Dilution rates and their transition modes influence organic acid productivity and bacterial community structure on continuous meta-fermentation using complex microorganisms.

We investigated the effect of dilution rates (D) (0.05, 0.15, and 0.4 h-1) and its transition mode strategies (constant, up, and down modes) on organic acid productivity and bacterial community structure on continuous meta-fermentation using complex microorganisms. The number of bacterial species decreased with increasing D in the constant mode while up and down modes maintained high and low values, respectively, regardless of the changing D values. Caldibacillus hisashii was the predominant species in all modes at all D values, while other bacterial species, including Anaerosalibacter bizertensis and Clostridium cochlearium were predominant in only certain modes and D values. The highest total organic acid productivity of 3.16 g L-1 h-1 was obtained with 82.2% lactic acid selectivity at D = 0.4 h⁻1 in constant mode. Heterofermentation occurred in the up mode, while the down mode exhibited the maximum butyric acid productivity of 0.348 g L-1 h-1 with 43.8% selectivity at D = 0.05 h-1. The constant, up, and down modes showed the distinct main products of lactic, acetic and formic, and butyric acids, respectively. In this study, we proposed a new parameter of species-specific productivity (SSP) to estimate which species and how much a bacterium quantitatively contributes to the targeted organic acid productivity in continuous meta-fermentation. SSP was determined based on the abundance of functional genes encoding key enzymes from the results of 16S amplicon analysis. In conclusion, D values and their transition modes affect productivity by changing the bacterial community structure, and are a significant factor in establishing a highly productive process in continuous meta-fermentation.

[A Cardiac Metastasis from Colorectal Cancer discovered due to Palpitation and Dyspnea:Report of a Case].

A 61-year-old woman presented to our hospital with complaints of palpitation, dyspnea, and complete atrioventricular block. A tumor filling the right atrium was detected by computed tomography (CT)and echocardiography. Since the symptoms were severe and there was a risk of sudden death due to pulmonary embolism, tumor resection was performed. Pathological results suggested that the tumor was well-differentiated metastatic adenocarcinoma originating from colorectal cancer. Since the tumor could not be completely removed, radiation therapy was performed after the operation. Cardiac metastases from colorectal cancer are relatively rare and are occasionally seen in autopsy cases, but infrequently in surviving cases. Regular follow-up is therefore required.

Revisiting the Aortic Valve Calcium Score in Evaluating the Severity of Aortic Stenosis in Japanese Patients　- A Single-Center Study.

Background: In patients with aortic stenosis (AS), measurement of aortic valve calcification (AVC) using computed tomography (CT) is recommended in cases where echocardiographic measurements are inconclusive. However, sex-specific AVC thresholds proposed in the guidelines for predicting severe AS (women: 1,200 arbitrary units [AU]; men: 2,000 AU) are based on studies from Western countries. Methods and Results: We retrospectively included 512 Japanese patients with at least moderate AS who underwent transthoracic echocardiography and CT. AVC was quantified using the Agatston method. AVC was positively correlated with peak aortic jet velocity and mean transvalvular gradient (mPG), and negatively correlated with aortic valve area (AVA) and the AVA index (AVAi). In 257 patients with concordant AS grading (152 severe AS [AVAi ≤0.6 cm2/m2, mPG ≥40 mmHg], 105 moderate AS [AVAi >0.6 cm2/m2, mPG <40 mmHg]), receiver operating characteristic curve analysis of AVC predicting severe AS yielded an area under the curve of 0.91 (95% confidence interval [CI] 0.87-0.95; P<0.001) in women and 0.86 (95% CI 0.75-0.98; P<0.001) in men. The optimal thresholds (women: 1,379 AU; men: 1,802 AU) were close to those proposed in the guidelines. The diagnostic accuracy of the thresholds in the guidelines was similar to that of the optimal thresholds. Conclusions: The sex-specific AVC thresholds proposed in international guidelines can be applied to Japanese AS patients, yielding similar diagnostic accuracy as the optimal cut-off derived from the study patients.

[Successful Surgical Management for Ischemic Heart Failure with Fractional Flow Reserve Derived from Computed Tomography:Report of a Case].

A 71-year-old woman was referred to our hospital for mitral valve repair and coronary artery bypass grafting (CABG). Conventional coronary artery angiography showed stenosis in the right coronary artery (RCA) and two diagonal branches, whereas transthoracic echocardiography (TTE) showed diffuse hypokinesis and mild-to-moderate mitral valve regurgitation. Fractional flow reserve derived from computed tomography (FFRct) demonstrated two additional lesions in the coronary artery at the left anterior descending artery (LAD) and the high lateral (HL) branch. Thus, we decided to perform CABG to RCA, LAD, the second diagonal branch, and HL as well as mitral valve repair. TTE one year after surgery showed trivial mitral regurgitation and progressive improvements in the left ventricular wall motion and the ejection fraction. FFRct is a usuful non-invasive method to identify coronary lesions that cause ischemia.

[Aortic Valve Replacement 36 Years after the First Mitral Valve Replacement with Björk-Shiley Prosthetic Valve;Report of a Case].

A 67-year-old woman was admitted with exertional dyspnea. She had undergone mitral valve replacement with Björk-Shiley prosthetic valve (convexo-concave type) 36 years previously for stenosis and regurgitation in another institute. An echocardiography showed a severe degree of aortic stenosis, and the implanted mitral valve function is normal. We performed aortic valve replacement with a bioprosthetic valve and no prophylactic reoperation for the implanted mitral valve. The postoperative courses were uneventful. The patient was discharged from the hospital in good clinical condition. Postoperative echocardiography showed the prosthetic valves were normal. The close follow-up should be needed to prevent fatal valve dysfunction.

[Debranching and Endovascular Repair for Kommerell's Diverticulum with Right-sided Aortic Arch;Report of a Case].

Right-sided aortic arch (RAA) is a rare congenital disorder. A 87-year-old man with chest pain was diagnosed with a right-sided aortic arch and Kommerell's diverticulum by computed tomography (CT). The diverticulum had a maximum diameter of 57 mm, and surgical intervention was chosen because of the possibility of rupture and dissection. We performed thoracic endovascular aortic repair( TEVAR) with a commercially available device, consisting of bypass grafting of the supra-aortic branches. The postoperative courses were uneventful. The patient was discharged from the hospital in good clinical condition. Postoperative CT showed complete exclusion of the diverticulum without endoleak and device migration. Debranching TEVAR for Kommerell's diverticulum was safe and effective.