Vitamin D induced microbicidal activity against Mycobacterium bovis BCG is dependent on the synergistic activity of bovine peripheral blood cell populations

A growing appreciation is emerging of the beneficial role of vitamin D for health and resistance against infectious diseases, including tuberculosis. However, research has predominantly focused on murine and human species and functional data in bovines is limited. Therefore, the objective of this study was to assess the microbicidal activity and immunoregulatory effect of the vitamin D metabolite 1,25(OH)2D3 on bovine peripheral blood leukocytes (PBL) in response to Mycobacterium bovis BCG (BCG) infection using a combination of functional assays and gene expression profiling. Blood from Holstein-Friesian bull calves with low circulating levels of 25(OH)D was stimulated with 1,25(OH)2D3 for 2 h, and then infected with M. bovis BCG. Results showed that 1,25(OH)2D3 supplementation significantly increased BCG killing by on average 16 %, although responses varied between 1 % and 38 % killing. Serial cell subset depletion was then performed on PBL prior to 1,25(OH)2D3 incubation and BCG infected as before to analyse the contribution of major cell types to mycobacterial growth control. Specific antibodies and either magnetic cell separation or density gradient centrifugation of monocytes, granulocytes, CD3+, CD4+, and CD8+ T lymphocytes were used to capture each cell subset. Results showed that depletion of granulocytes had the greatest impact on BCG growth, leading to a significant enhancement of bacterial colonies. In contrast, depletion of CD4+ or CD8+ T cells individually, or in combination (CD3+), had no impact on mycobacterial growth control. In agreement with our previous data, 1,25(OH)2D3 significantly increased bacterial killing in PBL, in monocyte depleted samples, and a similar trend was observed in the granulocyte depleted subset. In addition, specific analysis of sorted neutrophils treated with 1,25(OH)2D3 showed an enhanced microbicidal activity against both BCG and a virulent strain of M. bovis. Lastly, data showed that 1,25(OH)2D3 stimulation increased reactive oxygen species (ROS) production and the expression of genes encoding host defence peptides (HDP) and pathogen recognition receptors (PRRs), factors that play an important role in the microbicidal activity against mycobacteria. In conclusion, the vitamin D metabolite 1,25(OH)2D3 improves antimycobacterial killing in bovine PBLs via the synergistic activity of monocytes and granulocytes and enhanced activation of innate immunity.

Coronary computed tomography angiography improves coronary risk prediction in general population

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Carlos III Health Institute and the European Regional Development FundAgency for Management of University and Research Grants

Introduction

In the next decades, it is expected an increasing incidence of acute coronary syndrome in the Spanish population. Identify high-risk patients could be the most cost-effective way to reduce its incidence and morbi-mortality burden. We studied the effect of adding coronary artery calcification (CAC) and the extent of atherosclerotic disease (SIS score) to classical cardiovascular (CV) risk factors in coronary risk prediction.

Methods

This was a prospective cohort study of 325 asymptomatic patients recruited between 2013-2017. Demographic characteristics and CV risk factors were obtained and all participants underwent a coronary computed tomography angiography exam in which CAC and SIS were determined. The cohort was followed-up (median= 4 years) for a composite endpoint that included CV death, myocardial infarction, coronary angiography and/or revascularization. Improvement in discrimination and in reclassification by the inclusion of CAC/SIS in the Framingham-REGICOR function were examined with the Sommer's D index and with the Net reclassification index (NRI) (categorical and continuous), respectively.

Results

Nine of the 251 individuals included in the study had an event in the follow-up. Of the included participants, 94 had a CAC = 0 and 85 a SIS = 0. These participants had no events. The addition of SIS or of SIS and CAC scores to the Framigham-REGICOR risk function increased significantly the discrimination capacity from 0.71 to 0.88 (Table 1). Reclassification measured by the continuous NRI also improved significantly from 69.5 to 112.4/115.5 when SIS or both scores were included (Table 2).

Conclusions

CAC and SIS scores were associated to 4-year CV event incidence, independently of coronary risk estimation. Discrimination and reclassification of the Framigham-REGICOR coronary function were significantly improved by both indexes, but SIS overrode the effect of CAC.

Mycobacterial Infection of Precision-Cut Lung Slices Reveals Type 1 Interferon Pathway Is Locally Induced by Mycobacterium bovis but Not M. tuberculosis in a Cattle Breed

Tuberculosis exacts a terrible toll on human and animal health. While Mycobacterium tuberculosis (Mtb) is restricted to humans, Mycobacterium bovis (Mb) is present in a large range of mammalian hosts. In cattle, bovine TB (bTB) is a noticeable disease responsible for important economic losses in developed countries and underestimated zoonosis in the developing world. Early interactions that take place between mycobacteria and the lung tissue early after aerosol infection govern the outcome of the disease. In cattle, these early steps remain poorly characterized. The precision-cut lung slice (PCLS) model preserves the structure and cell diversity of the lung. We developed this model in cattle in order to study the early lung response to mycobacterial infection. In situ imaging of PCLS infected with fluorescent Mb revealed bacilli in the alveolar compartment, in adjacent or inside alveolar macrophages, and in close contact with pneumocytes. We analyzed the global transcriptional lung inflammation signature following infection of PCLS with Mb and Mtb in two French beef breeds: Blonde d'Aquitaine and Charolaise. Whereas, lungs from the Blonde d'Aquitaine produced high levels of mediators of neutrophil and monocyte recruitment in response to infection, such signatures were not observed in the Charolaise in our study. In the Blonde d'Aquitaine lung, whereas the inflammatory response was highly induced by two Mb strains, AF2122 isolated from cattle in the UK and Mb3601 circulating in France, the response against two Mtb strains, H37Rv, the reference laboratory strain, and BTB1558, isolated from zebu in Ethiopia, was very low. Strikingly, the type I interferon pathway was only induced by Mb but not Mtb strains, indicating that this pathway may be involved in mycobacterial virulence and host tropism. Hence, the PCLS model in cattle is a valuable tool to deepen our understanding of early interactions between lung host cells and mycobacteria. It revealed striking differences between cattle breeds and mycobacterial strains. This model could help in deciphering biomarkers of resistance vs. susceptibility to bTB in cattle as such information is still critically needed for bovine genetic selection programs and would greatly help the global effort to eradicate bTB.

