Comparison of Ring and Suture Annuloplasty in the Treatment of Tricuspid Regurgitation

Background: Significant TR is common in patients with cardiac disease and because of its prognostic importance, TV came to the spotlight in the last decades. Functional TR is mostly treated when undergoing left-sided valve surgery, whereas idiopathic TR surgery is uncommon. The aim of this study is to compare the durability of tricuspid valve annuloplasty techniques, and to explore the optimal method for TV repair surgery. Methods: 1005 patients who underwent tricuspid valve repair from February 2012 to March 2019, were retrospectively studied. The patients had tricuspid valve repair while receiving surgery for other cardiac conditions. The study population was divided into Suture group (n=483, 48.1%), and Ring group (n=522, 51.9%). Data variation between and within the groups was analyzed with Mann-Whitney U test, Wilcoxon rank-sum test, and Radit analysis. Results: At two-year follow-up, in the Suture group, none/trace TR subjects were 63.9%, and 1.4% had severe TR; In the Ring group were: 63.9% none/trace, and 0.6% severe. Both groups’ two-year follow-up TR status was significantly different with preoperative TR status (p<0.05). At two-year follow-up, Suture group had 63.9% none/trace and 1.4% severe; and Ring group had 63.9% none/trace and 0.6% severe TR and there was no significant difference between the groups (p>0.05). Conclusions: Both annuloplasty techniques have good short-term outcomes. However, suture annuloplasty deteriorates faster than ring annuloplasty, making the latter to be the ideal technique for TV repair.

Antioxidant vs. Prooxidant Properties of the Flavonoid, Kaempferol, in the Presence of Cu(II) Ions: A ROS-Scavenging Activity, Fenton Reaction and DNA Damage Study

Kaempferol is a flavonoid that occurs in tea and in many vegetables and fruits, including broccoli, cabbage, beans, grapes, apples, and strawberries. The efficacy of Kaempferol has been demonstrated in the treatment of breast, esophageal, cervical, ovarian, and liver cancers and leukemia, which very likely arises from its prooxidant properties and the activation of pro-apoptotic pathways. Indeed, this matter has already been the focus of a number of published studies and reviews. The aim of the present study was to elucidate the antioxidant vs. prooxidant properties of flavonoids in the presence of the redox-active metal, copper (II) ion, by means of the Fenton reaction. The specific motivation of this work is that, since an increased level of Cu(II) ions is known to be associated with many disease states such as neurological conditions (Alzheimer’s disease) and cancer, any interaction between these ions and flavonoids might affect the outcome of therapeutic uses of the latter. The structure of the Cu-kaempferol complex in DMSO was investigated by means of low temperature EPR spectroscopy, which confirmed the existence of at least two distinct coordination environments around the copper (II) ion. UV vis-spectra of kaempferol and its Cu(II) complex in DMSO revealed an interaction between the 5-OH (A ring) group and the 4-CO (C ring) group of kaempferol with Cu(II) ions. An ABTS assay confirmed that kaempferol acted as an effective radical scavenger, and that this effect was further enhanced in the form of the Cu(II)-kaempferol complex. Quantitative EPR spin trapping experiments, using DMPO as the spin trap, confirmed suppression of the formation of a mixture of hydroxyl, superoxide, and methyl radicals, in a Fenton reaction system, upon coordination of kaempferol to the redox-active Cu(II) ions, by 80% with respect to the free Cu(II) ions. A viscometric study revealed a better DNA-intercalating ability of the Cu-kaempferol complex than for free kaempferol, essential for conferring anticancer activity of these substances. The results of the viscometric measurements were compared with those from a DNA damage study of Cu-kaempferol complexes in a Fenton reaction system, using gel electrophoresis. At low concentrations of kaempferol (Cu–kaempferol ratios of 1:1 and 1:2), a very weak protective effect on DNA was noted, whereas when kaempferol was present in excess, a significant DNA-protective effect was found. This can be explained if the weakly intercalated kaempferol molecules present at the surface of DNA provide protection against attack by ROS that originate from the Fenton reaction involving intercalated Cu(II)-kaempferol complexes. Following the application of ROS scavengers, L-histidine, DMSO, and SOD, gel electrophoresis confirmed the formation of singlet oxygen, hydroxyl radicals, and superoxide radical anions, respectively. We propose that the prooxidant properties of Cu-kaempferol complexes may provide anticancer activity of these substances. When present in excess, kaempferol displays antioxidant properties under Cu-Fenton conditions. This suggests that kaempferol might prove a suitable candidate for the prevention or treatment of oxidative stress related medical conditions that involve a disturbed metabolism of redox metals such as copper, for example, Menkes disease, and neurological disorders, including Alzheimer’s disease. For the potential use of kaempferol in clinical practice, it will be necessary to optimize the dose size and critical age of the patient so that this flavonoid may be beneficial as a preventive drug against cancer and neurological disorders.

Three-dimensional assemblies of carbon nitride tubes as nanoreactors for enhanced photocatalytic hydrogen production

Three-dimensional assembly of carbon nitride tube was obtained from supramolecular precursor. The special morphology and triazole ring group modification endowed materials' enhanced photocatalytic hydrogen evolution property (71 mmol g−1 h−1).

