In silico evaluation of the acute occlusion effect of coronary artery on cardiac electrophysiology and the body surface potential map.

Body surface potential map, an electric potential distribution on the body torso surface, enables us to infer the electrical activities of the heart. Therefore, observing electric potential projected to the torso surface can be highly useful for diagnosing heart diseases such as coronary occlusion. The BSPM for the heart of a patient show a higher level of sensitivity than 12-lead ECG. Relevant research has been mostly based on clinical statistics obtained from patients, and, therefore, a simulation for a variety of pathological phenomena of the heart is required. In this study, by using computer simulation, a body surface potential map was implemented according to various occlusion locations (distal, mid, proximal occlusion) in the left anterior descending coronary artery. Electrophysiological characteristics of the body surface during the ST segment period were observed and analyzed based on an ST isointegral map. We developed an integrated system that takes into account the cellular to organ levels, and performed simulation regarding the electrophysiological phenomena of the heart that occur during the first 5 minutes (stage 1) and 10 minutes (stage 2) after commencement of coronary occlusion. Subsequently, we calculated the bipolar angle and amplitude of the ST isointegral map, and observed the correlation between the relevant characteristics and the location of coronary occlusion. In the result, in the ventricle model during the stage 1, a wider area of ischemia led to counterclockwise rotation of the bipolar angle; and, during the stage 2, the amplitude increased when the ischemia area exceeded a certain size.

Flavobacterium gilvum sp. nov., isolated from stream water.

A cream-coloured, non-gliding, aerobic Flavobacterium strain, designated EM1308T, was isolated from stream water. 16S rRNA gene sequence analysis indicated that this isolate is closely related to Flavobacterium glycines NBRC 105008T (97.3 % similarity) and Flavobacterium piscis CCUG 60099T (97.2 %). To evaluate the genomic relatedness of the isolate with its neighbours, the whole genome sequences of strain EM1308T and the type strains of F. glycines and F. piscis were determined. Average nucleotide identities revealed that strain EM1308T is independent from other Flavobacterium species. The properties of major cellular fatty acids, polar lipids, menaquinone and DNA G+C content of the isolate were within the general range for the genus Flavobacterium, but many biochemical and physiological characteristics distinguished the isolate from previously known species. Thus, strain EM1308T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium gilvum sp. nov. is proposed. The type strain is EM1308T (=KACC 18113T=JCM 30144T).

Estimation of the flow resistances exerted in coronary arteries using a vessel length-based method.

Flow resistances exerted in the coronary arteries are the key parameters for the image-based computer simulation of coronary hemodynamics. The resistances depend on the anatomical characteristics of the coronary system. A simple and reliable estimation of the resistances is a compulsory procedure to compute the fractional flow reserve (FFR) of stenosed coronary arteries, an important clinical index of coronary artery disease. The cardiac muscle volume reconstructed from computed tomography (CT) images has been used to assess the resistance of the feeding coronary artery (muscle volume-based method). In this study, we estimate the flow resistances exerted in coronary arteries by using a novel method. Based on a physiological observation that longer coronary arteries have more daughter branches feeding a larger mass of cardiac muscle, the method measures the vessel lengths from coronary angiogram or CT images (vessel length-based method) and predicts the coronary flow resistances. The underlying equations are derived from the physiological relation among flow rate, resistance, and vessel length. To validate the present estimation method, we calculate the coronary flow division over coronary major arteries for 50 patients using the vessel length-based method as well as the muscle volume-based one. These results are compared with the direct measurements in a clinical study. Further proving the usefulness of the present method, we compute the coronary FFR from the images of optical coherence tomography.

Rapidly developed squamous cell carcinoma after laser therapy used to treat chemical burn wound: a case report.

BACKGROUND: In chronic wounds, especially burn scars, malignant tumors can arise. However, it is rare for a subacute burn injury to change to a malignant lesion within one month. Moreover, a case of squamous cell carcinoma arising from HeNe laser therapy after a chemical burn has never been reported. CASE REPORT: In this report, we examine a rare case of squamous cell carcinoma arising from HeNe laser therapy after a chemical burn. Because pathologic investigations were made from the first operation, both early detection of the squamous cell carcinoma and consideration of the HeNe laser therapy as a risk factor for the skin cancer were possible. The cancer was completely removed and reconstruction of the defect was successfully achieved in a timely manner. CONCLUSION: Although there has as yet been no reported case of squamous cell carcinoma induced by laser therapy, it is important for clinicians to recognize both the possibility of laser-induced cancer and the rapid change of cancer, so they can provide appropriate and timely treatment.

