely from 1.12 to 7.71, indicating regional variation in both errors. The calibrated adjusted odds ratio for smoking vs non-smoking was higher than the uncalibrated odds ratio for PD defined by CPI (2.75 (2.01, 3.77) vs 2.02 (1.63, 2.52)) and LA (3.85 (2.44, 6.13) vs 1.93 (1.47, 2.54)) scores. Similar underestimation was noted for other risk factors.

CONCLUSION

The effects of risk factors on PD measured using CPI and LA in a large population-based survey were underestimated without correcting for measurement errors.

The study of the relationship between aberrant expression of hot shock protein 70 (HSP70) and spontaneous abortion

OBJECTIVE

The present study is aimed to explore the relationship between aberrant expression of heat shock protein 70 (HSP) and spontaneous abortion.

PATIENTS AND METHODS

50 patients with spontaneous abortion and 50 patients with induced abortion were continuously selected based on the nearest matching principle, and the proportion of age and gestational age was 1:1. The decidual tissues were obtained, and the cell apoptosis was determined by TUNEL assay. Further, the expression of HSP70 was assayed by immune-histochemical staining, and the expression of HSP70 mRNA was detected by the RT-PCR approach.

RESULTS

Apoptosis rate, HSP70 expression and HSP70 mRNA expression in the observation group were significantly higher than the control group.

CONCLUSIONS

HSP70 might induce apoptosis so as to cause spontaneous abortion.

[Comparison of anterolateral minithoracotomy versus partial upper hemisternotomy in aortic valve replacement]

OBJECTIVE

To compare the results of aortic valve replacement through anterolateral minithoracotomy (RT) and partial upper hemisternotomy (PS) approaches.

METHODS

This was a retrospective, observational, cohort study of collected data on 297 patients undergoing isolated primary aortic valve replacement between July 2009 and March 2016 at Department of Cardiovascular Surgery, Zhongshan Hospital, Fudan University. There were 174 male and 123 female patients, aging from 15 to 73 years with a mean age of (51±13) years. Of these, 132 were performed through right RT and 165 through PS. Outcomes of the two groups were compared by t test, t' test, rank-sum test and χ(2) test, respectively.

RESULTS

The overall in-hospital mortality was 1.7% (5/297), with no difference between the 2 groups (3.0%, 4/132 vs. 0.6%, 1/165, P=0.175 ). Patients in the RT group had longer cardiopulmonary bypass ((92±27) minutes vs. (76±18) minutes, t'=5.848, P=0.000)and crossclamping ((56±21) minutes vs. (43±12) minutes, t'=6.333, P=0.000)times. Three patients in the RT group and two patients required intraoperative conversion. Patients by way of RT was associated with a lower incidence of blood transfusions (20.4% vs. 39.4%, χ(2)=12.303, P=0.001) and less drainage (250 (307) ml vs. 570 (370) ml, Z=8.161, P=0.000). In addition, patients in RT group had a shorter postoperative length of stay (5(4) days vs. 9(10) days, Z=4.548, P=0.000).

CONCLUSIONS

Aortic valve replacement via RT and PS are both safe and feasible. The approach through PS is associated with better exposure, more extensive indication for surgery, and more suitable to heart centers which intend to carry out miminally invasive aortic valve replacement. While, for an experienced surgeon, the approach through right RT is worthy of clinical selective application for patients concern more about good cosmetic result, and patients have faster recovery by avoid sternotomy through RT approach.

Modified total arch replacement using a four-branched arch graft for acute type A aortic dissection with minimal brain and spinal cord ischemic time

AIM

This study aimed to evaluate the results of modified surgical strategies of total arch replacement using a four-branched arch graft, stented elephant trunk, and innovative organ protection method for acute type A aortic dissection.

