A hydrophobic deep eutectic solvent-based microextraction for the determination of ultra-trace arsenic in foods by an electrothermal atomization atomic absorption spectrometry

A hydrophobic deep eutectic solvent-based liquid-phase microextraction approach for the determination of ultra-trace arsenic (total) in foods by an electrothermal atomization atomic absorption spectrometry was developed. Various deep eutectic solvents based on tetraoctylammonium bromide and fatty acids (heptanoic, octanoic, nonanoic, decanoic acids) were studied as extraction solvents for preconcentration of arsenic (V) from mineralizates obtained after a microwave digestion of food samples. Phenomenon of ion-pairs formation between dihydroarsenate and precursor of deep eutectic solvent (tetraoctylammonium) and mass-transfer of the ion-pairs into deep eutectic solvent phase was presented for the first time. The proposed approach allowed to preconcentrate analyte into the deep eutectic solvent phase without the use of additional organic solvents (emulsifier agents or dispersive solvent), chelating and reducing agents. It was found, that the deep eutectic solvent based on tetraoctylammonium bromide and heptanoic acid provided more effective preconcentration of analyte from mineralizates (95% extraction recovery, 57-fold enrichment factor). The obtained limit of detection, calculated as a triple signal-to-noise ratio, was 10 ng L-1. The microextraction procedure was applied for the determination of trace arsenic in rice and wheat grains samples.

Russian collection of Brucella abortus vaccine strains: annotation, implementation and genomic analysis

Over the past 10 years, immunization of cattle in Russia has been performed using vaccines from Brucella abortus strains 82, 19 and 75/79. To prevent brucellosis in small ruminants, two vaccines have been used, from the Brucella melitensis strain REV-1 and the B. abortus strain 19; note that twice as many animals have been immunized with the former vaccine than with the latter vaccine. The disadvantage of using these preparations is the formation of prolonged post-vaccination seropositivity, which is especially pronounced in animals after immunization with vaccines from B. abortus strain 19 and B. melitensis strain REV-1. This study aims to perform the whole genome sequencing of Brucella vaccine strains from the Russian collection. A bioinformatics analysis of the genomic data proved that the vaccine strains 75/79AB, 82, R-1096, and the KV 17/100 belong to ST-2, 104 M to ST-1, KV 13/100 to ST-5. This analysis allowed us to characterize vaccine strains's phylogenetic relationships and to prove the close relation of vaccine strains 75/79AB, 82, R-1096. Also, we defined candidate mutations in genes pmm, wbdA, wbkA, wboA, and eryB, which could be responsible for the attenuated virulence of vaccine strains. The complete genomic sequences of B. abortus strains make further studies of bacterial pathogenicity determinants and virulence phenotype feasible, as well as their use in quality control of animal medicines.

Whole-genome sequencing of Histophilus somni strains isolated in Russia

Background and Aim: Histophilus somni is a Gram-negative bacterium belonging to the Pasteurellaceae family that can cause bovine histophilosis. Histophilus may act as a commensal or opportunistic bacterial cattle pathogen. Comparing genomes of the pathogenic strain 2336 with the non-pathogenic preputial 129Pt isolate revealed some putative virulence factors. The study of the complete genomes of H. somni strains circulating in Russia has never been conducted before. This study aimed to identify genetic features of the H. somni strains isolated in Russia and evaluate the possibility of using strains for vaccine development. Materials and Methods: Three strains of H. somni were isolated from different sources. Strain 188-VIEV was isolated from a vaginal swab sample of cattle with endometritis. 532-VIEV and 551-VIEV were cultured from the cryopreserved bull semen samples imported from Canada. Histophilus somni strain ATCC 700025 provided by ATCC (American Type Culture Collection) was also used in the study. DNA extraction was performed using QIAamp DNA Mini Kit (QIAGEN, USA). The whole-genome sequencing of the four strains was performed using Illumina Miseq. The comparison of the resulting sequences with the complete genomes of H. somni 2336 and 129Pt, and detection of the resistance genes and virulence factors, was performed using the ResFinder and Virulence Factor Database web services. Results: The genome size of the samples varied from 1.9 to 2.3 Mb. The number of coding sequences varied from 1795 to 2256. The average sequence density was 90%. The total guanine-cytosine (GC) content was 36.8%–37.2%, which coincided with data previously obtained for H. somni. Three out of four studied strains encoded putative virulence factors such as filamentous hemagglutinin homologs, lipooligosaccharide biosynthesis proteins, and proteins involved in iron transport and utilization. The Ser83Ile substitution was identified in the DNA topoisomerase II (gyrA) in H. somni strains 532-VIEV and 551-VIEV cultured from bull semen which led to resistance to fluoroquinolones. The gene (AAC-6-Ia + APH-2”) encoding a bifunctional aminoglycoside modification enzyme was detected in strain 551-VIEV. Conclusion: Strains with virulence genes identified could be candidates for designing vaccines and potentially represent antigen sources. The results show that antibiotic-resistant H. somni can be spread with semen used for artificial insemination.