Neutrophils Encompass a Regulatory Subset Suppressing T Cells in Apparently Healthy Cattle and Mice

Neutrophils that reside in the bone marrow are swiftly recruited from circulating blood to fight infections. For a long time, these first line defenders were considered as microbe killers. However their role is far more complex as cross talk with T cells or dendritic cells have been described for human or mouse neutrophils. In cattle, these new roles are not documented yet. We identified a new subset of regulatory neutrophils that is present in the mouse bone marrow or circulate in cattle blood under steady state conditions. These regulatory neutrophils that display MHC-II on the surface are morphologically indistinguishable from classical MHC-II^neg neutrophils. However MHC-II^pos and MHC-II^neg neutrophils display distinct transcriptomic profiles. While MHC-II^neg and MHC-II^pos neutrophils display similar bacterial phagocytosis or killing activity, MHC-II^pos only are able to suppress T cell proliferation under contact-dependent mechanisms. Regulatory neutrophils are highly enriched in lymphoid organs as compared to their MHC-II^neg counterparts and in the mouse they express PDL-1, an immune checkpoint involved in T-cell blockade. Our results emphasize neutrophils as true partners of the adaptive immune response, including in domestic species. They open the way for discovery of new biomarkers and therapeutic interventions to better control cattle diseases.

CR3 Engaged by PGL-I Triggers Syk-Calcineurin-NFATc to Rewire the Innate Immune Response in Leprosy

Mycobacterium leprae, the causative agent of leprosy, is unique amongst human pathogens in its capacity to produce the virulence factor phenolic glycolipid (PGL)-I. In addition to mediating bacterial tropism for neurons, PGL-I interacts with Complement Receptor (CR)3 on macrophages (MPs) to promote infection. We demonstrate here that PGL-I binding to CR3 also enhances bacterial invasion of both polymorphonuclear neutrophils (PMNs) and dendritic cells (DCs). Moreover, in all cell types CR3 engagement by PGL-I activates the Syk tyrosine kinase, inducing calcineurin-dependent nuclear translocation of the transcription factor NFATc. This selectively augments the production of IL-2 by DCs, IL-10 by PMNs and IL-1β by MPs. In intranasally-infected mice PGL-I binding to CR3 heightens mycobacterial phagocytosis by lung PMNs and MPs, and stimulates NFATc-controlled production of Syk-dependent cytokines. Our study thus identifies the CR3-Syk-NFATc axis as a novel signaling pathway activated by PGL-I in innate immune cells, rewiring host cytokine responses to M. leprae.

P6174On-site CT-derived FFR predicts the need for revascularization

Background and purpose

Coronary computed tomography angiography (CTA) in combination with CT-derived fractional flow reserve (CT-FFR) is a solid tool for assessing both the anatomical and functional impact of coronary atherosclerotic disease (CAD) in a single study. The development of new software for on-site CT-FFR quantification may reduce costs and increase availability. The aim of this study was to analyze the incremental value of CT-FFR over CTA alone and its ability to predict the need for revascularization.

Methods

Patients referred for invasive coronary angiography (ICA) who accepted to undergo a CTA/CT-FFR study were prospectively included. Patients with any contraindication for CT, atrial fibrillation, chronic total occlusions, severe ventricular hypertrophy or previous coronary revascularization were excluded. On-site CT-FFR was calculated for each coronary vessel. Invasive FFR was quantified during ICA, considering ≤0.8 as a surrogate for the need for revascularization.

Results

33 patients (90 vessels) were included. Mean age was 65±10 years, 88% were males, 60% had hypertension, 77% dyslipidaemia and 40% diabetes. The average analysis time of CT-FFR was 16±4 minutes. There was a good correlation between CT-FFR and FFR in all three main epicardial vessels as well as in proximal segments or in moderate to severe stenosis (see Table). 83% of vessels with FFR≤0.8 were predicted by CT-FFR study (89% of LAD lesions, 86% of LCX and 66% of RCA). CT-FFR added incremental diagnostic value over CTA alone to predict FFR≤0.8 (ΔAUC 0.0336 with a net reclassification index 1.4±0.23; p<0.001) (see Image).

n Mean difference from Bland-Altman Pearson's r coefficient p value All-vessels 90 0.037±0.1 0.8 <0.001 Lesions in LAD 40 0.005±0.11 0.81 <0.001 Lesions in LCX 32 0.061±0.094 0.85 <0.001 Lesions in RCA 18 0.06±0.11 0.83 <0.001 Moderate lesions (50–69% QCA stenosis) 24 0.02±0.06 0.88 <0.001 Severe lesions (70–99% QCA stenosis) 25 0.034±0.18 0.4 <0.001 Proximal lesions 42 0.012±0.11 0.84 <0.001 Non-proximal lesions 48 0.061±0.1 0.78 <0.001

Conclusions

On-site CT-FFR is a good predictor of the need for revascularization in all three main coronary vessels and adds incremental diagnostic value over CTA alone. There is higher dispersion of the values in severe stenosis, lesions in LCX or RCA although this do not result in misclassification.

2183Intravenous administration of IV-STATIN CARDIOSHIELD during myocardial infarction renders higher cardioprotection than oral atorvastatin given shortly after reperfusion: a translational CMR study

Background

Statins are known to exert rapid cardioprotective effects irrespective of their lipid-lowering properties. Several trials have suggested that high-dose statin treatment may reduce cardiovascular complications in patients undergoing invasive management. However, the ideal timing and administration regime is not clear.

Purpose

We compared the cardioprotective effects derived from IV-STATIN CARDIOSHIELD® administered intravenously during myocardial infarction (MI) with those attained by oral atorvastatin administration shortly after reperfusion. This study was conducted in a preclinical pig model of MI by serial CMR imaging.

Methods

Diet-induced hypercholesterolemic pigs (N=21; cholesterol: 387±74mg/dL) were subjected to 90 minutes of complete coronary occlusion (closed-chest model of MI), then reperfusion was established and animals were kept for 42 days. Within this experimental design animals were distributed in 3 groups (G) (7animals/arm): G1) animals received an intravenous bolus (0.3mg/kg) of IV-STATIN during MI; G2) animals received an intravenous bolus of the vehicle during MI (placebo-control); and G3) animals were administered atorvastatin p.o. initiated within the first 2h post-MI (Atorva-post-MI). G1 and G3 animals remained on atorvastatin p.o. for the following 42 days whereas G2 controls received placebo-pills. We assessed cardiac damage and global and regional functional parameters by CMR at day3 and day42 post-MI. Myocardial samples were processed for molecular studies on cardiac remodeling-related parameters (collagen and AMPK).

