Organometallic Synthesis of 2,3,6,7-Tetrasubstituted 1,8-Bis(dimethylamino)naphthalenes for Investigation of the Double Buttressing Effect in Proton Sponges.

The lithiation of 2,7-disubstituted derivatives of 1,8-bis(dimethylamino)naphthalene (DMAN, proton sponge) bearing potentially ortho-directing OMe, NMe2, and SMe groups was studied. It has been shown that OMe groups facilitate selective dual ß-lithiation of the naphthalene moiety while the 2(7)-NMe2 groups allow only monolithiation presumably due to the decreased acidity of the ring C-H bonds and conformational immobilization after coordination to the lithium atom. In contrast, the SMe groups provided no ring lithiation and underwent deprotonation of their methyl fragment. The first representatives of previously unknown 2,3,6,7-tetrasubstituted DMANs have been synthesized in good yield after treatment of 2,7-dimethoxy-3,6-dilithio DMAN with the appropriate electrophiles (MeI, Me2S2, Me3SiCl, DMF, etc.). Because the exceedingly high basicity of 2,7-dimethoxy DMAN is commonly attributed to the so-called "buttressing effect" (BE), the availability of 2,3,6,7-tetrasubstituted species provided the first opportunity to study the double BE version. Using X-ray diffraction and basicity measurements, we showed that due to the high conformational mobility of the methoxy groups, the most striking manifestations of double BE are the strong planarization of peri-NMe2 groups and a significant decrease in basicity, while the length and the other properties of the intramolecular NHN hydrogen bond in the corresponding protonated species undergo minor changes.

Minimizing visceral organ ischemia time for open repair of thoracoabdominal aortic disease: Description of a new method.

Minimizing ischemic injury during surgical repair of thoracoabdominal aortic aneurysms (TAAAs) is vital for preventing complications such as paraplegia and acute renal failure. In this report, we describe a new technique for TAAA open repair that aims to minimize visceral organ ischemia times. Unlike typical Crawford extent II TAAA open repair, which begins with aortic clamping and proceeds from the proximal to the distal anastomoses, our method reverses the anastomosis order and minimizes aortic clamping. Between January 2016 and December 2020, we used this approach in 29 patients undergoing TAAA repair. We present one of these cases, a 29-year-old patient with progressive aneurysmal dilatation of a DeBakey type III chronic aortic dissection that extended beyond the aortic bifurcation. Our technique reduced aortic cross-clamping, left heart bypass, and internal organ and spinal cord ischemia times and appears to be safe and effective.

Surgical treatment of Kommerell's diverticulum.

Kommerell's diverticulum (KD) is a rare congenital vascular abnormality due to the formation of an abnormal aortic arch, most commonly associated with dilatation at the proximal part of the aberrant subclavian artery. This article describes an option of surgical treatment in a patient with KD. The proposed new technique of aortic arch surgical reconstruction with a stent-graft placement in the descending aorta reduces CPB time, aortic clamp and circulatory arrest time.

Combination of "Buttressing" and "Clothespin" Effects for Reaching the Shortest NHN Hydrogen Bond in Proton Sponge Cations.

A series of previously unknown 2,4,5-tri- and 2,4,5,7-tetrasubstituted 1,8-bis(dimethylamino)naphthalenes and their salts with HBF4 containing bulky spherically shaped substituents (Me, Br, and SiMe3) in the naphthalene ring has been synthesized. Using XRD analysis of 11 samples, the influence of the so-called "buttressing" and "clothespin" effects on their molecular structure and the NHN hydrogen bond geometry in the solid cations were investigated. The combined action of both effects has been shown to significantly increase the compression of the hydrogen bond. As a result, the previous record of the hydrogen bond shortness (N···N = 2.524 Å) has been surpassed in favor of 2.502 Å found for the tetrafluoroborate of 2,4,5,7-tetramethyl-1,8-bis(dimethylamino)naphthalene. The molecular structure of the latter differs by perfect symmetry and practically barrier-free proton transfer in the [NHN]+ bond. On the basis of the results of quantum-chemical calculations, it is suggested that the value of 2.502 Å likely represents or lies very close to the theoretical limit for the short hydrogen bonds between the amine-type nitrogen atoms.

Wolfe procedure in a 78-year-old patient with aortic root aneurysm: A case report.

BACKGROUND: Aortic root and ascending aortic aneurysms are traditionally surgically treated through the deployment of a conduit with an artificial aortic valve, which significantly increases the risk of postoperative complications in the form of thrombosis. MATERIALS & METHODS: We report a case of Wolfe procedure in a 78-year-old female patient with aortic root aneurysm at high risk for conventional Bentall surgery. DISCUSSION AND CONCLUSION: We use this case to discuss the effectiveness and short-term results of this procedure.

Coronary-artery bypass surgery in patients with left ventricular dysfunction.