METHODS

Between August 2011 and December 2011, 21 patients with acute type A aortic dissection underwent modified total arch replacement using the four-branched arch graft technique. All 21 patients had emergency surgery. Five patients had undergone previous aortic or cardiac surgery. The operations were stented elephant trunk implantation in 17 patients, ascending aorta replacement in 21 patients, coronary artery bypass grafting in four patients, Bentall operation in two patients, and aortic valve replacement in one patient. Twenty-one operations were performed under deep hypothermic extracorporeal circulation, modified selective cerebral perfusion, and end-organ and spinal cord protection for arch reconstruction.

RESULTS

There was two in-hospital deaths (9.5%). No persisting neurologic deficits or paraplegia occurred in 21 patients. Cardiopulmonary bypass time was 177.9±37.8 minutes. Myocardial ischemic time was 110.3±29.3 minutes. ICU time was 8.8±6.9 days and in-hospital duration was 28.7±13.7 days. Ventilation time varied from 9 hours to 21 days. A tracheotomy was necessary in four patients. Mean follow-up was 7.3±1.7 months and all patients are still alive.

CONCLUSION

Modified total arch replacement using a four-branched arch graft with stented elephant trunk and innovative organ protection is a useful and safe alternative technique for the treatment of acute type A aortic dissection and the results are encouraging.

Assessing the reliability of MRI-CBCT image registration to visualize temporomandibular joints

OBJECTIVES

To evaluate image quality of two methods of registering MRI and CBCT images of the temporomandibular joint (TMJ), particularly regarding TMJ articular disc-condyle relationship and osseous abnormality.

METHODS

MR and CBCT images for 10 patients (20 TMJs) were obtained and co-registered using two methods (non-guided and marker guided) using Mirada XD software (Mirada Medical Ltd, Oxford, UK). Three radiologists independently and blindly evaluated three types of images (MRI, CBCT and registered MRI-CBCT) at two times (T1 and T2) on two criteria: (1) quality of MRI-CBCT registrations (excellent, fair or poor) and (2) TMJ disc-condylar position and articular osseous abnormalities (osteophytes, erosions and subcortical cyst, surface flattening, sclerosis).

RESULTS

75% of the non-guided registered images showed excellent quality, and 95% of the marker-guided registered images showed poor quality. Significant difference was found between the non-guided and marker-guided registration (χ(2) = 108.5; p < 0.01). The interexaminer variability of the disc position in MRI [intraclass correlation coefficient (ICC) = 0.50 at T1, 0.56 at T2] was lower than that in MRI-CBCT registered images [ICC = 0.80 (0.52-0.92) at T1, 0.84 (0.62-0.93) at T2]. Erosions and subcortical cysts were noticed less frequently in the MRI-CBCT images than in CBCT images.

CONCLUSIONS

Non-guided registration proved superior to marker-guided registration. Although MRI-CBCT fused images were slightly more limited than CBCT alone to detect osseous abnormalities, use of the fused images improved the consistency among examiners in detecting disc position in relation to the condyle.

Abstract 854: Inhibition of PRMT5 results in radiosensitization in lung cancer cell lines

Background: Protein arginine methylation is a post translational modification that influences signal transduction, mRNA splicing, gene transcription and DNA repair. Among the PRMT family members, PRMT5 is a type II enzyme that symmetrically methylates histone H4 at Arginine 3 and histone H3 at Arginine 8. Studies have recently linked this modification to carcinogenesis and metastasis. The function of PRMT5 in carcinogenesis is related to cell proliferation through modulation of E2F1, p53, EGFR, and CRAF. It is known to accelerate progression through the G1 phase of cell cycle by influencing proteins like CDK4 and CDK6. Previous work on human lung cancer specimens has demonstrated an overexpression of PRMT5 in cancerous tissue when compared to normal lung parenchyma. Suppression of PRMT5 significantly inhibits cell proliferation in lung cancer cell lines A549 and H1299. We hypothesized inhibition of PRMT5 can lead to increased radiosensitivity in lung cancer cells.