An effervescence-assisted dispersive liquid-liquid microextraction based on three-component deep eutectic solvent for the determination of fluoroquinolones in foods

An effervescence-assisted dispersive liquid-liquid microextraction approach using three-component deep eutectic solvent based on short-chain and medium-chain carboxylic acids and terpenoid was developed for the first time. The microextraction procedure was applied to the determination of fluoroquinolone antibiotics in foods (milk and shrimp samples) by high-performance liquid chromatography with fluorometric detection. In this microextraction procedure three-component deep eutectic solvent acted as a proton donor agent and an extractant. The carbon dioxide bubbles caused by the fast reaction between precursor of deep eutectic solvent (short-chain carboxylic acid) and effervescent agent (sodium carbonate) promoted the dispersion of the extractant in an aqueous sample phase. Various carboxylic acids were studied as hydrogen bond donors for the formation of deep eutectic solvents and proton donor agents for the generation of CO₂ bubbles. Two natural terpenoids (menthol and thymol) were studied as the hydrogen bond acceptors for the formation of three-component solvent. The extraction system based on heptanoic acid and thymol (1:2, mol/mol) containing formic acid (proton donor for generating CO₂ bubbles) provided maximum extraction recovery (86-99%) and a higher extraction efficiency of analytes compared to their extraction into individual hydrophobic precursors of the system. The LODs, calculated from the blank tests based on 3σ, were varied from 0.03 to 0.06 μg L^-1 and from 0.3 to 0.6 μg kg^-1 for fluoroquinolone antibiotics in milk and shrimp samples, respectively. The proposed approach provided effective dispersion of extractant speeding up the extraction process and fast separation of phases without any external energy assistance.

A derivatization and microextraction procedure with organic phase solidification on a paper template: Spectrofluorometric determination of formaldehyde in milk

A derivatization and air-assisted dispersive liquid-liquid microextraction procedure with organic phase solidification on a paper template was developed for the first time. The procedure was used for the spectrofluorometric determination of formaldehyde in milk samples. The Hantzsch reaction of formaldehyde with acetylacetone in the presence of ammonia to form a derivative (3,5-diacetyl-1,4-dihydrolutidine) was implemented for the microextraction and detection of analyte. Thymol was investigated as the extraction solvent for the air-assisted dispersive liquid-liquid microextraction for the first time. In the developed procedure, molten thymol was added to the thermostated aqueous sample solution containing reagents for formaldehyde derivatization, and cloudy solution of fine thymol droplets was formed by air bubbling. After separation of phases the liquid extract phase was withdrawn with a dispenser and distributed on the black paper template in a thin layer to be solidified. The solidified extract phase on the template was inserted to a sample holder of a spectrofluorometer and fluorescence intensity was measured without using cuvettes. Under optimal experimental conditions the linear detection range was found to be 45-500 µg L^-1 with LOD calculated from a blank test, based on 3σ, 15 µg L^-1. The developed procedure does not require the dilution of the solid extract phase in organic solvent to be introduced in an analytical instrumentation and the use of cuvettes for spectrofluorometric detection.

p-Dimethylaminobenzaldehyde-based chemosensor for on-site sensing of ammonia precursor in concrete

