Intraepithelial involvement of non-neoplastic glands in papillary preinvasive neoplasms of the biliary tract: a potential diagnostic pitfall.

Intracholecystic papillary neoplasms of the gallbladder (ICPN) and intraductal papillary neoplasms of the bile duct (IPNB) show intramural neoplastic growths in addition to intraluminal papillary or polypoid neoplastic growth. Such intramural growths include intraepithelial involvement of non-neoplastic glands by preinvasive neoplastic epithelia (glandular involvement) as well as stromal invasive carcinoma. A total of 29 ICPN cases and 84 IPNB cases were pathologically examined for their glandular involvement. Glandular involvement was characterized by intramural neoplastic glands (1) showing cytological and phenotypical similarities to intraluminal preinvasive papillary neoplasms and (2) showing reminiscent configurations of non-neoplastic glands, such as (i) a mixture of preinvasive neoplastic epithelia and non-neoplastic epithelia within the same glands, (ii) neoplastic glands close to or within clustered non-neoplastic glands, or (iii) continuous growth of intraluminal preinvasive neoplastic glands into the walls. Such glandular involvement was found in 16 of 29 ICPN and 48 of 84 IPNB, and 15 of the former and 28 of the latter were not associated with invasive carcinoma. Non-invasive ICPN and IPNB with glandular involvement showed a favorable postoperative overall survival (OS). Glandular involvement by preinvasive neoplastic epithelia was frequently found in ICPN and IPNB. Such lesions may be diagnostic pitfalls in ICPN and IPNB referring to invasion. Glandular involvement without invasive carcinoma was not associated with an unfavorable postoperative OS in ICPN and IPNB. Recognition of glandular involvement may thus prevent overestimation of invasive carcinoma in ICPN and IPNB.

[A Case of a Massive Retropharyngeal Hematoma Associated with Traumatic Cervical Cord Injury].

Retropharyngeal hematomas are uncommon, but they may rarely cause occlusion of the upper airway and threaten life. Retropharyngeal hematomas often occur due to head or neck injury;they rarely occur due to iatrogenic causes such as insertion of a gastric tube or anticoagulant therapy. It has been found that patients receiving anticoagulant therapy are more likely to experience potentially severe retropharyngeal hematomas. We report the case of a patient with retropharyngeal hematoma with cervical cord damage. A 75-year-old man was transferred to our hospital after he sustained a fall and damaged his face. CT showed a massive retropharyngeal hematoma, but he did not complain of any breathing issues. Therefore, we selected conservative therapy. However, after approximately 4 hours, he suddenly complained of breathing problems and suffered from loss of consciousness. We performed intubation and provided sedation. After one week, his condition clearly improved and he was extubated.

Analysis of aggregation and dispersion states of small particles in concentrated suspension by using diffused photon density wave spectroscopy.

Recently, inspection of chemical components like melamine plays an important role in food industry for the food safety. However, conventional analyzing methods require a lot of preparations and much of time. We propose a real-time method for investing the mean particle size and number density of concentrated suspensions without any preparations. There are several techniques of analyzing concentrated suspensions. Laser light scattering (LLS) and dynamic light scattering (DLS) are used to measure the particle size. Fourier transform infrared spectroscopy (FT-IR) is used to measure the number density. They have been successfully describing the physical and dynamics characteristics near single light scattering regions. On the other hand, they require samples to be highly diluted. This is a major disadvantage in studying real concentrated suspensions, or phenomena such as gelation. Our proposed method diffused photon density wave spectroscopy (DPDWS) is based on the multiple light scattering theory. Thus, DPDWS measures the particle size and number density of the concentrated suspensions without dilution in real time. Diffused photon density wave (DPDW) is a spherical energy wave generated from the intensity-modulated point light source in the concentrated suspensions. The absorption and scattering coefficients can be simultaneously obtained from the amplitude and phase of DPDW propagated through the concentrated suspensions. Furthermore, the particle size and number density of nanoparticles can be estimated from the obtained optical properties using the absorption and the scattering theory. In this study, we qualitatively estimated the gelation of milk from the measured particle size and number density by use of DPDWS.

Light diffusion model for determination of optical properties of rectangular parallelepiped highly scattering media.

A method to determine the absorption and reduced scattering coefficients of rectangular parallelepiped highly scattering media from frequency-domain photon migration measurements is presented. An analytical model for photon diffusion propagation in the rectangular parallelepiped media is established using the method of images and extrapolated boundary conditions. This present technique has simplicity, accuracy, and rapid computability as compared with the Monte Carlo or finite element methods. The theoretical predictions are verified with experimental measurements using a white polyacetal resin, and the errors introduced by using the slab geometry for the optical property determination are identified.

In-line type micropulse lidar with an annular beam: experiment.

An in-line type compact micropulse lidar (MPL) with an annular beam was developed for low-altitude cloud measurement. An optical circulator and a couple of axicon prisms for an annular beam were installed on the lidar optics. The advantage of using the in-line MPL is its ability to obtain a near-range measurement with a narrow field of view of 0.1 mrad and to obtain a depolarization measurement of the orthogonally polarized echoes caused by ice crystals of a low-altitude cloud. The total insertion loss of the lidar optics was 3 dB. Detectors such as avalance photodiode detectors can be operated in an analog mode near the breakdown voltage because of the high isolation of the optical circulator. The ideal lidar echo variation from the nearest distance was verified by measuring the mountain echoes at various distances. The depolarization measurement of a low-altitude ice cloud was also demonstrated.

In-line type micropulse lidar with an annular beam: theoretical approach.

An in-line type micropulse lidar (MPL) with an annular beam was designed and the transmitting and receiving characteristics were analyzed. Because the in-line MPL utilizes a common telescope for a transmitter and a receiver and the annular beam always overlaps with the receiver's field of view (FOV), it can measure near-range lidar echoes with a narrow FOV. The transmitting annular beam changes its shape to a nearly nondiffractive beam through propagation. It improves the spatial resolution of the lidar observation. The receiving characteristics showed the ideal lidar echo variation, which was inversely proportional to the square of the distance the beam propagated, even if it was in the near range.

Long-optical-path scanning mechanism for optical coherence tomography.

A new scanning mechanism for changing long optical paths is proposed. This mechanism consists of corner reflectors arranged equally upon a disk and an outer mirror. Rotating the 120-mm disk causes a long-optical-path change in each reflector with a near linearity of more than 40 mm. An optical coherence tomography system is described that confirms the usefulness of the proposed mechanism. Its operating characteristics and accuracy are evaluated by analysis and experiment. The deviation of the optical-path change is less than 1.52% at a reflector rotation angle of +/-10 degrees. A high-speed lock-in amplifier is utilized for fundamental measurements of glass samples.

Optical circulator for an in-line-type compact lidar.

The application of an optical circulator is demonstrated for an in-line-type lidar. The lidar's transmitter and receiver are installed in a telescope. The optical circulator of interest here can separate the transmitting laser beam and the echo lights on the same optical axis. It can also divide the echo lights simultaneously into orthogonally polarized components. An insertion loss of 2.2 dB and isolation of >60 dB for the developed optical circulator are obtained in a laser-transmitting situation. This optical circulator makes it possible to measure the polarization ratio caused by cloud phases with a narrow field of view in an in-line-type lidar operation.