Results

CMR analysis at day-3 revealed that G1 pigs showed a marked reduction in infarct size as compared to both G3 and G2 animals (19.1±2.8% LV vs. 29.0±1.8% and 29.3%±3.2%, respectively; p<0.05) with a resultant 50% increase in myocardial salvage (p<0.05 vs. both). At day-42 both G1 and G3 animals showed a significant decrease in the size of the scar vs. G2 animals; however, G1 animals showed a further 24% scar reduction as compared to G3 (14.4±1.1% vs. 18.8±1.0% LV; p<0.05). Functional analyses revealed higher LVESV in G1 animals as compared to G2 (p<0.05) and less wall motion abnormalities in the jeopardized myocardium (p<0.05) vs. both groups at day42 post-MI. Collagen expression and AMPK activation were found to be significantly enhanced in the scar of G1 (p<0.05 vs. both groups). No changes were detected in lipids levels or liver and renal parameters throughout the study in any pig group.

Conclusions

Intravenous IV-STATIN CARDIOSHIELD® treatment during MI limited cardiac damage and improved cardiac function and remodeling to a larger extent than when atorvastatin was administered orally shortly after reperfusion. Our results support this novel regime of intravenous administration of IV-STATIN CARDIOSHIELD® as a routine procedure during MI. Further investigation of the potential benefits of this new therapeutic approach in STEMI patients is warranted.

P6185Impact of coronary atherosclerotic plaque metrics on the correlation between on-site CT-FFR and invasive FFR

Background

Developed in the last years, coronary computed tomography-derived fractional flow reserve (CT-FFR) has shown good correlation with invasive fractional flow reserve (FFR). However, little is known about the interaction of coronary atherosclerotic plaque characteristics in the correlation between CT-FFR and FFR.

Purpose

This study sought to determine the effect of main coronary atherosclerotic plaque metrics (APM) on the correlation between on-site CT-FFR and invasive FFR.

Methods

Patients referred for invasive coronary angiography (ICA) who accepted to undergo a CT-FFR study were prospectively included. We excluded patients with atrial fibrillation, chronic total occlusions, severe ventricular hypertrophy or previous coronary revascularization, and those with any contraindication for CT. On-site CT-FFR and APM were calculated for each coronary vessel. Continuous variables of APM were dichotomized as above and below the median and their interaction on the correlation between on-site CT-FFR and invasive FFR was assessed by multiple linear regression model.

Results

33 patients (90 vessels) were included. Mean age was 65±10 years, 88% were males, 60% had hypertension, 77% dyslipidaemia and 40% diabetes. The mean delay time between CTA and ICA of 21 days. The average analysis time of CT-FFR was 16±4 minutes. Overall, correlation between FFR and CT-FFR showed a Pearson's r coefficient of 0.77±0.06 and a standardized beta coefficient of 0.8 (p<0.001). The beta coefficients between CT-FFR and FFR did not change significantly after the interaction with different APM (p>0.05 for all) (see Table).

Standardized Beta coefficients for on-site CT-FFR with invasive FFR as a gold standard Below the median Above the median p value for interaction Total atheroma volume (TAV) (mm3) 0.66 0.93 0.071 Percent atheroma volume (PAV) (%) 1.00 0.69 0.063 Calcified atheroma plaque volume (%) 0.89 0.68 0.175 Remodeling index 0.94 0.71 0.129 Lesion length (LL) (mm) 0.67 0.89 0.158 Minimal lumen area (mm2) 0.73 0.71 0.955

Conclusions

There is a good correlation between on-site CT-FFR and invasive FFR, which is not affected by main atherosclerotic plaque characteristics.

The C3HeB/FeJ mouse model recapitulates the hallmark of bovine tuberculosis lung lesions following Mycobacterium bovis aerogenous infection

Achieving the control of bovine tuberculosis (bTB) would require the discovery of an efficient combined immunodiagnostic and vaccine strategy. Since in vivo experiments on cattle are not ethically and economically acceptable there is a need for a cost-effective animal model capable of reproducing, as closely as possible, the physiopathology of bTB to (i) better characterize the cellular and molecular features of bTB immunopathogenesis and (ii) screen preclinical vaccine candidates. To develop such a model, we focused on the C3HeB/FeJ Kramnik’s mouse forming hypoxic, encapsulated granulomas with a caseous necrotic center following Mycobacterium tuberculosis infection. Our work represents the first investigation on C3HeB/FeJ interaction with M. bovis, the main agent of bTB. Detailed histopathological analysis of C3HeB/FeJ lung lesions development following aerogenous M. bovis infection unraveled a bimodal evolution of the pathology. The C3HeB/FeJ recapitulated all the hallmarks of classical bovine lung granulomas but also developed, to some extend, lethal necrotic large lesions characterized by high mycobacterial and neutrophil load, and an inefficient collagen-driven lesion encapsulation. Interestingly these rapidly invasive pneumonia lesions, occurring in a constant percentage of the mice, shared all features with some exacerbated lung lesions that we and others have observed in lungs of cattle naturally or experimentally infected with M. bovis. Together, our findings demonstrate the relevance of the C3HeB/FeJ mouse as a comprehensive model to study bTB immunopathology that could be used for further vaccine therapies in the future.

IL-17RA in Non-Hematopoietic Cells Controls CXCL-1 and 5 Critical to Recruit Neutrophils to the Lung of Mycobacteria-Infected Mice during the Adaptive Immune Response

During chronic infection with Mycobacterium tuberculosis (Mtb), bacilli multiplication is constrained within lung granulomas until excessive inflammation destroys the lung. Neutrophils are recruited early and participate in granuloma formation, but excessive neutrophilia exacerbates the tuberculosis disease. Neutrophils thus appear as potential targets for therapeutic interventions, especially in patients for whom no antibiotic treatment is possible. Signals that regulate neutrophil recruitment to the lung during mycobacterial infection need to be better understood. We demonstrated here, in the mouse model, that neutrophils were recruited to the lung in two waves after intranasal infection with virulent Mtb or the live attenuated vaccine strain Bacillus Calmette Guérin (BCG). A first wave of neutrophils was swiftly recruited, followed by a subsequent adaptive wave that reached the lung together with IFN-γ- and IL-17A-producing T cells. Interestingly, the second neutrophil wave did not participate to mycobacteria control in the lung and established contacts with T cells. The adaptive wave was critically dependent on the expression of IL-17RA, the receptor for IL-17A, expressed in non-hematopoietic cells. In absence of this receptor, curtailed CXCL-1 and 5 production in the lung restrained neutrophil recruitment. CXCL-1 and 5 instillation reconstituted lung neutrophil recruitment in BCG-infected IL17RA-/- mice.

[Improvement in the measurement technique of pulmonary artery pressure by Doppler echocardiography with contrast in chronic obstructive pulmonary disease]

OBJECTIVE

To evaluate the benefit of contrast echocardiography in the assessment of systolic pulmonary artery pressure (PAPs).

