Picosecond Laser-Induced Photothermal Skin Damage Evaluation by Computational Clinical Trial

Background and Objectives

Computational clinical trial (CCT) in the field of laser medicine promotes clinical application of novel laser devices, because this trial carried out based on numerical modeling of laser-tissue interactions and simulation of a series of treatment process. To confirm the feasibility of the computational clinical trial of skin treatment with a novel picosecond laser, this paper presents an evaluation method of the safety.

Study Design/Materials and Methods

In this method, the light propagation and thermal diffusion process after ultrashort light pulse irradiation to a numerical skin model is calculated and the safety based on the photothermal damage is evaluated by computational modeling and simulation. As an example, the safety of a novel picosecond laser device was examined by comparing with several laser devices approved for clinical use.

Results

The ratio of the maximum thermal damage induced by picosecond laser irradiation was 1.2 × 10^-2 % at the epidermis, while that caused by approved laser irradiation was 99 % at the capillary vessels. The numerical simulation demonstrated that less thermal damage was observed compared with the approved devices. The results show the safety simulated by photothermal damage calculation was consistent with the reported clinical trials.

Conclusions

This computational clinical trial shows the feasibility of applying computational clinical trials for the safety evaluation of novel medical laser devices. In contrast to preclinical and clinical tests, the proposed computational method offers regulatory science for appropriately and quickly predicting and evaluating the safety of a novel laser device.

SHAPE ESTIMATION OF BOWTIE FILTERS BASED ON THE LUMINESCENCE FROM POLYETHYLENE TEREPHTHALATE RESIN BY X-RAY IRRADIATION

In this study, we devised a novel method estimating the bowtie filter shapes by imaging luminescence from a polyethylene terephthalate (PET) resin with X-ray irradiation in a computed tomography (CT) scanner. The luminescence distribution of the PET resin corresponding to the thickness of bowtie filter was imaged using a charge-coupled device camera. On the assumption that the material of bowtie filter is aluminium (Al), the shape of bowtie filters was estimated from the correlation between Al attenuation curves and the angular-dependent luminance attenuation profiles according to the thickness of bowtie filters. Dose simulations based on the estimated bowtie filter shapes were performed using head and body PMMA phantoms with 16 and 32 cm in diameter. The simulated values of head and body weighted CT dose index (CTDIw) based on bowtie filter shape by the luminescence imaging method agreed within ~9% with the measured values by a dosemeter.

P932Structural changes in left ventricle after transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) has improved prognosis and quality of life of patients with severe aortic stenosis (AS) who had been considered inoperable or at high risk for surgical aortic valve replacement reflecting their age, frailty, and comorbidities. However, less is known about changes in cardiac geometry after TAVI procedure, and predictors of them.

Purpose

To clarify changes in cardiac geometry after TAVI, and their predictors.

Methods

We retrospectively analyzed patients with severe AS who underwent TAVI in our institute between May 2016 and June 2018. Of the 117 consecutive patients enrolled to this study, 12 patients died before six-month follow up, and finally 88 patients received follow up exams including echocardiography at six months after TAVI procedure.

Results

The analysis of echocardiographic data at the baseline and the six-month follow up of the 88 patients (age 86.2±4.0 years, male 19.3%, STS-PROM 6.76±3.28%, peak aortic jet velocity 4.67±0.75m/s) revealed that left ventricular end-diastolic volume index (LVEDVi) (from 80.1±20.9ml/m2to 74.2±15.9ml/m2, p=0.011), and left ventricular mass index (LVMi) (from 116.0±32.7g/m2to 93.6±25.6g/m2, p<0.001) had improved in six months after TAVI procedure. The difference of LVEDVi (ΔLVEDVi: six-month LVEDVi–baseline LVEDVi) and the difference of LVMi (ΔLVMi: six-month LVMi – baseline LVMi) were significantly higher in the patients with chronic atrial fibrillation compared to the rest (ΔLVEDVi: +7.7±8.7ml/m2 vs −7.2±18.1ml/m2, p=0.024; ΔLVMi: +7.1±11.5g/m2 vs −25.3±33.5g/m2, p=0.008). In echocardiographic data, ΔLVEDVi and ΔLVMi both had positive correlation between baseline E/e' ratio (ΔLVEDVi: r=0.224, p=0.048; ΔLVMi: r=0.240, p=0.034), and negative correlation between baseline LVEDVi (ΔLVEDVi: r=−0.674, p<0.001; ΔLVMi: r=−0.312, p=0.003), LVMi (ΔLVEDVi: r=−0.422, p<0.001; ΔLVMi: r=−0.699, p<0.001), peak aortic jet velocity (ΔLVEDVi: r=−0.257, p=0.016; ΔLVMi: r=−0.376, p<0.001), and mean transaortic pressure gradient (ΔLVEDVi: r=−0.269, p=0.011; ΔLVMi: r=−0.403, p<0.001).

