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.

"Clinical Impact of the Cryoballoon Temperature and Occlusion Status on the Success of Pulmonary Vein Isolation"

Background

Complete occlusion of the pulmonary veins (PVs) with the cryoballoon (CB) is considered to be the crucial factor for a successful PV isolation (PVI). We investigated whether a complete occlusion was indispensable for a successful CB based PVI of every PV.

Methods and Results

Atrial fibrillation patients (n=123, 97; paroxysmal) undergoing a de novo PVI were enrolled. A total of 477 PVs were analyzed. The occlusion grade (OG) was scored as follows: OG3 (complete occlusion), OG2 (incomplete occlusion with slight leakage), OG1 (poor occlusion with massive leakage). There was no significant difference in the CB temperature (CBT) at all measured time points (from 30 to 120sec after freezing) and nadir CBT between OG2 and OG3 in all PVs except for the right inferior PV (RIPV). The RIPV isolation success rate was significantly lower for the OG2 status than OG3 (97.5 vs. 57.6%; p<0.0001). In contrast, there was not significant difference in the isolation success rate of the other three PVs between OG2 and OG3. In particular, the success rate of the right superior PV (RSPV) isolation was >95% for both OG2 and OG3. Phrenic nerve paralysis (PNP) was provoked during the RSPV isolation in two patients in whom the RSPVs were frozen during OG3.

Conclusion

An OG3 may not always be required for a successful PVI of all PVs except the RIPV. OG2 could have comparable effects as OG3 in terms of a successful RSPV isolation. Not aiming for OG3 for the RSPV may reduce the risk of PNP.

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.

Subcutaneous implantable cardioverter-defibrillator implantation for ventricular fibrillation caused by coronary artery spasm: a case report

BACKGROUND

Coronary artery spasm usually has a good prognosis, except when it induces lethal ventricular arrhythmias. Implantable cardioverter-defibrillator (ICD) implantation in addition to optimal medical therapy including prescription of coronary vasodilators and smoking cessation is a therapeutic option for coronary artery spasm patients who present with lethal ventricular arrhythmia. Subcutaneous ICDs are now available as an alternative to conventional transvenous ICDs.

CASE SUMMARY

We report the first case of a 50-year-old Japanese male without any structural heart disease who presented with ventricular fibrillation caused by coronary artery spasm, and underwent subcutaneous ICD implantation for secondary prevention of sudden cardiac death (SCD). We attributed his aborted SCD to coronary artery spasm based on findings of cardiac catheterization including acetylcholine provocation test and cardiac electrophysiological study. During the 1 year of follow-up, the patient discharged on calcium channel blockers and nicorandil has been free of angina, ventricular arrhythmias, and appropriate ICD therapy.

DISCUSSION

Coronary artery spasm patients with aborted SCD may be good candidates for implantation of subcutaneous ICDs, because most of them have no need for concomitant bradycardia therapy, cardiac resynchronization therapy, or anti-tachycardia pacing therapy.

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.