Purpose: High-contrast tissue characterization of thermal ablation has been desired to evaluate therapeutic outcomes accurately. This paper presents a photoacoustic (PA) characterization of thermal tissue ablation in the visible spectrum, in which higher light absorbance can produce spectral contrast starker than in the near-infrared range. Methods: Ex vivo experiments were performed to measure visible PA spectra (480-700 nm) from fresh porcine liver tissues that received a thermal dose in a range of cumulative equivalent minutes at 43°C (CEM43). The local hemoglobin lobe area between 510-600 nm and wholespectral area under the curve were evaluated to represent the transition of hemoglobin into methemoglobin (MetHb) in the target tissue. Results: The thermal process below an estimated therapeutic CEM43 threshold (80-340 minutes) presented a progressive elevation of the PA spectrum and an eventual loss of local hemoglobin peaks in the visible spectrum, closer to the MetHb spectrum. Interestingly, an excessive CEM43 produced a substantial drop in the PA spectrum. In the spectral analysis, the visible spectrum yielded 13.9-34.1 times higher PA sensitivity and 1.42 times higher contrast change than at a near-infrared wavelength. Conclusion This novel method of PA tissue characterization in the visible spectrum could be a potential modality to evaluate various thermal therapeutic modalities at high-contrast resolution.

High-intensity focused ultrasound (HIFU) is an emerging therapeutic tool for the effective thermal ablation of pathological tissue. For accurate localization of the target and safe control of the HIFU dosage, real-time imaging guidance during the HIFU exposure is desired. Ultrasound imaging has the capability to guide clinicians toward a lesion in real time, but is not an ideal option, as HIFU application causes strong interference, thereby substantially distorting the images used for guidance. Thus, this study introduces singular value decomposition–based filtering capable of restoring ultrasound harmonic images from HIFU interference without undesirable spectral distortion. The results were experimentally validated with a custom-made phantom, indicating that this approach effectively eliminates HIFU-induced artifacts, which is essential for real-time monitoring of the therapeutic process.

BACKGROUND: We wanted to investigate the effect of infectious complications on the outcome of patients who received allogeneic hematopoietic stem cell transplantation (HSCT), and we determined the risk factors for predicting infectious complication and the mortality in allogeneic HSCT recipients. METHODS: We enrolled all the patients who underwent allogeneic HSCT at Samsung Medical Center from February 1996 to October 2003. RESULTS: A total of 139 patients were enrolled. A total of 450 infectious episodes were observed in 131 allogeneic recipients (90.8%). Infectious complications occurred in the allogeneic recipients [3.243.00 episodes/patient]. Microbiologically documented infection (MDI), clinically documented infection (CDI), and unknown fever (UF) accounted for 41.6%, 34.0% and 24.4%, respectively, of the total infections. Pneumonia (15.1%) was the most common infection. Among the 187 MDIs, bacterial infection, viral infection and fungal infection accounted for 50.3%, 39.6%, and 7.5%, respectively. Twelve of 24 deaths in the late post-transplantation period were related with infection. The statistically significant risk factors for infection related to mortality, by multivariate analysis, were the underlying disease risk, the duration of neutropenia, the failure of stem cell engraftment, acute GVHD, MDI, UF, the number of infectious episodes, bacteremia, fungemia, pneumonia, genitourinary tract infections, S. aureus, E. coli, Pseudomonas spp., Aspergillus spp., Non-albicans candida and CMV diseases. CONCLUSIONS: The incidence of fungal infections was still low in our institute, even though prophylaxis for fungal infections was not applied, except for gargling with nystatin. In addition, most of them were non-albican Candida and Aspergillus species. Therefore, routine fluconazole prophylaxis may not be needed in our institute.
Aspergillus ; Bacteremia ; Bacterial Infections ; Candida ; Fever ; Fluconazole ; Fungemia ; Hematopoietic Stem Cell Transplantation* ; Hematopoietic Stem Cells* ; Humans ; Incidence ; Mortality ; Multivariate Analysis ; Neutropenia ; Nystatin ; Pneumonia ; Pseudomonas ; Risk Factors ; Stem Cells

