Closed-suction compared with Penrose drainage after free flap reconstruction in the head and neck.

Microsurgical free flaps are common in head and neck reconstruction, and their techniques and outcomes have continuously improved during the past decades. However, there are variations in practice among surgeons between the use of closed-suction drainage systems and Penrose drains. The proponents of Penrose drains propose that the negative pressure generated by the closed-suction drainage system may harm the microvascular anastomosis. We know of no previous studies that have compared the two drains for microvascular free flap reconstruction, so our aim was to compare them in a single-centre, retrospective review of all patients who had microvascular free flap reconstruction of the head and neck region in our department between 1 November 2010 and 1 September 2017. During this period 84 patients had 87 free flap reconstructions in the head and neck, 43 of which had Penrose, and 44 closed-suction, drainage. We compared the number of complications between the groups including haematomas, seromas, wound infections, anastomostic thrombosis, anastomotic revision, and need for re-exploration. There were no significant differences between the groups, despite a trend toward fewer negative explorations in the closed-suction group. There were no differences in complications between suction and passive drainage systems after microvascular free flaps, which suggests that closed suction drainage could be safely used after free flap reconstruction in the head and neck.

Impact of attributed audit on procedural performance in cardiac electrophysiology catheter laboratory.

PURPOSE: Audit has played a key role in monitoring and improving clinical practice. However, audit often fails to drive change as summative institutional data alone may be insufficient to do so. We hypothesised that the practice of attributed audit, wherein each individual's procedural performance is presented will have a greater impact on clinical practice. This hypothesis was tested in an observational study evaluating improvement in fluoroscopy times for AF ablation. METHODS: Retrospective analyses of fluoroscopy times in AF ablations at the Barts Heart Centre (BHC) from 2012-2017. Fluoroscopy times were compared pre- and post- the introduction of attributed audit in 2012 at St Bartholomew's Hospital (SBH). In order to test the hypothesis, this concept was introduced to a second group of experienced operators from the Heart Hospital (HH) as part of a merger of the two institutions in 2015 and change in fluoroscopy times recorded. RESULTS: A significant drop in fluoroscopy times (33.3 ± 9.14 to 8.95 ± 2.50, p < 0.0001) from 2012-2014 was noted after the introduction of attributed audit. At the time of merger, a significant difference in fluoroscopy times between operators from the two centres was seen in 2015. Each operator's procedural performance was shared openly at the audit meeting. Subsequent audits showed a steady decrease in fluoroscopy times for each operator with the fluoroscopy time (min, mean±SD) decreasing from 13.29 ± 7.3 in 2015 to 8.84 ± 4.8 (p < 0.0001) in 2017 across the entire group. CONCLUSIONS: Systematic improvement in fluoroscopy times for AF ablation procedures was noted byevaluating individual operators' performance. Attributing data to physicians in attributed audit can promptsignificant improvement and hence should be adopted in clinical practice.

Aflibercept as a Second Line Therapy for Neovascular Age Related Macular Degeneration in Israel (ASLI) study.

PurposeThe purpose of this study is to evaluate an early switch to aflibecept in eyes with neovascular age-related macular degeneration (nvAMD) showing partial or lack of response for initial therapy with bevacizumab.MethodsThe Aflibercept as a Second Line Therapy for Neovascular Age Related Macular Degeneration in Israel (ASLI) was a prospective, multicenter, single-arm clinical trial. Eyes with nvAMD having incomplete response to 3-9 prior bevacizumab injections were recruited. Three monthly intravitreal aflibercept (2 mg) injections were administered, followed by two bi-monthly injections and a final examination at week 28. An optional injection was allowed at week 20.ResultsForty-seven eyes of 46 patients (mean±SD age 76±8 years) were recruited. The mean number of prior bevacizumab injections was 5.5±2.9. The mean visual acuity improved from 60.3±10 ETDRS letters at baseline to 63.1±15 letters at week 28 (P=0.02, paired t-test). The central subfield thickness (CST) reduced from 409±127 micron at baseline to 330±110 microns at week 4 (P=0.0002; paired t-test), and 277±70 microns at week 28 (P=0.00002; paired t-test). Twenty-two eyes had three to five prior bevacizumab injections (mean 5.1±0.7), and 25 eyes had six to nine prior injections (7.32±1.2). Both groups had reduced CST from baseline to week 28 (P=0.0004 and P=0.0007; paired t-test, respectively). Thirty-five (75%) eyes required the optional additional aflibercept injection at week 20.ConclusionsThe ASLI study demonstrated improved BCVA and reduced CST following an early switch to aflibercept therapy in eyes with prior incomplete response to initial therapy with three to nine bevacizumab injections.

