Metabolic Engineering of Pseudomonas putida KT2440 for De Novo Biosynthesis of Vanillic Acid.

Vanillic acid (VA), as a plant-derived phenolic acid compound, has widespread applications and good market prospects. However, the traditional production process cannot meet market demand. In this study, Pseudomonas putida KT2440 was used for de novo biosynthesis of VA. Multiple metabolic engineering strategies were applied to construct these P. putida-based cell factories, including the introduction of a Hs-OMTopt, engineering the cofactor S-adenosylmethionine supply pathway through the overexpression of metX and metH, reforming solubility of Hs-OMTopt, increasing a second copy of Hs-OMTopt, and the optimization of the fermentation medium. The resulting strain, XCS17, de novo biosynthesized 5.4 g/L VA from glucose in a fed-batch fermentation system; this is the highest VA production titer reported up to recently. This study showed that P. putida KT2440 is a robust platform for achieving the effective production of phenolic acids.

Highly Efficient Biosynthesis of Protocatechuic Acid via Recombinant Pseudomonas putida KT2440.

Owing to their physiological activities, plant-derived phenolic acids, such as protocatechuic acid (PCA), have extensive applications and market prospects. However, traditional production processes present numerous challenges and cannot meet increasing market demands. Hence, we aimed to biosynthesize PCA by constructing an efficient microbial factory via metabolic engineering of Pseudomonas putida KT2440. Glucose metabolism was engineered by deleting the genes for gluconate 2-dehydrogenase to enhance PCA biosynthesis. To increase the biosynthetic metabolic flux, one extra copy of the genes aroGopt, aroQ, and aroB was inserted into the genome. The resultant strain, KGVA04, produced 7.2 g/L PCA. By inserting the degradation tags GSD and DAS to decrease the amount of shikimate dehydrogenase, PCA biosynthesis was increased to 13.2 g/L in shake-flask fermentation and 38.8 g/L in fed-batch fermentation. To the best of our knowledge, this was the first use of degradation tags to adjust the amount of a key enzyme at the protein level in P. putida KT2440, evidencing the remarkable potential of this method for naturally producing phenolic acids.

The Efficacy of Rosuvastatin, Amlodipine, and Aspirin in the Treatment of Hypertension with Coronary Heart Disease and Its Effect on Platelet Aggregation.

Objective: This study was to study the efficacy of rosuvastatin, amlodipine, and aspirin in the treatment of hypertension with coronary heart disease and its effect on platelet aggregation. Methods: The participants included 60 patients with hypertension and coronary heart disease who were treated at our hospital between January 2020 and May 2021 and were randomly assigned to receive either rosuvastatin, amlodipine, and Ziyin Huoxue Recipe (observation group) or rosuvastatin, amlodipine, Ziyin Huoxue Recipe, and aspirin (experimental group), with 30 patients in each. Outcome measures included clinical effectiveness, blood pressure indicators, blood lipid indices, plasma viscosity, platelet aggregation, cardiac function, and adverse responses. Results: The clinical efficacy in the experimental group was significantly higher than that in the observation group (P < 0.05). The differences were found in blood pressure indices and blood lipid indices between the two groups before treatment (P > 0.05). However, after treatment, the blood pressure indices in the experimental group were significantly lower than those in the observation group (P < 0.05). After treatment, the blood lipid indices, plasma viscosity, and platelet aggregation in the experimental group were significantly lower than those in the observation group (P < 0.05). The left ventricular ejection fraction (LVEF) of patients in the experimental group after treatment was significantly higher than that of patients in the observation group (P < 0.05). There was no significant difference in the incidence of adverse reactions among patients in the two groups (P > 0.05). Conclusion: The clinical efficacy of rosuvastatin, amlodipine, and aspirin markedly reduces the blood pressure indices, blood lipid indices, plasma viscosity, and platelet aggregation of patients with hypertension and coronary heart disease, improves LVEF, and has a good safety profile.

Model Embraced Electromechanical Coupling Time for Estimation of Heart Failure in Patients With Hypertrophic Cardiomyopathy.

