Safety and immunogenicity of the oral, inactivated, enterotoxigenic Escherichia coli vaccine ETVAX in Bangladeshi children and infants: a double-blind, randomised, placebo-controlled phase 1/2 trial.

BACKGROUND: Enterotoxigenic Escherichia coli causes diarrhoea, leading to substantial mortality and morbidity in children, but no specific vaccine exists. This trial tested an oral, inactivated, enterotoxigenic E coli vaccine (ETVAX), which has been previously shown to be safe and highly immuongenic in Swedish and Bangladeshi adults. We tested the safety and immunogenicity of ETVAX, consisting of four E coli strains overexpressing the most prevalent colonisation factors (CFA/I, CS3, CS5, and CS6) and a toxoid (LCTBA) administered with or without a double-mutant heat-labile enterotoxin (dmLT) as an adjuvant, in Bangladeshi children. METHODS: We did a randomised, double-blind, placebo-controlled, dose-escalation, age-descending, phase 1/2 trial in Dhaka, Bangladesh. Healthy children in one of three age groups (24-59 months, 12-23 months, and 6-11 months) were eligible. Children were randomly assigned with block randomisation to receive either ETVAX, with or without dmLT, or placebo. ETVAX (half [5·5 × 1010 cells], quarter [2·5 × 1010 cells], or eighth [1·25 × 1010 cells] adult dose), with or without dmLT adjuvant (2·5 µg, 5·0 µg, or 10·0 µg), or placebo were administered orally in two doses 2 weeks apart. Investigators and participants were masked to treatment allocation. The primary endpoint was safety and tolerability, assessed in all children who received at least one dose of vaccine. Antibody responses to vaccine antigens, defined as at least a two-times increase in antibody levels between baseline and post-immunisation, were assessed as secondary endpoints. This trial is registered with ClinicalTrials.gov, NCT02531802. FINDINGS: Between Dec 7, 2015, and Jan 10, 2017, we screened 1500 children across the three age groups, of whom 430 were enrolled and randomly assigned to the different treatment groups (130 aged 24-59 months, 100 aged 12-23 months, and 200 aged 6-11 months). All participants received at least one dose of vaccine. No solicited adverse events occurred that were greater than moderate in severity, and most were mild. The most common solicited event was vomiting (ten [8%] of 130 patients aged 24-59 months, 13 [13%] of 100 aged 12-23 months, and 29 [15%] of 200 aged 6-11 months; mostly of mild severity), which appeared related to dose and age. The addition of dmLT did not modify the safety profile. Three serious adverse events occurred but they were not considered related to the study drug. Mucosal IgA antibody responses in lymphocyte secretions were detected against all primary vaccine antigens (CFA/I, CS3, CS5, CS6, and the LCTBA toxoid) in most participants in the two older age groups, whereas such responses to four of the five antigens were less frequent and of lower magnitude in infants aged 6-11 months than in older children. Faecal secretory IgA immune responses were recorded against all vaccine antigens in infants aged 6-11 months. 78 (56%) of 139 infants aged 6-11 months who were vaccinated developed mucosal responses against at least three of the vaccine antigens versus 14 (29%) of 49 of the infants given placebo. Addition of the adjuvant dmLT enhanced the magnitude, breadth, and kinetics (based on number of responders after the first dose of vaccine) of immune responses in infants. INTERPRETATION: The encouraging safety and immunogenicity of ETVAX and benefit of dmLT adjuvant in young children support its further assessment for protective efficacy in children in enterotoxigenic E coli-endemic areas. FUNDING: PATH (Bill & Melinda Gates Foundation and the UK's Department for International Development), the Swedish Research Council, and The Swedish Foundation for Strategic Research.

Evaluation of the safety and immunogenicity of the oral inactivated multivalent enterotoxigenic Escherichia coli vaccine ETVAX in Bangladeshi adults in a double-blind, randomized, placebo-controlled Phase I trial using electrochemiluminescence and ELISA assays for immunogenicity analyses.

