Pulmonary artery coarctation repair in univentricular heart: indications and optimal timing.

BACKGROUND: To analyse surgical outcomes of pulmonary artery coarctation in univentricular hearts, focusing on surgical indications and optimal timing. METHODS: We retrospectively reviewed 49 patients with pulmonary artery coarctation in univentricular hearts treated at our institution between 1993 and 2022. Twenty-eight patients were diagnosed before first-stage palliation. Of these, 14 underwent systemic-pulmonary shunt only as first-stage palliation (Group 1), and 14 underwent systemic-pulmonary shunt plus surgical pulmonary artery plasty as first-stage palliation (Group 2). Twenty-one patients diagnosed after first-stage palliation underwent surgical pulmonary artery plasty at the time of bidirectional Glenn procedure (Group 3). RESULTS: Follow-up period after initial palliation was 6±8 years. The Fontan procedure was successful in 35 patients (71%) aged 28±26 months (range 18-139). Freedom from interstage death (Group 1, 53%; Group 2, 85%; Group 3, 93%) and interstage reintervention (Group 1, 50%; Group 2, 75%; Group 3, 73%) rates were significantly lower in Group 1 (p = 0.01). Five and four patients in Group 1 and Group 3, respectively, needed additional shunts before the bidirectional Glenn procedure. In Group 1, one patient with a non-confluent pulmonary artery achieved hemi-lung Fontan circulation. In Group 2, one patient suffering with a non-confluent pulmonary artery could not achieve Fontan circulation, whereas another patient with pulmonary venous obstruction achieved hemi-lung Fontan circulation. CONCLUSIONS: Surgical pulmonary artery plasty performed at first-stage palliation improved outcomes of pulmonary artery coarctation in univentricular hearts, particularly when pulmonary artery coarctation had already progressed during the neonatal period or early infancy.

Congenital Non-Confluent Pulmonary Artery Sourced from Bilateral Arterial Ducts: A Rare Anomaly.

This study aimed to identify the influence of the non-confluent pulmonary artery originating from the bilateral arterial ducts (AD) on the outcomes of the Fontan circulation. We retrospectively reviewed the records of nine patients with bilateral AD and a non-confluent pulmonary artery in a single ventricle at our institution between 1993 and 2023. Three patients showed maintained AD or underwent a systemic-pulmonary shunt for stenotic AD, followed by the Glenn procedure. Four patients underwent systemic-pulmonary shunt with angioplasty as the first palliation, followed by the Glenn procedure. Two patients underwent systemic-pulmonary shunt or AD stenting as the first palliation and systemic-pulmonary shunt with angioplasty as the second palliation. There were no cases of interstage mortality. Pulmonary arteries grew and achieved a good balance (pre-Fontan pulmonary artery index [PAI], 164 ± 27 mm2/m2; right/left PAI ratio, 1.06 ± 0.23). All patients underwent the Fontan procedure (median, 3.5 years; range, 2.3-6.4 years) and were followed up for 7.8 years (range, 0.1-16.4 years) after the procedure. One patient required hospitalization for heart failure at 1.8 years, and three patients required catheter intervention for pulmonary stenosis within 2 months after the Fontan procedure. Non-confluent pulmonary arteries originating from the bilateral AD do not preclude Fontan completion and good Fontan outcomes by restoring balance to pulmonary blood flow. Due to the limited sample size in this study, additional research is imperative to delve deeper into our findings and enhance understanding of the most effective surgical approach for this disease.

Norwood Operation with Right Ventricular-Pulmonary Artery Shunt Versus Comprehensive Stage II After Bilateral Pulmonary Artery Banding Palliation.

As a strategy for the primary Norwood operation, the right ventricular-pulmonary artery shunt is associated with satisfactory early outcome. However, use of this shunt after bilateral pulmonary artery banding remains controversial. This study compared the operative outcomes and late hemodynamics in patients who underwent the Norwood operation, preceded by bilateral pulmonary artery banding, with a right ventricular-pulmonary artery shunt or with bidirectional Glenn anastomosis (comprehensive stage II strategy). We retrospectively reviewed 38 patients who underwent the Norwood operation preceded by bilateral pulmonary artery banding between 2004 and 2017. Of these, 17 underwent the Norwood operation with a right ventricular-pulmonary artery shunt (Group S), whereas 21 underwent the comprehensive stage II strategy (Group G). 5 years after the Norwood operation, 10 (60%) and 17 (81%) patients in Group S and Group G, respectively, underwent the Fontan procedure. Group S showed significantly lower pressure in the superior vena cava after bidirectional Glenn anastomosis than Group G (13 ± 2 mmHg vs. 18 ± 3 mmHg; p < 0.01), but pressures were similar after the Fontan procedure. The right ventricular end-diastolic volume at 1 year post-Fontan procedure was significantly higher in Group S than in Group G (142 ± 41% vs. 91 ± 28%; p < 0.01). In terms of early outcomes, the Norwood operation with a right ventricular-pulmonary artery shunt enabled low pressure in the superior vena cava, but in the long term, this shunt adversely influenced the right ventricular volume.