A chemosensor for on-site sensing of ammonia precursor in concrete to avoid a problem of ammonia emission into the indoor space of concrete buildings was designed and implemented. It was found that aqueous extracts of concrete samples containing antifreeze additives and excreting ammonia were colored in the presence of p-dimethylaminobenzaldehyde. This phenomenon was used for the fast visual sensing of main ammonia precursor (urea) in concrete for the first time. The developed sensor consisted of a sensing solid phase based on an adsorbent modified with p-dimethylaminobenzaldehyde. Various adsorbents were investigated for the immobilization of the reagent and it was established that silica adsorbent Silochrom C-120 provided effective retention of the reagent and Schiff's base formation during the sampling. Moreover, Silochrom C-120 modified with ascorbic acid was proposed to eliminate the oxidant interference. The sensor displayed excellent selectivity and sensitivity with the visual detection limit of 15 mg kg^-1 in terms of urea. The chemosensor was successfully applied by builders on different construction sites. Sample preparation and sensing times were about 2 min and 1 min, respectively.

In-a-syringe surfactant-assisted dispersive liquid-liquid microextraction of polycyclic aromatic hydrocarbons in supramolecular solvent from tea infusion

In this work, an automated surfactant-assisted dispersive liquid-liquid microextraction approach based on in-a-syringe concept was developed for the first time. The procedure assumed mixing aqueous sample phase and hydrophilic emulsion containing hexanoic acid and sodium hexanoate in a syringe of flow system. Sodium hexanoate acted as an emulsifier in dispersive liquid-liquid microextraction process and it was required for the formation of supramolecular solvent phase. After spontaneous separation of phases in the syringe, the upper supramolecular solvent phase containing target analytes was withdrawn and analyzed. The procedure was applied to the determination of 13 polycyclic aromatic hydrocarbons in tea infusion by high performance liquid chromatography with fluorescence detection. It was shown that the supramolecular solvent provided effective extraction of polycyclic aromatic hydrocarbons and fast phase separation in the syringe without centrifugation. The enrichment factors were in the range of 38-46. The automated microextraction procedure lasted 4 min including syringe cleaning. Under optimal experimental conditions the linear detection ranges were found to be 0.05-50.00 μg L^-1 with limits of detection calculated from a blank test, based on 3σ, 0.02-0.04 μg L^-1. Recovery values in the range of 85-105% were achieved for tea infusion with a reproducibility expressed as RSD less than 4.1%.

Learning From Controversy: Contemporary Surgical Management of Aortic Valve Endocarditis

Aortic valve replacement is the commonest cardiac surgical operation performed worldwide for infective endocarditis (IE). Long-term durability and avoidance of infection relapse are goals of the procedure. However, no detailed guidelines on prosthesis selection and surgical strategies guided by the comprehensive evaluation of the extension of the infection and its microbiological characteristics, clinical profile of the patient, and risk of infection recurrence are currently available. Conventional mechanical or stented xenografts are the preferred choice for localized aortic infection. However, in cases of complex IE with the involvement of the root or the aortomitral continuity, the use of homograft is suggested according to the surgeon and center experience. Homograft use should be counterbalanced against the risk of structural degeneration. Prosthetic bioroot or prosthetic valved conduit (mechanical and bioprosthetic) are also potentially suitable alternatives. Further development of preservation techniques enabling longer durability of allogenic substitutes is required. We evaluate the current evidence for the use of valve substitutes in aortic valve endocarditis and propose an evidence-based algorithm to guide the choice of therapy. We performed a systemic review to clarify the contemporary surgical management of aortic valve endocarditis.