Huge cystic lymphangioma involving the entire breast.

We report a case of a 31-year-old female who required mastectomy with the diagnosis of cystic lymphangioma of the entire left breast. We tried operative management that is not mastectomy since it was not malignant, but finally mastectomy was needed. In reduction mammaplasty patients, plastic surgeons should consider cystic lymphangioma as a differential diagnosis of unilateral large breasts.

Factors that contribute to disagreement in satisfaction between surgeons and patients after corrective septorhinoplasty.

BACKGROUND: Corrective septorhinoplasty is one of the most common facial plastic surgeries. However, surgeons and patients sometimes disagree about postoperative-outcome satisfaction after corrective septorhinoplasty. OBJECTIVE: We investigated the factors that influenced the disagreement in satisfaction between surgeons and patients after corrective septorhinoplasty. METHODS: Surgeon satisfaction was assessed by other plastic surgeons by comparing patient photographs taken at the preoperative and 12-month postoperative periods. Patient satisfaction was assessed by the Rhinoplasty Outcome Evaluation Questionnaire (ROEQ) before surgery and 12 months after surgery. The dissatisfied group was defined as showing a negative change or no change in the ROEQ quartile between baseline and 12 months after surgery. RESULTS: A total of 70 patients were included. No significant differences were observed between the satisfied and dissatisfied groups in sex, marital status, depression history, and major anesthetic problems. However, the dissatisfied group was significantly younger, more likely to be employed, and better educated than the satisfied group. In addition, a multivariate logistic regression analysis indicated that being highly educated was a predictor of disagreement in satisfaction between surgeons and patients. CONCLUSION: Our findings indicated that highly educated patients who underwent corrective septorhinoplasty required more detailed preoperative guidance, including more complete information on the limitations of the surgery.

Diagnostic Performance of a Novel Method for Fractional Flow Reserve Computed from Noninvasive Computed Tomography Angiography (NOVEL-FLOW Study).

Coronary computed tomography angiography (CCTA)-derived fractional flow reserve from computed tomography (CT-FFR) may provide better diagnostic performance over CCTA alone, but the complexity of its method limits the use in clinical environment. The aim of the present study is to validate a newly developed vessel-length based computational fluid dynamics scheme for the computation of FFR based on CCTA data, compare them with invasively measured FFR, and evaluate its diagnostic performance with that of CCTA. One hundred seventeen patients from 4 medical institutions who had clinically indicated invasive coronary angiography for suspected coronary artery disease (CAD) were enrolled. Invasive FFR measurement was performed in 218 vessels and these measurements were regarded as the reference standard. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR on a per-vessel basis were 85.8%, 86.2%, 85.5%, 79.8%, and 90.3%, respectively, for CT-FFR ≤0.80, and 66.1%, 75.9%, 59.5%, 55.5%, and 78.8%, respectively, for CCTA ≥50%. A higher area under the receiver operating characteristic curve for CT-FFR was observed compared with CCTA (0.93 vs 0.74, p <0.0001). The CT-FFR and FFR correlated well (r = 0.76, p <0.001) with slight underestimation by CT-FFR (0.014 ± 0.077, p = 0.007). With a novel method of vessel-length based computational fluid dynamics scheme, CT-FFR can be performed at a personal computer enhancing its applicability in clinical situation. The diagnostic accuracy of CT-FFR for the detection of functionally significant CAD was good and was superior to that of CCTA within a population of suspected CAD.

Non-contiguous finished genome sequence and description of the gliding bacterium Flavobacterium seoulense sp. nov.

Flavobacterium seoulense strain EM1321(T) is the type strain of Flavobacterium seoulense sp. nov., a proposed novel species within the genus Flavobacterium. This strain is a Gram-reaction-negative, aerobic, rod-shaped bacterium isolated from stream water in Bukhansan National Park, Seoul. This organism is motile by gliding. Here, we describe the features of Flavobacterium seoulense EM1321(T), together with its genome sequence and annotation. The genome comprised 3,792,640 bp, with 3,230 protein-coding genes and 52 RNA genes.

