Delineation of the internal iliac vein using MRI with true FISP sequence in patients with locally recurrent rectal cancer: A pilot study using CT/MRI fusion

PURPOSE

This study assessed the feasibility of using three-dimensional (3D) models of intrapelvic vascular patterns constructed using computed tomography (CT) and magnetic resonance imaging (MRI) fusion data for preoperative planning in patients with locally recurrent rectal cancer.

METHODS

Eleven patients scheduled for pelvic exenteration were included. The 3D fusion data of the intrapelvic vessels constructed using CT and MRI with true fast imaging with steady-state precession sequence (True FISP) were evaluated preoperatively. Contrast ratios (CR) between the piriformis muscle and the intrapelvic vessels were calculated to identify a valid modality for 3D modeling and creating CT/MRI fusion-reconstructed volume-rendered images.

RESULTS

The CR values of the internal and external iliac arteries were significantly higher on CT images than MR images (CT vs. MRI; 0.63 vs. 0.45, p < 0.01). However, the CR value of the internal iliac vein was significantly higher on MR than CT images (CT vs. MRI; 0.23 vs. 0.55, p < 0.01).

CONCLUSIONS

MRI with True FISP yielded high signal-to-noise ratios and aided in delineating the internal iliac vein around the piriformis muscle. More precise 3D models can be constructed using this technique in the future to aid in the resection of locally recurrent rectal cancer.

Influence of Diffusion Time and Temperature on Restricted Diffusion Signal: A Phantom Study

PURPOSE

Diffusion MRI is a physical measurement method that quantitatively indicates the displacement of water molecules diffusing in voxels. However, there are insufficient data to characterize the diffusion process physically in a uniform structure such as a phantom. This study investigated the transitional relationship between structure scale, temperature, and diffusion time for simple restricted diffusion using a capillary phantom.

METHODS

We performed diffusion-weighted pulsed-gradient stimulated-echo acquisition mode (STEAM) MRI with a 9.4 Tesla MRI system (Bruker BioSpin, Ettlingen, Germany) and a quadrature coil with an inner diameter of 86 mm (Bruker BioSpin). We measured the diffusion coefficients (radial diffusivity [RD]) of capillary plates (pore sizes 6, 12, 25, 50, and 100 μm) with uniformly restricted structures at various temperatures (10ºC, 20ºC, 30ºC, and 40ºC) and multiple diffusion times (12-800 ms). We evaluated the characteristics of scale, temperature, and diffusion time for restricted diffusion.

RESULTS

The RD decayed and became constant depending on the structural scale. Diffusion coefficient fluctuations with temperature occurred mostly under conditions of a large structural scale and short diffusion time. We obtained data suggesting that temperature-dependent changes in the diffusion coefficients follow physical laws.

CONCLUSION

No water molecules were observed outside the glass tubes in the capillary plates, and the capillary plates only reflected a restricted diffusion process within the structure.We experimentally evaluated the characteristics of simple restricted diffusion to reveal the transitional relationship of the diffusion coefficient with diffusion time, structure scale, and temperature through composite measurement.

Local alternating heat and cold stimulation affects hemodynamics and oxygenation in fatigued muscle tissue and autonomic nervous activity: a single-arm interventional study

BACKGROUND

Local alternating heat and cold stimulation as an alternative to contrast bath may cause intermittent vasoconstriction and vasodilation, inducing a vascular pumping effect and consequently promoting increased tissue blood flow and oxygenation. This study aimed to examine the effects of local alternating heat and cold stimulation, using a wearable thermal device, on the hemodynamics of fatigued muscle tissue and autonomic nervous activity.

METHODS

Twenty healthy individuals experienced fatigue in the periarticular muscles of the shoulder joint due to a typing task. Local alternating heat and cold stimulations were then applied to the upper trapezius muscle. Muscle hardness was measured using a muscle hardness meter, and muscle tissue hemodynamics and oxygenation were evaluated using near-infrared spectroscopy before and after the stimulation. Autonomic nervous activity was also evaluated using heart rate variability.

RESULTS

Alternating heat and cold stimulation decreased muscle hardness of the fatigued trapezius muscle from 1.38 ± 0.15 to 1.31 ± 0.14 N (P < 0.01). The concentration of total hemoglobin in the trapezius muscle tissue increased from - 0.21 ± 1.36 to 2.29 ± 3.42 µmol/l (P < 0.01), and the tissue hemoglobin oxygen saturation also increased from 70.1 ± 5.4 to 71.1 ± 6.0% (P < 0.05). Additionally, the heart rate variability parameter, which is an index of sympathetic nervous activity, increased from 3.82 ± 2.96 to 6.86 ± 3.49 (P < 0.01). A correlation was found between increased tissue hemoglobin oxygen saturation and increased parameters of sympathetic nervous activity (r = 0.50, P < 0.05).

CONCLUSIONS

Local alternating heat and cold stimulation affected the hemodynamic response in fatigued muscle tissue and autonomic nervous activity. This stimulation is more efficient than conventional contrast baths in terms of mobility and temperature control and has potential as a new versatile therapeutic intervention for muscle fatigue.

TRIAL REGISTRATION

UMIN-CTR (UMIN000040087: registered on April 7, 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000045710 . UMIN000040620: registered on June 1, 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046359 ).

Restricted diffusion characteristics in oscillating gradient spin echo with mesoscopic phantom

In diffusion magnetic resonance imaging, oscillating gradient spin echo (OGSE) has an extremely short diffusion time if motion probing gradient (MPG) is applied to the waveform. Further, it can detect microstructural specificity. OGSE changes sensitivity to spin displacement velocity based on the MPG phase. The current study aimed to investigate the restricted diffusion characteristics of each OGSE waveform using the capillary phantom with various b-values, frequencies, and MPG phases. We performed OGSE (b-value = 300, 500, 800, 1200, 1600, and 2000 s/mm2) for the sine and cosine waveforms using the capillary phantom (6, 12, 25, 50, and 100 μm and free water) with a 9.4-T experimental magnetic resonance imaging system and a solenoid coil. We evaluated the axial and radial diffusivity (AD, RD) of each structure size. The output current of the MPG was assessed with an oscilloscope and analyzed with the gradient modulation power spectra by fast Fourier transform. In sine, the sidelobe spectrum was enhanced with increasing frequency, and the central spectrum slightly increased. The difference in RD was detected at 6 and 12 μm; however, it did not depend on the structure scale at 50 or 100 μm and free water. In cosine, the diffusion spectrum was enhanced, whereas the central spectrum decreased with increasing frequency. Both AD and RD in cosine had a frequency dependence, and AD and RD increased with a higher frequency regardless of structure size. AD and RD in either sine or cosine had no evident b-value dependence. We evaluated the OGSE-restricted diffusion characteristics. The measurements obtained diffusion information similar to the pulsed gradient spin echo. Hence, the cosine measurements indicated that a higher frequency could capture faster diffusion within the diffusion phenomena.

Effects of preceding antiplatelet agents on severity of ischemic stroke in patients with a history of stroke

INTRODUCTION

Antiplatelet agents are effective for secondary prevention of ischemic stroke and can reduce the severity of first-ever ischemic stroke. However, it is uncertain if prophylactic antiplatelet therapy reduces the severity of recurrent ischemic stroke. The aim of this study was to determine the effect of preceding antiplatelet treatment on the severity of thrombotic stroke (TS) in patients with a prior history of stroke.

METHODS

From a prospective hospital registry of 1338 consecutive patients with acute ischemic stroke, we identified patients with a prior history of stroke who were admitted for cardioembolic stroke (CE); TS including large-artery atherosclerosis, small vessel occlusion, and branch atheromatous disease; or other cause or cryptogenic stroke (OCS). Cases in each subtype were categorized based on preceding medication: antiplatelet agents (AP) and none (N). Severity of stroke (National Institutes of Health Stroke Scale: NIHSS) on admission was compared between AP and N cases.

RESULTS

The total cohort of 252 patients included 83 with CE, 102 with TS, and 67 with OCS. After excluding those with prior anticoagulants, the median NIHSS on admission was lower in AP cases than in N cases (3 vs. 5, p = 0.002). In multivariate analysis, preceding AP treatment was independently associated with minor stroke (NIHSS ≤4) on admission in CE group (OR 8.48, 95% CI 1.71-62.9, p = 0.008) and TS group (OR 4.24, 95% CI 1.44-13.4, p = 0.009).

CONCLUSION

Preceding antiplatelet treatment in patients with a prior history of stroke may reduce the severity of subsequent thrombotic and cardiogenic stroke.