A propensity matched case-control study comparing efficacy, safety and costs of the subcutaneous vs. transvenous implantable cardioverter defibrillator.

BACKGROUND: Subcutaneous implantable cardioverter defibrillators (S-ICD) have become more widely available. However, comparisons with conventional transvenous ICDs (TV-ICD) are scarce. METHODS: We conducted a propensity matched case-control study including all patients that underwent S-ICD implantation over a five-year period in a single tertiary centre. Controls consisted of all TV-ICD implant patients over a contemporary time period excluding those with pacing indication, biventricular pacemakers and those with sustained monomorphic ventricular tachycardia requiring anti-tachycardia pacing. Data was collected on device-related complications and mortality rates. A cost efficacy analysis was performed. RESULTS: Sixty-nine S-ICD cases were propensity matched to 69 TV-ICD controls. During a mean follow-up of 31±19 (S-ICD) and 32±21months (TV-ICD; p=0.88) there was a higher rate of device-related complications in the TV-ICD group predominantly accounted for by lead failures (n=20, 29% vs. n=6, 9%; p=0.004). The total mean cost for each group, including the complication-related costs was £9967±4511 ($13,639±6173) and £12,601±1786 ($17,243±2444) in the TV-ICD and S-ICD groups respectively (p=0.0001). Even though more expensive S-ICD was associated with a relative risk reduction of device-related complication of 70% with a HR of 0.30 (95%CI 0.12-0.76; p=0.01) compared to TV-ICDs. CONCLUSIONS: TV-ICDs are associated with increased device-related complication rates compared to a propensity matched S-ICD group during a similar follow-up period. Despite the existing significant difference in unit cost of the S-ICD, overall S-ICD costs may be mitigated versus TV-ICDs over a longer follow-up period.

[ANALYSIS OF EFFECTIVENESS OF USINGJIgY FROM CHICKEN IN SANDWICH METHOD OF HBsAg TESTING].

AIM: Study antigen-binding ability of polyclonal antibodies (PCA) of chicken compared with monoclonal -antibodies (MCA) of mice in the model of interaction with HBsAg. MATERIALS AND METHODS: Mice MCA 18C8 and MKA F3/F4 (IgG) were used, effective in enzyme immunoassay sandwich method of HBsAg determination (with a minimal detection dose of 0.017 ng/ml), and affinity purified anti-HBsAg PCA of chicken (IgY), obtained from 2 immunized birds (PCA No. 1 and PCA No. 2). The ability of antibodies to bind HBsAg was evaluated by analytical sensitivity (slope of binding curve) of solid-phase enzyme immunoassay system using mice MCA and chicken PCA. RESULTS: PCA No. 2 has provided a statistically significant 40% increase of analytical sensitivity, compared with <

[Effect of pH of Adsorption Buffers on the Number and Antigen-Binding Activity of Monoclonal Antibodies Immobilized on the Surface of Polystyrene Microplates].