Virtual ablation for atrial fibrillation in personalized in-silico three-dimensional left atrial modeling: comparison with clinical catheter ablation.

BACKGROUND: Although catheter ablation is an effective rhythm control strategy for atrial fibrillation (AF), empirically-based ablation has a substantial recurrence rate. The purposes of this study were to develop a computational platform for patient-specific virtual AF ablation and to compare the anti-fibrillatory effects of 5 different virtual ablation protocols with empirically chosen clinical ablations. METHODS: We included 20 patients with AF (65% male, 60.1 ± 10.5 years old, 80% persistent AF [PeAF]) who had undergone empirically-based catheter ablation: circumferential pulmonary vein isolation (CPVI) for paroxysmal AF (PAF) and additional posterior box lesion (L1) and anterior line (L2) for PeAF. Using patient-specific three-dimensional left atrial (LA) geometry, we generated a finite element model and tested the AF termination rate after 5 different virtual ablations: CPVI alone, CPVI + L1, CPVI + L1,2, CPVI with complex fractionated atrial electrogram (CFAE) ablation, and CFAE ablation alone. RESULTS: 1. Virtual CPVI + L1,2 ablation showed the highest AF termination rate in overall patients (55%) and PeAF patients (n = 16, 62.5%). 2. The virtual AF maintenance duration was shortest in the case of virtual CPVI + L1,2 ablation in overall patients (2.19 ± 1.28 vs. 2.91 ± 1.04 s, p = 0.009) and in patients with PeAF (2.05 ± 1.23 vs. 2.93 ± 10.2 s, p = 0.004) compared with other protocols. CONCLUSION: Virtual AF ablation using personalized in-silico model of LA is feasible. Virtual ablation with CPVI + L1,2 shows the highest antifibrillatory effect, concordant with the empirical ablation protocol in patients with PeAF.

A novel patient-specific model to compute coronary fractional flow reserve.

The fractional flow reserve (FFR) is a widely used clinical index to evaluate the functional severity of coronary stenosis. A computer simulation method based on patients' computed tomography (CT) data is a plausible non-invasive approach for computing the FFR. This method can provide a detailed solution for the stenosed coronary hemodynamics by coupling computational fluid dynamics (CFD) with the lumped parameter model (LPM) of the cardiovascular system. In this work, we have implemented a simple computational method to compute the FFR. As this method uses only coronary arteries for the CFD model and includes only the LPM of the coronary vascular system, it provides simpler boundary conditions for the coronary geometry and is computationally more efficient than existing approaches. To test the efficacy of this method, we simulated a three-dimensional straight vessel using CFD coupled with the LPM. The computed results were compared with those of the LPM. To validate this method in terms of clinically realistic geometry, a patient-specific model of stenosed coronary arteries was constructed from CT images, and the computed FFR was compared with clinically measured results. We evaluated the effect of a model aorta on the computed FFR and compared this with a model without the aorta. Computationally, the model without the aorta was more efficient than that with the aorta, reducing the CPU time required for computing a cardiac cycle to 43.4%.

A patient-specific model of virtual ablation for atrial fibrillation.

The purpose of this study was to propose a patient-specific model of atrial fibrillation (AF) and apply it to virtual radiofrequency ablation (RFA). We obtained patient-specific geometries of the left atrium (LA) from CT data and constructed three-dimensional (3D) simulation models. A bidomain Courtemanche model was used to simulate the 3D electric waves on the LA surface, and an S1-S2 protocol was applied to induce AF in the model. To identify scar areas in the models, we converted clinically measured voltage data on the LA surface to the scar maps of the simulation model. Then, after initiation of AF, we applied the virtual ablation scheme to the model and investigated whether the AF was terminated by the scheme. The computed results of AF and ablation were similar to those of clinical observation, providing a clinically important simulation method for preclinical virtual trials of AF treatment.

Computational modeling of apoptotic signaling pathways induced by cisplatin.