Anaerobic threshold using sweat lactate sensor under hypoxia

We aimed to investigate the reliability and validity of sweat lactate threshold (sLT) measurement based on the real-time monitoring of the transition in sweat lactate levels (sLA) under hypoxic exercise. In this cross-sectional study, 20 healthy participants who underwent exercise tests using respiratory gas analysis under hypoxia (fraction of inspired oxygen [FiO2], 15.4 ± 0.8%) in addition to normoxia (FiO2, 20.9%) were included; we simultaneously monitored sLA transition using a wearable lactate sensor. The initial significant elevation in sLA over the baseline was defined as sLT. Under hypoxia, real-time dynamic changes in sLA were successfully visualized, including a rapid, continual rise until volitionary exhaustion and a progressive reduction in the recovery phase. High intra- and inter-evaluator reliability was demonstrated for sLT's repeat determinations (0.782 [0.607-0.898] and 0.933 [0.841-0.973]) as intraclass correlation coefficients [95% confidence interval]. sLT correlated with ventilatory threshold (VT) (r = 0.70, p < 0.01). A strong agreement was found in the Bland-Altman plot (mean difference/mean average time: - 15.5/550.8 s) under hypoxia. Our wearable device enabled continuous and real-time lactate assessment in sweat under hypoxic conditions in healthy participants with high reliability and validity, providing additional information to detect anaerobic thresholds in hypoxic conditions.

Relationship of Lesion Location to Postoperative Steroid Use in Eosinophilic Chronic Rhinosinusitis

OBJECTIVES

Eosinophilic chronic rhinosinusitis (ECRS) is known to recur after surgery. The treatment choice for recurrent ECRS, such as oral steroids or biological agents, must be chosen carefully, and identifying the lesion location may be useful. This study aimed to evaluate the postoperative course of ECRS patients and assess the relationship between endoscopic lesion location and postoperative oral steroid use.

METHODS

Patients with chronic rhinosinusitis who underwent bilateral endoscopic sinus surgery from April 2018 to March 2020 were divided into two groups based on the presence or absence of oral steroid use after surgery. The primary endpoint was the lesion location on endoscopic findings during surgery: middle turbinate, middle meatus, superior turbinate, superior meatus, nasal septum, and sphenoethmoidal recess. Subjective symptoms, blood tests, and computerized tomography (CT) findings (Lund-Mackay score) were evaluated as secondary endpoints.

RESULTS

Among 264 patients, 88 were diagnosed histologically with ECRS (mean 48.98 ± 1.40 years, 67 males/21 females). Twenty-three patients were steroid-using, 65 were steroid-free, and six stopped attending their appointments. Patients with sphenoethmoidal recess lesions were significantly more likely to require steroids (p = 0.019). There was a significant association between steroid use and younger age (p = 0.041), olfactory dysfunction (p = 0.021), and all sinuses (Frontal sinus: p < 0.001, Anterior ethmoid sinus: p = 0.002, Posterior ethmoid sinus: p = 0.011, Maxillary sinus: p = 0.018, Sphenoid sinus: p = 0.034, Total score: p < 0.001).

CONCLUSION

A sphenoethmoidal recess lesion was a risk factor for requiring postoperative steroids. Young age, olfactory dysfunction, and preoperative severe CT findings were also significant risk factors.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2511-2516, 2023.

Estimation of maximal lactate steady state using the sweat lactate sensor

A simple, non-invasive algorithm for maximal lactate steady state (MLSS) assessment has not been developed. We examined whether MLSS can be estimated from the sweat lactate threshold (sLT) using a novel sweat lactate sensor for healthy adults, with consideration of their exercise habits. Fifteen adults representing diverse fitness levels were recruited. Participants with/without exercise habits were defined as trained/untrained, respectively. Constant-load testing for 30 min at 110%, 115%, 120%, and 125% of sLT intensity was performed to determine MLSS. The tissue oxygenation index (TOI) of the thigh was also monitored. MLSS was not fully estimated from sLT, with 110%, 115%, 120%, and 125% of sLT in one, four, three, and seven participants, respectively. The MLSS based on sLT was higher in the trained group as compared to the untrained group. A total of 80% of trained participants had an MLSS of 120% or higher, while 75% of untrained participants had an MLSS of 115% or lower based on sLT. Furthermore, compared to untrained participants, trained participants continued constant-load exercise even if their TOI decreased below the resting baseline (P < 0.01). MLSS was successfully estimated using sLT, with 120% or more in trained participants and 115% or less in untrained participants. This suggests that trained individuals can continue exercising despite decreases in oxygen saturation in lower extremity skeletal muscles.

Implications of the Onset of Sweating on the Sweat Lactate Threshold

The relationship between the onset of sweating (OS) and sweat lactate threshold (sLT) assessed using a novel sweat lactate sensor remains unclear. We aimed to investigate the implications of the OS on the sLT. Forty healthy men performed an incremental cycling test. We monitored the sweat lactate, blood lactate, and local sweating rates to determine the sLT, blood LT (bLT), and OS. We defined participants with the OS during the warm-up just before the incremental test as the early perspiration (EP) group and the others as the regular perspiration (RP) group. Pearson's correlation coefficient analysis revealed that the OS was poorly correlated with the sLT, particularly in the EP group (EP group, r = 0.12; RP group, r = 0.56). Conversely, even in the EP group, the sLT was strongly correlated with the bLT (r = 0.74); this was also the case in the RP group (r = 0.61). Bland-Altman plots showed no bias between the mean sLT and bLT (mean difference: 19.3 s). Finally, in five cases with a later OS than bLT, the sLT tended to deviate from the bLT (mean difference, 106.8 s). The sLT is a noninvasive and continuous alternative to the bLT, independent of an early OS, although a late OS may negatively affect the sLT.

Miliary tuberculosis-associated hemophagocytic lymphohistiocytosis with a high level of soluble interleukin-2 receptor successfully treated with concomitant recombinant thrombomodulin: A case report

Hemophagocytic lymphohistiocytosis (HLH) is a fatal disease characterized by a highly inflammatory state due to the abnormal activation of T lymphocytes and macrophages. Miliary tuberculosis (MTB) is a rare cause of HLH and its clinical appearances occasionally resembles that of intravascular lymphoma (IVL). A 76-year-old woman presented with persistent fever and fatigue. Abnormal laboratory findings showing thrombocytopenia (13,000/μL), hypofibrinogenemia (101 mg/dL), hyperferritinemia (2,312 ng/mL), and markedly elevated soluble interleukin-2 receptor (sIL-2R) level (32,200 U/mL), in addition, hemophagocytosis in the bone marrow (BM) smear, were suggestive of IVL-associated HLH. The pathology of the BM biopsy specimen showed granuloma with non-caseous necrosis, and culture tests using sputum, gastric fluid, urine, and peripheral and bone marrow blood revealed the presence of Mycobacterium tuberculosis, leading to the final diagnosis of MTB-associated HLH. Anti-TB medications and corticosteroids were administered, but thrombocytopenia, hypofibrinogenemia, and hyperferritinemia persisted. Concomitant use of recombinant thrombomodulin (rTM) enabled regression of clinical status. In this case, BM biopsy served as the diagnosis of MTB-associated HLH, although IVL-associated HLH is initially suspected by an extremely high level of sIL-2R. Furthermore, this case report informs that using rTM could improve the outcomes of MTB-associated HLH.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Chondrule-like objects and Ca-Al-rich inclusions in Ryugu may potentially be the oldest Solar System materials

Chondrule-like objects and Ca-Al-rich inclusions (CAIs) are discovered in the retuned samples from asteroid Ryugu. Here we report results of oxygen isotope, mineralogical, and compositional analysis of the chondrule-like objects and CAIs. Three chondrule-like objects dominated by Mg-rich olivine are ¹⁶O-rich and -poor with Δ¹⁷O (=δ¹⁷O - 0.52 × δ¹⁸O) values of ~ -23‰ and ~ -3‰, resembling what has been proposed as early generations of chondrules. The ¹⁶O-rich objects are likely to be melted amoeboid olivine aggregates that escaped from incorporation into ¹⁶O-poor chondrule precursor dust. Two CAIs composed of refractory minerals are ¹⁶O-rich with Δ¹⁷O of ~ -23‰ and possibly as old as the oldest CAIs. The discovered objects (<30 µm) are as small as those from comets, suggesting radial transport favoring smaller objects from the inner solar nebula to the formation location of the Ryugu original parent body, which is farther from the Sun and scarce in chondrules. The transported objects may have been mostly destroyed during aqueous alteration in the Ryugu parent body.