The change in the concentration and antigen-binding activity of 28 monoclonal antibodies was studied after their adsorption on the surface of polystyrene microplates in buffers with different pH values (1.0, 2.8, 7.5, 9.6, and 11.9). We used 16 clones to the HIV p24 protein and 12 clones to the surface antigen of Hepatitis B Virus. The binding efficiency of adsorbed antibodies to the labeled antigen was evaluated by the slope of the linear region of the binding curve to the concentration axis. It was shown that the antigen-binding activity of six antibodies (21.5%) statistically significantly increased after adsorption at pH 2.8 and 11.9 as compared to pH 7.5 and 9.5. The maximum amount of antibodies was found to be adsorbed on the solid surface at pH 7.5. The analysis of the binding of 125I-HBs-antigen to adsorbed antibodies made it possible to evaluate the concentration of active antibodies on the polystyrene surface. It was shown that the increase in the antigen-binding activity was due to an increase in the proportion of antibodies with retained activity after adsorption at pH 2.8 and 11.9. Under these conditions, about 20% of the antibodies retained their antigen-binding activity, and 6% did so after immobilization at pH 7.5.

Decreased dopaminergic treatment of hospitalized Parkinson's disease patients during infectious diseases is associated with poor outcomes.

A retrospective analysis of consecutive Parkinson's disease (PD) patients hospitalized in internal medicine wards during the years 2008 to 2013 due to infectious disease was performed. PD patients are prone to infections, often leading to hospitalization in internal medicine wards. We observed that during these hospitalizations, chronic anti-Parkinson's medications are frequently overlooked and withdrawn, their reintroduction is delayed and dosages are decreased. Only patients on chronic therapy with at least one anti-Parkinson's medication were included in this study. Multivariate analyses established the association between medication dose reductions on short-term clinical outcomes, including in-hospital mortality and change in discharge destination. Medical records from 528 PD patients were analyzed and 430 were excluded. Of the 98 included, 53 had pneumonia and 58 had urinary tract infections. The overall in-hospital mortality rate was 11.2%. 56.1% of patients' dopaminergic medications were decreased in dose upon admission (22.5% mean decrease in levodopa equivalent daily dose [LEDD]; p<0.001). Both absolute and relative LEDD reductions were associated with significantly increased in-hospital mortality (mean reduction of 394.5 mg versus 188.4 mg; p=0.035 by analysis of variance adjusted to age, sex and renal function) and was also associated with worse discharge destination relative to original place of arrival (mean reduction of 377.8 mg versus 150.7 mg; p=0.014). Decreased dopaminergic medication dosing upon admission of PD patients due to infection is widespread and potentially associated with worse clinical outcomes.

Safety and efficacy of multipolar pulmonary vein ablation catheter vs. irrigated radiofrequency ablation for paroxysmal atrial fibrillation: a randomized multicentre trial.

AIMS: The current challenge in atrial fibrillation (AF) treatment is to develop effective, efficient, and safe ablation strategies. This randomized controlled trial assesses the medium-term efficacy of duty-cycled radiofrequency ablation via the circular pulmonary vein ablation catheter (PVAC) vs. conventional electro-anatomically guided wide-area circumferential ablation (WACA). METHODS AND RESULTS: One hundred and eighty-eight patients (mean age 62 ± 12 years, 116 M : 72 F) with paroxysmal AF were prospectively randomized to PVAC or WACA strategies and sequentially followed for 12 months. The primary endpoint was freedom from symptomatic or documented >30 s AF off medications for 7 days at 12 months post-procedure. One hundred and eighty-three patients completed 12 m follow-up. Ninety-four patients underwent PVAC PV isolation with 372 of 376 pulmonary veins (PVs) successfully isolated and all PVs isolated in 92 WACA patients. Three WACA and no PVAC patients developed tamponade. Fifty-six percent of WACA and 60% of PVAC patients were free of AF at 12 months post-procedure (P = ns) with a significant attrition rate from 77 to 78%, respectively, at 6 months. The mean procedure (140 ± 43 vs. 167 ± 42 min, P<0.0001), fluoroscopy (35 ± 16 vs. 42 ± 20 min, P<0.05) times were significantly shorter for PVAC than for WACA. Two patients developed strokes within 72 h of the procedure in the PVAC group, one possibly related directly to PVAC ablation in a high-risk patient and none in the WACA group (P = ns). Two of the 47 patients in the PVAC group who underwent repeat ablation had sub-clinical mild PV stenoses of 25-50% and 1 WACA patient developed delayed severe PV stenosis requiring venoplasty. CONCLUSION: The pulmonary vein ablation catheter is equivalent in efficacy to WACA with reduced procedural and fluoroscopy times. However, there is a risk of thrombo-embolic and pulmonary stenosis complications which needs to be addressed and prospectively monitored. CLINICALTRIALSGOV IDENTIFIER: NCT00678340.