Conclusion

TAVI resulted in reverse remodeling and regression of hypertrophy in left ventricle. And these improvement were grater in patients with more advanced left ventricular remodeling and hypertrophy, and higher severity of AS at the baseline, however, less in patients with chronic atrial fibrillation and worse diastolic dysfunction.

P1221Effect of transcatheter aortic valve implantation on cardiac sympathetic nervous function assessed by 123I-metaiodobenzylguanidine scintigraphy in patients with severe aortic stenosis

Background

Cardiac sympathetic nervous (CSN) function assessed by 123I-metaiodobenzylguanidine (MIBG) scintigraphy is associated with poor prognosis in patients with heart failure.

Purpose

The aim of this study was to investigate the effects of transcatheter aortic valve implantation (TAVI) on CSN function in patients with severe aortic stenosis (AS) using MIBG scintigraphy.

Methods

This was a single-center prospective observational study that enrolled patients between July 2017 and July 2018. Among 77 registered patients who scheduled to undergo TAVI, 35 patients (7 men; mean age: 87 years) were evaluated. The MIBG scintigraphy was performed at baseline and 6 months after TAVI procedure to evaluate the heart-mediastinum ratio (H/M) and washout rate (WR). The MIBG parameter changes were compared with B-type natriuretic peptide (BNP) levels and echocardiographic parameters, including aortic valve area (AVA), peak velocity (Vmax), mean pressure gradient (PG), and left ventricular ejection fraction (LVEF).

Results

All patients successfully underwent TAVI with improved BNP level (388±341 pg/mL vs. 167±118 pg/mL, p<0.001). The AVA, Vmax, mean PG and LVEF improved after TAVI (0.6±0.2 cm2 vs. 1.6±0.5 cm2, p<0.001; 4.6±0.8 m/s vs. 2.1±0.3 m/s, p<0.001; 54±20 mmHg vs. 9±3 mmHg, p<0.001; 58±11% vs. 63±9%, p=0.01, respectively). In the MIBG imaging, the delayed H/M significantly increased (2.5±0.6 vs. 2.6±0.7, p=0.03), and the WR decreased (32±8% vs. 29±8%, p=0.047) after TAVI. There was a correlation between the changes in the MIBG parameters and the change in mean PG from baseline to 6 months (delayed H/M: r=0.391, p=0.02; WR: r=0.347, p=0.04). Multivariate logistic regression analysis showed that baseline mean PG was an independent predictor of improved both delayed H/M and WR (odds ratio=1.062; 95% confidence interval: 1.009–1.137; p=0.042).

Conclusions

TAVI can improve the CSN function in patients with AS. Such CSN improvement was related with hemodynamic changes.

Acknowledgement/Funding

None

Reliability of ultrasonographic measurements of bovine sole structures in relation to sole horn thickness, measured by computed tomography, and sole horn hardness