Objective: This study aimed to establish a model embraced electromechanical coupling time (EMC-T) and assess the value of the model for the prediction of heart failure (HF) in patients with hypertrophic cardiomyopathy (HCM). Materials and Methods: Data on 82 patients with HCM at Shaanxi Provincial People's Hospital between February 2019 and November 2021 were collected and then formed the training dataset (n = 82). Data were used to screen predictors of HF using univariate and multivariate analyses. Predictors were implemented to discover the optimal cut-off value, were incorporated into a model, and shown as a nomogram. The cumulative HF curve was calculated using the Kaplan-Meier method. Additionally, patients with HCM at other hospitals collected from March 2019 to March 2021 formed the validation dataset. The model's performance was confirmed both in training and validation sets. Results: During a median of 22.91 months, 19 (13.38%) patients experienced HF. Cox analysis showed that EMC-T courses in the lateral wall, myoglobin, PR interval, and left atrial volume index were independent predictors of HF in patients with HCM. Five factors were incorporated into the model and shown as a nomogram. Stratification of patients into two risk subgroups by applying risk score (<230.65, ≥230.65) allowed significant distinction between Kaplan-Meier curves for cumulative incidence of HF events. In training dataset, the model had an AUC of 0.948 (95% CI: 0.885-1.000, p < 0.001) and achieved a good C-index of 0.918 (95% CI: 0.867-0.969). In validation dataset, the model had an AUC of 0.991 (95% CI: 0.848-1.000, p < 0.001) and achieved a strong C-index of 0.941 (95% CI: 0.923-1.000). Calibration plots showed high agreement between predicted and observed outcomes in both two datasets. Conclusion: We established and validated a novel model incorporating electromechanical coupling time courses for predicting HF in patients with HCM.

Arrhythmogenic right ventricular cardiomyopathy characterized by recurrent syncope during exercise: A case report.

BACKGROUND: Arrhythmogenic right ventricular (RV) cardiomyopathy is a rare and currently underrecognized cardiomyopathy characterized by the replacement of RV myocardium by fibrofatty tissue. It may be asymptomatic or symptomatic (palpitations or syncope) and may induce sudden cardiac death, especially during exercise. To prevent adverse events such as sudden cardiac death and heart failure, early diagnosis and treatment of arrhythmogenic RV cardiomyopathy (ARVC) are crucial. We report a patient with ARVC characterized by recurrent syncope during exercise who was successfully treated with combined endocardial and epicardial catheter ablation. CASE SUMMARY: A 43-year-old man was referred for an episode of syncope during exercise. Previously, the patient experienced two episodes of syncope without a firm etiological diagnosis. An electrocardiogram obtained at admission indicated ventricular tachycardia originating from the inferior wall of the right ventricle. The ventricular tachycardia was terminated with intravenous propafenone. A repeat electrocardiogram showed a regular sinus rhythm with negative T waves and a delayed S-wave upstroke from leads V1 to V4. Cardiac magnetic resonance imaging showed RV free wall thinning, regional RV akinesia, RV dilatation and fibrofatty infiltration (RV ejection fraction of 38%). An electrophysiological study showed multiple inducible ventricular tachycardia as of a focal mechanism from the right ventricle. Endocardial and epicardial voltage mapping demonstrated scar tissue in the anterior wall, free wall and posterior wall of the right ventricle. Late potentials were also recorded. The patient was diagnosed with ARVC and treated with combined endocardial and epicardial catheter ablation with a very satisfactory follow-up result. CONCLUSION: Clinicians should be aware of ARVC, and further workup, including imaging with multiple modalities, should be pursued. The combination of epicardial and endocardial catheter ablation can lead to a good outcome.

Pheochromocytoma in a 49-year-old woman presenting with acute myocardial infarction: A case report.

BACKGROUND: Pheochromocytoma is a rare endocrine tumor arising from chromaffin cells and having extensive and profound effects on the cardiovascular system by continuously or intermittently releasing catecholamines. The clinical manifestations of pheochromocytoma are diverse, and the typical triad, including episodic headache, palpitations, and sweating, only occurs in 24% of pheochromocytoma patients, which often misleads clinicians into making an incorrect diagnosis. We herein report the case of a patient with intermittent chest pain and elevated myocardial enzymes for 2 years who was diagnosed with pheochromocytoma. CASE SUMMARY: A 49-year-old woman presented with intermittent chest pain for 2 years. Two years ago, the patient experienced chest pain and was diagnosed with acute myocardial infarction, with 25% stenosis in the left circumflex. The patient still had intermittent chest pain after discharge. Two hours before admission to our hospital, the patient experienced chest pain with nausea and vomiting, lasting for 20 min. Troponin I and urinary norepinephrine and catecholamine levels were elevated. An electrocardiogram indicated QT prolongation and ST-segment depression in leads II, III, aVF, and V3-V6. A coronary computed tomography angiogram revealed no evidence of coronary artery disease. Echocardiography showed left ventricular enlargement and a decreased posterior inferior wall motion amplitude. Contrast-enhanced computed tomography demonstrated an inhomogeneous right adrenal mass. The patient successfully underwent laparoscopic right adrenalectomy, and histopathology confirmed adrenal pheochromocytoma. During the first-year follow-up visits, the patient was asymptomatic. The abnormal changes on echocardiography and electrocardiogram disappeared. CONCLUSION: Clinicians should be aware of pheochromocytoma. A timely and accurate diagnosis of pheochromocytoma is essential for alleviating serious cardiac complications.