[Effect of conditions of monoclonal antibody adsorption on antigen-binding activity].

The dependence of the antigen-binding activity of immobilized antibodies on pH of a saturating buffer has been investigated. We analyzed 28 monoclonal antibodies (MCAs) produced by various hybridomas to three virus antigens, i.e., the nuclear p23 protein of hepatitis C virus (C core protein p23), p24 protein of HIV 1, and the surface antigen of hepatitis B virus (HBsAg). Antibodies were adsorbed on the surfaces of immune plates in acidic (pH 2.8), neutral (pH 7.5), and alkaline (pH 9.5) buffers. The binding of labeled antigens, i.e., biotinylated or conjugated with horseradish peroxidase, with immobilized antigens was tested. It was shown that 10 out of 28 analyzed MCAs (36%) considerably better preserved their antigen-binding activity if their passive adsorption was carried out on the surface of polystyrene plates in an acidic buffer (pH 2.8). This approach allowed constructing a highly sensitive sandwich method for HBsAg assay with a minimal reliably determined antigen concentration of 0.013-0.017 ng/ml. The described approach may be recommended for the optimization of sandwich methods and solid-phase competitive methods.

[Use of pH-sensitive immobilized monoclonal antibodies for optimization of immunoenzyme sandwich technique of detection of HBsAg of hepatitis B virus].

AIM: To develop highly sensitive sandwich technique for identification of surface hepatitis B virus antigen (HBsAg) in serum and analyse of possible improvement of solid phase for immunoenzyme sandwich technique of HBsAg identification through variation of pH-dependent sorption of monoclonal antibodies on the surface of immune plates. MATERIALS AND METHODS: Calibration curves for identification of HBsAg in sandwich techniques using 36 possible binary combinations of monoclonal antibodies of our panel (including high affinity antibodies to HBsAg produced by 6 hybridomas) were compared. Immobilization of antibodies on solid phase (by passive sorption) was performed at different pH values (2.8, 7.5, and 9.5). RESULTS: Analysis of panel of antibodies to HBsAg produced by 6 hybridomas revealed pH-dependent monoclonal antibodies (18C8), which immobilization at low pH values together with detecting antibodies F4F3 allowed to greatly improve sensitivity of the sandwich technique. Minimal credibly detectable concentration of HBsAg in sera of persons infected with hepatitis B virus was 0.013 - 0.017 ng/ml. Validation of sandwich technique was performed on certified panel of serum samples with various concentrations of HBsAg (different serotypes). CONCLUSION: Highly sensitive sandwich technique for detection of HBsAg was developed. It was shown that analysis of panel of monoclonal antibodies on pH-dependence could be used as simple methodical approach for optimization of immunoenzyme sandwich techniques for detection of different antigens.

Analysis of serotonin transporter in human platelets by immunoblotting using site-specific antibodies.