The safety and immunogenicity of the second generation oral enterotoxigenic Escherichia coli (ETEC) vaccine ETVAX, consisting of inactivated recombinant E. coli strains over-expressing the colonization factors (CFs) CFA/I, CS3, CS5 and CS6 and the heat labile toxoid LCTBA, were evaluated in Bangladeshi volunteers. To enable analysis of antibody responses against multiple vaccine antigens for subsequent use in small sample volumes from children, a sensitive electrochemiluminescence (ECL) assay for analysis of intestine-derived antibody-secreting cell responses using the antibodies in lymphocyte secretions (ALS) assay was established using Meso Scale Discovery technology. Three groups of Bangladeshi adults (n = 15 per group) received two oral doses of ETVAX with or without double mutant LT (dmLT) adjuvant or placebo in the initial part of a randomized, double-blind, placebo-controlled, age-descending, dose-escalation trial. CF- and LTB-specific ALS and plasma IgA responses were analyzed by ECL and/or ELISA. ETVAX was safe and well tolerated in the adults. Magnitudes of IgA ALS responses determined by ECL and ELISA correlated well (r = 0.85 to 0.98 for the five primary antigens, P < 0.001) and ECL was selected as the ALS readout method. ALS IgA responses against each of the primary antigens were detected in 87-100% of vaccinees after the first and in 100% after the second vaccine dose. Plasma IgA responses against different CFs and LTB were observed in 62-93% and 100% of vaccinees, respectively. No statistically significant adjuvant effect of dmLT on antibody responses to any antigen was detected, but the overall antigenic breadth of the plasma IgA response tended to favor the adjuvanted vaccine when responses to 4 or more or 5 vaccine antigens were considered. Responses in placebo recipients were infrequent and mainly detected against single antigens. The promising results in adults supported testing ETVAX in descending age groups of children. ClinicalTrials.gov Identifier: NCT02531802.

Kinetics of antibody-secreting cell and fecal IgA responses after oral cholera vaccination in different age groups in a cholera endemic country.

Immune responses to oral enteric vaccines in children and infants may be influenced by factors such as age, previous priming with related microorganisms and breast feeding. In this study, we aimed to determine optimal time points to assess immune responses to oral enteric vaccines in different clinical specimens. This was done by investigating antibody secreting cell (ASC) and fecal antibody responses on different days after vaccination using the licensed oral cholera vaccine Dukoral, containing cholera toxin B-subunit (rCTB) and inactivated Vibrio cholerae bacteria, as a model vaccine. Two vaccine doses were given 2weeks apart to infants (6-11months), young children (12-18months), toddlers (19months-5years) and adults in a cholera endemic country (Bangladesh). IgA ASC responses, as determined by the antibodies in lymphocyte supernatant (ALS) assay, plasma IgA and IgG responses and secretory IgA (SIgA) responses in extracts of fecal samples were evaluated 4/5 and 7days after each vaccination. After the first vaccine dose, anti-CTB ALS IgA responses in adults and toddlers were high and comparable on day 5 and 7, while responses were low and infrequent in young children. After the second dose, highest ALS responses were detected on day 5 among the time points studied in all age groups and the responses declined until day 7. In contrast, plasma IgA and IgG anti-CTB responses were high both on day 5 and 7 after the second dose. Fecal SIgA responses in young children and infants were highest on day 7 after the second dose. Our results suggest that ASC/ALS responses to two doses of the oral cholera vaccine Dukoral and related oral vaccines should be analyzed earlier than previously recommended (day 7) at all ages. Fecal antibody responses should preferably be analyzed later than ASC/ALS responses to detect the highest antibody responses.

Effect of intravenous dopamine infusion on plasma concentrations of dopamine and dopamine sulfate in men, during and up to 18 h after infusion.