Preliminary evaluation of autologous pericardium ring for tricuspid Annuloplasty: a two-year follow-up study

Objective To evaluate the effectiveness of autologous pericardium ring in tricuspid annuloplasty surgery for the treatment of tricuspid regurgitation (TR). Methods From December 2010 to December 2012, a total of 107 patients with secondary TR underwent tricuspid annuloplasty. The patients were divided into three groups: autologous pericardium ring group (n = 38), Edwards-MC3 ring group (n = 35), and DeVega group (n = 34). The patients were followed-up for two years. The survival rates and free from hospital readmission rates were measured and analyzed. The patients also received transthoracic echocardiography (TTE) in order to obtain TR regurgitant jet area to right atrial area (STR/STA), diastolic tricuspid annuloplasty diameter (DTAD), right atrial diameter (RAD), and right ventricular diameter (RVD). Results One patient from DeVega group and one patient from autologous pericardium ring died from low cardiac output syndrome during the perioperative period. In the two-year follow-up period, each group has one instance of death for unclear reasons. One month after operation, the STR/STA, DTAD, RAD, and RVD values in all groups were significantly lower than the pre-operation values (P < 0.05). During the two year follow-up period, DTAD values of patients from DeVega group increased significantly as compared to the values at one month post operation (P<0.05), which is different from the other two groups in which DTAD values remained stable (P>0.05). In both pericardium ring group and Edwards-MC3 group, STR/SRA, remained stable (P>0.05) during the follow-up period, whereas STR/SRA of the DeVega group had showed a tendency of increase (although statistically insignificant, P>0.05). There was no significant difference in the survival rates among three study groups (P > 0.05), but the rate of free from hospital readmission in the DeVega group was significantly lower than those in the other two groups (P < 0.05) during the two-year follow-up period. Conclusions Autologous pericardium tissue based ring annuloplasty demonstrated remarkable clinical utility for treating tricuspid regurgitation. It shows similar beneficial results to Edwards-MC3 annuloplasty within a short-term follow-up period, and outperforms the widely used DeVega annuloplasty. Autologous pericardium tissue annuloplasty represents a promising technique for tricuspid annuloplasty and holds great potential for treating tricuspid valve dysfunctions.

NORMAL ELEMENT ON IDENTIFY PROPERTIES

One type of element in the ring with involution is normal element. Their main properties is commutative with their image by involution in ring. Group invers of element in ring is always commutative with element which is commutative with itself. In this paper, properties of normal element in ring with involution which also have generalized Moore Penrose invers are constructed by using commutative property of group invers in ring. Keywords: Normal, Moore Penrose, group, involution

Cryptanalysis of Low-Data Instances of Full LowMCv2

LowMC is a family of block ciphers designed for a low multiplicative complexity. The specification allows a large variety of instantiations, differing in block size, key size, number of S-boxes applied per round and allowed data complexity. The number of rounds deemed secure is determined by evaluating a number of attack vectors and taking the number of rounds still secure against the best of these. In this paper, we demonstrate that the attacks considered by the designers of LowMC in the version 2 of the round-formular were not sufficient to fend off all possible attacks. In the case of instantiations of LowMC with one of the most useful settings, namely with few applied S-boxes per round and only low allowable data complexities, efficient attacks based on difference enumeration techniques can be constructed. We show that it is most effective to consider tuples of differences instead of simple differences, both to increase the range of the distinguishers and to enable key recovery attacks. All applications for LowMC we are aware of, including signature schemes like Picnic and more recent (ring/group) signature schemes have used version 3 of the roundformular for LowMC, which takes our attack already into account.

De Vega annuloplasty versus ring annuloplasty for repair of functional tricuspid regurgitation

Background: Tricuspid insufficiency (TI) is a functional insufficiency in most of the cases and associated with the dilatation of the annulus and remolding. Pulmonary hypertension and right ventricular volume overload due to chronic aortic or / and mitral valve disease in most of the time causes the functional tricuspid insufficiency. Despite the different techniques used to repair the tricuspid valve, the recurrent TR is still occurring in 20- 30 % of the patients and the development of late TR is an important complication of left heart surgery. Our study aims to compare the long-term outcome of ring annuloplasty with De Vega annnuloplasty in patients with secondary tricuspid regurgitation (TR).Methods: A retrospective study of 320 patients who underwent tricuspid valve repair surgery for secondary tricuspid regurgitation from January 2002 to December 2010 at Queen Alia Heart Institute (QAHI). Patients were divided into two groups, in group (1) (n=180) patients had an annuloplasty ring. Group (2) (n=140) patients had De Vega procedure (no ring). The procedures were performed in association with mitral valve surgery in 78% of patients, aortic valve surgery in 15% and combined aortic and mitral valve surgery in 7% of patients. TR grade, NYHA functional class and Pulmonary artery pressure were nearly similar and no significant preoperative difference between the two groups.Results: Echocardiographic and clinical follow up were done for all patients. The duration of procedure for both De Vega and ring annuloplasty were nearly similar. The overall survival in ring group at 5year was 83.9% versus 77.9% in De Vega group. Freedom from residual and recurrent TR, event free survival and long-term survival were significantly better in the ring group and also the tricuspid valve reoperation were less in the ring group.Conclusions: The implantation of annuloplasty ring results in lower incidence of residual or recurrent of tricuspid regurgitation, improved the event-free survival and long-term survival when compared with the sewing techniques such as De Vega.