BACKGROUND: Apoptosis is an essential property of all higher organisms that involves extremely complex signaling pathways. Mathematical modeling provides a rigorous integrative approach for analyzing and understanding such intricate biological systems. RESULTS: Here, we constructed a large-scale, literature-based model of apoptosis pathways responding to an external stimulus, cisplatin. Our model includes the key elements of three apoptotic pathways induced by cisplatin: death receptor-mediated, mitochondrial, and endoplasmic reticulum-stress pathways. We showed that cisplatin-induced apoptosis had dose- and time-dependent characteristics, and the level of apoptosis was saturated at higher concentrations of cisplatin. Simulated results demonstrated that the effect of the mitochondrial pathway on apoptosis was the strongest of the three pathways. The cross-talk effect among pathways accounted for approximately 25% of the total apoptosis level. CONCLUSIONS: Using this model, we revealed a novel mechanism by which cisplatin induces dose-dependent cell death. Our finding that the level of apoptosis was affected by not only cisplatin concentration, but also by cross talk among pathways provides in silico evidence for a functional impact of system-level characteristics of signaling pathways on apoptosis.

Antimicrobial effect of Korean propolis against the mutans streptococci isolated from Korean.

The aim of this study was to determine the optimal concentration of Korean propolis against clinical isolates of mutans streptococci (MS) from Koreans. The antimicrobial activity was evaluated using the minimum inhibitory concentration (MIC) and time-kill curves against mutans streptococci. The MIC(90) values of propolis for MS were 35 µg/ml. Propolis had a bacteriostatic effect on Streptococcus mutans ATCC 25175(T) and bactericidal effects on Streptococcus sobrinus ATCC 33478(T) at > 2 × MIC (70 µg/ml). These results suggest that the propolis can be used in the development of oral hygiene products for the prevention of dental caries.

Lateral calcaneal artery as a recipient pedicle for microsurgical foot reconstruction.

In the microsurgical reconstruction of the foot, anterior tibial artery-dorsalis pedis artery and posterior tibial artery-plantar artery are mainly used as recipient arterial pedicles. These arteries are the main sources for foot circulation and the preservation of these arterial circulations is very important. Although the end-to-side technique or the flow-through technique is selected for the microsurgical anastomosis, the possibility of injury to the circulation of these main arteries exists. We showed the availability of this artery with an angiographic injection study in five fresh cadavers as a reliable recipient artery. We also used the lateral calcaneal artery as a recipient pedicle in foot reconstruction without sacrificing the main circulation in two clinical cases. The diameters at the level of the calcaneus were 1.3 mm and 1.5 mm, respectively.

Venous drainage system of the transverse rectus abdominis musculocutaneous flap.

The transverse rectus abdominis musculocutaneous (TRAM) flap has been widely used for reconstruction of the breast. Partial loss of the flap is still a problem, however, and venous congestion may cause partial necrosis of the flap. There are few studies of the venous anatomy of the TRAM flap that compares with that of the arterial system, so the aim of this study was to investigate the venous anatomy of the TRAM flap and assess its drainage pathway using venography. A mixture of barium and gelatin were injected through the cutaneous veins such as the superficial inferior epigastric vein (SIEV), the superficial circumflex iliac vein (SCIV), or the perforating branch of the deep inferior epigastric vein (DIEV) in 11 hemiTRAM flaps. Venograms of TRAM flaps were taken, and the venous anatomy evaluated. The study showed that it consisted of the dominant superficial venous system, the SIEV and SCIV, and the secondary deep venous system, and the perforating vein of DIEV (DIEV perforator). In addition, we saw the large communicating veins between the SIEV and DIEV perforator near the umbilicus. We think that these communicating veins, which are considered as the DIEV perforators between the superficial and deep venous system, are an important venous drainage pathway after the TRAM flap has been raised.

Nasal packs with X-ray indicators.

Nasal packing is routinely performed by many surgeons following nasal surgery and is also frequently used for the treatment of epistaxis. The use of nasal packing, however, is sometimes associated with serious complications such as aspiration, bowel perforation, obstructive apnea, and hypoxia. This author has also once had the experience of losing a nasal pack during a procedure performed on a mentally impaired patient. If a nasal pack could be easily tracked by x-ray, treatment would be faster and easier. We now use x-ray indicators quilted into our nasal packs, which enable us to find the packs quickly and easily with plain x-ray film.