Ethnically specific data on genetic variation are crucial for understanding human biology and for clinical interpretation of variant pathogenicity. We analyzed data obtained by deep sequencing 1303 Korean whole exomes; the data were generated by three independent whole exome sequencing projects (named the KOEX study). The primary focus of this study was to comprehensively analyze the variant statistics, investigate secondary findings that may have clinical actionability, and identify loci that should be cautiously interpreted for pathogenicity. A total of 495 729 unique variants were identified at exonic regions, including 169 380 nonsynonymous variants and 4356 frameshift insertion/deletions. Among these, 76 607 were novel coding variants. On average, each individual had 7136 nonsynonymous single-nucleotide variants and 74 frameshift insertion/deletions. We classified 13 pathogenic and 13 likely pathogenic variants in 56 genes that may have clinical actionability according to the guidelines of the American College of Medical Genetics and Genomics, and the Association for Molecular Pathology. The carrier frequency of these 26 variants was 2.46% (95% confidence interval 1.73–3.46). To identify loci that require cautious interpretation in clinical sequencing, we identified 18 genes that are prone to sequencing errors, and 671 genes that are highly polymorphic and carry excess nonsynonymous variants. The catalog of identified variants, its annotation and frequency information are publicly available (https://koex.snu.ac.kr). These findings should be useful resources for investigating ethnically specific characteristics in human health and disease.
Biology ; Clinical Coding ; Exome ; Exons ; Genetic Variation ; Genetics, Medical ; Genomics ; High-Throughput Nucleotide Sequencing ; Humans ; Pathology, Molecular ; Virulence

In this study, we sought to describe a novel imaging apparatus that is lightweight, inexpensive, and highly eff ective for use in colorectal diagnostic and treatment settings. Typical probes for use in colorectal ultrasonic imaging applications are developed for surgeons to diagnose and stage rectal tumors and image the rectum and anus. Here we outline a new technique and use it for colorectal imaging in an animal. This technique involves use of an ultrasound array module positioned along the axis of rotation such that improved rotation is possible. This module is in the shape of a linear rod with a rotary linear component that allows for emission of focused ultrasonic echo signals from a linear section of the probe. The usability of the transducer and rectal image quality are satisfactory in a porcine model with the technique proposed here, axial/lateral resolution as 0.96/2.24 mm with 6 dB applied through the contour map using the point spread function. When compared to currently available methods, this technique provides superior diagnostic 3D volumetric image quality with reduced acquisition time. Given this, the ultrasound device proposed here may prove a viable and preferable method to those currently available for urology and colorectal imaging applications.
Anal Canal ; Animals ; Methods ; Rectal Neoplasms ; Rectum ; Surgeons ; Transducers ; Ultrasonics ; Ultrasonography ; Urology

Lipid-coated microbubbles are widely used as an ultrasound contrast agent, as well as drug delivery carriers. However, the two main limitations in ultrasound diagnosis and drug delivery using microbubbles are the short half-life in the blood system, and the difficulty of surface modification of microbubbles for active targeting. The exosome, a type of extracellular vesicle, has a preferentially targeting ability for its original cell. In this study, exosome-fused microbubbles (Exo-MBs) were developed by embedding the exosome membrane proteins into microbubbles. As a result, the stability of Exo-MBs is improved over the conventional microbubbles. On the same principle that under the exposure of ultrasound, microbubbles are cavitated and self-assembled into nano-sized particles, and Exo-MBs are self-assembled into exosome membrane proteins-embedded nanoparticles (Exo-NPs). The Exo-NPs showed favorable targeting properties to their original cells. A photosensitizer, chlorin e6, was loaded into Exo-MBs to evaluate therapeutic efficacy as a drug carrier. Much higher therapeutic efficacy of photodynamic therapy was confirmed, followed by cancer immunotherapy from immunogenic cell death. We have therefore developed a novel ultrasound image-guided drug delivery platform that overcomes the shortcomings of the conventional ultrasound contrast agent and is capable of simultaneous photodynamic therapy and cancer immunotherapy.