Evaluation of Infection Resistance of Biodegradable versus Conventional Annuloplasty Rings in an in vivo Rat Subcutaneous Model

Background: Biodegradable atrioventricular annuloplasty rings are theoretically more infection resistant due to their intra-annular implantation technique and nonporous structures (monofilament of poly-1,4-dioxanone). The aim of this study was to investigate the infection resistance of a biodegradable annuloplasty ring (Kalangos-Bioring®) in a rat subcutaneous implantation model and to compare it with a commonly used conventional annuloplasty ring (Edwards Physio II®). Methods: This study included 32 Wistar albino rats which were divided into 2 groups according to the implantation of sterile or infected annuloplasty rings as control and study groups. Each animal had 2 implantation pockets (made on the right and left side of the dorsal median line) where 1 cm of the biodegradable annuloplasty ring was implanted into one pocket and 1 cm of the conventional annuloplasty ring was implanted into the other pocket. The infection model was created by topical inoculation of 1 mL Staphylococcus aureus strain (2 × 107 colony-forming units/mL) into the implantation pockets before skin closure. Each group was equally divided into 4 subgroups according to different follow-up schedules. The animals were inspected for local as well as systemic infection signs, and the rings were explanted at weeks 2, 4, 9, and 14 following implantation. Implantation pockets were evaluated macroscopically as well as by histopathological examinations. Microbiological analysis of the explanted implants with surrounding tissue was done by using quantitative sonication method. Results: Conventional ring-implanted pockets showed a more prominent inflammation reaction than the biodegradable ring-implanted pockets, and this characteristic was found to be accentuated with bacterial contamination. The sterile rings did not reveal any positive cultures in either group. The number of positive cultures found in conventional rings contaminated with S. aureus was greater than in the biodegradable ring group (11/16 vs. 2/16 positive cultures, respectively; p = 0.0032). The amounts of growing bacteria in the culture environment were also statistically significantly higher in the conventional ring group (7,175 ± 5,936 vs. 181 ± 130 colony-forming units/mL, respectively; p < 0.0005). Conclusions: This is the first experimental study confirming the theoretical advantage of the infection resistance of the biodegradable annuloplasty ring (Kalangos-Bioring®) when implanted in an active infectious environment. Large animal models mimicking clinical scenarios and clinical comparative studies are needed to verify our results.

Regioselective Nitration of Halogenated Benzo[c]cinnolines and Benzenoids

Electrophilic nitration of halo-substituted benzo[c]cinnolines and benzenoids has been achieved regioselectively. The nitro group entry was always ortho to the halo group or/and the aromatic ring. This regioselective electrophilic ortho-nitration was accomplished in mixed acid/mild temperature conditions. Regioselectivity ortho to the halo/ring group(s) was observed with or without proximal steric hindrance. Chlorides and bromides worked equally well in directing these high-yielding ortho-selective reactions.

Comparison of weight loss, food consumption and frequency of vomiting among Roux-en-Y gastric bypass patients with or without constriction ring

BACKGROUND: After Roux-en-Y gastric bypass to avoid rapid gastric emptying, dumping syndrome and regained weight due to possible dilation of the gastric pouch, was proposed to place a ring around the gastric pouch. AIM: To compare weight loss, consumption of macronutrients and the frequency of vomiting among patients who underwent Roux-en-Y gastric bypass with and without the placement of a constriction ring around the pouch. METHOD: A retrospective study, in which an analysis of medical records was carried out, collecting data of two groups of patients: those who underwent the operation with the placement of a constriction ring (Ring Group) and those who underwent without the placement of a ring (No-Ring Group). The food intake data were analyzed using three 24-hour recalls collected randomly in postoperative nutritional accompaniment. Data on the percentage of excess weight loss and the occurrence of vomiting were collected using the weight corresponding to the most recent report at the time of data collection. RESULTS: Medical records of 60 patients were analyzed: 30 from the Ring Group (women: 80%) and 30 from the No-Ring Group (women: 87%). The average time since the Ring Group underwent the operation was 88±17.50 months, and for the No-Ring Group 51±15.3 months. The percentage of excess weight loss did not differ between the groups. The consumption of protein (g), protein/kg of weight, %protein and fiber (g) were higher in the No-Ring Group. The consumption of lipids (g) was statistically higher in the Ring Group. The percentage of patients who never reported any occurrence was statistically higher in the No-Ring Group (80%vs.46%). The percentage who frequently reported the occurrence was statistically higher in the Ring Group (25%vs.0%). CONCLUSION: The placement of a ring seems to have no advantages in weight loss, favoring a lower intake of protein and fiber and a higher incidence of vomiting, factors that have definite influence in the health of the bariatric patient.