Constant Load Pedaling Exercise Combined with Electrical Muscle Stimulation Leads to an Early Increase in Sweat Lactate Levels

A novel exercise modality combined with electrical muscle stimulation (EMS) has been reported to increase cardiovascular and metabolic responses, such as blood lactate concentration. We aimed to examine the effect of constant load pedaling exercise, combined with EMS, by non-invasively and continuously measuring sweat lactate levels. A total of 22 healthy young men (20.7 ± 0.8 years) performed a constant load pedaling exercise for 20 min at 125% of the pre-measured ventilatory work threshold with (EMS condition) and without (control condition) EMS stimulation. Blood lactate concentration was measured by blood samples obtained from the earlobe every minute. Sweat lactate was monitored in real time using a sensor placed on the forearm. The sweat lactate threshold (sLT) was defined as the point of increase in sweat lactate. sLT occurred significantly earlier in the EMS condition than in the control condition. In the single regression analysis, the difference in sLT between the two conditions, as the independent variable, was a significant predictor of the difference in blood lactate concentrations at the end of the exercise (p < 0.05, r = −0.52). Sweat lactate measurement may be a noninvasive and simple alternative to blood lactate measurement to determine the effectiveness of exercise combined with EMS.

Rare earth element identification and quantification in millimetre-sized Ryugu rock fragments from the Hayabusa2 space mission

Millimetre-sized primordial rock fragments originating from asteroid Ryugu were investigated using high energy X-ray fluorescence spectroscopy, providing 2D and 3D elemental distribution and quantitative composition information on the microscopic level. Samples were collected in two phases from two sites on asteroid Ryugu and safely returned to Earth by JAXA's asteroid explorer Hayabusa2, during which time the collected material was stored and maintained free from terrestrial influences, including exposure to Earth's atmosphere. Several grains of interest were identified and further characterised to obtain quantitative information on the rare earth element (REE) content within said grains, following a reference-based and computed-tomography-assisted fundamental parameters quantification approach. Several orders of magnitude REE enrichments compared to the mean CI chondrite composition were found within grains that could be identified as apatite phase. Small enrichment of LREE was found for dolomite grains and slight enrichment or depletion for the general matrices within the Ryugu rock fragments A0055 and C0076, respectively.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s40623-022-01705-3.

Realtime Monitoring of Local Sweat Rate Kinetics during Constant-Load Exercise Using Perspiration-Meter with Airflow Compensation System

Epidermal wearable sweat biomarker sensing technologies are likely affected by sweat rate because of the dilution effect and limited measurement methods. However, there is a dearth of reports on the local sweat rate (LSR) monitored in real-time during exercise. This explorative study investigated the feasibility of real-time LSR monitoring and clarified LSR kinetics on the forehead and upper arm during constant-load exercise using a perspiration meter with an airflow compensation system. This observational cross-sectional study included 18 recreationally trained males (mean age, 20.6 ± 0.8 years). LSR on the forehead and upper arm (mg/cm²/min) were measured during a constant-load exercise test at 25% of their pre-evaluated peak power until exhaustion. The LSR kinetics had two inflection points, with a gradual decrease in the incremental slope for each section. After the second flexion point, the LSR slope slightly decreased and was maintained until exhaustion. However, the degree of change varied among the participants. Although the ratio of forehead LSR to upper arm LSR tended to decrease gradually over time, there was little change in this ratio after a second flexion point of LSR in both. These findings suggest possible differences in LSR control between the forehead and upper arm during constant-load exercise to prolonged exhaustion.

Effects of alternating heat and cold stimulation at different cooling rates using a wearable thermo device on shoulder muscle stiffness: a cross-over study

Background

A small, wearable thermo device that uses Peltier elements for programmed heat and cold stimulation has been developed recently and is expected to be applied in conventional contrast bath therapy. This study was aimed to examine improvements in trapezius muscle hardness and subjective symptoms resulting from alternating heat and cold stimulation, with different rates of cooling.

Methods

This cross-over study included four conditions. Twenty healthy young male individuals (age, 22.3 ± 4.5 years) participated in this study. These four interventions targeted the unilateral trapezius muscle of the dominant arm after a 15-min typing task. Specifically, heat and cold stimulations were applied at different ratios (the heating/cooling rate of 3:1, 3:2, and 3:3) or not applied. Each intervention was separated by at least one week. Skin temperature at the stimulation area was recorded using a data logger. Outcome measures included muscle hardness (measured using a portable tester) and subjective symptoms (muscle stiffness and fatigue). Each item was assessed at three time points: baseline, after typing, and after the intervention.

Results

Two-way analysis of variance with repeated measures found an interaction effect for muscle hardness between four conditions (3:1, 3:2, 3:3, and no) and three time points (p < 0.05). Only in the 3:1 condition were the post-intervention values lower than those after typing (p < 0.01). There was also an interaction effect for subjective muscle stiffness (p < 0.05); the values after the intervention in the 3:1 condition were lower than those after intervention in the no stimulation condition (p < 0.01). There was no significant relationship between changes in muscle hardness and changes in subjective symptoms in the 3:1 condition.

Conclusions

Our results demonstrate that alternating heat and cold stimulations with a different cooling rate could affect the degree of improvement in muscle hardness and subjective symptoms. In particular, the 3:1 condition has the possibility to improved muscle hardness within the condition and subjective muscle stiffness between conditions.

Trial registration

UMIN000040620. Registered 1 June 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046359

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05623-z.

Sweep Pulse Excitation Method for Enhancing Photoacoustic Elastic Waves at Different Laser Irradiation Parameters

Laser remote sensing using a sweep pulse excitation method, in which a laser beam is irradiated at the same repetition frequency as the natural frequency, for enhancing photoacoustic elastic waves through resonance effect has been studied. The sweep pulse excitation method, which is based on the principle of detecting natural frequency fluctuations, such as hammering tests, can detect natural frequencies in the audible sound region with low average laser power and contribute to the convenience and low cost of an installation strength diagnosis of fastening bolts. In this study, we investigated the dynamics of the swept excitation method for optimization by evaluating the dependence of the laser irradiation conditions (pulse width, spot size, and average power) on different metal disc samples. We discovered that the magnitude of the photoacoustic elastic wave is proportional to the absorption of laser power, and the spatiotemporal dynamics can be explained through thermal diffusion phenomena. These findings contribute to the development of laser-sensing technology based on photoacoustic elastic waves.

Effects of alternating heat and cold stimulation using a wearable thermo-device on subjective and objective shoulder stiffness

BACKGROUND

Technological innovations have allowed the use of miniature apparatus that can easily control and program heat and cold stimulations using Peltier elements. The wearable thermo-device has a potential to be applied to conventional contrast bath therapy. This study aimed to examine the effects of alternating heat and cold stimulation (HC) using a wearable thermo-device on subjective and objective improvement of shoulder stiffness.

METHODS

Twenty healthy young male individuals (20.3 ± 0.6 years) participated in this study. The interventions were randomly conducted under four conditions, including HC, heat stimulation, cold stimulation, and no stimulation on their bilateral trapezius muscle, after a 30-min typing task. Each intervention was administered at least 1 week apart. The analyzed limb was the dominant arm. Muscle hardness was assessed using a portable muscle hardness meter, as well as the skin temperature over the stimulated area. After each condition, the participants were asked for feedback regarding subjective improvement in refreshed feelings, muscle stiffness, and muscle fatigue using an 11-point numerical rating scale.

RESULTS

With regard to muscle hardness, only the HC condition significantly decreased from 1.43 N to 1.37 N (d = 0.44, p < 0.05). Additionally, reduced muscle hardness in HC condition was associated with the degree of skin cooling during the intervention (cold max: r = 0.634, p < 0.01; cold change: r = -0.548, p < 0.05). Subjective improvement in refreshed feelings, muscle stiffness, and muscle fatigue was determined in the HC and heat stimulation conditions compared with the no stimulation condition (p < 0.01 and p < 0.05, respectively). Moreover, the HC condition showed significantly greater improvements in muscle stiffness and fatigue compared to the cold stimulation condition (p < 0.05).

CONCLUSIONS

The current study demonstrated that HC promoted not only better subjective symptoms, such as muscle stiffness and fatigue, but also lesser muscle hardness. Furthermore, an association was observed between the degree of skin temperature cooling and reduced muscle hardness during HC. Further investigations on the ratio and intensity of cooling should be conducted in the future to establish the optimal HC protocol for muscle stiffness or fatigue.