The goal of the present study was to determine the effect of sole horn thickness (SHT) and sole horn hardness (SHD) on ultrasonographic visualization of sole structures in the inner and outer claws of 150 Holstein-Friesian cows, and to evaluate different ultrasound frequencies for this purpose. Ultrasonographic views of the sole structure were considered complete when 3 echogenic lines, representing the ventral surface of the sole horn, the borders of the sole horn and soft-tissue layer, and the ventral surface of the distal phalanx, were seen. The proportion of complete ultrasonographic views of the sole structures, designated as the ultrasonographic visualization proportion (UVP), and the measurement errors of SHT were evaluated by comparing images from computed tomography (CT) and ultrasonography. The latter images were generated using 3 different probes, frequencies of 6.5 and 5.0 MHz, and 2 different ultrasound machines (#1 and #2) to assess the apex, middle, and heel regions of the claws. The UVP were 60.8 to 77.9% for the 6.5-MHz probe in ultrasound machine #1 (probe A), which were lower than those (>90%) for both the 5.0-MHz probe in ultrasound machine #1 (probe B) and the 5.0-MHz probe in ultrasound machine #2 (probe C). The UVP was significantly lower in claws with an SHD ≥50 units than in claws with an SHD <40 or 40 to <50 units (UVP: 77.1% compared with 93.7 and 91.4%, respectively) when measured with probe B. In claws with an SHT <10 mm, the UVP was significantly lower when SHD was ≥50 units compared with <40 or 40 to >50 units; the values were 69.0% versus 91.3 and 85.9%, respectively, for probe A, and 89.7% versus 100 and 100%, respectively, for probe B. When SHT were measured by either probes A or B in ultrasound machine #1, the proportions of claws in which ultrasonographic values were within a ±1 mm range compared with the values obtained by CT were 84.9 to 91.3% for CT-determined SHT <5 mm, 66.7 to 71.9% for CT-determined SHT 5 to <7 mm, 28.9 to 51.2% for CT-determined SHT 7 to <10 mm, and 6.2 to 19.7% for CT-determined SHT ≥10 mm. The data indicated that increased SHT was associated with a decrease in ultrasonographic measurement accuracy. In claws with an SHT <5 mm, the high proportion of ultrasonographic values that were accurate within a ±1 mm range suggests that this imaging modality would be useful in cows with thin soles.

[A Case of Small Cell Lung Cancer Diagnosed with Metastasis-Induced Acute Pancreatitis]

A 56-year-old man was admitted to our hospital for management of acute epigastric abdominal pain and elevation of pancreatic enzymes. The CT scan revealed enlargement ofthe pancreatic body as well as the lung tumor ofthe right hilar and superior mediastinum. Therefore, bronchoscopy was performed and a diagnosis of small cell lung cancer with metastasisinduced acute pancreatitis(MIAP)was made. Prompt improvement in pancreatic findings was observed following chemotherapy. MIAP, which is a rare complication of lung cancer may affect the prognosis and quality of life of the patients; therefore, rapid diagnosis and appropriate treatment are important.

MEASUREMENT OF INTERNAL RADIATION DOSE DISTRIBUTION IN CT EXAMINATIONS USING POLYETHYLENE TEREPHTHALATE RESIN

This study proposes a new dosimetry method for the estimation of the internal radiation dose distribution of a subject undergoing computed tomography (CT) examinations. In this novel method, dose distribution of a subject by CT scans was estimated based on radiophotoluminance distribution with polyethylene terephthalate (PET) resin which was cut to the average head size of a Japanese 1-year-old child. The difference in dose distribution depending on the type of bowtie filter was visualized by imaging luminance distribution with the PET phantom using a charge-coupled device camera. Dose distribution images simulated from a water phantom of the same size as the PET phantom were compared with the luminance distribution images. The linear correlation was demonstrated between luminance of the PET phantom and the simulated water dose. In comparison with the simulated water doses and the converted water doses from luminance of the PET phantom, the relative differences were within 20%.

Changes in surface tension of saliva in Down syndrome

OBJECTIVE

Surface tension in saliva might contribute to the maintenance of upper airway patency. The present study aimed to determine whether salivary surface tension is altered in patients with Down syndrome who are predisposed to upper airway collapse.

PATIENTS AND METHODS

We used the pull-off force technique to measure surface tension in samples (100 μL) of saliva collected from twenty-three male patients with Down syndrome and twenty-three healthy males (controls). p < 0.05 was considered to indicate significance.

RESULTS

Salivary surface tension was significantly lower in the patients than in the controls (57.3 ± 4.9 vs. 60.3 ± 4.7 mN/m; p = 0.039). Age and surface tension positively correlated in the patients (p = 0.001).