DESIGN

Compare standard reference (Doppler-echocardiography) with contrast.

LOCATION

Echocardiography department.

PATIENTS

Ambulatory chronic obstructive patient disease (COPD).

INTERVENTION

Continuous wave Doppler spectral signal of tricuspid regurgitation (TR) was evaluated before and after intravenous injection of a galactose-based intravenous echo-enhancing agent. A four patterns scale classified the quality of the TR signal: 0=absent regurgitation; 1=protosystolic signal not allowing the recognition of peak velocity; 2=non-homogenous signal intensity, albeit allowing the measurement of maximal velocity; and 3=uniform pansystolic velocity signal. PAPs was estimated adding 10 mm Hg to the transtricuspid gradient, calculated from the TR peak velocity.

RESULTS

PAPs was only calculated reliably in 20 (49%) patients before the administration of contrast. Seventeen patients were classified as pattern 2, and three as pattern 3 on the scale of the TR quality signal. After contrast 41 (95%) patients showed a reliable TR signal. Two were classified as pattern 1, 11 as pattern 2 and 28 as pattern 3 on the scale of the TR quality signal. In the 20 patients in whom PAPs was estimated before contrast, a significant increase in PAPs values occurred after contrast, 44±10 mm Hg vs. 56±15 mm Hg (p<0.01).

CONCLUSION

The use of an echocardiography contrast agent increases the number of COPD patients in whom PAPs can be estimated non-invasively and may avoid underestimation of the PAP value.

A normalized framework for the design of feature spaces assessing the left ventricular function

A through description of the left ventricle functionality requires combining complementary regional scores. A main limitation is the lack of multiparametric normality models oriented to the assessment of regional wall motion abnormalities (RWMA). This paper covers two main topics involved in RWMA assessment. We propose a general framework allowing the fusion and comparison across subjects of different regional scores. Our framework is used to explore which combination of regional scores (including 2-D motion and strains) is better suited for RWMA detection. Our statistical analysis indicates that for a proper (within interobserver variability) identification of RWMA, models should consider motion and extreme strains.

A pilot experience launching a national dose protocol for vascular and interventional radiology

The design of a national dose protocol for interventional radiology has been one of the tasks during the European SENTINEL Coordination Action. The present paper describes the pilot experience carried out in cooperation with the Spanish Society on Vascular and Interventional Radiology (SERVEI). A prospective sample of procedures was initially agreed. A common quality control of the X-ray systems was carried out, including calibration of the air kerma area product (KAP) meters. Occupational doses of the radiologists involved in the survey were also included in the survey. A total of 10 Spanish hospitals with interventional X-ray units were involved. Six hundred and sixty-four patient dose data were collected from 397 diagnostic and 267 therapeutic procedures. Occupational doses were evaluated in a sample of 635 values. The obtained KAP median/mean values (Gy.cm2) for the gathered procedures were: biliary drainage (30.6/68.9), fistulography (4.5/9.8), lower limb arteriography (52.2/60.7), hepatic chemoembolisation (175.8/218.3), iliac stent (45.9/73.2) and renal arteriography (39.1/59.8). Occupational doses (mean monthly values, in mSv) were 1.9 (over apron); 0.3 (under apron) and 4.5 (on hands). With this National experience, a protocol was agreed among the SENTINEL partners to conduct future similar surveys in other European countries.

[Transthoracic echocardiography in stroke performed by neurologist: pilot study]

INTRODUCTION

The aim of this study is to assess concordance between transthoracic echocardiography (TTE) performed by neurologists and cardiologists for the screening of cardioembolic sources in patients with ischemic stroke.

METHODS

We examined prospectively 27 consecutive patients with ischemic stroke. A potential source of embolism in all of the patients was sought by means of a TTE study. This study was performed by one neurologist after one-month full-time training on the technique and independently by one cardiologist whose results were considered as the reference standard. Regarding the risk of cardioembolism, findings from TTE studies were considered as normal, or indicative of either moderate or high risk, according to the TOAST criteria. Agreement between the two observers on the diagnosis of cardioembolic source was analyzed with the Cohen's Kappa Test (K). A K > 0,6 was considered as good agreement.

RESULTS

The 27 patients studied had a mean age of 68,7 +/- 10,2 years and 70 % were men. A cardioembolic source was detected in 9 patients by the cardiologist and 8 of these were also identified by the neurologist: in 1 patient a mitral annulus calcification was not detected in the examination performed by the neurologist. In 2 patients with poor echocardiographic window, the neurologist underestimated the left ventricular function. Diagnostic agreement between both examinations was 88,9 % (K: 0,77; p = 0,001).

CONCLUSION

Compared with cardiologists, trained neurologists show a fairly high degree of accuracy in the TTE screening of patients with stroke. Those cases with poor echocardiographic window or with abnormal findings should be confirmed by the cardiologists.

Immunological responses and protective efficacy against Brucella melitensis induced by bp26 and omp31 B. melitensis Rev.1 deletion mutants in sheep

The commonly used live attenuated vaccine in ovine brucellosis prophylaxis is Brucella melitensis Rev.1. This vaccine is known to induce antibody responses in vaccinated animals indistinguishable by the current conventional serological tests from those observed in challenged animals. Brucella BP26 and Omp31 proteins have shown an interesting potential as diagnostic antigens for ovine brucellosis. Accordingly, the bp26 gene and both bp26 and omp31 genes have been deleted from the vaccine strain Rev.1. Immunogenicity and vaccine efficacy of the parental Rev.1 strain and of both mutants in protecting sheep against B. melitensis strain H38 challenge was evaluated by clinical and bacteriological examination of ewes. They were conjunctivally or subcutaneously vaccinated when 4 months old and then challenged with B. melitensis H38 at the middle of the first pregnancy following vaccination. Deletion of bp26 and omp31 genes did not significantly affect the well recognised capacity of Rev.1 to protect sheep against B. melitensis challenge. However, the protection conferred by the CGV2631 mutant was significantly lower than that conferred by the CGV26 mutant or the Rev.1 strain. Vaccinated and challenged animals were detected positive in classical serological tests and in the IFN-gamma assay. A BP26-based ELISA was investigated to discriminate between ewes vaccinated by the mutants and ewes challenged with B. melitensis H38. The cut-off which was chosen in order to have 100% specificity resulted in a moderate sensitivity for the detection of challenged ewes. The use in the field of one of the mutants as vaccine against a B. melitensis infection, combined with classic diagnostic tests and a BP26 ELISA, could thus give an improvement in the differentiation between vaccinated and infected animals and contribute to the objective of eradication of brucellosis in small ruminants.