TRIAL REGISTRATION

UMIN000040620 . Registered 1 June 2020.

Kinetic changes in sweat lactate following fatigue during constant workload exercise

It is useful to investigate various physiological responses induced by fatigue in athletes. Moreover, wearable noninvasive sensors, including sweat sensors, are compatible with fatigue evaluation because of their ease of use, and ability to measure repeatedly and continual data. This cross-sectional study aimed to clarify how sweat lactate elimination curves obtained during constant workload exercise changed following fatigue. Seventeen recreationally trained males (average age, 20.6 ± 0.8 years) completed two consecutive constant workload exercise tests (at 25% peak power) with rest intervals; the participants were encouraged to perform Test 1 until exhaustion and Test 2 only for 10 min. Subjective fatigue (numerical rating scale with face rating scale), sweat lactate, and sweat rate were measured for 10 min in each test. Subjective fatigue was compared using the Wilcoxon signed-rank test and time to each constant value between Tests 1 and 2 was compared using paired t-test. Subjective fatigue significantly increased during Test 2 compared with that during Test 1. After Test 1, the sweat lactate elimination curve demonstrated a leftward shift, as proved by the significantly sooner observation of the peak and constant values of sweat lactate (2, 3, and 4 μA) (p < 0.01). Our preliminary results suggest that the sweat lactate elimination curve is different in the fatigue state. Further research may provide insight in the application of this curve to the evaluation for fatigue.

Machine Learning-Based Diagnosis in Laser Resonance Frequency Analysis for Implant Stability of Orthopedic Pedicle Screws

Evaluation of the initial stability of implants is essential to reduce the number of implant failures of pedicle screws after orthopedic surgeries. Laser resonance frequency analysis (L-RFA) has been recently proposed as a viable diagnostic scheme in this regard. In a previous study, L-RFA was used to demonstrate the diagnosis of implant stability of monoaxial screws with a fixed head. However, polyaxial screws with movable heads are also frequently used in practice. In this paper, we clarify the characteristics of the laser-induced vibrational spectra of polyaxial screws which are required for making L-RFA diagnoses of implant stability. In addition, a novel analysis scheme of a vibrational spectrum using L-RFA based on machine learning is demonstrated and proposed. The proposed machine learning-based diagnosis method demonstrates a highly accurate prediction of implant stability (peak torque) for polyaxial pedicle screws. This achievement will contribute an important analytical method for implant stability diagnosis using L-RFA for implants with moving parts and shapes used in various clinical situations.

Laser resonance frequency analysis of pedicle screw stability: A cadaveric model bone study

There is no evaluation method currently available to assess intraoperative pedicle screw fixation (PSF) strength. In this study, we established a laser-based resonance frequency analysis (RFA) system with high-speed, noncontact, quantitative measurements of PSF. Clinical investigations in the future can assess surgical failure risk of implants. We investigated the characteristics of the laser RFA and compared them with the conventional methods. We inserted a pedicle screw in the vertebral pedicle of human cadaver or model bone, followed by screw pull-out, peak torque, implant stability quotient (ISQ) value obtained by the magnetic dental RFA system, and fixation force of laser RFA. We compared the outcomes using best-fit linear or logarithmic approximations. For the model bone study, the resonance frequency (RF) versus peak torque/pull-out force (POF) demonstrated strong correlations using logarithmic approximation (vs. peak torque: R = 0.931, p < .001, vs. POF: R = 0.931, p < .001). RF strongly correlated with the ISQ value using linear approximation (R = 0.981, p < .001). For the cadaveric vertebrae study, the correlation coefficients between RF and the peak torque/POF were significant regardless of approximation method (peak torque: logarithmic: R = 0.716 vs. linear: R = 0.811; p < .001) (POF: logarithmic: R = 0.644 vs. linear: R = 0.548; p < .05). Thus, the results of this study revealed a constant correlation between RFA and conventional methods as a measurement validation, predicting favorable support for intraoperative PSF. RFA has the potential to be a new index for evaluating the implant fixation force.

Attack Interval Is the Key to the Likely Pathogenesis of Multiple Transient Ischemic Attacks

INTRODUCTION

The aim of this study was to test the hypothesis that the attack interval of multiple transient ischemic attacks (TIAs) is correlated with the underlying pathogenesis of ischemia.

METHODS

Patients with multiple TIAs, defined as 2 or more motor deficits within 7 days, were studied. The attack interval between the last 2 episodes was classified into 3 groups: 2 episodes within an hour (Hour group), over hours within a day (Day group), and over days within a week (Week group). Patients with a lacunar syndrome, no cortical lesions, and no embolic sources were recognized as having a small vessel disease (SVD) etiology for their multiple events.

RESULTS

Of 312 TIA patients admitted over a 9-year period, 50 (37 males, 13 females, mean 67.6 years) had multiple TIAs. Twelve patients were classified as being within the Hour group, 23 within the Day group, and 15 within the Week group. Lacunar syndromes were observed in 30 (75%, 35%, and 67%), embolic sources were detected in 28 (25%, 65%, and 67%), and a high signal lesion on diffusion-weighted imaging was depicted in 30 (75%, 48%, and 67%) patients (18 cortical, 11 subcortical, and one cerebellar). Patients in the Hour group had a significantly higher prevalence of SVD etiology (75%) than those in the Day and Week groups (30%, p = 0.0165; 27%, p = 0.0213, respectively). Four patients had a subsequent stroke within 7 days.

CONCLUSION

Attack intervals of multiple TIAs may be correlated with the underlying pathogenesis of ischemia. Two motor deficits within an hour are more likely to suggest a SVD etiology.

Ultrasonography-detected synovitis of hand is associated with the presence of synovitis in the forefoot of patients with rheumatoid arthritis

BACKGROUND

In rheumatoid arthritis, forefoot disease activity can lead to joint damage, pain, and disability during weight-bearing activities; therefore, the evaluation and control of forefoot disease activity is important. We aimed to investigate an association between the prevalence of abnormalities in the forefoot based on ultrasonography (US) and the clinical and US findings related to arthritis and identify factors related to the presence of synovitis in the forefoot of RA patients.

METHODS

In total, 810 metatarsophalangeal joints of 81 rheumatoid arthritis patients were examined using US. Patients were assigned to either a forefoot synovitis group (n = 22), with foot synovitis detected using US, or a non-forefoot synovitis group (n = 59). We assessed associations between clinical parameters and US finding of the hand and US finding of the metatarsophalangeal joints.

RESULTS

The following were significantly higher in forefoot synovitis group than in non-forefoot synovitis group: swollen joint count [P < 0.001]; Disease Activity Score 28 based on C-reactive protein [P < 0.05]; clinical disease activity index [P < 0.001]; and total Power Doppler score of the hand [P < 0.001]. Receiver-operating characteristic analysis for total Power Doppler scores of the hand to suggest the presence of synovitis in the metatarsophalangeal joints showed that a total Power Doppler score of the hand of ≥5 was associated with synovitis in the metatarsophalangeal joints, with a sensitivity of 68% and a specificity of 85% (odds ratio = 11.9).

CONCLUSION

Total Power Doppler scores of the hand had a good valuable score for suggesting the presence of synovitis in metatarsophalangeal joints of rheumatoid arthritis patients.

Preemptive analgesia for endoscopic sinus surgery: a retrospective study

BACKGROUND

Chronic rhinosinusitis (CRS) is a common disease, and endoscopic sinus surgery (ESS) is widely performed. However, there is no consensus regarding postoperative pain control after ESS, and postoperative opioid abuse is a problem in many countries. Acetaminophen is reportedly effective for postoperative pain control. Preemptive analgesia has received more attention lately, wherein pain is prevented before it occurs. In this study, we assessed the use of acetaminophen for preemptive analgesia during the perioperative period in ESS.

METHODOLOGY

This is a retrospective study of 175 patients who underwent ESS, septoplasty, and bilateral inferior turbinate mucosal resection at our hospital from April 2016 to February 2018. In total, 82 patients received 1,000 mg of acetaminophen during surgery and 4 hours after the first dose, while 93 patients did not receive it routinely. We compared these two groups. The primary outcome was the need to use additional analgesics prescribed by the ward physician and the secondary outcomes included postoperative pain, postoperative bleeding, reoperation, blood pressure, and body temperature.

RESULTS

The use of additional oral and intravenous analgesics was significantly reduced in the patients who received acetaminophen perioperatively.