OBJECTIVE: We investigated whether sulfoconjugation contributes to the inactivation of intravenously infused dopamine (DA) in low concentrations with a predominant action on the kidney. METHODS: Plasma DA and dopamine sulfate (DA-S) concentrations were determined during 4 h of intravenous infusion of DA (2 microg/kg/min) and up to 18 h after cessation of infusion. Twenty-seven healthy young subjects participated in the placebo controlled, randomised and double-blind study. RESULTS: Intravenously administered DA was sulfoconjugated rapidly and to a great extent. After starting the infusion, DA levels rose within minutes and reached a steady state after 30-60 min. The steady-state levels averaged 151.3 +/- 8.2 nmol/l. DA-S levels also increased markedly with infusion from 16.7 +/- 9.9 nmol/l at the start of infusion up to 261.2 +/- 24.2 nmol/l at 30 min after cessation of infusion. Plasma DA concentrations after cessation of the infusion decreased rapidly with an initial half-life of elimination of 4.8 min. Concentrations of plasma DA-S declined with a half-life of 4.5 h. Persistent elevations of free and conjugated DA compared with pre-treatment levels were observed even 18 h after cessation. Heart rate and blood pressure remained unchanged both during DA and saline infusion. CONCLUSION: Findings indicate that the sulfoconjugation pathway contributes markedly to the inactivation of intravenously infused DA and seems not to be saturable by DA infusion in low doses.

Tricuspid valve reconstruction, a treatment option in acute endocarditis.

Tricuspid valve endocardititis is treated surgically by total valve excision or valve replacement. Both procedures are controversial with regard to the hemodynamic consequences and to the long-term prognosis. In the following, results of tricuspid valve repair in acute infective endocarditis are reported and discussed as an additional treatment option. Between January 1988 and December 1993, 118 patients were operated on for acute valve endocarditis at our institution. Eleven of these patients had tricuspid valve endocarditis, isolated (n = 7) or combined with endocarditis of a left-sided valve (n = 4). In the cases with isolated tricuspid valve endocarditis, the indication for surgery was intractable infection in six and hemodynamically relevant tricuspid insufficiency in one out of seven patients. In all patients with associated left-sided endocarditis, the indication was hemodynamic deterioration. In eight patients the tricuspid valve endocarditis was treated as follows: debridement, vegectomy, patch reconstruction of the cusps, reducing the cusps to two. In three patients reconstruction was not possible because of extensive involvement of all parts of the valve, including the valve ring and the papillary muscles. In these patients primary valve replacement (n = 1) or valve excision with secondary replacement (n = 2) was performed. In four patients tricuspid reconstruction was combined with mitral (n = 1), aortic (n = 1) or double valve replacement (n = 2). Postoperatively, signs of infection vanished in all surviving patients (n = 10) and tricuspid valve endocarditis healed without recurrences. Implanted prosthetic material did not lead to recurrent infection. One patient died early postoperatively after valve excision, in septic shock and multi-organ failure. In seven patients late echocardiographic follow-up showed tricuspid regurgitation grade 0 in three patients, I in two, II in one and III in one. Our results suggest that valve repair is a reasonable treatment option for tricuspid valve endocarditis in all cases with localized infection of the valve. Only if extensive valve destruction excludes valve repair, would we now favor primary valve replacement over simple valvulectomy. In all other cases primary valve reconstruction is the treatment of choice for tricuspid valve endocarditis, if surgery is indicated.

[Surgical therapy of acute tricuspid valve endocarditis: indications, technique and results]. / Chirurgische Therapie der akuten Trikuspidalklappen-Endokarditis: Indikation, Technik und Ergebnisse.

Tricuspid valve endocarditis is treated by antibiotics alone in the majority of the cases. However, intractable infection or hemodynamic compromise may warrant surgery. In those cases total valve-excision or valve-replacement had been the most common surgical procedures. Both are controversial in regards to the hemodynamic consequences and to the long-term prognosis. In the following, results of tricuspid valve repair in acute infective endocarditis are reported and discussed as an additional treatment option. Between January 1988 and December 1993, 118 patients were operated for acute valve endocarditis at our institution. Eleven of these patients had tricuspid valve endocarditis, isolated (n = 7) or combined with endocarditis of a left-sided valve (n = 4). In the cases with isolated tricuspid valve endocarditis, the indication for surgery was intractable infection in 6 and hemodynamically relevant tricuspid-insufficiency in 1 out of 7 patients, respectively. In all patients with associated left-sided endocarditis, the indication was hemodynamic deterioration. In 8 patients the tricuspid valve endocarditis was treated as follows: Debridement, vegectomy, patch-reconstruction of the cusps, bicuspidalization. In 3 patients reconstruction was not possible because of extended involvement of all parts of the valve, including the valve ring and the papillary muscles. In these patients, primary valve-replacement (n = 1) or valve-excision with secondary replacement (n = 2) was performed. In 4 patients tricuspid-reconstruction was combined with mitral- (n = 1), aortic- (n = 1) or double-valve replacement (n = 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Modified surgical concept for fulminant pulmonary embolism.