Method: Several lung cancer cell lines were used in the experiments, including A549, H1299 and H23. SiRNA (Dharmacon) and lentiviral shRNA (Sigma) were used to knock down (KD) PRMT5 levels transiently or stably in A549 cell line in which p53 is present in its wild type form. Forty eight hours after transient transfection, cells were plated for clonogenic survival assay and subsequently exposed to ionizing radiation at 0, 2, and 8 Gy. Cellular PRMT5 protein levels were estimated by western blotting analysis for PRMT5 KD and scramble control cell lines. The scramble control and siRNA knockdown cells were subjected to cell cycle analysis by flow cytometry. We also tested specific PRMT5 inhibitors with and without radiation therapy in the lung cancer cell lines to see if PRMT5 inhibitors could lead to increased radiosensitivity.

Results: We observed a &gt;90% PRMT5 KD in transiently transfected cells at 48 h and 72 h post transfection as verified by western blot analysis. This transient KD lead to a small but significant decrease in colony survival after radiation. This radiosensitization was not observed in cells selected for stable KD of PRMT5 protein by lentiviral RNA transfection. There is an increase of cell population in G1 arrest in PRMT5 transient KD cells but not in stable KD cells. Additionally, cells treated with PRMT5 specific inhibitors (“cpd5” or “cpd65”) demonstrated increased radiosensitivity in A549 cells but not in H1299 suggesting that this effect may be p53-dependent.

Conclusion: PRMT5 inhibition by siRNA or its specific inhibitors lead to radiosensitivity in A549 lung cancer cell line. This effect may be partially dependent on p53-dependent cell cycle arrest. Further work to inhibit PRMT5 in other lung cancer cell lines with different p53 activities will be investigated.

Citation Format: Smitha Sharma, X Wu, P Smith, N Denko, C Li, H Lai, F Yan, K Shilo, A Chakravarti, S Sif, R Baiocchi, G Otterson, Meng Xu-Welliver. Inhibition of PRMT5 results in radiosensitization in lung cancer cell lines. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 854. doi:10.1158/1538-7445.AM2014-854

Relationship between Community Periodontal Index and Fecal Hemoglobin Concentration, an Indicator for Colorectal Neoplasm

Periodontal disease and colorectal cancer have inflammatory processes in common. It is therefore worthwhile to investigate whether there is an association between periodontal probing depth and fecal hemoglobin concentration (FHbC), an indicator of colorectal neoplasms, in 40- to 44-year-old Taiwanese. We enrolled a total of 6,214 attendees aged 40 to 44 yr who were participating in a community-based integrated screening program and who received both periodontal and FHbC examinations between 2003 and 2008. A proportional odds logistic regression model was used to estimate the odds ratios of different FHbC levels in treating an increased level of community periodontal index (CPI) measuring periodontal probing depth as ordinary data from 0 to 4. Periodontal probing depth with the order of CPI was in parallel with an increase in the mean values of FHbC: 21.3 ± 156.3, 26.0 ± 167.7, 27.2 ± 151.1, and 39.5 ± 255.7 ng/mL for CPI 0, CPI 1, CPI 2, and CPI 3/4, respectively. The log-FHbC varied across the categories of CPI (p = .0078). After adjusting for age, sex, education level, smoking, alcohol intake, exercise, body mass index, and intake of meat and vegetables, subjects with positive fecal immunochemical test results (FHbC ≥ 100 ng/mL) had a 33% higher risk of deteriorating to severe CPI than did those within the normal range of fecal immunochemical test (FHbC < 100 ng/mL) (adjusted odds ratio = 1.33, 95% confidence interval: 1.03-1.73). A positive association was demonstrated between FHbC and periodontal probing depth assessed by CPI among 6,214 Taiwanese aged 40 to 44 yr who participated in a community-based integrated health screening program. These results could have significant implications for early identification of high-risk individuals, as those with deep periodontal pockets should be advised to undergo screening for colorectal cancer at a younger age than commonly recommended.