CONCLUSION

Preemptive analgesia during the perioperative period of ESS could lead to satisfactory postoperative pain control.

Development of a standardized histopathology scoring system for intervertebral disc degeneration in rat models: An initiative of the ORS spine section

BACKGROUND

Rats are a widely accepted preclinical model for evaluating intervertebral disc (IVD) degeneration and regeneration. IVD morphology is commonly assessed using histology, which forms the foundation for quantifying the state of IVD degeneration. IVD degeneration severity is evaluated using different grading systems that focus on distinct degenerative features. A standard grading system would facilitate more accurate comparison across laboratories and more robust comparisons of different models and interventions.

AIMS

This study aimed to develop a histology grading system to quantify IVD degeneration for different rat models.

MATERIALS & METHODS

This study involved a literature review, a survey of experts in the field, and a validation study using 25 slides that were scored by 15 graders from different international institutes to determine inter- and intra-rater reliability.

RESULTS

A new IVD degeneration grading system was established and it consists of eight significant degenerative features, including nucleus pulposus (NP) shape, NP area, NP cell number, NP cell morphology, annulus fibrosus (AF) lamellar organization, AF tears/fissures/disruptions, NP-AF border appearance, as well as endplate disruptions/microfractures and osteophyte/ossification. The validation study indicated this system was easily adopted, and able to discern different severities of degenerative changes from different rat IVD degeneration models with high reproducibility for both experienced and inexperienced graders. In addition, a widely-accepted protocol for histological preparation of rat IVD samples based on the survey findings include paraffin embedding, sagittal orientation, section thickness < 10 μm, and staining using H&E and/or SO/FG to facilitate comparison across laboratories.

CONCLUSION

The proposed histological preparation protocol and grading system provide a platform for more precise comparisons and more robust evaluation of rat IVD degeneration models and interventions across laboratories.

Evaluation of various confirmatory tests for the diagnosis of aldosterone-producing adenoma

Introduction:

Adrenal venous sampling is useful for discriminating unilateral and bilateral hypersecretion in patients with primary aldosteronism, but it is relatively invasive. To determine the site of hypersecretion more non-invasively, we evaluated predictors of unilateral hypersecretion.

Materials and methods:

We evaluated the baseline characteristics and the results of confirmatory tests of 123 patients with primary aldosteronism who underwent adrenal venous sampling.

Results:

Unilateral hypersecretion was identified in 22.0%. The plasma aldosterone concentration and aldosterone–renin ratio were significantly higher and serum potassium concentration and plasma renin activity were significantly lower in patients with unilateral hypersecretion. Plasma aldosterone concentrations after captopril challenge test, saline infusion test and rapid adrenocorticotropic hormone stimulation test were significantly higher among patients with unilateral hypersecretion. The plasma aldosterone concentration reduction ratio in saline infusion test and plasma aldosterone concentration elevation ratio during rapid adrenocorticotropic hormone stimulation test were significantly higher in patients with unilateral hypersecretion. However, areas under the curve for these parameters were not superior to the values after confirmatory tests.

Conclusions:

The plasma aldosterone concentration values after captopril challenge test, saline infusion test and rapid adrenocorticotropic hormone stimulation test were useful for identifying patients with unilateral hypersecretion. However, value changes or ratios during confirmatory tests are less useful for this aim.

Observation of Coulomb-Assisted Nuclear Bound State of Ξ^{-}-^{14}N System

In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}N→_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21  MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.

Laminar flow ventilation system to prevent airborne infection during exercise in the COVID-19 crisis: A single-center observational study

Particulate generation occurs during exercise-induced exhalation, and research on this topic is scarce. Moreover, infection-control measures are inadequately implemented to avoid particulate generation. A laminar airflow ventilation system (LFVS) was developed to remove respiratory droplets released during treadmill exercise. This study aimed to investigate the relationship between the number of aerosols during training on a treadmill and exercise intensity and to elucidate the effect of the LFVS on aerosol removal during anaerobic exercise. In this single-center observational study, the exercise tests were performed on a treadmill at Running Science Lab in Japan on 20 healthy subjects (age: 29±12 years, men: 80%). The subjects had a broad spectrum of aerobic capacities and fitness levels, including athletes, and had no comorbidities. All of them received no medication. The exercise intensity was increased by 1-km/h increments until the heart rate reached 85% of the expected maximum rate and then maintained for 10 min. The first 10 subjects were analyzed to examine whether exercise increased the concentration of airborne particulates in the exhaled air. For the remaining 10 subjects, the LFVS was activated during constant-load exercise to compare the number of respiratory droplets before and after LFVS use. During exercise, a steady amount of particulates before the lactate threshold (LT) was followed by a significant and gradual increase in respiratory droplets after the LT, particularly during anaerobic exercise. Furthermore, respiratory droplets ≥0.3 μm significantly decreased after using LFVS (2120800±759700 vs. 560 ± 170, p<0.001). The amount of respiratory droplets significantly increased after LT. The LFVS enabled a significant decrease in respiratory droplets during anaerobic exercise in healthy subjects. This study's findings will aid in exercising safely during this pandemic.

Detecting Mild Lower-limb Skeletal Muscle Fatigue with Stimulated-echo q-space Imaging

The feasibility of detecting mild exercise-related muscle fatigue via stimulated echo (STE) and q-space imaging (qsi) was evaluated. The right calves of seven healthy volunteers were subjected to mild exercise loading, and qsi was generated using spin echo (Δ: 45.6 ms) and three different STE (Δ: 114, 214, and 414 ms) acquisitions. We concluded that qsi with an increased STE diffusion time can detect mild fatigue in the gastrocnemius muscle.

Comparison of bacterial culture results of preoperative synovial fluid and intraoperative specimens in patients with joint infection

OBJECTIVES

The details of relationship between bacterial culture results of preoperative and intraoperative specimens in same patients with native joint septic arthritis (NJSA) and periprosthetic joint infection (PJI) are unknown. This study aims to reveal the difference of culture results of preoperative synovial fluid and intraoperative specimens and evaluate the risk factors for detecting different species intraoperatively from preoperative synovial fluid.

METHODS

This study included 55 joints diagnosed with 16 NJSA and 39 PJI. Bacterial culture positive rates and identified bacterial species were compared between preoperative synovial fluid and intraoperative tissue/synovial fluid. We also examined the presence or absence of sinus tracts and antimicrobial agents as risk factors in patients with different bacterial species in intraoperative specimens from preoperative synovial fluid.

RESULTS

The culture positive rates were not significantly different between preoperative synovial fluid and intraoperative specimens. Different bacterium were detected in 10.9% joints by intraoperative tissue and 14.6% joints by intraoperative synovial fluid. The positive rate of sinus tract was significantly higher in patients with different bacterial species (62.5%) than without different bacterial species (12.8%, p < 0.01). Conversely, antimicrobial agent was not significantly difference.

CONCLUSION

This study demonstrated that different bacterium from preoperative culture results were detected in 10-15% joints by intraoperative specimens in NJSA and PJI. The sinus tract was a risk factor for identifying different bacterial species in the intraoperative specimens. Therefore, in cases of sinus tract, it is necessary to examine multiple specimens of both intraoperative tissue and synovial fluid for increasing the detection rate.

Endoscopic third ventriculostomy for myelomeningocele-related hydrocephalus after shunt failure: Long-term outcome in a series of 8 patients

OBJECTIVE

Endoscopic third ventriculostomy (ETV) has now become an accepted mode of hydrocephalus treatment. However, the long-term effects of ETV for myelomeningocele-related hydrocephalus (MMC-rH) after shunt malfunction remains unclear. We aimed to assess the long-term outcome and the factors associated with the success of ETV for MMC-rH after shunt malfunction.

METHODS

We performed a retrospective analysis of data collected between 2001 and 2018 from 8 patients with MMC-rH after shunt malfunction, who underwent ETV at the Kurume University Hospital and were followed up for at least 5 years. We extracted data regarding age, sex, clinical symptoms, radiological imaging, intraoperative findings, and outcomes.

RESULTS

The overall success rate was 62.5% and their ETV success score is 67.5. The most frequent clinical symptom was intracranial hypertension symptoms (100 %), followed by Chiari type II symptoms (87.5 %). In preoperative MRI scans, we observed aqueduct stenosis in 6 cases, Chiari type II malformations in 7 cases, four patients had a narrow prepontine cistern, five patients had an absent septum pellucidum, and three presented with stenosis of the foramen of Monro. All cases in the failure group had the above 5 symptoms. Based on intraoperative findings, a thick third ventricle floor was found in 5 patients. Two patients had a thin hypothalamic adhesion in the third ventricle floor. They had no major complications.