[Diagnosis of right ventricular function by transesophageal echocardiography]

Transesophageal echocardiography allows the complex structure of the right ventricle to be adequately visualized. Image analysis with specially designed software provides qualitative and quantitative information on right ventricular function, whether during surgery or in the intensive care unit, where the technique has proven particularly useful for early diagnosis of right ventricular insufficiency in patients receiving assisted ventilation. Loading conditions and degree of dysfunction of the right ventricle can be monitored in real time under various clinical conditions, significantly facilitation management.

An unusual case of bioprosthetic mitral valve thrombosis

Bioprosthetic valve thrombosis and related embolism are considered extremely unlikely, thus allowing most patients to avoid long-term anticoagulation. There is, however, limited experience in the diagnosis and treatment of such a condition. We present the case of a patient with a porcine mitral bioprosthesis who presented with acute thrombosis with unusual echocardiographic features. A favorable outcome was observed after conventional anticoagulant treatment.

[Comparative study of echocardiography and magnetic resonance imaging in the assessment of left ventricular mass]

AIM OF THE STUDY

Echocardiography is a widely applied technique for the estimation of left ventricular mass, although magnetic resonance is considered as a reference method for this purpose. Both techniques were compared in the present study and the usefulness of a simplified method of calculation by magnetic resonance was also tested.

METHODS

Left ventricular mass was determined in 42 patients by M-mode echocardiography by the application of two equations: the so-called Penn's convention and that proposed by the American Society of Echocardiography. Magnetic resonance studies were also performed, left ventricular mass being estimated from an anatomical method (summation of contiguous transverse ventricular slices) that was considered as a reference, and also by means of a geometrical method (planimetry on a single longitudinal view).

RESULTS

Echocardiographic studies were judged as technically inadequate in 3/42 (7%) patients, while magnetic resonance was performed in all cases. Comparison between each echocardiographic method and the anatomical method of magnetic resonance showed a coefficient correlation of r = 0.70 (Penn's convention formula), and r = 0.71 (American Society of Echocardiography), with an overestimation being observed, particularly with Penn's convention method. The geometrical method of magnetic resonance showed an excellent correlation with the anatomical technique (r =0.93).

CONCLUSIONS

Magnetic resonance is more applicable for the estimation of left ventricular mass than M-mode echocardiography, with the latter showing an overestimation when compared with magnetic resonance, particularly with the Penn's convention method. A simplified method of geometrical estimation of left ventricular mass by magnetic resonance is a reliable alternative to the anatomical method.

Myocardial cell damage in human hypertension

OBJECTIVES

The goal of this study was to investigate the presence of myocardial cell damage in patients with systemic hypertension and its relationship with left ventricular hypertrophy (LVH).

BACKGROUND

Although initially compensatory, LVH adversely affects myocellular integrity and contributes to congestive heart failure in hypertensive patients. Noninvasive detection of myocardial damage can be of value.

METHODS

We performed imaging studies with 111In-labeled monoclonal antimyosin antibodies to identify myocardial damage in 39 patients with systemic hypertension and variable degrees of LVH. Three groups were considered: 16 asymptomatic patients with normal echocardiographic left ventricular mass (LVM) (group I); 14 asymptomatic patients with LVH (group II) and 9 patients with symptomatic hypertensive heart disease and advanced LVH (group III). The severity of myocardial damage was represented as heart-to-lung (target-to-background) antibody uptake ratio (normal: <1.55).

RESULTS

Mean LVM index was 105+/-14 g/m2 in group I, 124+/-24 in group II and 174+/-29 in group III. Heart-to-lung ratios of antimyosin uptake were: 1.45+/-0.14 in group I, 4 of the 16 (25%) patients showing an abnormal scan; 1.50+/-0.07 in group II with abnormal scans in 2 of the 14 (16%) patients and 1.77+/-0.16 (p < 0.001) in group III, all 9 patients presenting with abnormal antimyosin scans. On multivariate regression analysis LVM index was the main variable that independently correlated with the degree of myocardial uptake of antimyosin (r = 0.815; p = 0.001).

CONCLUSIONS

This study provides the first in vivo evidence of myocyte damage in patients with hypertension. The severity of myocardial damage can be related to the magnitude of LVH.

Usefulness of the I/D angiotensin-converting enzyme genotype for detecting the risk of left ventricular hypertrophy in pharmacologically treated hypertensive men

The insertion/deletion polymorphism (I/D) of the angiotensin-converting enzyme (ACE) gene has been associated in some studies with a higher prevalence of left ventricular hypertrophy (LVH), but few of them were performed on pharmacologically treated hypertensive patients. The present study was undertaken to determine whether ACE genotype determination could help in the identification of pharmacologically treated hypertensive patients at a higher risk of LVH. Ninety-six consecutive men with essential hypertension were selected for the study. Left ventricular mass (LVM) was assessed by echocardiography and indexed by body surface area and 82 patients were considered suitable for the study. Three groups of patients were defined on the basis of their I/D ACE genotype: DD (n = 39), ID (n = 33) and II (n = 10). There were no statistically significant differences between the three groups regarding to the severity of hypertension at diagnosis, degree of control of blood pressure or type of antihypertensive drug therapy used. No statistically significant differences were found between the three groups regarding to LVM index (total 124 +/- 31, DD 121 +/- 29, ID 127 +/- 35 and II 122 +/- 18 g/m2), relative wall thickness (total 0.5 +/- 0. 2, DD 0.5 +/- 0.3, ID 0.48 +/- 0.07 and II 0.47 +/- 0.04) or prevalence of LVH (total 34%, DD 31%, ID 39% and II 30% by Cornell criteria and total 39%, DD 33%, ID 45% and II 40% by Framingham criteria). Furthermore, the I and D allele frequency distribution was similar in the whole group of patients, in patients with LVH, and in a control group of healthy volunteers. Our data do not support that the I/D ACE genotype determination helps in identifying treated hypertensive patients at higher risk of LVH. Journal of Human Hypertension (2000) 14, 327-331

Allopatric combination of Fasciola hepatica and Lymnaea truncatula is more efficient than sympatric ones