Surgical intervention in fulminant pulmonary embolism (PE) is still associated with an overall 30% fatal outcome which increases to about 60% when cardiopulmonary resuscitation (CPR) is necessary. Despite unfavorable conditions like hemodynamic instability, failed lysis or CPR, the surgical strategy might have a certain impact on the patient's outcome since 30-40% of the surgical mortality is related to persistent right heart failure and early thromboembolic recurrence. From 1/88 to 8/94 a total of 25 patients (15 females, 10 men, mean age 57 [25-78]) years underwent emergency pulmonary embolectomy with the use of the heart-lung machine. Seventeen patients were operated upon between 1988 and 1992. A standard approach by central pulmonary artery incision with extraction of adjacent pulmonary emboli using forceps, suction of Fogarty catheters was used. Six of these patients (35%) died, with four out of six operated upon under CPR. Since 1993 we have used a modified surgical strategy in eight patients. Five patients (63%) were operated on after or under CPR. In these cases, left and right pulmonary arteries were incised peripherally and all segmental arteries were desobliterated selectively using small suction devices. Thereafter the right atrium was opened and inspected. After removal of the inferior caval vein cannula all inferior body blood was taken with cardiotomy suction while both legs and the abdomen were massaged centripetally to mobilize additional fresh thrombotic material. In three cases up to 50 cm long thrombi could be delivered. All patients have survived to date with two patients receiving a LGM caval filter placed percutaneously after bilateral postoperative phlebography had revealed ongoing thrombotic disease. We conclude that selective desobliteration of every segmental pulmonary artery in combination with simultaneous clearance of major body veins from additional thrombotic material will probably lower surgical mortality in these critically ill patients.

Adjustable tricuspid valve annuloplasty assisted by intraoperative transesophageal color Doppler echocardiography.

Intraoperative transesophageal echocardiography (TEE) can play a major role in active guidance of cardiac surgery. This study describes a new application of TEE for assisting tricuspid suture annuloplasty. Twenty-five patients (aged 52 +/- 11 years) who underwent mitral valve replacement and tricuspid valve annuloplasty were studied intraoperatively by TEE. After cardiopulmonary bypass, the suture annuloplasty was adjusted on the beating heart until palpable regurgitation was eliminated. Further adjustment of the suture was performed under echocardiographic guidance until color Doppler flow imaging showed the most adequate correction of tricuspid regurgitation (TR). A significant decrease in the semiquantitative grade of TR, of regurgitant jet area and of the ratio jet area/right atrial area was obtained when the suture was adjusted under echocardiographic guidance. The peak inflow velocity and the gradient across the tricuspid valve did not show significant changes throughout the procedures. The results showed that the tricuspid suture annuloplasty guided by TEE enables a substantial reduction in residual TR without creating valve stenosis.

[Intraoperative evaluation of tricuspid valve annuloplasty with transesophageal echocardiography]. / Valutazione intraoperatoria dell'anuloplastica tricuspidale mediante ecocardiografia transesofagea.

The present study shows a new application of transesophageal echocardiography (TEE) to optimize tricuspid valve annuloplasty. Eighteen patients with tricuspid regurgitation (TR) underwent De Vega tricuspid annuloplasty. After cardiopulmonary bypass the tension on the suture was adjusted until the surgeon could not feel any regurgitant jet by intraatrial palpation; subsequently, the tension was further adjusted on the basis of TEE. The post-pump residual tricuspid regurgitation was assessed by semiquantitative grading of tricuspid regurgitation (0 to 4+), area of regurgitant jet and percentage of right atrial area subtended by jet area. The data obtained by intraatrial palpation were compared with the data obtained by TEE. A significant reduction of residual tricuspid regurgitation was shown by TEE when compared to intraatrial palpation. After a follow-up period of 2 weeks, no significant changes in the grade of TR were observed. The results showed that the use of TEE was able to optimize the De Vega's tricuspid annuloplasty.