CONCLUSIONS

The lower surface tension of saliva in patients with Down syndrome might compensate for an anatomical predisposition towards upper airway collapsibility and other risk factors. The function of surface tension in saliva might be altered due to aging in such patients.

Endogenous viral gene ev21 is not responsible for the expression of late feathering in chickens

The late-feathering (LF) gene K on the Z chromosome is an important gene in the chicken industry, which is frequently utilized for the feather sexing, a type of autosexing, of neonatal chicks. The K gene is closely associated with the endogenous ev21 gene from an avian leukosis virus and the incomplete duplication (ID) of prolactin receptor (PRLR) and sperm flagellar protein 2 (SPEF2) genes, and ev21 has been used as a molecular marker to detect LF birds. In the present study, a comprehensive survey for the presence or absence of ev21 and ID across 1,994 birds from 52 chicken breeds, three commercial hybrid groups, and the Red Jungle Fowl revealed that almost all LF breeds have both ev21 and ID. However, only one LF breed (Ingie) has only ID and no ev21. Moreover, this study revealed that almost all early (normal)-feathering (EF) breeds lack both ev21 and ID, but only one breed (White Plymouth Rock) included EF birds with ev21 but no ID. Therefore, regarding LF expression, the results indicated that ID is responsible, but ev21 is not required. Henceforth, ID should be used as a molecular marker to detect LF birds instead of ev21. Because ev21 contains the full genome of an avian leukosis virus, there is a risk of disease development in breeds with this gene. Therefore, the Ingie breed, which has no ev21 at the K locus, represents excellent material for the establishment of new LF stocks.

Skin inflammation exacerbates food allergy symptoms in epicutaneously sensitized mice

BACKGROUND

Cutaneous exposure to food antigen through impaired skin barrier has been shown to induce epicutaneous sensitization, thereby causing IgE-mediated food allergies.

OBJECTIVE

We examined whether skin barrier impairment following epicutaneous sensitization exacerbates food allergies.

METHODS

BALB/c mice were epicutaneously sensitized by repeated application of ovalbumin (OVA) to MC903-pretreated ear skin for 48 hours weekly and then intragastrically challenged with OVA. After the first oral challenge, the skin barrier was disrupted with topical application of MC903 or by tape-stripping. Mice were monitored for changes in body temperature and the occurrence of diarrhea after undergoing the second oral challenge. Serum levels of mouse mast cell protease-1 (mmcp1) and OVA-specific IgE, IgG1, IgG2a antibodies and OVA-specific IgA levels in intestinal lavage fluid were measured by ELISA. Tissue accumulation of eosinophils was determined histologically.

RESULTS

Epicutaneously sensitized mice developed anaphylaxis after intragastric challenge, as evidenced by diarrhea, decreased body temperature, and increased serum mmcp1 levels. Skin barrier disruption by MC903 treatment or tape-stripping exacerbated allergic reactions induced by oral challenge. MC903 treatment increased serum baseline and postchallenge mmcp1 levels. Topical pretreatment with dexamethasone alleviated allergic reactions that were exacerbated by MC903 treatment.

CONCLUSION

Even after eliminating exposure to the antigen, inflammation from skin barrier disruption can exacerbate the severity of food allergy symptoms. Serum baseline mmcp1 levels might be an effective marker for predicting the severity of antigen-induced allergic symptoms.

A Rapid in vivo Bioassay for the Carcinogenicity of Pesticides

Eight pesticides were tested in a bioassay based on the induction of preneoplastic lesions in the liver. Rats were given diethylnitrosamine intraperitoneally at 200 mg/kg bw and two weeks later were treated with pesticides for six weeks and then killed; all rats had a partial hepatectomy at week 3. Hepatocarcinogenic potential was assessed by comparing the number and area of glutathione s-transferase (placental form) -positive foci In the liver with those of controls given diethylnitrosamine alone. Positive results were seen with Chinomethionat, Phosmet and Propiconazole; the results obtained with Captan and Prochloraz were borderline; Benomyl, Daminozide and Folpet gave negative results. Our findings provide enough experimental evidence to indicate that great care should be exercised in the use of these compounds.

