The conformational propensities of unfolded states of apomyoglobin have been investigated by measurement of residual dipolar couplings between
15N and
1H in backbone amide groups. Weak alignment of ...apomyoglobin in acid and urea-unfolded states was induced with both stretched and compressed polyacrylamide gels. In 8 M urea solution at pH 2.3, conditions under which apomyoglobin contains no detectable secondary or tertiary structure, significant residual dipolar couplings of uniform sign were observed for all residues. At pH 2.3 in the absence of urea, a change in the magnitude and/or sign of the residual dipolar couplings occurs in local regions of the polypeptide where there is a high propensity for helical secondary structure. These results are interpreted on the basis of the statistical properties of the unfolded polypeptide chain, viewed as a polymer of statistical segments. For a folded protein, the magnitude and sign of the residual dipolar couplings depend on the orientation of each bond vector relative to the alignment tensor of the entire molecule, which reorients as a single entity. For unfolded proteins, there is no global alignment tensor; instead, residual dipolar couplings are attributed to alignment of the statistical segments or of transient elements of secondary structure. For apomyoglobin in 8 M urea, the backbone is highly extended, with φ and ψ dihedral angles favoring the β or P
II regions. Each statistical segment has a highly anisotropic shape, with the N–H bond vectors approximately perpendicular to the long axis, and becomes weakly aligned in the anisotropic environment of the strained acrylamide gels. Local regions of enhanced flexibility or chain compaction are characterized by a decrease in the magnitude of the residual dipolar couplings. The formation of a small population of helical structure in the acid-denatured state of apomyoglobin leads to a change in sign of the residual dipolar couplings in local regions of the polypeptide; the population of helix estimated from the residual dipolar couplings is in excellent agreement with that determined from chemical shifts. The alignment model described here for apomyoglobin can also explain the pattern of residual dipolar couplings reported previously for denatured states of staphylococcal nuclease and other proteins. In conjunction with other NMR experiments, residual dipolar couplings can provide valuable insights into the dynamic conformational propensities of unfolded and partly folded states of proteins and thereby help to chart the upper reaches of the folding landscape.
Negative through-the-thickness Poisson’s ratios are investigated macroscopically and microscopically in the elastic–viscoplastic behavior of angle-ply carbon fiber-reinforced plastic (CFRP) ...laminates. For this purpose, an analysis method is proposed based on a homogenization theory for nonlinear time-dependent composites with point-symmetric internal structures. This method is able to efficiently analyze both the macroscopic and microscopic elastic–viscoplastic properties of angle-ply CFRP laminates fully modeled with microstructures consisting of fibers and a matrix. Using the proposed method, the elastic–viscoplastic analysis of angle-ply carbon fiber/epoxy laminates with various laminate configurations is performed to investigate their Poisson’s ratios in the viscoplastic region. It is revealed that, for a range of laminate configurations, the through-the-thickness Poisson’s ratios exhibit negative values which become increasingly negative as the viscoplastic deformation progresses in the laminates. The effect of strain rate on this increasing negativity is also demonstrated, and microscopic mechanisms are investigated to explain this trend. It is further shown that the increasing negativity significantly affects microscopic interlaminar stress distributions.
Background
The efficacy and safety of transanal lateral pelvic lymph node dissection (TaLPLND) in rectal cancer has not yet been clarified. The aim of the present study was to evaluate the short-term ...results as an initial experience of TaLPLND.
Methods
This retrospective study included patients with middle to lower rectal cancer who underwent TaLPLND from July 2018 to July 2021. Our institutions targeted lymph nodes in the internal iliac area and the obturator area for lateral pelvic lymph node dissection (LPLND).
Results
A total of 30 consecutive patients with rectal cancer were included in this analysis. The median age was 60 years (range, 36–83 years), and the male–female ratio was 2:1. The median operative time was 362 min (IQR, 283–661 min), and the median intraoperative blood loss was 74 ml (IQR, 5–500 ml). Intraoperative blood transfusion was required in one case. No cases required conversion to laparotomy. TaLPLND was performed bilaterally in 13 patients (43.3%). Five patients (16.7%) underwent LPLND with combined resection of the internal iliac vessels. The median distance of the distal margin from the anal verge was 20 mm. The pathological radial margin (pRM) was positive in one case, and the negative pRM rate was 96.7%. Short-term postoperative complications (Clavien–Dindo classification grade ≥ II) were observed in nine cases (30.0%). There were no cases of reoperation or mortality. The median number of harvested lateral pelvic lymph nodes was 11 (range, 3–28). On pathological examination, lateral pelvic lymph nodes were positive for metastasis in seven cases (23.3%).