We have produced a panel of site-specific antibodies recognizing different regions of the human serotonin transporter (SERT). This panel included: 1) monoclonal antibodies 23C5 (mAbs 23C5) to the C-terminal region (amino acid residues 597-630); 2) polyclonal antibodies (pAbs) to the N-terminal region (amino acid residues 69-83); 3) pAbs to the region (amino acid residues 86-100) in the beginning of the first transmembrane domain (TMD). The antibodies were produced using recombinant proteins and synthetic peptides (containing certain sequences of SERT) as antigens. These antibodies were purified by affinity chromatography, conjugated to horseradish peroxidase (HRP), and used for immunoblotting analysis of SERT in extracts of human platelets. Sodium dodecyl sulfate extracts were prepared under conditions preventing non-specific proteolytic degradation of the proteins. In platelet extracts, all antibodies were able to detect the 67 kD protein, apparently corresponding to full-length SERT molecule (its theoretical mass is about 70 kD). These antibodies also detected several polypeptides of smaller size (56, 37, 35, 32, 22, and 14 kD), apparently corresponding to N-terminal, C-terminal, and non-terminal SERT fragments. Specificity of immunostaining was confirmed by preincubation of HRP-labeled anti-SERT antibodies with excess of corresponding antigen, which resulted in disappearance of protein band staining. It is suggested that SERT undergoes a programmed proteolytic cleavage (processing) resulting in formation of several SERT-derived polypeptides of smaller size. It is possible that one of the cleaved SERT species is required for serotonin transport activity. Possible sites for specific proteolysis may be located in the region near TMD1 and in the intracellular loop between TMD4 and TMD5.

Analysis of bispecific monoclonal antibody binding to immobilized antigens using an optical biosensor.

The interaction between two different monoclonal antibodies (Mabs) and their corresponding bispecific antibodies (Babs) with immobilized antigens was investigated using an optical biosensor (IAsys). The analyzed panel of affinity-purified antibodies included two parental Mabs (one of which was specific to human IgG (hIgG), and another one to horseradish peroxidase (HRP)), as well as Babs derived thereof (anti-hIgG/HRP). Babs resulting from the fusion of parental hybridomas bear two antigen-binding sites toward two different antigens and thus may interact with immobilized antigen through only one antigen-binding site (monovalently). Using an IAsys biosensor this study shows that the bivalent binding of Mabs predominates over the monovalent binding with immobilized HRP, whereas anti-hIgG parental Mabs were bound monovalently to the immobilized hIgG. The observed equilibrium association constant (K(ass)) values obtained in our last work [1] by solid-phase radioimmunoassay are consistent with those constants obtained by IAsys. The K(ass) of anti-HRP Mabs was about 50 times higher than that of anti-HRP shoulder of Babs. The dissociation rate constant (k(diss)) for anti-HRP shoulder of Babs was 21 times higher than k(diss) for anti-HRP Mabs. The comparison of the kinetic parameters for bivalent anti-HRP Mabs and Babs derived from anti-Mb/HRP and anti-hIgG/HRP, allowed to calculate that 95% of bound anti-HRP Mabs are bivalently linked with immobilized HRP, whereas only 5% of bound anti-HRP Mabs are monovalently linked. In general, the data obtained indicate that Babs bearing an enzyme-binding site may not be efficiently used instead of traditional antibody-enzyme conjugates in the case of binding of bivalent Mabs.

[The binding of bispecific monoclonal antibodies to the solid phase-adsorbed antigens]. / Sviazyvanie bispetsificheskikh monoklonal'nykh antitel s antigenami, adsorbirovannymi na tverdoi faze.

The ability of bispecific antibodies (Babs) formed by fusion of hybridomas and parent monoclonal antibodies (Mabs) to interact with the solid phase-adsorbed antigens was studied. Mabs specific to the three different antigens [horseradish peroxidase (HRP), human IgG (hIgG), and human myoglobin (Mb)] as well as Babs with the double specificity [antimyoglobin/antiperoxidase (anti-Mb/HRP) and anti-hIgG/antiperoxidase (anti-hIgG/HRP)] were used. It was shown by radioimmunological and immunoenzyme assays that parent Mabs bind to solid phase-adsorbed antigens considerably more effectively than Babs. The observed equilibrium binding constant (Ka) of antiperoxidase parental Mabs to immobilized HRP is 21 and 38 times higher than Ka for Babs binding sites (anti-Mb/HRP and anti-hIgG/HRP, respectively) to peroxidase. It was calculated that about 90-95% of all bound parental antiperoxidase Mabs were associated with immobilized HRP bivalently, and only about 5-10% were bound monovalently. On the contrary, parental Mabs against hIgG bind to the sorbed antigen essentially only monovalently. It was also shown that the avidity of anti-Mb/HRP Babs significantly increased when two antigens, Mb and HRP, were simultaneously adsorbed on the solid phase. These data imply that Babs bearing an enzyme-binding site (for example, binding to HRP) cannot be more effective than standard conjugates (e.g., enzyme-conjugated antibodies) in heterogeneous noncompetitive immunoassays.

