Method for Evaluating Cortical Bone Young's Modulus: Numerical Twin Reconstruction, Finite Element Calculation, and Microstructure Analysis

The determination of bone mechanical properties remains crucial, especially to feed up numerical models. An original methodology of inverse analysis has been developed to determine the longitudinal elastic modulus of femoral cortical bone. The method is based on a numerical twin of a specific three-point bending test. It has been designed to be reproducible on each test result. In addition, the biofidelity of the geometric acquisition method has been quantified. As the assessment is performed at the scale of a bone shaft segment, the Young's modulus values obtained (between 9518.29 MPa and 14181.15 MPa) are considered average values for the whole tissue, highlighting some intersubject variability. The material microstructure has also been studied through histological analysis, and bone-to-bone comparisons highlighted discrepancies in quadrants microstructures. Furthermore, significant intrasubject variability exists since differences between the bone's medial-lateral and anterior-posterior quadrants have been observed. Thus, the study of microstructures can largely explain the differences between the elastic modulus values obtained. However, a more in-depth study of bone mineral density would also be necessary and would provide some additional information. This study is currently being setup, alongside an investigation of the local variations of the elastic modulus.

Potential and limitations of machine meta-learning (ensemble) methods for predicting COVID-19 mortality in a large inhospital Brazilian dataset

The majority of early prediction scores and methods to predict COVID-19 mortality are bound by methodological flaws and technological limitations (e.g., the use of a single prediction model). Our aim is to provide a thorough comparative study that tackles those methodological issues, considering multiple techniques to build mortality prediction models, including modern machine learning (neural) algorithms and traditional statistical techniques, as well as meta-learning (ensemble) approaches. This study used a dataset from a multicenter cohort of 10,897 adult Brazilian COVID-19 patients, admitted from March/2020 to November/2021, including patients [median age 60 (interquartile range 48-71), 46% women]. We also proposed new original population-based meta-features that have not been devised in the literature. Stacking has shown to achieve the best results reported in the literature for the death prediction task, improving over previous state-of-the-art by more than 46% in Recall for predicting death, with AUROC 0.826 and MacroF1 of 65.4%. The newly proposed meta-features were highly discriminative of death, but fell short in producing large improvements in final prediction performance, demonstrating that we are possibly on the limits of the prediction capabilities that can be achieved with the current set of ML techniques and (meta-)features. Finally, we investigated how the trained models perform on different hospitals, showing that there are indeed large differences in classifier performance between different hospitals, further making the case that errors are produced by factors that cannot be modeled with the current predictors.

Hospital characteristics associated with COVID-19 mortality: data from the multicenter cohort Brazilian Registry

The COVID-19 pandemic caused unprecedented pressure over health care systems worldwide. Hospital-level data that may influence the prognosis in COVID-19 patients still needs to be better investigated. Therefore, this study analyzed regional socioeconomic, hospital, and intensive care units (ICU) characteristics associated with in-hospital mortality in COVID-19 patients admitted to Brazilian institutions. This multicenter retrospective cohort study is part of the Brazilian COVID-19 Registry. We enrolled patients ≥ 18 years old with laboratory-confirmed COVID-19 admitted to the participating hospitals from March to September 2020. Patients' data were obtained through hospital records. Hospitals' data were collected through forms filled in loco and through open national databases. Generalized linear mixed models with logit link function were used for pooling mortality and to assess the association between hospital characteristics and mortality estimates. We built two models, one tested general hospital characteristics while the other tested ICU characteristics. All analyses were adjusted for the proportion of high-risk patients at admission. Thirty-one hospitals were included. The mean number of beds was 320.4 ± 186.6. These hospitals had eligible 6556 COVID-19 admissions during the study period. Estimated in-hospital mortality ranged from 9.0 to 48.0%. The first model included all 31 hospitals and showed that a private source of funding (β = - 0.37; 95% CI - 0.71 to - 0.04; p = 0.029) and location in areas with a high gross domestic product (GDP) per capita (β = - 0.40; 95% CI - 0.72 to - 0.08; p = 0.014) were independently associated with a lower mortality. The second model included 23 hospitals and showed that hospitals with an ICU work shift composed of more than 50% of intensivists (β = - 0.59; 95% CI - 0.98 to - 0.20; p = 0.003) had lower mortality while hospitals with a higher proportion of less experienced medical professionals had higher mortality (β = 0.40; 95% CI 0.11-0.68; p = 0.006). The impact of those association increased according to the proportion of high-risk patients at admission. In-hospital mortality varied significantly among Brazilian hospitals. Private-funded hospitals and those located in municipalities with a high GDP had a lower mortality. When analyzing ICU-specific characteristics, hospitals with more experienced ICU teams had a reduced mortality.