Outlet Ventricular Septal Defect: Impact of Surgery on the Late Aortic and Pulmonary Valve Functions.

This study retrospectively evaluated long-term post-operative aortic and pulmonary valve functions in outlet ventricular septal defects. We evaluated aortic regurgitation and pulmonary regurgitation using pre- and post-operative echocardiograms. Overall, 158 patients who underwent intracardiac repair due to outlet ventricular septal defects with aortic valve deformity or congestive heart failure were included. The median follow-up period was 7 years (interquartile range: 0-17 years), without deaths or pacemaker implantations. The age, weight, ventricular septal defect size, and mild aortic regurgitation at surgery were factors associated with post-operative residual aortic regurgitation. Mild pulmonary regurgitation was observed in 12%, 30%, and 40% of patients 5, 10, and 15 years after surgery, respectively. There were no significant differences in age and weight at which surgery was performed between patients with mild pulmonary regurgitation and those with less than mild pulmonary regurgitation. However, the number of sutures across the pulmonary valve was associated with post-operative pulmonary regurgitation (P < 0.01). As some patients with mild pre-operative aortic regurgitation may not improve even after surgery, early surgical intervention is necessary when aortic regurgitation appears. Some patients may develop post-operative pulmonary regurgitation in the long term, suggesting the need for careful follow-up.

Influence of Bovine Arch Anatomy on Surgical Outcomes of Coarctation of the Aorta.

This study aimed to evaluate the outcome of coarctation of the aorta (CoA) repair with a special interest in bovine arch anatomy. Fifty-six patients who underwent CoA repair between 2010 and 2021 were included in this retrospective study. Of these, 11 patients had bovine arch anatomy. Surgical outcomes were reviewed. Computed tomography was used to analyze aortic arch geometry for all cases preoperatively. The gap between anastomotic sites was calculated at the linear region of the lesser curvature of the aortic arch between the distal ascending aorta and the proximal descending aorta. CoA repair was performed at a median age of 39 days (median body weight 3.3 kg). Thirty-two patients underwent extended direct anastomosis, 22 patients underwent direct anastomosis, and two patients underwent lesser curvature patch augmentation. The median follow-up period was 47 months. There were no early deaths. In patients who underwent direct and extended direct anastomosis, nine recoarctation and one left pulmonary venous obstruction events occurred. Moreover, freedom from these adverse events was 81% in normal arch and 50% in bovine arch patients at 10 years (P = 0.04). Two patients with a bovine arch anatomy who underwent lesser curvature patch augmentation had good outcomes. The distal arch was narrower and longer, and the gap between anastomotic sites was longer in patients with a bovine arch anatomy than with a normal arch (P < 0.01). In CoA with a bovine arch anatomy, the gap between anastomotic sites was long. This adversely influenced the outcomes of the CoA repairs.

Discovery of Novel Chromenopyridine Derivatives as Readthrough-Inducing Drugs.

Hurler syndrome, a type of Mucopolysaccharidosis type I, is an inherited disorder caused by the accumulation of glycosaminoglycans (GAG) due to a deficiency in lysosomal α-L-iduronidase (IDUA), resulting in multiorgan dysfunction. In many patients with Hurler syndrome, IDUA proteins are not produced due to nonsense mutations in their genes; therefore, readthrough-inducing compounds, such as gentamycin, are expected to restore IDUA proteins by skipping the premature termination codon. In the present study, we synthesized a series of chromenopyridine derivatives to identify novel readthrough-inducing compounds. The readthrough-inducing activities of synthesized compounds were examined by measuring cellular IDUA activities and GAG concentrations in Hurler syndrome patient-derived cells. Compounds with a difluorophenyl group at the 2-position of chromenopyridine, a cyclobutyl group at the 3-position, and a basic side chain or basic fused ring exhibited excellent readthrough-inducing activities. KY-640, a chromenopyridine derivative with a tetrahydroisoquinoline sub-structure, increased the cellular IDUA activities of patient-derived cells by 3.2-fold at 0.3 µM and significantly reduced GAG concentrations, and also significantly increased enzyme activity in mouse models, suggesting its therapeutic potential in patients with Hurler syndrome.