Mitral regurgitation after transcatheter aortic valve replacement

Patients undergoing transcatheter aortic valve replacement (TAVR) might have an associated significant MR that can potentially lead to left ventricular (LV) failure after procedure. Considering the specific alterations in the mitral valve in TAVR scenario and the widespread use of TAVR in recent years, it appears important to know and understand the anatomical, functional and clinical implications to develop adequate strategies for the future. Patients with severe mitral regurgitation (MR) have been generally excluded from randomized clinical trials, making poor the impact that associated MR can have on clinical outcomes after TAVR. Several factors must be considered whose presence influences the severity of MR. For example, the elevated prevalence of coronary disease with consequent ischemic MR may account for LV dilation observed at the end stage of aortic stenosis. Evidence randomized studies and registries suggests that the rate of concomitant moderate-to-severe MR in patients undergoing TAVR oscillates between 2% and 33%, and patients with moderate to severe MR may have hemodynamic frailty with clinical deterioration during mechanical intervention. Short- and long-term outcomes, including cardiac mortality, appear to be influenced by the existence of preoperative moderate-to-severe MR or by the postprocedural worsening of mild MR, generally due to adverse LV remodeling. The incidence and the prognostic effect of concomitant MR in patients undergoing TAVR requires specific attention as might trigger adjunctive strategy treatment which should be carefully evaluated in clinical trials.

Are the dynamic changes of the aortic root determinant for thrombosis or leaflet degeneration after transcatheter aortic valve replacement?

The role of the aortic root is to convert the accumulated elastic energy during systole into kinetic flow energy during diastole, in order to improve blood distribution in the coronary tree. Therefore, the sinuses of Valsalva of the aortic root are not predisposed to accept any bulky material, especially in case of uncrushed solid calcific agglomerates. This concept underlines the differences between surgical aortic valve replacement, in which decalcification is a main part of the procedure, and transcatheter aortic valve replacement (TAVR). Cyclic changes in shape and size of the aortic root influence blood flow in the Valsalva sinuses. Recent papers have been investigating the dynamic changes of the aortic root and whether those differences might be correlated with clinical effects, and this paper aims to summarize part of this flourishing literature. Post-TAVR aortic root remodeling, dynamic flow and TAVR complications might have a fluidodynamic background, and clinically observed side effects such as thrombosis or leaflet degeneration should be further investigated in basic researches. Also, aortic root changes could impact valve type and size selection, affecting the decision of over-sizing or under-sizing in order to prevent valve embolization or coronary ostia obstruction.

Mitral regurgitation: lessons learned from COAPT and MITRA-Fr

Recent studies about percutaneous treatment of secondary mitral regurgitation (MR) underlined the importance of left ventricular geometry and features of mitral valve as determinants of procedural and long-term success. Guideline-directed medical therapy (GDMT), transcatheter mitral valve treatment (TMVT) and surgical procedures (mitral valve replacement, mitral valve repair at level of the annulus or subvalvular apparatus) have been extensively evaluated but not adequately compared in current clinical studies. A detailed analysis of the results of the study about transcatheter mitral valve repair would allow to evaluate the safety and effectiveness of such procedure and would provide potential indications for improving the quality of percutaneous and surgical repair in patients with moderate-to-severe secondary MR. Patients with proportionate MR (i.e., MR severity is proportional to the amount of left ventricular dilatation) are prone to respond to the optimization of medical therapy, while patients with disproportionate MR (i.e., MR severity is disproportionately higher than predicted by left ventricular dilatation, with high EROA and small left ventricle) are likely to benefit from additional repair. The identification of specific subpopulation of "high responders", based on the anatomic characteristics of the mitral valve and the relative dimensions of the annulus, the regurgitation and the left ventricle, can also apply to medical therapy. However, some pivotal component of MR (such as the symmetry of tethering and the differences in biomechanical features of leaflets) are not adequately investigated in current studies and warrant further evaluation.

Magnetic headspace adsorptive microextraction using Fe3O4@Cr(OH)3 nanoparticles for effective determination of volatile phenols

Simple and available procedure for the determination of volatile phenols in food samples based on magnetic headspace adsorptive microextraction using Fe₃O₄@Cr(OH)₃ nanoparticles followed by HPLC with fluorescence detection was developed in this work.

The Radial Artery for Coronary Bypass Grafting: The Fifth Decade

BACKGROUND

In 1989, we reported the use of the radial artery as a second target conduit for coronary artery bypass grafting. However, underpowered randomized trials have reported differences in clinical outcomes between the radial artery and other grafts. As we approach 50 years of experience with radial artery grafting, we reviewed the literature to determine the second-best target vessel for coronary operations.

METHODS

An electronic review of the literature with an emphasis on randomized controlled trials, propensity-matched observational series, and meta-analyses identified a large population of patients who received arterial conduit and saphenous vein grafts.