BACKGROUND: The role of coronary-artery bypass grafting (CABG) in the treatment of patients with coronary artery disease and heart failure has not been clearly established. METHODS: Between July 2002 and May 2007, a total of 1212 patients with an ejection fraction of 35% or less and coronary artery disease amenable to CABG were randomly assigned to medical therapy alone (602 patients) or medical therapy plus CABG (610 patients). The primary outcome was the rate of death from any cause. Major secondary outcomes included the rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes. RESULTS: The primary outcome occurred in 244 patients (41%) in the medical-therapy group and 218 (36%) in the CABG group (hazard ratio with CABG, 0.86; 95% confidence interval [CI], 0.72 to 1.04; P=0.12). A total of 201 patients (33%) in the medical-therapy group and 168 (28%) in the CABG group died from an adjudicated cardiovascular cause (hazard ratio with CABG, 0.81; 95% CI, 0.66 to 1.00; P=0.05). Death from any cause or hospitalization for cardiovascular causes occurred in 411 patients (68%) in the medical-therapy group and 351 (58%) in the CABG group (hazard ratio with CABG, 0.74; 95% CI, 0.64 to 0.85; P<0.001). By the end of the follow-up period (median, 56 months), 100 patients in the medical-therapy group (17%) underwent CABG, and 555 patients in the CABG group (91%) underwent CABG. CONCLUSIONS: In this randomized trial, there was no significant difference between medical therapy alone and medical therapy plus CABG with respect to the primary end point of death from any cause. Patients assigned to CABG, as compared with those assigned to medical therapy alone, had lower rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes. (Funded by the National Heart, Lung, and Blood Institute and Abbott Laboratories; STICH ClinicalTrials.gov number, NCT00023595.).

Effects of Metal Oxide Nanoparticles on Toll-Like Receptor mRNAs in Human Monocytes.

For the widespread application of nanotechnology in biomedicine, it is necessary to obtain information about their safety. A critical problem is presented by the host immune responses to nanomaterials. It is assumed that the innate immune system plays a crucial role in the interaction of nanomaterials with the host organism. However, there are only fragmented data on the activation of innate immune system factors, such as toll-like receptors (TLRs), by some nanoparticles (NPs). In this study, we investigated TLRs' activation by clinically relevant and promising NPs, such as Fe3O4, TiO2, ZnO, CuO, Ag2O, and AlOOH. Cytotoxicity and effects on innate immunity factors were studied in THP-1(Tohoku Hospital Pediatrics-1) cell culture. NPs caused an increase of TLR-4 and -6 expression, which was comparable with the LPS-induced level. This suggests that the studied NPs can stimulate the innate immune system response inside the host. The data obtained should be taken into account in future research and to create safe-by-design biomedical nanomaterials.

Left ventricular assist device implantation combined with surgical ventricular reconstruction.

Nine months after sustaining a transmural anteroseptal myocardial infarction, a 45-year-old man presented with ischemic heart disease, severe mitral valve insufficiency, New York Heart Association functional class IV congestive heart failure, and a left ventricular aneurysm. Coronary angiography revealed 3-vessel disease. Echocardiography showed severe left ventricular impairment, pronounced thrombosis in the left ventricular apex, and low myocardial reserve. To reduce the high risk of performing left ventricular and mitral valve reconstruction concurrently with revascularization, we decided to perform ventricular reconstruction and to implant a Berlin Heart INCOR left ventricular assist device as a bridge to heart transplantation. The patient had an uncomplicated recovery, was discharged from the hospital with symptomatic improvement after 20 days, and was placed on the list for heart transplantation. We describe the patient's case, the surgical procedure, and the reasoning behind the chosen course of treatment.

Results of coronary artery bypass grafting alone and combined with surgical ventricular reconstruction for ischemic heart failure.

In this study, we included 236 patients with ischemic heart failure and ejection fraction (EF) <35% who underwent surgical treatment. Patients were randomized in two groups. There were 116 patients who underwent coronary artery bypass grafting (CABG) with surgical ventricular reconstruction (SVR) and 120 patients who underwent CABG alone. The hospital mortality rate was 5.8% after isolated CABG and 3.5% after CABG combined with SVR. All survivors had follow-up investigation from four months to five years, with a mean follow-up time of 31±13 months. The mean New York Heart Association (NYHA) functional class decreased from 2.9±0.5 to 2.2±0.7 one year after CABG and from 3.1±0.4 to 2.0±0.6 one year after CABG with SVR. We showed that left ventricular reconstruction significantly decreased EDV from 237±52 to 176±30 and correspondingly increased EF from 32±6 to 39±9. However, after isolated CABG EF did not increase significantly (32±7 preoperatively and 34±11 postoperatively). One- and three-year rates were 95% and 78% after SVR with CABG and 83% and 78% after CABG alone. Despite the more aggressive surgical strategy, left ventricular reconstruction did not increase operative mortality and early results were significantly effective compared with coronary artery bypass grafting alone.