Intraoperative transesophageal echocardiography for the evaluation of mitral, aortic and tricuspid valve repair. A tool to optimize surgical outcome.

The present study reviews the clinical applicability and usefulness of intraoperative transesophageal echocardiography (TEE) during valve repair. Intraoperative TEE was performed in 48 consecutive patients, who were divided into three groups: 1. mitral valve repair (MVR), 2. aortic valve repair (AVR), 3. tricuspid valve repair (TVR). Residual valve regurgitation was assessed by color Doppler echocardiography on a scale from 0 to 4. The ratios of the jet area (JA) to the left- and right-atrial areas (JA/LAA and JA/RAA) were analyzed before and after cardiopulmonary bypass (CPB). In group 1, 14 patients were scheduled for MVR, of which 4 patients underwent valve replacement and 10 MVR. Post-repair TEE studies showed a significant decrease of mitral regurgitation. In 2 of the 10 patients, TEE demonstrated severe residual regurgitation requiring valve replacement during the same thoracotomy. In group 2, 11 patients underwent aortic commissurotomy. Post-repair TEE showed an increase in the systolic opening diameter and opening area of the aortic valve. One patient underwent valve substitution because of severe aortic regurgitation. In group 3, 23 patients were scheduled for TVR. In 3 of them TEE showed no significant regurgitation thus rendering tricuspid valve surgery unnecessary. Twenty patients underwent TVR of whom two showed unacceptable post-repair regurgitation requiring further surgery. Eighteen patients showed a significant reduction of valve regurgitation after TVR, and a further reduction was achieved by adjusting the tricuspid annuloplasty under TEE guidance.

Non-invasive assessment of perioperative myocardial cell damage by circulating cardiac troponin T.

Troponin T is a unique cardiac antigen which is continuously released from infarcting myocardium. Its cardiospecificity as a marker protein might be particularly useful in assessing myocardial cell damage in patients undergoing cardiac surgery. Therefore, circulating troponin T was measured in serial blood samples from 56 patients undergoing cardiac surgery and in two control groups--22 patients undergoing minor orthopaedic surgery and 12 patients undergoing lung surgery by median sternotomy. In both control groups no troponin T could be detected, whereas activities of creatine kinase were raised in all 12 lung surgery controls and activities of the MB isoenzyme were raised in five of the 12 patients in the lung surgery group and in four of the 22 patients in the orthopaedic surgery group, respectively. All the patients undergoing coronary artery bypass grafting (n = 47) and cardiac surgery for other reasons (n = 9) had detectable concentrations of troponin T. Five patients had perioperative myocardial infarction detected as new Q waves and R wave reductions. In these five patients troponin T release persisted and serum concentrations (5.5-23 micrograms/l) reached a peak on the fourth postoperative day. In the 51 patients without perioperative myocardial infarction serum concentrations and the release kinetics of troponin T depended on the duration of cardiac arrest. In patients in whom aortic cross clamping was short troponin T increased slightly on the first postoperative days; in patients with longer periods of aortic cross clamping troponin T concentrations were higher and remained so beyond the fifth postoperative day. In patients with non-specific changes on the electrocardiogram troponin T concentrations were significantly higher on days 1 and 4 after operation than in patients with normal postoperative electrocardiograms(11.2 (5) and 4.5 (2.6) v 8.2 (3.4) and 2.9 (1.6) 1microg/l). Serum concentrations of troponin T showed some myocardial cell damage in every patient undergoing cardiac surgery. The persistent increases that were more common in patients with longer periods of cardiac arrest must have been caused by damage to the contractile apparatus. These results suggest that perioperative myocardial cell necrosis may be more common than indicated by changes of the QRS complex on the electrocardiogram.

[Results of prosthetic heart valve replacement. Primary, secondary and emergency operations]. / Ergebnisse des prothetischen Herzklappenersatzes. Erst-, Zweit- und Notoperationen.