RESULTS

The radial artery has been proven to be reliable as a second target conduit for coronary artery bypass grafting, with outcomes and patency rates superior to those for saphenous vein graft. It has also been proven to be both safe and effective as a third conduit in the territory of the right coronary artery. A paucity of evidence with few comparable series limits the use of the gastroepiploic artery.

CONCLUSION

In its fifth decade of use, we can definitively conclude that the aorto-to-coronary radial bypass graft is the conduit of choice for coronary operations after the left internal thoracic artery to the left anterior descending artery.

Fe3O4-based composite magnetic nanoparticles for volatile compound sorption in the gas phase: determination of selenium(iv)

On-line selenium separation based on hydride generation followed by sorption on magnetic nanoparticles.

Infections after T-replete haploidentical transplantation and high-dose cyclophosphamide as graft-versus-host disease prophylaxis

BACKGROUND

Recently, a platform of T-cell replete haploidentical hematopoietic stem cell transplantation (haplo-HSCT) using post-transplant cyclophosphamide (Cy) has shown high reproducibility and acceptable safety profile.

METHOD

This prospective cohort analysis allowed us to collect data on infections among 70 consecutive recipients of haplo-HSCT affected by various hematologic malignancies.

RESULTS

After a median follow-up of 23 months, cumulative incidence of viral infections was 70% (95% confidence interval [CI] 59-81) at 100 days and 77% (95% CI 67-87) at 1 year; 35 of 65 patients at risk had CMV reactivation (54%) and the rate of polyomavirus-virus-associated cystitis was 19% (13/70). Cumulative incidence of bacterial and fungal infections at 1 year were 63% (95% CI 51-75) and 12% (95% CI 4-19), respectively. Of note, only 1 invasive fungal infection occurred beyond 1 year after transplant (day +739).

CONCLUSION

In conclusion, despite a high rate of viral infections in the early period, present data suggest a satisfactory infectious profile after T-cell replete haplo-HSCT using post-transplant Cy. These results may help clinicians to improve both prophylactic and therapeutic antimicrobial strategies in this emerging haploidentical setting.

Risk Factors for Intimate Partner Violence Against Women in St. Petersburg, Russia

This exploratory study examines which risk factors are associated with intimate partner violence against women in St. Petersburg, Russia. Women attending two crisis centers and a birthing house constituted the study sample. The male partner's frequent alcohol consumption and seeing his father hit his mother in childhood were associated with an increased risk of violence, whereas living in a communal apartment reduced the risk of intimate partner violence. The importance of crisis centers in Russia is highlighted by the study, as the women who turn to them are likely to have experienced more severe forms of violence.

IGEV regimen and a fixed dose of lenograstim: an effective mobilization regimen in pretreated Hodgkin's lymphoma patients

We explored the efficacy of the IGEV regimen (ifosfamide, gemcitabine, vinorelbine and prednisone) combined with a fixed dose of lenograstim (263 mug/day) to mobilize peripheral blood stem cells (PBSCs) in 90 Hodgkin's lymphoma patients. The median total CD34+ cells/mul peak, colony-forming units granulocyte-macrophage and white blood cells for all individual collection sets were 85/mul, 12 x 10(4)/kg and 20 700/mul, respectively. An adequate number of CD34+ cells (more than 3 x 10(6) or 6 x 10(6) CD34+ cells/kg depending on whether single or tandem high-dose chemotherapy was used) were collected in 89 out of 90 (98.7%) mobilized patients, whereas the only failure reached 2.3 x 10(6) CD34+ cells/kg. The median CD34+ cell collections were 11 x 10(6)/kg (range 2.3-39 x 10(6)/kg) and 10 x 10(6)/kg (range 6-22.0 x 10(6)/kg) with a median of 1 and 2 leukaphereses for patients eligible for single high-dose treatment and for candidates for tandem transplant, respectively. Target yields were reached in 71.43 and 49.09% and additionally in 17.14 and 43.64% of cases after the first and second apheresis procedures, respectively. Hematological and non-hematological side effects were acceptable, and no toxic deaths occurred. Thirty-four patients received a single and 47 received tandem transplantation with rapid engraftment. These results confirm that the IGEV regimen with lenograstim support can be used successfully and safely to mobilize PBSCs.