CONCLUSION

ETV for MMC-rH after shunt malfunction is an effective treatment option. However, we recommend that a neurosurgeon with extensive experience in neuroendoscopy perform ETV because MMC patients more often had intraventricular malformations than those with other hydrocephalus diseases.

Synovial fluid presepsin as a novel biomarker for the rapid differential diagnosis of native joint septic arthritis from crystal arthritis

OBJECTIVE

To investigate whether presepsin can be used as a novel biomarker to differentiate between native joint septic arthritis (NJSA) and crystal arthritis (CA).

METHODS

This study included 75 patients diagnosed with either NJSA (n = 21) or CA (n = 54). Presepsin in synovial fluid and blood, C-reactive protein, and procalcitonin were measured and compared between the NJSA and CA groups. Receiver operating characteristic (ROC) curve analyses were performed to differentiate between the two groups.

RESULTS

Synovial fluid and blood presepsin were significantly higher in the NJSA group than in the CA group (p < 0.0001 and p < 0.01, respectively). The area under the ROC curve for synovial fluid presepsin in the NJSA group compared with the CA group was 0.93 (sensitivity 85.7%, specificity 85.2%, positive predictive value 69.2%, negative predictive value 93.9%, positive likelihood ratio 5.79, negative likelihood ratio 0.17). Among the tests, synovial fluid presepsin was the most accurate.

CONCLUSIONS

Measurement of synovial fluid presepsin is reliable for the early diagnosis of NJSA, and synovial fluid presepsin could be used as a novel biomarker for differentiating between NJSA and CA.

Relationship between hip joint proximity area and sagittal balance parameters: an upright computed tomography study

PURPOSE

A close relationship between sagittal spinal alignment and hip osteoarthritis (OA) has been documented. This study aimed to examine the relationship between hip joint proximity area and sagittal balance parameters in healthy subjects.

METHODS

This prospective study enrolled 47 healthy volunteers who underwent 320-detector row upright computed tomography. Acquired data were reconstructed in a virtual three-dimensional space. The proximity area was determined by < 1 mm of the Hausdorff distance between the acetabulum and the femoral head. Volunteers were divided into the anterior and posterior proximity groups depending on the position of the closest area. Sagittal balance parameters [sagittal vertical axis (SVA), T1 spinopelvic inclination (T1-SPi), T1-pelvic angle, pelvic tilt, sacral slope, pelvic incidence, lumbar lordosis, thoracic kyphosis), offset distance between the centre of the acoustic meati (CAM) and C7 plumb line (CAM-C7-offset), and offset distance between the CAM and hip axis (HA) (CAM-HA-offset)] were compared between the two groups using independent sample t test.

RESULTS

The anterior proximity group (n = 24) had higher SVA (p = 0.016) and T1-Spi (p = 0.015) than the posterior proximity group (n = 23). CAM-HA-offset was higher in the posterior than in the anterior proximity group (p < 0.000). There was no difference in other parameters (p > 0.05).

CONCLUSION

The anterior proximity group had a positive anterior spinal balance; the posterior proximity group may have a more posterior gravity line than the hip joint centre. The anterior spinal balance may contribute to the anterior loading of the hip joint, with known relation with the initiation and onset of hip OA.

Quantitative analysis of intervertebral disc degeneration using Q-space imaging in a rat model

The degree of intervertebral disc (IVD) degeneration is qualitatively evaluated on T2-weighted imaging (T2WI). However, it is difficult to assess subtle changes in IVD degeneration using T2WI. Q-space imaging (QSI) is a quantitative diffusion-weighted imaging modality used to detect subtle changes in microenvironments. This study aimed to evaluate whether QSI can detect the inhibitory effects of the antioxidant N-acetylcysteine (NAC) in IVD degeneration. We classified female Wistar rats into control, puncture, and NAC groups (n = 5 per group). In the puncture and NAC groups, IVDs were punctured using a needle. The antioxidant NAC, which suppresses the progression of IVD degeneration, was orally administered in the NAC group 1 week prior to puncture. The progression and inhibitory effect of NAC in IVD degeneration were assessed using magnetic resonance imaging (MRI): IVD height, T2 mapping, apparent diffusion coefficient (ADC), and QSI. MRI was performed using a 7-Tesla system with a conventional probe (20 IVDs in each group). QSI parameters that were assessed included Kurtosis, the probability at zero displacement (ZDP), and full width at half maximum (FWHM). IVD degeneration by puncture was confirmed by histology, IVD height, T2 mapping, ADC, and all QSI parameters (P < .001); however, the inhibitory effect of NAC was confirmed only by QSI parameters (Kurtosis and ZDP: both P < .001; FWHM: P < .01). Kurtosis had the largest effect size (Kurtosis: 1.13, ZDP: 1.06, and FWHM: 1.02) when puncture and NAC groups were compared. QSI has a higher sensitivity than conventional quantitative methods for detecting the progressive change and inhibitory effect of NAC in IVD degeneration.

A randomized, double-blind, placebo-controlled, phase 3 study of tivantinib in Japanese patients with MET-high hepatocellular carcinoma

A previous randomized phase 2 study of hepatocellular carcinoma revealed that the c‐Met inhibitor tivantinib as second‐line treatment significantly prolonged progression‐free survival in a subpopulation whose tumor samples highly expressed c‐Met (MET‐high). Accordingly, this phase 3 study was conducted to evaluate the efficacy of tivantinib as a second‐line treatment for Japanese patients with MET‐high hepatocellular carcinoma. This randomized, double‐blind, placebo‐controlled study was conducted at 60 centers in Japan. Hepatocellular carcinoma patients with one prior sorafenib treatment and those with MET‐high tumor samples were eligible for inclusion. Registered patients were randomly assigned to either the tivantinib or placebo group at a 2:1 ratio and were treated with twice‐a‐day oral tivantinib (120 mg bid) or placebo until the discontinuation criteria were met. The primary endpoint was progression‐free survival while the secondary endpoints included overall survival and safety. Between January 2014 and June 2016, 386 patients provided consent, and 195 patients were randomized to the tivantinib (n = 134) or placebo (n = 61) group. Median progression‐free survival was 2.8 (95% confidence interval: 2.7‐2.9) and 2.3 (1.5‐2.8) mo in the tivantinib and placebo groups, respectively (hazard ratio = 0.74, 95% confidence interval: 0.52‐1.04, P = .082). Median overall survival was 10.3 (95% confidence interval: 8.1‐11.6) and 8.5 (6.2‐11.4) mo in the tivantinib and placebo group, respectively (hazard ratio = 0.82, 95% confidence interval: 0.58‐1.15). The most common tivantinib‐related grade ≥3 adverse events were neutropenia (31.6%), leukocytopenia (24.8%), and anemia (12.0%). This study did not confirm the significant efficacy of tivantinib as a second‐line treatment for Japanese patients with MET‐high hepatocellular carcinoma. (NCT02029157).

[Utility of transesophageal echocardiography for etiologic diagnosis of centrum ovale infarcts]

A small centrum ovale infarct in the territory of the white matter medullary artery can be caused not only by embolism but also small-vessel disease. In our study, thorough screening for emboligenic diseases was performed, including the modality of transesophageal echocardiography (TEE), in patients with an acute, isolated, small (less than 1.5 cm) infarct in the centrum ovale. Of 79 patients enrolled in this study, 45 had emboligenic diseases, in whom a patent foramen ovale was detected in 29 patients, complicated aortic arch lesion in 15, atrial fibrillation in 6, occlusive carotid disease in 2, and others in 2. The majority (80%) of the emboligenic diseases were diagnosed by TEE. Therefore, TEE may be mandatory for the etiologic diagnosis of centrum ovale infarcts.

Changes in the global spine alignment in the sitting position in an automobile

BACKGROUND CONTEXT

Studies of the changes in spine alignment in the sitting position have been limited to specific spine segments. Because there have been few studies of global spinopelvic alignment in the sitting position, it is important to assess the changes associated with this position for such settings as developing future design of seats and achieving appropriate restoration of spine alignment.

PURPOSE

This study aimed to measure changes in global spine alignment when people are sitting in car seats and to analyze the characteristics of those changes.

STUDY DESIGN

This was a prospective, collaborative study of the radiological evaluation of changes in global spine alignment.

PATIENT SAMPLE

The study included 113 asymptomatic adult participants (56 men and 57 women) without a history of spine disease or lower limb surgery, and with no current lower back or leg pain.