From 1962 to 1984, 2460 prosthetic valve implantations in the heart were performed at the Department of Surgery of the University of Heidelberg. In addition to 2291 primary surgical interventions, 169 re-interventions were carried out. 153 emergency operations were necessary. The frequency rate of operations increased continuously; 52% of the operations were performed at the aortic valve and 37% at the mitral valve. In 9% of the cases, two valves had to be replaced, and in 2% even three valve prostheses were implanted. The indications for re-intervention included prosthetic thromboses, paravalvular leakages and prosthetic valve endocarditis. The situations requiring emergency intervention differed from case to case. Early mortality, which had been initially high, could be considerably reduced due to increased experience in surgical technique, anaesthesia, intensive care and improved myocardial protection. The extent and quality of medical postoperative care will determine the success of medical rehabilitation and hence the future professional activity of the patient.

Late pulmonary embolization of a retained pacemaker electrode fragment after attempted transatrial extraction.

Embolization of pacemaker electrode fragments into the pulmonary circulation is a rare complication following transvenous pacemaker implantation. One such case is reported here. In a 67-year-old patient, a battery pocket infection developed after transvenous pacemaker implantation and subsequent surgical revision. After removal of the pacemaker and ventricular pacing lead, the atrial lead broke within the superior vena cava when prolonged traction was applied after frustrating attempts to extract the electrode. Attempts to extract the fragment transvenously using endoscopic forceps were unsuccessful. Due to firm fixation of the electrode by extensive fibrous scar tissue in the atrial wall, a further attempt to remove the retained electrode fragment by atriotomy also failed. On the first postoperative day, the fragment migrated to the left pulmonary artery, from where it was successfully extracted by means of a Dormier basket.

Reduction of postoperative donor blood requirement by use of the cell separator.

In a prospective, randomized study of 20 patients undergoing elective open-heart surgery, up to c. one-third of the total intraoperative and postoperative transfusion requirement could be provided by autologous centrifuged blood. Retransfusion of washed, packed red blood cells freed from cellular debris, heparin and activated clotting factors significantly reduced blood loss during and after surgery. The cell separator is a valuable aid in autotransfusion technique.

[The Haemonetics cell saver in open heart surgery (author's transl)]. / Erfahrungen mit dem Haemonetics-Cell-Saver in der offenen Herzchirurgie.

A prospective study in 20 patients undergoing open heart surgery showed that up to 48 per cent of the required transfusion volume could be provided by autologous centrifuged blood. Re-transfusion of the washed packed red cells free of cell debris, heparin and aggregate significantly reduced blood loss both during and after the operation. The haemonetics cell saver is a valuable aid in the auto-transfusion technique.

Technique of implantation and removal of balloon catheters for the intra-aortic balloon counter pulsation.

During recent years, intra-aortic balloon counterpulsation has become the treatment of choice in patients suffering from left ventricular power failure following cardiac operations. In our clinic IABP became necessary in 55 patients out of 1873 patients operated with heart lung machine during the period under study. The patients were studied in two groups. In Group I the intra aortic balloon counter pulsation was started only after there was no response to pharmacological agents, which often included high doses of catecholamines and vasoconstrictors. The mortality in this group was 74%. The second group consisted of patients treated since 1975. In this group, the counter pulsation was started early before ventricular damage was irreversible. In this group the survival was 52%. In addition we have paid careful attention to the technique of implantation of the balloon catheter, thrombosis prophylaxis during the counter pulsation and removal of any possible thrombi in proximal and distal segments to the arteriotomy with the help of Fogarty catheters together with the closure of the arteriotomy with a vein patch. The technique described has resulted in almost no peripheral vascular complications.

[Effects of various forms of myocardial protection on cardiac function, metabolism, and blood flow (author's transl)]. / Funktion, Stoffwechsel und Durchblutung des Myokards bei verschiedenen Formen des Myokardschutzes.

The myocardial protective effect of two cardioplegic solutions was studied after an ischemic period of 2 h in eight dogs. Group I received a high potassium solution (St. Thomas Hospital) and group II a sodium withdrawal solution with high colloid osmotic pressure (Eppendorf solution). With the exception of a prolonged myocardial K+ washout (10 min) in group I, which was presumably responsible for fibrillation in the early reperfusion period, no major metabolic or perfusion differences between the two groups were observed. After 30 min of reperfusion, postischemic LV function (-43%) and O2 uptake (-43%) were equally reduced in both groups.