Parasites are capable of rapid evolutionary changes relative to their hosts, due to short life cycle, short generation time, and high fecundity. The direction of the evolution of parasite virulence can be studied in cross-transfer experiments, combining hosts and parasites from different localities, and comparing the outcome of established (sympatric and potentially locally adapted) and novel (allopatric) combinations of hosts and parasites. We aimed to compare the compatibility with snails hosts, the infectivity of metacercariae in rabbits and rats, and the fitness among different combinations (French-FF and Spanish-SS sympatries and allopatry-FS). The first isolate of Fasciola hepatica and its corresponding intermediate host, Lymnaea truncatula originated from Lugo's northwestern Spain. The second isolate of parasite and snail was collected in the Limoges area in central France. The Spanish snails were more susceptible to their sympatric trematode than the French snails. The Spanish flukes were more infective to intermediate hosts (snails) than the French flukes, but subsequent definitive hosts (rats or rabbits) infections remained similar. The estimated fitness was low in sympatric infections and highly similar (from 4.7 to 5.3). The fitness similarity corresponds, however, to different variations in life-history traits that could represent different strategies among the host-parasite local combinations. The infection rate in snails, metacercarial productivity, metacercarial infectivity, and the estimated fitness were better for allopatric combination (FS). The susceptibility data showed a higher efficiency of flukes in the allopatric snail population than in their local snail population. However, our results were obtained after one generation and from a single isolate and it remains to be determined if all allopatric fluke-snail isolates may present a better fitness. Nevertheless our results indicate that introduction of liver fluke-infected cattle should be monitored carefully, as it could result in the introduction of more efficient parasites.

Fasciola hepatica: influence of gender and liver biotransformations on flukicide treatment efficacy of rats infested and cured with either clorsulon/ivermectin or triclabendazole

Two fasciolicide preparations have been compared in 130 rats experimentally infected with Fasciola hepatica. Parasitological, immunological, and biochemical parameters have been followed to monitor the efficacy of the treatments. While Fascinex (triclabendazole) efficiently cured both male and female rats when administered as soon as 4 weeks postinfection, treatment with Ivomec-D (clorsulon + ivermectin) displayed a low efficacy on either male or female rats at this time point (54 and 0%, respectively). Moreover, when administered 8 weeks postinfection, the Ivomec-D treatment proved highly efficient on male rats while it displayed little effect on the female population (100 and 53%, respectively). This unexpected result has been related to an overexpression of a P4503A isoform that is observed only in females that have been treated with Ivomec-D. The influence of this P4503A cytochrome on drug metabolism and the need for the incorporation of both genders in clinical trials are discussed.

[Emergency valvular replacement in infective endocarditis: hospital and long term clinical course. Analysis of 45 patients]

BACKGROUND

To define the evolution of patients with infective endocarditis who require urgent valve replacement in our environment.

PATIENTS AND METHODS

We followed 45 consecutive cases of infective endocarditis that require valve replacement during their hospitalization. 32 patients had native valve infective endocarditis, 7 early prosthesis valve endocarditis and 6 late prosthesis valve endocarditis. Patients were followed for a long-term period, clinical and echocardiographycally.

RESULTS

In 39 cases valve replacement was performed before ending antibiotic therapy. The main indications for surgery were refractory heart failure (24 patients) and shock (11 patients). The mortality rate was 24%: 19% in native valve infective endocarditis, 43% in early prosthetic valve endocarditis and 33% in late prosthesis valve endocarditis. The first cause of death was septic shock (46%). We followed 31 over 34 survivors for a mean time 65 (DS 49) months. We found two relapses and six deaths (1 sudden death, 2 endocarditis) and 72% of patients presented class I NYHA. We detected 17% prosthetic leaks (34% in the prosthetic valve endocarditis group).

CONCLUSIONS

The need of urgent valve replacement in the context of infective endocarditis is associated with a high mortality rate, and should be considered a serious condition. Long term prognosis is, however, acceptable, although 17% of patients had prosthesis leak, specially those with prosthetic valve endocarditis.

[Patency study of internal mammary artery grafts: the usefulness of echo-enhancers for identifying the flow signal by color Doppler echocardiography]

OBJECTIVES

a) To study the capacity of the technique of high-frequency color Doppler to detect flow signal of left internal mammary artery grafts; b) to assess the usefulness of an echo-enhancer agent to facilitate the detection of the signal, and c) to evaluate the patency of the graft according to its pulsed Doppler velocity profile pattern.

METHODS

39 consecutive patients were studied. A Hewlett-Packard 5500 echocardiograph was used, with a high-frequency probe (S12) applied at the high left parasternal border. When a graft signal was not elicited after a predetermined 5-minute check period, an intravenous dose of 4 g of Levovist (Schering España) at 400 mg/ml was administrated. According to previous studies, a pulsed Doppler flow profile with a predominantly diastolic pattern was considered a normal graft patency, while a systolic one was deemed as abnormal.

RESULTS

Graft flow was identified by color Doppler in 33/39 patients (85%). The additional use of an echo-enhancer in 6 patients with no detected signal increased this proportion to 38/39 (97%). Normal flow patterns were seen in 34/38 (89%). Among the four patients with abnormal pattern, 1 case of early myocardial infarction was observed, while angiographic studies showed distal occlusion of the graft in 1 or the presence of competitive flow in 2 patients.

CONCLUSIONS

The high-frequency color Doppler technique allows the detection of a flow signal from internal mammary artery grafts in most patients. The administration of an echo-enhancer agent is useful in those with non detectable signals. An abnormal pulsed Doppler velocity pattern indicates graft malfunction.

[Acute myocardial infarct studied by magnetic resonance with gadolinium-DTPA contrast compared to echocardiography]

INTRODUCTION AND OBJECTIVES

Gadolinium-DTPA used as a contrast agent in magnetic resonance imaging allows the detection and quantification of the necrotic area in acute myocardial infarction. The aim of the present study is to assess the value of this method for the diagnosis of myocardial infarction in comparison with clinical and echocardiographic data.

METHODS

Contrast magnetic resonance imaging and echocardiographic studies were performed on 16 patients during the first week after admission for acute myocardial infarction. Necrotic and total myocardial mass were calculated from magnetic resonance images and this was compared to the extension of the myocardial infarction assessed by electrocardiography and the peak level of total creatinine-phosphokinase serum enzyme. The number and localization of myocardial segments showing contrast uptake was related to segments with contractile abnormalities at the echocardiographic exam.

RESULTS

The mean value of the mass of myocardial necrosis calculated from the total area of gadolinium-DTPA uptake in each patient was 25 g (range: 2-67 g), corresponding to 17% of the total myocardial mass (range: 1-45%). This value correlated with the peak serum level of total creatinine-phosphokinase enzyme (r = 0.714; p < 0.003) and with the number of Q waves present at the electrocardiogram (r = 0.69; p < 0.005). A very good agreement between the location of the myocardial infarction by ECG, echocardiography and magnetic resonance was evidenced, and a satisfactory correlation existed between myocardial segments with gadolinium-DTPA uptake and akinetic echocardiographic segments (kappa = 0.65).