Conclusions
TaLPLND appeared to be beneficial from an oncological point of view because it was close to the upstream lymphatic drainage from the tumor. The short-term outcomes of this initial experience indicate that this novel approach is feasible.
Objective The aim of this study was to evaluate the usefulness of hypothetical monoenergetic images after dual-energy computed tomography (DECT) for assessment of the bone encircling dental implant ...bodies. Study design Seventy-two axial images of implantation sites clipped out from image data scanned using DECT in dual-energy mode were used. Subjective assessment on reduction of dark-band-like artifacts (R-DBAs) and diagnosability of adjacent bone condition (D-ABC) in 3 sets of DECT images—a fused image set (DE120) and 2 sets of hypothetical monoenergetic images (ME100, ME190)—was performed and the results were statistically analyzed. Results With regards to R-DBAs and D-ABC, significant differences among DE120, ME100, and ME190 were observed. The ME100 and ME190 images revealed more artifact reduction and diagnosability than those of DE120. Conclusions DECT imaging followed by hypothetical monoenergetic image construction can cause R-DBAs and increase D-ABC and may be potentially used for the evaluation of postoperative changes in the bone encircling implant bodies.
Background
We previously reported that indocyanine green fluorescence imaging (ICG-FI)-guided laparoscopic lateral pelvic lymph node dissection (LPLND) was able to increase the total number of ...harvested lateral pelvic lymph nodes without impairing functional preservation. However, the long-term outcomes of ICG-FI-guided laparoscopic LPLND have not been evaluated. The aim of the present study was to compare the long-term outcomes of ICG-FI-guided laparoscopic LPLND to conventional laparoscopic LPLND without ICG-FI.
Methods
This was a retrospective, multi-institutional study with propensity score matching. The study population included consecutive patients with middle-low rectal cancer (clinical stage II to III) who underwent laparoscopic LPLND between January 2013 and February 2018. The main evaluation items in this study were the 3-year overall survival, relapse-free survival (RFS), local recurrence rate, and lateral local recurrence (LLR) rate.
Results
A total of 172 patients with middle-lower rectal cancer who had undergone laparoscopic LPLND were included in this study. After propensity score matching, 58 patients were matched in each of the ICG-FI and non-ICG-FI groups. There were no substantial differences in the baseline characteristics between the two groups. The ICG-FI group and non-ICG-FI group included 40 and 38 women and had a median age of 65 (IQR 60–72) and 66 (IQR 60–73) years, respectively. The median follow-up for all patients was 63.7 (IQR 51.3–76.8) months. The estimated respective 3-year overall survival, RFS, and local recurrence rates were 93.1%, 70.7%, and 5.2% in the ICG-FI group and 85.9%, 71.7%, and 12.8% in the non-ICG-FI group (
p
= 0.201, 0.653, 0.391). The 3-year cumulative LLR rate was 0% in the ICG-FI group and 9.3% in the non-ICG-FI group (
p
= 0.048).
Conclusions
This study revealed that laparoscopic LPLND combined with ICG-FI was able to decrease the LLR rate. It appears that ICG-FI could contribute to improving the quality of laparoscopic LPLND and strengthening local control of the lateral pelvis.
Trials Registration
This study was registered with the Japanese Clinical Trials Registry as UMIN000041372 (
http://www.umin.ac.jp/ctr/index.htm
).
Magnesium supplementation has been reported to have a nephroprotective effect on cisplatin-induced renal dysfunction, but little evidence exists regarding the effect of magnesium preloading before ...cisplatin administration. We started to include magnesium preloading (8 mEq) in cisplatin-containing treatment regimens in January 2011. The aim of the present study was to evaluate whether magnesium preloading reduces cisplatin-induced nephrotoxicity.