Synthesis and Evaluation of Novel Triaryl Derivatives with Readthrough-Inducing Activity.

The readthrough mechanism, which skips the premature termination codon and restores the biosynthesis of the defective enzyme, is an emerging therapeutic tactic for nonsense mutation-related diseases, such as Hurler syndrome, a type of mucopolysaccharidosis. In the present study, novel triaryl derivatives were synthesized and their readthrough-inducing activities were evaluated by a luciferase reporter assay with a partial α-L-iduronidase (IDUA) DNA sequence containing the Q70X nonsense mutation found in Hurler syndrome and by measuring the enzyme activity of IDUA knockout cells transfected with the mutant IDUA gene. KY-516, a representative compound in which the meta position carboxyl group of the left ring of the clinically used ataluren was converted to the para position sulfamoylamino group, the central ring to triazole, and the right ring to cyanobenzene, exhibited the most potent readthrough-inducing activity in the Q70X/luciferase reporter assay. In Q70X mutant IDUA transgenic cells, KY-516 significantly increased enzyme activity at 0.1 µM. After the oral administration of KY-516 (10 mg/kg), the highest plasma concentration of KY-516 was above 5 µM in rats. These results indicate that KY-516, a novel triaryl derivative, exhibits potent readthrough-inducing activity and has potential as a therapeutic agent for Hurler syndrome.

Prediction of Dissolution Data Integrated in Tablet Database Using Four-Layered Artificial Neural Networks.

A large number of dissolution data were measured and integrated into a previously constructed tablet database composed of 14 kinds of compounds as model active pharmaceutical ingredients (APIs) with contents ranging from 10 to 80%. The database has contained physicochemical and powder properties of APIs, together with basic physical attributes of tablets such as the tensile strength and the disintegration time. In order to enhance the value of this database, drug dissolution data are essential to improving key information for designing tablet formulations. A four-layered artificial neural network (4LNN), newly implemented in commercially available software, was employed to predict dissolution data from physicochemical and powder properties of APIs. Our results showed that an excellent model for the prediction of dissolution data was achieved with 4LNN method. The function of 4LNN was appreciably better than that of conventional three-layered model, despite both models adopting the same number of nodes and algorithms for activation functions. Furthermore, linear regression models resulted in poor prediction of dissolution data.

Improvement of a direct electron transfer-type fructose/dioxygen biofuel cell with a substrate-modified biocathode.

The fructose/dioxygen biofuel cell, one of the direct electron transfer (DET)-type bioelectrochemical devices, utilizes fructose dehydrogenase (FDH) on the anode and multi-copper oxidase such as bilirubin oxidase (BOD) on the cathode as catalysts. The power density in the literature is limited by the biocathode performance. We show that the DET-type biocathode performance is greatly improved, when bilirubin or some related substances are adsorbed on electrodes before the BOD adsorption. Several data show that the substrate modification induces the appropriate orientation of BOD on the electrode surface for the DET. The substrate-modification method has successfully been applied to air-breathing gas-diffusion-type biocathodes. We have also optimized the conditions of the FDH adsorption on carbon cryogel electrodes. Finally, a one-compartment DET-type biofuel cell without separators has been constructed, and the maximum power density of 2.6 mW cm(-2) was achieved at 0.46 V of cell voltage under quiescent (passive) and air atmospheric conditions.

Impact of Optimal Fenestration Size on Outcomes of High-Risk Fontan Patients.

BACKGROUND: We aimed to analyze mid-term outcomes of the fenestrated Fontan procedure, focusing on the fenestration size. METHODS: We retrospectively reviewed the outcomes of the fenestrated Fontan procedure. Among 165 patients who underwent the Fontan procedure from 2011 to 2021, fenestration was created in 27 patients with the highest risks, including those with hypoplastic left heart syndrome, hypoplastic pulmonary arteries, heterotaxy syndrome with high pulmonary vascular resistance, and pulmonary arterial pressure >15 mm Hg. The patients underwent the procedure at a median age of three years (body weight, 11.4 kg; body surface area, 0.54 m2). Fenestration sizes were 3.5 to 5 mm. RESULTS: Spontaneous fenestration closure occurred within one year postoperatively in nine patients. Among them, three experienced Fontan failure, necessitating refenestration. Although fenestration size did not differ, the size corrected by body surface area at the time of surgery was smaller in patients with fenestration closure (6.4 mm/m2 vs 8.3 mm/m2, P < .05). Patients with a fenestration <7 mm/m2 were more likely to have fenestration closure within one year postoperatively, and those with a fenestration >9 mm/m2 were more likely to have severe desaturation and require home oxygen therapy following discharge. CONCLUSIONS: Spontaneous fenestration closure affected the frequency of Fontan complications. A very small fenestration size corrected by body surface area was a significant risk factor for spontaneous closure. Conversely, a very large fenestration size corrected by body surface area resulted in severe desaturation. The optimal fenestration size to prevent early spontaneous closure and severe desaturation is approximately 8 mm/m2.