High resolution computed tomography and classification of children with interstitial lung diseases

High resolution computed tomography (HRCT) was used to classify children with interstitial lung diseases (ILD). Sixty children with ILD underwent HRCT in supine position under free-respiratory conditions during scanning. Children under 5 years old were sedated with chloral hydrate and the scanning scope was from the lung apex to the diaphragm. In children older than 5 years old, scans were obtained at three levels: aortic arch, tracheal carina, and 1 cm above the right diaphragm. Five infectious patients were followed up. Two experienced radiologists read the films blindly to observe the type and distribution of ground-glass opacities and bronchovascular bundle abnormalities. Bronchovascular bundles were thick in 49 patients, and were thick and stiff in 27 patients. Of the 41 infectious patients, 39 showed thickened bronchovascular bundles, and 26 showed thick and stiff bronchovascular bundles. Of the 19 non-infectious patients, bronchovascular bundles were thickened in 10 patients, and were thick and stiff in 1 patient. Forty-one patients showed lobular ground-glass opacity (32 infectious, 9 non-infectious). Twenty-seven patients showed both bronchovascular bundle abnormality and lobular ground-glass opacity (20 infectious, 7 non-infectious). Eighteen patients showed patchy or mosaic ground-glass opacity (16 infectious, 2 non-infectious). There were 4 cases of bronchiectasis. HRCT is the first non-invasive diagnostic method for children with ILD, and its different manifestations can be classified. In early manifestation, bronchovascular bundles were abnormal and complicated with lobular ground-glass opacity. Patchy ground-glass opacity was the most common manifestation, and appeared to be difficult to disappear. Bronchiectasis indicated that the disease is irretrievable.

The Medicago genome provides insight into the evolution of rhizobial symbioses

Legumes (Fabaceae or Leguminosae) are unique among cultivated plants for their ability to carry out endosymbiotic nitrogen fixation with rhizobial bacteria, a process that takes place in a specialized structure known as the nodule. Legumes belong to one of the two main groups of eurosids, the Fabidae, which includes most species capable of endosymbiotic nitrogen fixation. Legumes comprise several evolutionary lineages derived from a common ancestor 60 million years ago (Myr ago). Papilionoids are the largest clade, dating nearly to the origin of legumes and containing most cultivated species. Medicago truncatula is a long-established model for the study of legume biology. Here we describe the draft sequence of the M. truncatula euchromatin based on a recently completed BAC assembly supplemented with Illumina shotgun sequence, together capturing ∼94% of all M. truncatula genes. A whole-genome duplication (WGD) approximately 58 Myr ago had a major role in shaping the M. truncatula genome and thereby contributed to the evolution of endosymbiotic nitrogen fixation. Subsequent to the WGD, the M. truncatula genome experienced higher levels of rearrangement than two other sequenced legumes, Glycine max and Lotus japonicus. M. truncatula is a close relative of alfalfa (Medicago sativa), a widely cultivated crop with limited genomics tools and complex autotetraploid genetics. As such, the M. truncatula genome sequence provides significant opportunities to expand alfalfa's genomic toolbox.

Nipple sparing mastectomy: can we predict the factors predisposing to necrosis?

BACKGROUND

Nipple sparing mastectomy (NSM) is an accepted surgical approach in selected breast cancer and prophylactic mastectomy, nevertheless post-mastectomy skin necrosis is one of the frequent complications. This study aimed to analyze the factors that may lead to skin necrosis after NSM.

PATIENTS AND METHODS

From May 2010 to July 2010, we prospectively registered 50 consecutive NSM from 45 patients. There were 40 mastectomies for cancer, and 10 prophylactic mastectomies. The various patient's and surgical factors were registered during pre-, intra- and postoperative period.

RESULTS

No total necrosis of the nipple areola complex (NAC) was observed. There were thirteen cases with partial necrosis (26.0%) of the areola or the adjacent skin. All these necrosis were partial both for the surface and the thickness. Surgical debridement was performed in 9 (18.0%) cases. The significant risk factors are smoking, young age, type of incision and NAC involvement with areola flap thickness less than 5 mm.

CONCLUSION

NSM should be done with high caution in smokers. Young patients, periareolar incision and superior circumareolar incision have also a higher risk of necrosis. We recommend keeping areolar flap thickness more than 5 mm in areola region.