OUTCOME MEASURES

Radiographic findings were assessed by measurement of various angles: cervical lordosis (CL), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), C7 sagittal vertical axis (C7-SVA), T1 spinopelvic inclination (T1SPI), and T1 pelvic angle (TPA).

METHODS

Radiographs were obtained in the standing and sitting positions. The objective variables analyzed statistically were spine alignments (CL, TK, TLK, LL, C7-SVA, T1SPI, TPA, SS, PT, and PI) measured in the standing position, body alignments (CL, TK, TLK, LL, C7-SVA, T1SPI, TPA, SS, and PT) measured in the sitting position, and stand-to-sit changes (∆CL, ∆TK, ∆TLK, ∆LL, ∆C7-SVA, ∆T1SPI, ∆TPA, ∆SS, and ∆PT). Explanatory variables were sex, age, body height, and body mass index.

RESULTS

Changing posture from standing to sitting decreased CL by an average of 5.3°, slightly decreased TK by an average of 1.3°, increased TLK by an average of 6.8°, decreased LL by an average of 35°, decreased SS by an average of 49.2°, increased PT by an average of 49.2°, shifted C7-SVA backward by an average of 106.7 mm, decreased T1SPI by an average of 18.8°, and increased TPA by an average of 21.1°. Statistical analysis revealed that ΔLL was significantly decreased in elderly participants. After the stand-to-sit change, ΔTLK and ∆TPA were significantly increased in taller participants and ΔT1SPI was significantly decreased in taller participants.

CONCLUSIONS

Among other changes, most notably LL is decreased and the pelvic tilt is increased when a person is sitting in a car seat. However, these changes in spine alignment differ with age and height. These findings may be useful for the development of future design of seats and for achieving appropriate surgical restoration of spine alignment.

[Recurrent cerebral embolism due to the disseminated carcinomatosis of bone marrow with early gastric cancer]

A 67-year-old woman who had undergone laparoscopic proximal gastrectomy for early gastric cancer 10 months previously was admitted to our hospital due to dysarthria. Brain MRI demonstrated acute multiple small infarcts in the right middle cerebral artery (MCA) and the right posterior inferior cerebellar artery (PICA) territory, and she was diagnosed as embolic stroke. Anticoagulant therapy did not prevent further ischemic stroke. No embolic sources were detected by MR angiography, carotid duplex sonography, transthoracic and transesophageal echocardiography, and Holter electrocardiography. We also performed upper gastrointestinal endoscopy and contrast-enhanced CT of the thoracoabdominal area, but there was no evidence of local recurrence or lymph node metastases of gastric cancer. As the ALP and D-dimer levels were gradually increasing, we performed PET/CT, which revealed fluorodeoxyglucose (FDG) uptake in the vertebra bone, and disseminated carcinomatosis of bone marrow with early gastric cancer was diagnosed after bone marrow biopsy on Day 41. After undergoing chemotherapy, she had no further stroke and died on Day 207.

Extended chondrule formation intervals in distinct physicochemical environments: Evidence from Al-Mg isotope systematics of CR chondrite chondrules with unaltered plagioclase

Al-Mg isotope systematics of twelve FeO-poor (type I) chondrules from CR chondrites Queen Alexandra Range 99177 and Meteorite Hills 00426 were investigated by secondary ion mass spectrometry (SIMS). Five chondrules with Mg#'s of 99.0 to 99.2 and Δ¹⁷O of -4.2‰ to -5.3‰ have resolvable excess ²⁶Mg. Their inferred (²⁶Al/²⁷Al)₀ values range from (3.5 ± 1.3) × 10^‒6 to (6.0 ± 3.9) × 10^‒6. This corresponds to formation times of 2.2 (-0.5/+1.1) Myr to 2.8 (‒0.3/+0.5) Myr after CAIs, using a canonical (²⁶Al/²⁷Al)₀ of 5.23 × 10^-5, and assuming homogeneously distributed ²⁶Al that yielded a uniform initial ²⁶Al/²⁷Al in the Solar System. Seven chondrules lack resolvable excess ²⁶Mg. They have lower Mg#'s (94.2 to 98.7) and generally higher Δ¹⁷O (-0.9‰ to -4.9‰) than chondrules with resolvable excess ²⁶Mg. Their inferred (²⁶Al/²⁷Al)₀ upper limits range from 1.3 × 10^‒6 to 3.2 × 10^‒6, corresponding to formation >2.9 to >3.7 Myr after CAIs. Al-Mg isochrons depend critically on chondrule plagioclase, and several characteristics indicate the chondrule plagioclase is unaltered: (1) SIMS ²⁷Al/²⁴Mg depth profile patterns match those from anorthite standards, and SEM/EDS of chondrule SIMS pits show no foreign inclusions; (2) transmission electron microscopy (TEM) reveals no nanometer-scale micro-inclusions and no alteration due to thermal metamorphism; (3) oxygen isotopes of chondrule plagioclase match those of coexisting olivine and pyroxene, indicating a low extent of thermal metamorphism; and (4) electron microprobe data show chondrule plagioclase is anorthite-rich, with excess structural silica and high MgO, consistent with such plagioclase from other petrologic type 3.00-3.05 chondrites. We conclude that the resolvable (²⁶Al/²⁷Al)₀ variabilities among chondrules studied are robust, corresponding to a formation interval of at least 1.1 Myr. Using relationships between chondrule (²⁶Al/²⁷Al)₀, Mg#, and Δ¹⁷O, we interpret spatial and temporal features of dust, gas, and H₂O ice in the FeO-poor chondrule-forming environment. Mg# ≥ 99, Δ¹⁷O ~-5‰ chondrules with resolvable excess ²⁶Mg initially formed in an environment that was relatively anhydrous, with a dust-to-gas ratio of ~100×. After these chondrules formed, we interpret a later influx of ¹⁶O-poor H₂O ice into the environment, and that dust-to-gas ratios expanded (100× to 300×). This led to the later formation of more oxidized Mg# 94-99 chondrules with higher Δ¹⁷O (-5‰ to -1‰), with low (²⁶Al/²⁷Al)₀, and hence no resolvable excess ²⁶Mg. We refine the mean CR chondrite chondrule formation age via mass balance, by considering that Mg# ≥ 99 chondrules generally have resolved positive (²⁶Al/²⁷Al)₀ and that Mg# < 99 chondrules generally have no resolvable excess ²⁶Mg, implying lower (²⁶Al/²⁷Al)₀. We obtain a mean chondrule formation age of 3.8 ± 0.3 Myr after CAIs, which is consistent with Pb-Pb and Hf-W model ages of CR chondrite chondrule aggregates. Overall, this suggests most CR chondrite chondrules formed immediately before parent body accretion.

Clinical outcomes and prognostic factors for cavernous hemangiomas of the spinal cord: a retrospective cohort study

OBJECTIVE

Intramedullary cavernous hemangioma (CH) is a rare vascular lesion that is mainly characterized by the sudden onset of hemorrhage in young, asymptomatic patients, who then experience serious neurological deterioration. Despite the severity of this condition, the therapeutic approach and timing of intervention for CH remain matters of debate. The aim of this study was to evaluate the clinical characteristics of CH patients before and after surgery and to identify prognostic indicators that affect neurological function in these patients.

METHODS

This single-center retrospective study included 66 patients who were treated for intramedullary CH. Among them, 57 underwent surgery and 9 patients received conservative treatment. The authors collected demographic, symptomology, imaging, neurological, and surgical data. Univariate and multivariate logistic regression analyses were performed to identify the prognostic indicators for neurological function.

RESULTS

When comparing patients with stable and unstable gait prior to surgery, patients with unstable gait had a higher frequency of hemorrhagic episodes (52.4% vs 19.4%, p = 0.010), as assessed by the modified McCormick Scale. The lesion was significantly smaller in patients who underwent conservative treatment compared with surgery (2.5 ± 1.5 mm vs 5.9 ± 4.1 mm, respectively; p = 0.024). Overall, the patients experienced significant neurological recovery after surgery, but a worse preoperative neurological status was identified as an indicator affecting surgical outcomes by multivariate analysis (OR 10.77, 95% CI 2.88–40.36, p < 0.001). In addition, a larger lesion size was significantly associated with poor functional recovery in patients who had an unstable gait prior to surgery (8.6 ± 4.5 mm vs 3.5 ± 1.6 mm, p = 0.011).