Impact of the Rudimentary Chamber on Outcomes in Fontan Patients.

Background: We sought to evaluate the influence of the rudimentary ventricle on long-term outcomes after the Fontan operation, focusing on exercise capacity and cardiac performance. Methods: Between 1995 and 2021, 290 patients underwent a total cavopulmonary connection. "Two-ventricle" Fontan circulation was defined as a rudimentary ventricle >30% of the dominant ventricle or >50% of its predicted normal value. This cohort was compared with patients with single-ventricle Fontan circulation. The primary endpoint was Fontan failure, and the secondary endpoints were VO2 and cardiac catheterization data at ten years postoperatively. Results: The median follow-up after the Fontan operation was 7.9 years (interquartile range: 1.9-13.9). No significant difference was found in Fontan failure-free survival between the "two-ventricle" Fontan circulation group and the single-ventricle Fontan circulation group (83/91, 93% vs 156/199, 78%), respectively at 20 years; P = .11). No significant difference was found in VO2 or cardiac performance except cardiac index, with 2.9 (2.3-4.8) versus 2.5 (2.3-4.3) L/min/m2 (P = .047). Fifty-one patients in the "two-ventricle" Fontan circulation group were followed up for over ten years after the Fontan operation. In the subgroup analysis of this cohort, the rudimentary ventricular end-diastolic volume/dominant ventricular end-diastolic volume ratio showed a significant positive correlation with dominant ventricular end-diastolic pressure (r = 0.58 [95% CI 0.35-0.74], P = .002) and a significant negative correlation with VO2 (r = -0.61 [95% CI -0.80 to -0.28], P = .001). Conclusions: The rudimentary ventricle was not significantly associated with any clinical disadvantages regarding Fontan failure. However, a large rudimentary ventricle was significantly associated with higher end-diastolic pressure and lower exercise capacity.

Heterologous overexpression and characterization of a flavoprotein-cytochrome c complex fructose dehydrogenase of Gluconobacter japonicus NBRC3260.

A heterotrimeric flavoprotein-cytochrome c complex fructose dehydrogenase (FDH) of Gluconobacter japonicus NBRC3260 catalyzes the oxidation of d-fructose to produce 5-keto-d-fructose and is used for diagnosis and basic research purposes as a direct electron transfer-type bioelectrocatalysis. The fdhSCL genes encoding the FDH complex of G. japonicus NBRC3260 were isolated by a PCR-based gene amplification method with degenerate primers designed from the amino-terminal amino acid sequence of the large subunit and sequenced. Three open reading frames for fdhSCL encoding the small, cytochrome c, and large subunits, respectively, were found and were presumably in a polycistronic transcriptional unit. Heterologous overexpression of fdhSCL was conducted using a broad-host-range plasmid vector, pBBR1MCS-4, carrying a DNA fragment containing the putative promoter region of the membrane-bound alcohol dehydrogenase gene of Gluconobacter oxydans and a G. oxydans strain as the expression host. We also constructed derivatives modified in the translational initiation codon to ATG from TTG, designated (TTG)FDH and (ATG)FDH. Membranes of the cells producing recombinant (TTG)FDH and (ATG)FDH showed approximately 20 times and 100 times higher specific activity than those of G. japonicus NBRC3260, respectively. The cells producing only FdhS and FdhL had no fructose-oxidizing activity, but showed significantly high d-fructose:ferricyanide oxidoreductase activity in the soluble fraction of cell extracts, whereas the cells producing the FDH complex showed activity in the membrane fraction. It is reasonable to conclude that the cytochrome c subunit is responsible not only for membrane anchoring but also for ubiquinone reduction.

Congenital Mitral Regurgitation Repair Based on Carpentier's Classification: Long-Term Outcomes.