CONCLUSIONS

The detection and quantitation of the necrotic area in the acute myocardial infarction with gadolinium-DTPA contrast magnetic resonance shows a good correlation with clinical and echocardiographic data.

[Evaluation of the patency of left internal mammary artery graft by transcutaneous Doppler flow velocity analysis]

OBJECTIVE

To analyze the features of Doppler flow velocity curve of left internal mammary artery by-pass grafts in relation with their permeability as assessed by selective angiography.

METHODS

Twenty-five consecutive patients with a left mammary artery graft were studied by angiography and transcutaneous Doppler technique. From the Doppler tracings, peak velocity and time-velocity integral of the systolic and diastolic components were determined. Patency of the graft and the characteristics of the distal native coronary artery were evaluated at angiography.

RESULTS

Doppler flow signal was obtained in 23 (92%) of 25 analyzed patients. The graft was angiographically patent in 17 (68%) of 25 patients; in 15 (88%) of them the Doppler flow velocity signal was mainly diastolic and in only 2 (12%) it was predominantly systolic. In 8 (32%) of the 25 patients the graft was angiographically occluded, 6 (75%) of these patients showing a predominantly systolic Doppler signal, while the remaining 2 (25%) patients were those in whom the signal could not be elicited. Sensitivity and specificity of a predominantly diastolic Doppler flow pattern for the presence of graft patency was 88% and 100% respectively, with a predictive positive value of 100% and a negative one of 80%.

CONCLUSIONS

Doppler flow velocity pattern of internal mammary artery by-pass grafts is related with patency of the graft, the presence of a predominantly diastolic curve being highly indicative of a patent graft.

Detection of Enterocytozoon bieneusi in two human immunodeficiency virus-negative patients with chronic diarrhea by polymerase chain reaction in duodenal biopsy specimens and review

Intestinal microsporidiosis has been associated traditionally with severely immunocompromised patients with AIDS. We describe two new cases of intestinal microsporidiosis due to Enterocytozoon bieneusi in human immunodeficiency virus-negative adults. Both patients presented with chronic nonbloody diarrhea, and one had intestinal lymphangiectasia as well. Intestinal microsporidiosis was diagnosed by evaluation of stool samples, and the specific species was determined by use of polymerase chain reaction (PCR) in duodenal biopsy specimens. To our knowledge, this is the first report of confirmation of E. bieneusi in the intestinal epithelium of HIV-negative individuals by use of PCR in duodenal biopsy specimens. Cases of intestinal microsporidiosis in HIV-negative individuals reported in the English-language literature are reviewed. These two new cases along with those described previously corroborate the need to evaluate for microsporidia in HIV-negative individuals with unexplained diarrhea.

Short-course thrombolysis as the first line of therapy for cardiac valve thrombosis

OBJECTIVE

To retrospectively evaluate the clinical and echocardiographic criteria of thrombolytic therapy for mechanical heart valve thrombosis.

METHODS

Nineteen consecutive patients with 22 instances of prosthetic heart valve thrombosis (14 mitral, 2 aortic, 3 tricuspid, and 3 pulmonary) were treated with short-course thrombolytic therapy as first option of treatment in absence of contraindications. The thrombolytic therapy protocol consisted of streptokinase (1,500,000 IU in 90 minutes) (n = 18) in one (n = 7) or two (n = 11) cycles or recombinant tissue-type plasminogen activator (100 mg in 90 minutes) (n = 4).

RESULTS

Overall success was seen in 82%, immediate complete success in 59%, and partial success in 23%. Six patients without total response to thrombolytic therapy underwent surgery, and pannus was observed in 83%. Six patients showed complications: allergy, stroke, transient ischemic attack, coronary embolism, minor bleeding, and one death. At diagnosis, 10 patients evidenced atrial thrombus by transesophageal echocardiography, 3 of whom experienced peripheral embolism during thrombolysis. Four episodes of rethrombosis were observed (16%). The survivorship was 84% with a mean follow-up of 42.6 months.

CONCLUSIONS

A short-course of thrombolytic therapy may be considered first-line therapy for prosthetic heart valve thrombosis. The risk of peripheral embolism may be evaluated for the presence of atrial thrombus by transesophageal echocardiography at diagnosis.

Myocardial damage does not occur in untreated hyperthyroidism unless associated with congestive heart failure

Even in the absence of underlying cardiac disease, hyperthyroidism has seldom been reported to be associated with left ventricular dysfunction and congestive heart failure. The left ventricular function invariably improves with achievement of euthyroid status. Anecdotal autopsy reports have suggested that myocardial necrosis associated with hyperthyroidism may be responsible for congestive heart failure. This study prospectively evaluates the role of myocardial necrosis in untreated hyperthyroidism by imaging with Indium-111 antimyosin antibody. Thirteen consecutive patients (7 men and 6 women, mean age 36 +/- 11 years) with hyperthyroidism and Graves' disease (10 patients), subacute thyroiditis (2 patients), or multinodular goiter (1 patient) formed the basis of the study. The T4 levels ranged from 33 to 183 pmol/L (mean 103 +/- 47 pmol/L) and cardiac output from 5.47 to 11.0 L/min (mean 7.17 +/- 1.75 L/min). Two patients had clinical congestive heart failure and mildly depressed left ventricular ejection fraction. Both patients had scintigraphic evidence of myocardial damage with abnormal antimyosin scans. In the remaining 11 patients with normal left ventricular ejection fraction, no antimyosin uptake was observed. The reevaluation of two patients with abnormal initial scans 6 to 8 months after treatment revealed euthyroid status, resolution of antimyosin uptake, and normalization of left ventricular function. This study indicates that myocardial necrosis may be detected in a small proportion of patients with hyperthyroidism, which could contribute to left ventricular systolic dysfunction.

