[Mitral Regurgitation Repaired by Papillary Heads Optimization Technique].

Functional mitral regurgitation( FMR) is a risk factor that increases the mortality rate and incidence of heart failure. Surgical intervention is important. Mitral valve (MV) reconstruction can preserve the valvular apparatus;no anticoagulation therapy is required, left ventricular function is preserved. Some studies have reported a high mitral regurgitation (MR) recurrence rate with only restrictive MV annuloplasty for FMR. Therefore, various reconstructive techniques for FMR have been developed. Papillary heads optimization( PHO),reported by Komeda, is one technique. We performed MV repair with the PHO technique in 3 FMR cases. The 1st case had severe tethering and annulus dilatation due to chronic MR, the 2nd and 3rd were caused by ischemic and dilated cardiomyopathy (DCM),respectively. In the early postoperative period, we achieved technical success in all cases. However, 9 months later, moderate MR had recurred in the 3rd case. Geometric measurements with transthoracic echocardiography showed an increase of the papillary muscle distance between the papillary muscle origin and the posterior MV anuulus. The correction of papillary muscles position by PHO might have failed by the progress of DCM, and MR recurred. The operative method and indication for DCM should be carefully considered.

A Quantum Mechanics-Based Method to Predict Intramolecular Hydrogen Bond Formation Reflecting P-glycoprotein Recognition.

Passive membrane permeability and an active transport process are key determinants for penetrating the blood-brain barrier. P-glycoprotein (P-gp), a well-known transporter, serves as the primary gatekeeper, having broad substrate specificity. A strategy to increase passive permeability and impair P-gp recognition is intramolecular hydrogen bonding (IMHB). 3 is a potent brain penetrant BACE1 inhibitor with high permeability and low P-gp recognition, although slight modifications to its tail amide group significantly affect P-gp efflux. We hypothesized that the difference in the propensity to form IMHB could impact P-gp recognition. Single-bond rotation at the tail group enables both IMHB forming and unforming conformations. We developed a quantum-mechanics-based method to predict IMHB formation ratios (IMHBRs). In a given data set, IMHBRs accounted for the corresponding temperature coefficients measured in NMR experiments, correlating with P-gp efflux ratios. Furthermore, the method was applied in hNK2 receptor antagonists, demonstrating that the IMHBR could be applied to other drug targets involving IMHB.

Head CT dose reduction with organ-based tube current modulation.

BACKGROUND: A helical head CT examination uses a pitch factor (PF) of <1.0, resulting in a part of the slice being directly irradiated twice. This raises the possibility of double irradiation, which may increase the amount of radiation to the lens. Organ-based tube current modulation (OBTCM) is an effective method for reducing lens exposure because it reduces the dose to the anterior aspect of the patient. However, it is challenging to visualize the complex dose distribution when factoring in double irradiation. PURPOSE: To visualize twice-irradiated areas in helical head CT in three dimensions and to clarify the exposure reduction effect of OBTCM. MATERIAL AND METHODS: A leuco crystal violet (LCV) dosimeter was placed into an empty polyethylene terephthalate bottle 16.5 cm in diameter. Helical scans were performed without and with OBTCM using the following parameters: tube voltage 120 kV, tube current 600 mA, pitch factor 0.637, rotation time 0.5 s, 80 (detector rows) × 0.5 mm (detector collimation), and ten scans. Exposed areas were visualized using an optical computed tomography (OCT) system designed by our group. The dose reduction rate of OBTCM was defined as the ratio of the average values of the histogram with the dose value on the x-axis and the frequency on the y-axis without and with OBTCM at 90° to the anterior midline. RESULTS: The LCV dosimeter visualized the spiral-shaped twice-irradiated areas. Double irradiation resulted in a dose of 2.19/1.90 and 1.38/1.19 Gy (15.0% and 15.9% increase) without and with OBTCM, respectively. The dose reduction using OBTCM was 29.6% at 90° anterolateral. CONCLUSION: The LCV dosimeter visualized the complex three-dimensional irradiated areas and enabled dose measurement in twice-irradiated areas. Increased exposure from double irradiation was attenuated by OBTCM.

The mimivirus R355 gene product: preliminary crystallographic analysis of a putative ubiquitin-like protein-specific protease.

The complete genome sequence of the largest known double-stranded DNA virus, mimivirus, reveals the presence of a gene (denoted R355) that potentially encodes a cysteine protease that is expressed late (after 6 h) in the infectious cycle of the virus. In order to verify a sequence-based functional prediction and understand its role during the infectious process, the R355 protein was produced to assay its proteolytic activity and solve its three-dimensional structure. Here, the preliminary crystallographic analysis of the recombinant viral protein is reported. The crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with a monomer in the asymmetric unit. A MAD data set was used for preliminary phasing using the selenium signal from a selenomethionine-substituted protein crystal.

In vitro survival kinetics of microfluidic-sorted bovine spermatozoa.