CONCLUSIONS

Once a hemorrhage occurs, surgical intervention should be considered to avoid recurrence of the bleeding and further neurological injury. In contrast, if the patients with larger lesion presented with worse preoperative functional status, surgical intervention could have a risk for aggravating the functional deficiencies by damaging the thinning cord parenchyma. Conservative treatment may be selected if the lesion is small, but regular neurological examination by MRI is needed for assessment of a change in lesion size and for detection of functional deterioration.

Quantitative CT-based bone strength parameters for the prediction of novel spinal implant stability using resonance frequency analysis: a cadaveric study involving experimental micro-CT and clinical multislice CT

BACKGROUND

To predict conventional test forces (peak torque and pull-out force) and a new test force (implant stability quotient [ISQ] value of a spinal pedicle screw) from computed tomography (CT) parameters, including micro-architectural parameters, using high-resolution micro-CT and clinical multislice CT (MSCT) in human cadaveric vertebrae.

METHODS

Micro-CT scans before/after screw insertion (n = 68) and MSCT scans before screw insertion (n = 58) of human cadaveric vertebrae were assessed for conventional test forces and ISQ value. Three-dimensional volume position adjustment between pre-insertion micro-CT and MSCT scans and post-insertion scans (micro-CT) was performed to extract the volume of the cancellous bone surrounding the pedicle screw. The following volume bone mineral density and micro-architectural parameters were calculated: bone volume fraction, bone surface density (bone surface/total volume (BS/TV)), trabecular thickness, trabecular separation, trabecular number, structure model index, and number of nodes (branch points) of the cancellous bone network/total volume (NNd/TV) using Spearman's rank correlation coefficient with Bonferroni correction.

RESULTS

Conventional test forces showed the strongest correlation with BS/TV: peak torque, ρ = 0.811, p = 4.96 × 10^-17(micro-CT) and ρ = 0.730, p = 7.87 × 10^-11 (MSCT); pull-out force, ρ = 0.730, p = 1.64 × 10^-12 (micro-CT) and ρ = 0.693, p = 1.64 × 10^-9 (MSCT). ISQ value showed the strongest correlation with NNd/TV: ρ = 0.607, p = 4.01 × 10^-8 (micro-CT) and ρ = 0.515, p = 3.52 × 10^-5 (MSCT).

CONCLUSIONS

Test forces, including the ISQ value, can be predicted using micro-CT and MSCT parameters. This is useful for establishing a preoperative fixation strength evaluation system.

Preclinical and phase I clinical studies of KW-2450, a dual IGF-1R/IR tyrosine kinase inhibitor, in combination with lapatinib and letrozole

Background:

KW-2450 is an oral dual insulin-like growth factor-1 receptor/insulin receptor tyrosine kinase inhibitor. We investigated the in vitro and in vivo preclinical activity of KW-2450 plus lapatinib and letrozole and conducted a phase I trial of the triple-drug combination in one male and 10 postmenopausal female patients with advanced/metastatic hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-positive breast cancer.

Methods:

A series of in vitro and in vivo animal studies was undertaken of KW-2450 in combination with lapatinib and hormonal agents. The phase I trial was conducted to establish the safety, tolerability, and recommended phase II dose (RP2D) of KW-2450 administered in combination with lapatinib and letrozole.

Results:

Preclinical studies showed KW-2450 and lapatinib act synergistically to induce in vitro apoptosis and inhibit growth of HER2-positive MDA-MB-361 and BT-474 breast cancer cell lines. This combined effect was confirmed in vivo using the MDA-MB-361 xenograft model. KW-2450 showed synergistic in vitro growth inhibition with letrozole and 4-hydroxytamoxifen in ER-positive MCF-7 breast cancer cells and MCF-7-Ac1 aromatase-transfected MCF-7 cells. In the phase I study, dose-limiting toxicity (DLT; grade 3 rash and grade 3 hyperglycemia, respectively) occurred in two of three patients at the dose of KW-2450 25 mg/day plus lapatinib 1500 mg/day and letrozole 2.5 mg/day. The RP2D of the triple-drug combination was established as KW-2450 25 mg/day, lapatinib 1250 mg/day, and letrozole 2.5 mg/day with no DLT at this dose level.

Conclusions:

The proposed phase II study of the RP2D for the triple-drug combination did not progress because of anticipated difficulty in patient enrollment and further clinical development of KW-2450 was terminated.

A study on the use of the Osstell apparatus to evaluate pedicle screw stability: An in-vitro study using micro-CT

Pull-out force and insertion torque have not been generally used as intraoperative measures for the evaluation of pedicle screw stability because of their invasiveness. On the other hand, resonance frequency analysis is a non-invasive and repeatable technique that has been clinically used in dentistry to evaluate implant stability e.g. by the Osstell apparatus. In this study, the characteristics of the implant stability quotient (ISQ) value obtained by the Osstell apparatus in the field of spinal surgery were investigated. Biomechanical test materials simulating human bone were used to provide a comparative platform for evaluating each fixation strength measure, including pull-out force, insertion torque, and the ISQ value. To perform pull-out force measurement and to repeat pedicle screw insertion and removal, loosening was artificially created, and its effect was investigated. The grade of loosening was quantified on a micro-CT image after pedicle screw removal. In the comparison of the 3 fixation strength measures, the correlations of the ISQ value with the pull-out force (R² = 0.339 p <0.0001) and the insertion torque (R² = 0.337 p <0.0001) were lower than the correlation between pull-out force and insertion torque (R² = 0.918 p <0.0001). On a micro-CT study, the material volume of the internal threads disappeared after destruction of its integrity due to repeated pedicle screw insertion and removal. Material integrity destruction of the internal threads decreased only the pull-out force and the insertion torque, but it did not affect the ISQ value. The ISQ value only decreased when the material volume of the internal threads disappeared, probably because the ISQ value reflects the resistance against a force in the perpendicular direction of the screw, unlike the conventional measures of fixation strength, such as pull-out force and insertion torque, which reflect axial load.

Finite element analysis of compression fractures at the thoracolumbar junction using models constructed from medical images

Vertebral fractures commonly occur at the thoracolumbar junction. These fractures can be treated with mild residual deformity in many cases, but are reportedly associated with increased risk of secondary vertebral fractures. In the present study, a three-dimensional (3D) whole spine model was constructed using the finite element method to explore the mechanism of development of compression fractures. The 3D model of the whole spine, from the cervical spine to the pelvis, was constructed from computed tomography (CT) images of an adult male. Using a normal spine model and spine models with compression fractures at the T11, T12 or L1 vertebrae, the distribution of strain was analyzed in the vertebrae after load application. The normal spine model demonstrated greater strain around the thoracolumbar junction and the middle thoracic spine, while the compression fracture models indicated focused strain at the fracture site and adjacent vertebrae. Increased load time resulted in the extension of the strain region up to the middle thoracic spine. The present findings, that secondary vertebral fractures commonly occur around the fracture site, and may also affect the thoracic vertebrae, are consistent with previous clinical and experimental results. These results suggest that follow-up examinations of compression fractures at the thoracolumbar junction should include the thoracic spine and adjacent vertebrae. The current data also demonstrate that models created from CT images can be used for various analyses.

Biomechanical analysis of brachial plexus injury: Availability of three-dimensional finite element model of the brachial plexus

Adult brachial plexus injuries frequently lead to significant and permanent physical disabilities. Investigating the mechanism of the injury using biomechanical approaches may lead to further knowledge with regard to preventing brachial plexus injuries. However, there are no reports of biomechanical studies of brachial plexus injuries till date. Therefore, the present study used a complex three-dimensional finite element model (3D-FEM) of the brachial plexus to analyze the mechanism of brachial plexus injury and to assess the validity of the model. A complex 3D-FEM of the spinal column, dura mater, spinal nerve root, brachial plexus, rib bone and cartilage, clavicle, scapula, and humerus were conducted. Stress was applied to the model based on the mechanisms of clinically reported brachial plexus injuries: Retroflexion of the cervical, lateroflexion of the cervical, rotation of the cervical, and abduction of the upper limb. The present study analyzed the distribution and strength of strain applied to the brachial plexus during each motion. When the cervical was retroflexed or lateroflexed, the strain was focused on the C5 nerve root and the upper trunk of the brachial plexus. When the upper limb was abducted, strain was focused on the C7 and C8 nerve roots and the lower trunk of the brachial plexus. The results of brachial plexus injury mechanism corresponded with clinical findings that demonstrated the validity of this model. The results of the present study hypothesized that the model has a future potential for analyzing pathological conditions of brachial plexus injuries and other injuries or diseases, including that of spine and spinal nerve root.