We retrospectively reviewed 496 thoracic malignancy patients treated with cisplatin (≥60 mg/m²)-containing regimens as a first-time chemotherapy between January 2009 and December 2011. We compared the incidence of Grade ≥2 serum creatinine elevation according to the Common Terminology Criteria for Adverse Events, version 4.0, between magnesium preloading group (n = 161 32%) and non-magnesium preloading group (n = 335 68%) during the first cycle and all cycles.
The median number of administered cycles was four in both groups. The incidence of Grade ≥2 serum creatinine elevation in magnesium preloading group was significantly lower during both the first cycle and all cycles than in the non-magnesium preloading group (4.9 versus 19.1% during the first cycle, and 14.2 versus 39.7% during all the cycles). A multivariate analysis indicated that magnesium preloading significantly reduced cisplatin-induced nephrotoxicity throughout the entire period from after the first administration (odds ratio: 0.262, 95% confidence interval: 0.106-0.596 during the first cycle, and odds ratio: 0.234, 95% confidence interval: 0.129-0.414 during all cycles).
Magnesium preloading before cisplatin administration significantly reduced cisplatin-induced nephrotoxicity.
Knowledge of black carbon (BC) concentrations and size distributions within surface snow in Antarctica is limited. However, these measurements are important to understanding global aerosol transport ...from combustion sources, and BC contributes to positive radiative forcing. This study analyzed the concentrations and size distributions of BC and inorganic ions in snow samples collected at the Syowa station in Antarctica from April to December 2011 and along a traverse route to an inland (Mizuho) station. The BC size distributions in snow were bimodal with mass median diameters of ~140 and ~690 nm. We also estimated the mass median diameter from unimodal distributions and found smaller diameters than were reported by other studies. The mass concentrations of BC in snow were higher in inland samples than in Syowa samples. Among Syowa samples, the BC concentrations in December (2117.3 ng L−1 on average) were higher than in other periods (288.2 ng L−1 on average). The December samples experienced ambient temperatures above 0 °C, and the atmospheric BC concentrations did not increase simultaneously. Inorganic ions originated from the ocean and decreased with increasing distance from the coastal area. We conclude that the BC concentrations in surface snow increased mainly by postdeposition processes through the loss of water mass due to melting, evaporation, and sublimation. Our study is the first to report detailed BC concentrations and size distributions in eastern Antarctica, and the results will help to evaluate BC global transport, the snow albedo estimations in this region, and the climate impacts of BC.
Key Points
BC concentrations and size distributions in snow samples were measured during a 9‐month observation period in Antarctica
BC in our snow samples showed bimodal mass size distributions and smaller diameters than those in other regions
The snow samples that experienced temperatures above 0 degrees had the highest BC concentrations, possibly due to postdeposition processes
Exercises in space are not always effective for prevention of atrophy in soleus, which is most susceptible to gravitational unloading. Therefore, this study was performed to investigate the optimum ...exercise prescription for prevention of the gravitational unloading-related atrophy in human soleus. Effects of active plantar-flexion of ankle joints or front sole, or passive dorsi-flexion of ankle joints during various exercises on the mobilization of soleus muscles were studied. Electromyogram (EMG) activities in soleus were recorded in 7 healthy male subjects during 1) cycling at 70, 130, and/or 170 W, by pedalling using arch or front sole, 2) weight lifting (isometric and/or squat push-up) with or without active plantar-flexion of the ankle joints, and 3) knee extension/flexion exercise in a supine position with or without forced passive dorsi-flexion of ankle joints. Greater EMG levels were observed, when the cycling load was increased and the subjects pedaled by using front sole. Mobilization of soleus was increased, when the subjects tried to plantar-flex the ankle joints during weight lifting. Soleus muscles were not mobilized during knee extension/flexion exercise with passively plantar-flexed ankle joint. But EMGs of soleus were elevated ~22 times in response to forced ankle-joint dorsi-flexion, not knee-joint extension/flexion exercise. The data indicated that active plantar-flexion or passive dorsi-flexion of ankle joints is essential for stimulation of soleus muscle mobilization.
•Exercise for prevention of the unloading-related atrophy in human soleus was studied.•Effects of ankle joint movement during cycling and/or weight lifting were studied.•Soleus activity was stimulated by active ankle plantar- and/or passive dorsi-flexion.
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