BACKGROUND: There are few reports of the outcomes of standardized surgical management addressing the etiologic and morphologic aspects of mitral valve malformation according to Carpentier's classification. This study aimed to evaluate the long-term outcomes of mitral valve repair in children according to Carpentier's classification. METHODS: Patients who underwent mitral valve repair at our institution between 2000 and 2021 were retrospectively reviewed. Preoperative data, surgical techniques, and outcomes were analyzed according to Carpentier's classification. The proportion of patients free of mitral valve replacement and reoperation was estimated using Kaplan-Meier analysis. RESULTS: Twenty-three patients (median operative age, four months) were followed up for 10 (range, 2-21) years. Preoperative mitral regurgitation was severe in 12 patients and moderate in 11 patients. Eight, five, seven, and three patients had Carpentier's type 1, 2, 3, and 4 lesions, respectively. Ventricular septal defect (N = 9) and double outlet of the great arteries from the right ventricle (N = 3) were the most commonly associated cardiac malformations. There were no cases of operative mortality or deaths during the follow-up. The overall five-year rate of freedom from mitral valve replacement was 91%, whereas the five-year rates of freedom from reoperation were 74%, 80%, 71%, and 67% in type 1, 2, 3, and 4 lesions, respectively. Postoperative mitral regurgitation at the last follow-up was moderate in three patients and less than mild in 20 patients. CONCLUSIONS: Current surgical management of congenital mitral regurgitation is generally considered adequate; however, more complicated cases required a combination of various surgical techniques.

Total Synthesis of (-)-Sigillin A: A Polychlorinated and Polyoxygenated Natural Product.

The total synthesis of (-)-sigillin A, a highly chlorinated and oxygenated octahydroisocoumarin, is described herein. A hexahydroisocoumarin skeleton was constructed from (R)-4-(trichloromethyl)oxetan-2-one in seven steps. Its unique manganese oxidation provided an enone as the key intermediate of sigillin A. Stereoselective installation of two hydroxy groups and formation of gem-dichloroalkene from the corresponding ketone led to the total synthesis of (-)-sigillin A in a total of 16 steps.

Dynamics of the Cellular Metabolism of Leptosperin Found in Manuka Honey.

Leptosperin (methyl syringate ß-d-gentiobioside) is abundantly found in manuka honey, which is widely used because of its antibacterial and possible anti-inflammatory activities. The aim of this study was to examine the molecular mechanism underlying the metabolism of leptosperin. Five phytochemicals (leptosperin, methyl syringate (MSYR), glucuronate conjugate of MSYR (MSYR-GA), sulfonate conjugate of MSYR (MSYR-S), and syringic acid (SYR)) were separately incubated with HepG2 and Caco-2 cells. After incubation, we found that the concentration of MSYR decreased, whereas the concentrations of SYR, MSYR-GA, and MSYR-S increased. By profiling with inhibitors and carboxylesterases (CES1, 2), we found that the conversion from MSYR to SYR was mediated by CES1. Lipopolysaccharide-stimulated RAW264.7 cells restored MSYR-GA to MSYR possibly by the secreted ß-glucuronidase. All of the mice administered with leptosperin, MSYR, or manuka honey showed higher MSYR (13.84 ± 11.51, 14.29 ± 9.19, or 6.66 ± 2.30 nM) and SYR (1.85 ± 0.66, 6.01 ± 1.20, or 8.16 ± 3.10 nM) levels in the plasma compared with that of the vehicle controls (3.33 ± 1.45 (MSYR) and 1.85 ± 0.66 (SYR) nM). The findings of our study indicate that the unique metabolic pathways of these compounds may account for possible functionalities of manuka honey.

Contribution of the physicochemical properties of active pharmaceutical ingredients to tablet properties identified by ensemble artificial neural networks and Kohonen's self-organizing maps.

The aim of this study was to create a tablet database for use in designing tablet formulations. We focused on the contribution of active pharmaceutical ingredients (APIs) to tablet properties such as hardness and disintegration time (DT). Before we investigated the effects of the APIs, we optimized the tablet base formulation (placebo tablet) according to an expanded simplex search. The optimal placebo tablet showed sufficient hardness and rapid disintegration. We then tested 14 kinds of compounds as the model APIs. The APIs were characterized in terms of their physicochemical properties using Kohonen's self-organizing maps. We also prepared model tablets by incorporating the APIs into the optimal placebo tablet, and then examined the tablet properties, including tensile strength and DT. On the basis of the experimental data, an ensemble artificial neural network incorporating general regression analysis was conducted. A reliable model of the correlation between the physicochemical properties of the APIs and the tablet properties was thus constructed. From the correlation model, we clarified the detailed contributions of each physicochemical property to the tablet attributes.