Percutaneous Intramyocardial Septal Radiofrequency Ablation for Interventricular Septal Reduction: An Ovine Model with 1-Year Outcomes.

BACKGROUND: Percutaneous intramyocardial (PIM) septal radiofrequency ablation (SRA) is a novel treatment approach for hypertrophic obstructive cardiomyopathy patients, but there has been lack of a large animal model to study PIM-SRA. We aimed to validate the long-term safety and efficacy of PIM-SRA and to observe pathological changes of the ablated interventricular septum (IVS) in a healthy sheep model. METHODS AND RESULTS: Twelve sheep were randomized to the PIM-SRA group (n = 6) and the sham group (n = 6). In the PIM-SRA group, a radiofrequency (RF) electrode was inserted into the IVS with a maximum power of 80 W for 5 min. In the sham group, the RF electrode tip was positioned in the IVS segment but without RF power delivery. Septal hypokinesis was seen in all PIM-SRA group animals immediately after the procedure; the systolic wall thickening rate and motion amplitude of the ablated region decreased (p < 0.01), and the diastolic IVS thickness also decreased significantly over time (p < 0.01). ECG showed that all the sheep had normal sinus rhythm during the follow-up. Pathological examinations revealed scar tissue in the ablated region as expected. CONCLUSIONS: PIM-SRA produced precisely ablated myocardial tissue, reduced the IVS thickness significantly, preserved the global LV function, and avoided the incidence of conduction system damage in the long term. PIM-SRA was found to be a safe and effective minimally invasive septal reduction therapy.

Meta-analysis of vitamin D supplementation in the treatment of chronic heart failure.

Objectives. We performed a meta-analysis to determine whether vitamin D supplementation is beneficial in patients with chronic heart failure (CHF). Design. Meta-analysis of randomised controlled trials. Results. Vitamin D supplementation in patients with CHF improved health-related quality of life and C-reactive protein levels [weighted mean difference (WMD): 6.75, 95% confidence interval (CI): 2.87 to 10.64, p < .001; standardised mean difference (SMD): -0.41, 95% CI: -0.71 to -0.11, p = .007]. However, this supplementation was not superior to conventional treatment in terms of mortality, changes in left ventricular ejection fraction (ΔLVEF), N-terminal pro-B-type natriuretic peptide or B-type natriuretic peptide levels, and 6-minute walk distance (risk ratio: 1.11, 95% CI: 0.79 to 1.57, p = .53; WMD: 2.56, 95% CI: -2.18 to 7.31, p = .29; SMD: -0.18, 95% CI: -0.42 to 0.06, p = .15; WMD: -23.30, 95% CI: -58.31 to 11.72, p = .19). In contrast, ΔLVEF significantly improved (WMD: 6.75, 95% CI: 4.16 to 9.34, p < .001) in the subgroup without calcium supplementation. Additionally, some randomised controlled trials showed that adverse events were more frequent in people with high vitamin D levels. Conclusions. Vitamin D supplementation decreases serum levels of inflammatory markers and improves quality of life in CHF patients. Pooled analysis of vitamin D supplementation did not show reduced mortality or improved left ventricular function perhaps because of excessive increase in plasma 25-hydroxyvitamin D and calcium levels. Future studies should pay attention to vitamin D and calcium levels achieved.

Transthoracic echocardiography guided percutaneous laser ablation of the interventricular septum: A successful sheep model for septal thickness reduction and one year follow-up.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease, causing breathlessness, chest pain, syncope and sudden death. One-year outcome of echo-guided transthoracic percutaneous laser ablation (TPLA) of the sheep interventricular septum was studied as a novel treatment to reduce the septal thickness. It may partially address the limitations of surgical myectomy and alcohol septal ablation in terms of trauma, safety, and efficacy. METHODS: Twelve healthy adult sheep were randomly categorized into two groups: with and without the laser application of TPLA of the interventricular septum (IVS) at the energy level of 5 W for 3 min. Echocardiography, electrocardiography (ECG), cardiac magnetic resonance (CMR), serological and pathological examinations were performed over a 12-month follow-up. RESULTS: After the laser ablation all animals survived with normal cardiac function; No severe complications or bundle branch block were noted. The septal thickness (3.11 ±â€¯1.14 vs. 8.40 ±â€¯0.45 mm, p < 0.05), regional movement of ablated IVS and longitudinal strain significantly decreased when comparing the experimental and control groups. The Troponin I level was significantly elevated after the operation, which validated immediate cardiac coagulation necrosis. On cardiac magnetic resonance (CMR) imaging, the ablated myocardium showed significant fibrosis evidenced by late gadolinium enhancement. Pathological results revealed damaged ultra-structure of the ablated myocardium and development of fibrosis. CONCLUSIONS: TPLA is a safe and effective minimally invasive method to reduce IVS thickness in the long term, making it a potential alternative for HOCM treatment.