[Levels and molecular heterogeneity of serotonin transporter protein in platelets of patients with different mental diseases: a comparative analysis with the use of monoclonal and polyclonal antibodies]. / Soderzhanie i molekuliarnaia geterogennost' belka--perenoschika serotonina v trombotsitakh bol'nykh s razlichnymi psikhicheskimi zabolevaniiami: sravnitel'nyi analiz s ispol'zovaniem monoklonal'nykh i poliklonal'nykh antitel.

Polyclonal (PAb) and monoclonal (MAb) antibodies to CT2-epitope of the C-terminal fragment of serotonin transporter (SERT) protein were used to study the levels and molecular heterogeneity of platelet SERT in healthy donors and patients with affective (AD) and somatoform (SD) disorders, schizoaffective disorder (SAD) and schizophrenia. SERT was found to exist as high molecular wight (HMW) and low molecular weight (LMW) forms separated after electrophoresis. The levels of HMW and LMW forms of SERT were significantly, decreased in mentally ill patients as compared to healthy individuals. Unlike PAb, horse radish peroxidase (HRP)-conjugated MAbs were more sensitive and specific to SERT and could detect the LMW form of SERT as a duplet protein form with MW about 40 and 43 kDa. The MAb to CT2 C-terminal fragment of SERT conjugated with HRP is considered to be a new valuable tool for further investigation of SERT expression, properties, and posttranslation modification in the controls and in patients with different psychopathology.

The comparison of the ability of monoclonal antibodies directed to different proteins (human IgG, human myoglobin and HRP) and bispecific antibodies derived thereof to bind antigens immobilized on a surface of a solid phase.

BACKGROUND: Bindings of mouse monoclonal antibodies (mAbs) and affinity purified bispecific antibodies (bAbs), derived thereof, to antigens adsorbed on immunoplates have been compared, using ELISA and RIA methods. METHODS: The analysed panel of antibodies included mAbs specific to human myoglobin (Mb), human IgG (hIgG) and horseradish peroxidase (HRP) and biologically produced bAbs with double specificity to Mb and HRP, and to hIgG and HRP. RESULTS: The degree of difference between different mAbs and corresponding bAbs varied markedly from antibody to antibody, depending on whether the parental mAbs could bind immobilized antigens bivalently. The observed equilibrium binding constant (K(obs)) for anti-HRP mAbs was 21-38 times higher that of anti-HRP site of bAbs (anti-hIgG/HRP or anti-Mb/HRP, respectively), due to bivalent binding of mAbs. Anti-Mb mAbs also bound bivalently with immobilized Mb. On the contrary, anti-hIgG mAbs bound monovalently with immobilized hIgG in the same conditions. The avidity of anti-Mb/HRP bAbs increased, if both antigens were simultaneously adsorbed on a solid phase. CONCLUSIONS: The obtained data indicate that the use of bAbs in heterogeneous immunoassays instead of traditional mAb-enzyme conjugates hardly can provide the significant gain in assay performance if parental mAbs bind bivalently.

Speech perception results--the first 10 years of a cochlear implant program.

Long-term speech perception test results for prelingually deaf children were compared with those of postlingually deafened adults, both groups having undergone cochlear implant at our Center. Average open-set score results of adults were similar to those of the children. However, some qualitative differences were demonstrated on the perception of phonological contrasts between the groups.