Prospective study of high-dose chemotherapy and autologous peripheral stem cell transplantation in adult patients with advanced desmoplastic small round-cell tumour

A total of 10 desmoplastic small round-cell tumour patients were treated by high-dose chemotherapy with stem cell support. After high-dose chemotherapy, no complete response conversion was obtained and EWS-WT1 fusion transcript detection was positive in the peripheral blood during follow-up in all patients. High-dose chemotherapy did not seem to change the results in desmoplastic small round-cell tumour.

Reduced intensity conditioning regimen followed by glycosylated G-CSF mobilized PBSCT in patients with solid tumors and malignant lymphomas

The aim of this pilot study was to exploit the graft-versus-tumor potential of allogeneic transplants while improving safety of the procedure. Twelve patients with advanced hematological malignancies and solid tumors underwent a low intensity conditioning regimen (fludarabine and cyclophosphamide) followed by an allogeneic peripheral blood stem cell transplantation. The median time to achieve an absolute neutrophil count of more than 0.5 x 10(9)/l and an untransfused platelet count of more than 20 x 10(9)/l was 15 and 14 days, respectively. The main extra-hematological toxicities were mucositis and infections. Acute graft-versus-host (GVHD) disease was experienced by 62% of evaluable patients (grade II/B or III/C 80%) responsive to steroids. Extensive chronic GVHD was observed in 62% of patients. Non-relapse transplant-related mortality by day +30 was observed in three patients (25%). Eight out of 12 patients were full donor chimeric by day +100. One patient showed a mixed chimerism at day +37 when he died from progressive disease. One patient was in complete remission (CR) before allogeneic transplantation, and after transplantation four patients achieved CR and four experienced progressive disease. Our study confirms that a low intensity conditioning regimen for allogeneic stem cell transplantation is feasible and effective in heavily pretreated patients.

Allogeneic peripheral blood stem cell transplantation with reduced intensity conditioning in primary refractory prolymphocytic leukemia: graft-versus-leukemia effect without graft-versus-host disease

A patient with progressive prolymphocytic leukemia (PLL) received an allogeneic stem cell transplant using a reduced intensity conditioning regimen to avoid prohibitive toxicities. Early in the post-transplant period, a high donor-derived CD8+ count was observed. One year from transplantation, the patient was in complete remission, fully donor chimeric and with a normal performance status, suggesting that this approach may represent a useful treatment option in patients with refractory PLL.

Mobilizing potential of ifosfamide/vinorelbine-based chemotherapy in pretreated malignant lymphoma

The mobilizing potential and therapeutic activity of ifosfamide/vinorelbine-containing regimens with G-CSF support were explored in patients with pretreated malignant lymphomas. Ten patients with non-Hodgkin's lymphoma (NHL) received ifosfamide and vinorelbine, and 17 with Hodgkin's disease (HD) received ifosfamide, vinorelbine and gemcitabine (IGEV regimen), as induction chemotherapy before high-dose chemotherapy (HDT) with peripheral blood stem cell (PBSC) support. Most of the patients had been heavily pretreated with various chemotherapy regimens +/- radiotherapy. The target yield was > or =3 x 10(6) CD34+ cells/kg of body weight in order to support the subsequent myeloablative chemotherapy. The optimal PBSC harvest occurred on days 11 and 12, with no difference in CD34+ cell mobilization kinetics between the ifos- famide/vinorelbine and IGEV regimens. The median number of CD34+ cells/kg body weight collected was 10.9 x 10(6) (range 1.76-61.1 x 10(6)). The median total CD34+ cell/microl, CFU-GM and white blood cells (WBC) for all individual collections was 81.5/microl, 10 x 10(4)/kg, and 17 900/microl, respectively. The target yield of CD34+ cells was reached in 24 of 27 patients. Hematological side-effects were acceptable and no treatment-related hospitalizations or toxic deaths occurred. Fifteen patients have so far received high-dose therapy and PBSC reinfusion with rapid engraftment. These results confirm that ifosfamide and vinorelbine-based chemotherapy regimen with G-CSF support can be successfully and safely used to mobilize PBSCs.