BACKGROUND: The isolation and characterization of sperm subpopulations that can achieve fertilization is a major challenge of assisted reproduction methods. We focused on the microfluidic sperm sorter as a novel tool for collecting highly motile spermatozoa from heterogeneous semen samples. OBJECTIVES: This study primarily aims to obtain baseline information on sorted spermatozoa according to its characteristics and in vitro life span. MATERIALS AND METHODS: Frozen-thawed bull semen was subjected to microfluidic sperm sorting using diffuser-type microfluidic sperm sorter (DMSS). After sorting, samples were collected as the sorted spermatozoa and unsorted residual spermatozoa and incubated at 37°C for subsequent evaluation. The samples were assessed at different time points (0 or 1, 6, and 24 h) in terms of motility, which was measured by computer-assisted sperm analysis (CASA), membrane integrity, mitochondrial function, and adenosine triphosphate (ATP) production after sorting (0 h). To determine the characteristics and efficiency of DMSS sorting, the sorted spermatozoa were compared with samples collected using the swim-up method, a conventional method in motile sperm selection. RESULTS: A comparison between the sorted and residual spermatozoa demonstrated significantly higher motility parameters, membrane integrity, and mitochondrial function of the sorted spermatozoa until 6 h after incubation. The time course decrement of membrane and mitochondrial status were subjected to curve fitting and theoretically supported. Sperm ATP production measured immediately after sorting showed higher ATP generation of the sorted spermatozoa compared with the unsorted, frozen-thawed spermatozoa. The motility parameters and mitochondrial activity of DMSS-sorted spermatozoa were higher than the swim-up-collected spermatozoa (p < 0.05). DISCUSSION AND CONCLUSION: These results indicate that DMSS sorting can strictly select highly motile spermatozoa with the ability to maintain its membrane integrity and mitochondrial function related to ATP production. We speculate that the device that is able to sort high-quality spermatozoa can have great potential in assisted reproduction.

Pulse rate variability: a new biomarker, not a surrogate for heart rate variability.

With the popularization of pulse wave signals by the spread of wearable watch devices incorporating photoplethysmography (PPG) sensors, many studies are reporting the accuracy of pulse rate variability (PRV) as a surrogate of heart rate variability (HRV). However, the authors are concerned about their research paradigm based on the assumption that PRV is a biomarker that reflects the same biological properties as HRV. Because PPG pulse wave and ECG R wave both reflect the periodic beating of the heart, pulse rate and heart rate should be equal, but it does not guarantee that the respective variabilities are also the same. The process from ECG R wave to PPG pulse wave involves several transformation steps of physical properties, such as those of electromechanical coupling and conversions from force to volume, volume to pressure, pressure impulse to wave, pressure wave to volume, and volume to light intensity. In fact, there is concreate evidence that shows discrepancy between PRV and HRV, such as that demonstrating the presence of PRV in the absence of HRV, differences in PRV with measurement sites, and differing effects of body posture and exercise between them. Our observations in adult patients with an implanted cardiac pacemaker also indicate that fluctuations in R-R intervals, pulse transit time, and pulse intervals are modulated differently by autonomic functions, respiration, and other factors. The authors suggest that it is more appropriate to recognize PRV as a different biomarker than HRV. Although HRV is a major determinant of PRV, PRV is caused by many other sources of variability, which could contain useful biomedical information that is neither error nor noise.

Reimplantation of an anomalous left coronary artery with a malignant course.

A 14-year-old boy was diagnosed with an anomalous left coronary artery coursing between the ascending aorta and the main pulmonary artery and associated with a single coronary ostium. Owing to the high risk of sudden cardiac death, surgery was performed although he was asymptomatic with no sign of myocardial ischemia. Reimplantation of an anomalous left coronary artery is generally considered difficult because an aortic cuff is unavailable for coronary anastomosis; however, we accomplished a successful direct reimplantation in this patient. This procedure offers another choice in the surgical treatment of anomalous left coronary artery.

Conservative management of persistent pleural effusion using somatostatin.

Persistent pleural effusion developed in an 81-year-old man with acute pulmonary edema due to myocardial dysfunction. Daily chest tube drainage was 1,000 to 1,400 mL. Despite total parenteral nutrition and albumin supplementation, drainage did not decrease. However, continuous infusion of a somatostatin analog was effective in controlling the effusion.

Substituent effects on the in situ activation of the double activated cross-linking reaction.

We have previously reported that the oligonucleotides (ODN) containing 2-amino-6-(1-ethylsulfinyl)vinyl purine derivatives (2) exhibit selective and efficient cross-linking to a cytidine at the target site under neutral conditions. In addition, bis-alkylsulfinyl derivative (3b) as the stable precursor of 2 showed the moderate reactivity. In this study, we have searched other bis-alkylsulfinyl precursors to achieve higher cross-linking ability, and found that acetamidoethyl and hydroxyethyl derivatives showed highly efficient and selective reactivity.