Enhancement of Satellite Cell Transplantation Efficiency by Leukemia Inhibitory Factor

BACKGROUND AND OBJECTIVES

Cell transplantation is a promising therapy for several muscle diseases, including Duchenne muscular dystrophy. Satellite cells are stem cells in skeletal muscle that provide an important cell source for transplantation therapy. However, culture of satellite cells in vitro causes them to lose their undifferentiated state, associated with reduced transplantation efficiency. It is therefore necessary to develop optimal culture conditions for maintaining the undifferentiated state of satellite cells.

METHODS

Primary satellite cells were cultured with or without leukemia inhibitory factor (LIF). The expression of undifferentiation and differentiation markers, and the transplantation efficiency were analyzed.

RESULTS

LIF-treated satellite cells showed increased expression of Pax7, and enhanced transplantation efficiency in a mouse model of Duchenne muscular dystrophy.

CONCLUSIONS

Our study showed that the treatment with LIF effectively maintained the undifferentiated state of satellite cells, and enhanced their transplantation efficiency. These results will contribute to the optimization of culture conditions for cell transplantation therapy.

Development of 2-D horn-antenna millimeter-wave imaging device (HMID) for the plasma diagnostics

The two-dimensional (2-D) Horn-antenna Millimeter-wave Imaging Device (HMID) has been developed for the O-mode Microwave Imaging Reflectometry (O-MIR) in the Large Helical Device (LHD). The detectable frequency range of the HMID is 23-33 GHz, which corresponds to the cutoff electron density of 0.8-1.5 × 10¹⁹ m^-3 in the O-MIR. The HMID is a 2-D imaging device that improves on the horn-antenna mixer array, which had been developed for the X-mode MIR in the LHD. In the HMID, the signal (RF) wave from the horn antenna is transmitted to the microstrip line by the finline transmitter, and this is mixed by the double-balanced-mixer with the local oscillation wave that is fed by a coaxial cable. By using the HMID, the MIR optical system can be significantly simplified.

A 60-GHz interferometer with a local oscillator integrated antenna array for divertor simulation experiments on GAMMA 10/PDX

In conventional multichannel/imaging microwave diagnostics of interferometry, reflectometry, and electron cyclotron emission measurements, a local oscillator (LO) signal is commonly supplied to a receiver array via irradiation using LO optics. In this work, we present a 60-GHz interferometer with a new eight-channel receiver array, called a local oscillator integrated antenna array (LIA). An outstanding feature of LIA is that it incorporates a frequency quadrupler integrated circuit for LO supply to each channel. This enables simple and uniform LO supply to the receiver array using only a 15-GHz LO source and a coaxial cable transmission line instead of using an expensive 60-GHz source, LO optics, and a waveguide transmission line. The new interferometer system is first applied to measure electron line-averaged density inside the divertor simulation experimental module (D-module) on GAMMA 10/PDX tandem mirror device.

Effects of protease inhibitors on LPS-mediated activation of a mouse macrophage cell line (J774)

Pretreatment (1 h) of a mouse macrophage-like cell line, J774, with the protease inhibitor, phenylalanine-chloromethyl ketone (PCK) or its structural analogue, tosylphenylalanine chloromethyl ketone (TPCK) was found to cause substantial inhibition of LPS-triggered activation of NF-κB. Pretreatment of cells with other types of protease inhibitors or their various structural analogues had no effect. PCK or TPCK appeared to exert its inhibitory effect by: (i) partially preventing LPS-triggered degradation of IκBα protein; (ii) preventing LPS-triggered nuclear translocation of NF-κB proteins (p50, RelA and Rel); and (iii) inhibiting the DNA-binding activities of NF-κB proteins. Pretreatment of cells with PCK or TPCK also resulted in the total or partial inhibition of LPS activatable (AP-1 or CREB) or constitutively-existing (Oct-1) transcription factors, but not of another constitutively-expressed transcription factor (SP-1). Pretreatment of J774 cells with PCK was found to substantially suppress LPS-induced expression of mRNAs specific for cytokine genes (TNFα, IL-1α and β, and IL-6), inducible nitric oxide synthase (iNOS) gene and IκBα gene, but not NF-κB1 p105 gene or β-actin gene. Furthermore, PCK pretreatment inhibited, in a dose-dependent manner, LPS-triggered production of nitric oxide production and tumoricidal activity.