Comparison of morphologic assessment of hypertrophic cardiomyopathy by magnetic resonance versus echocardiographic imaging

To compare the value of echocardiography and magnetic resonance imaging (MRI) in the assessment of the amount and extent of hypertrophy in hypertrophic cardiomyopathy (HC) and, second, to correlate the degree of hypertrophy, as assessed by MRI, with clinical and electrocardiographic parameters, 30 consecutive patients (16 men and 14 women, aged 20 to 74 years) with HC were studied. Measurements of left ventricular wall thickness were performed at 11 predetermined segments (5 basal, 5 midventricular, and 1 apical) by 2-dimensional echocardiography and MRI. Two parameters derived from MRI studies were considered as indicators of the degree and extent of hypertrophy: (1) mean of the measured wall thickness at the 11 segments, and (2) the number of segments with thickness > 15 mm. Results showed that, from a total of 330 myocardial segments, thickness could be measured by echocardiography in 221 (67%), whereas MRI allowed measurement of 320 segments (97%). When compared with clinical and electrocardiographic data, no correlation was found regarding mean wall thickness and number of hypertrophied segments by MRI except for the presence of an abnormal electrocardiographic repolarization pattern. It is concluded that MRI allows a better assessment of the degree and extension of left ventricular hypertrophy than echocardiography in HC. Despite the precise information on hypertrophy provided by MRI, the amount and degree of hypertrophy bears no correlation with most of the clinical data in these patients.

Spectrum of alcohol-induced myocardial damage detected by indium-111-labeled monoclonal antimyosin antibodies

OBJECTIVES

We sought to determine the prevalence, intensity and evolving changes of myocardial damage detected by myocardial uptake of antimyosin antibodies in patients with alcohol-induced dilated cardiomyopathy, alcohol addicts attending a detoxification unit and healthy subjects with short-term alcohol consumption.

BACKGROUND

Evidence of alcohol-induced myocardial damage may be provided by myocardial uptake of indium-111-labeled monoclonal antimyosin antibodies. The spectrum of such damage in patients who are heavy drinkers (> 100 g for > 10 years), with or without cardiomyopathy, and the impact of short-term alcohol ingestion on antimyosin antibody uptake have not been adequately explored.

METHODS

One hundred twenty antimyosin studies were performed in 56 patients with dilated cardiomyopathy (group I), 15 alcohol addicts attending a detoxification unit (group II) and 6 volunteers for short-term alcohol ingestion (group III). Estimation of antibody uptake was calculated through a heart/lung ratio (HLR) (normal < 1.55).

RESULTS

The 56 patients in group I (54 men, 2 women; mean [+/-SD] age 46 +/- 11 years) had consumed 123 +/- 60 g/day of alcohol for 21 +/- 9 years, for a cumulative intake of 914 +/- 478 kg. Mean duration of symptoms was 46 +/- 49 months. Mean left ventricular end-diastolic diameter was 71 +/- 10 mm, and mean ejection fraction was 28 +/- 12%. No differences in New York Heart Association functional class, ventricular size or ejection fraction were noted between 28 active and 28 past consumers, except for the prevalence and intensity of antibody uptake (75% vs. 32%, p < 0.001) and HLR (1.75 +/- 0.26 vs. 1.49 +/- 0.17, p = 0.0001). In 19 patients in the active group restudied after alcohol withdrawal, antibody uptake decreased (from 1.76 +/- 0.17 to 1.55 +/- 0.19, p < 0.001), and ejection fraction improved (from 30 +/- 12% to 43 +/- 16%, (p < 0.001). No changes occurred in the 15 past consumers restudied. The 15 male patients in group II (mean age 36 +/- 4 years) had consumed 156 +/- 59 g/day for 17 +/- 5 years, for a cumulative alcohol intake of 978 +/- 537 kg, an amount similar to that in patients in group I, but antimyosin antibody uptake was detected in only 3 (20%) of 15 patients. None of six group III subjects developed antibody uptake after short-term ethanol ingestion. Despite the small sample size, the power to detect clinically relevant differences in most variables that did not reach statistical significance was amply sufficient.

CONCLUSIONS

In alcohol-induced dilated cardiomyopathy, alcohol withdrawal is associated with the reduction or disappearance of myocardial damage and improvement of function. The difference in prevalence of antimyosin antibody uptake in patients with and without cardiac disease who consume similar amounts of alcohol suggests the presence of those with different myocardial susceptibilities to alcohol. Short-term ethanol ingestion in healthy subjects does not induce detectable uptake of antimyosin antibodies.

The 20 mm Medtronic Hall prosthesis in the small aortic root

BACKGROUND AND AIMS OF THE STUDY

The choice of prosthesis becomes crucial in the narrow aortic annulus. The 20 mm Medtronic Hall valve has a reduced sewing ring that fits in an annulus where only a 19 mm valve would fit. This study assesses the hemodynamic performance of this prosthesis at rest and at exercise, and compares it with two 19 mm mechanical prostheses.

MATERIALS AND METHODS

Forty-two patients were studied by Doppler echocardiography, a mean of 34 months following surgery. Twenty-six had a 19 mm prosthesis implanted (12 standard St. Jude Medical and 14 Monostrut valves) and 16 had a 20 mm Medtronic Hall. Parameters studied were peak velocity and transvalvular gradient, both at rest and at exercise, effective orifice area and valve index.

RESULTS

No differences were found between the two 19 mm valves, but when compared with the Medtronic Hall valve at rest, this valve showed significantly lower peak velocity and gradient (2.9 vs. 3.3 m/sec, p < 0.01, and 17 vs. 23 mmHg, p < 0.003, respectively) and higher effective orifice area and valve index (1.3 vs. 1.0 cm2, p < 0.01 and 0.81 vs. 0.62 cm2, p < 0.006, respectively). There were also significant differences under exercise.

CONCLUSIONS

The 20 mm Medtronic Hall prosthesis shows a significantly better hemodynamic performance, both at rest and under exercise, than other, 19 mm mechanical prostheses and represents a superior choice in valve replacement with a small aortic root.

Doppler-derived gradients in normally functioning Monostrut Björk-Shiley prostheses

In summary, reference values of Doppler gradients obtained in a large number of patients with normal-functioning mitral and aortic Monostrut Björk-Shiley prostheses are reported. It is shown that the value of the transprosthetic gradient increases with decreasing valve size in patients with aortic prostheses. No individual significant variations of the transprothetic Doppler gradient during a 3-year follow-up were observed.

Laparoscopic cholecystectomy and endoscopic sphincterotomy under a single anesthetic: a case report

Several options have been described for the management of unsuspected common bile duct stones diagnosed for the first time by transcystic cholangiography during laparoscopic surgery. These include immediate conversion to open laparotomy and formal common bile duct exploration, laparoscopic bile duct exploration, or postoperative biliary endoscopy (i.e., ERCP with sphincterotomy and stone extraction). Herein we describe a fourth option which allows the surgeon to manage both cholelithiasis and choledocholithiasis at the time of laparoscopic intervention: endoscopic sphincterotomy performed immediately after laparoscopic cholecystectomy under one anesthetic. This option seems the most logical when the surgeon wishes to preserve the minimally invasive approach.