Predictors of venous thromboembolism in COVID-19 patients: results of the COVID-19 Brazilian Registry

Previous studies that assessed risk factors for venous thromboembolism (VTE) in COVID-19 patients have shown inconsistent results. Our aim was to investigate VTE predictors by both logistic regression (LR) and machine learning (ML) approaches, due to their potential complementarity. This cohort study of a large Brazilian COVID-19 Registry included 4120 COVID-19 adult patients from 16 hospitals. Symptomatic VTE was confirmed by objective imaging. LR analysis, tree-based boosting, and bagging were used to investigate the association of variables upon hospital presentation with VTE. Among 4,120 patients (55.5% men, 39.3% critical patients), VTE was confirmed in 6.7%. In multivariate LR analysis, obesity (OR 1.50, 95% CI 1.11-2.02); being an ex-smoker (OR 1.44, 95% CI 1.03-2.01); surgery ≤ 90 days (OR 2.20, 95% CI 1.14-4.23); axillary temperature (OR 1.41, 95% CI 1.22-1.63); D-dimer ≥ 4 times above the upper limit of reference value (OR 2.16, 95% CI 1.26-3.67), lactate (OR 1.10, 95% CI 1.02-1.19), C-reactive protein levels (CRP, OR 1.09, 95% CI 1.01-1.18); and neutrophil count (OR 1.04, 95% CI 1.005-1.075) were independent predictors of VTE. Atrial fibrillation, peripheral oxygen saturation/inspired oxygen fraction (SF) ratio and prophylactic use of anticoagulants were protective. Temperature at admission, SF ratio, neutrophil count, D-dimer, CRP and lactate levels were also identified as predictors by ML methods. By using ML and LR analyses, we showed that D-dimer, axillary temperature, neutrophil count, CRP and lactate levels are risk factors for VTE in COVID-19 patients.

Effect of neonatal bacille Calmette-Guérin on the tuberculin skin test reaction in the first 2 years of life

SETTING

Latent tuberculous infection (LTBI) is an important reservoir of disease reactivation that is sufficient to generate new cases for decades. The tuberculin skin test (TST) is an important tool to diagnose LTBI; however, neonatal bacille Calmette-Guérin (BCG) vaccination may impact interpretation of TST data.

OBJECTIVES

To analyse the effect of the neonatal BCG vaccine on TST reaction in the first 2 years of life in children with no identified contact with tuberculosis (TB).

DESIGN

This was a cross-sectional study in children up to 2 years of age who received neonatal BCG vaccination. In the absence of baseline comorbidities or contact with the bacillus, the children were given the TST.

RESULTS

Seventy-nine children participated in the study. A decline in TST reactivity was observed in the first 12-24 months of age in patients who had been vaccinated with neonatal BCG but with no contact with TB. After the age of 10 months, no patient showed a TST reaction of >5 mm.

CONCLUSION

BCG had low impact on the TST in children with no TB contact. This finding suggests the need to reassess the cut-off point to 5 mm of induration to improve TST specificity in LTBI identification.

Sepse tardia em Unidade de Tratamento Intensivo Neonatal

Justificativa e Objetivos: É essencial conhecer os microrganismos presentes em hemoculturas de pacientes pediátricos internados para uma melhor escolha da terapêutica antibiótica. Dessa forma, este trabalho tem como objetivo verificar a associação entre parâmetros clínicos e epidemiológicos com o desenvolvimento de sepse neonatal tardia em pacientes internados em um serviço de pediatria de um hospital do sul do Brasil. Métodos: Estudo transversal, descritivo, retrospectivo e qualiquantitativo que utilizou dados secundários oriundos dos prontuários de pacientes que apresentaram critérios clínicos para sepse neonatal, internados na Unidade de Tratamento Intensivo Neonatal (UTIN) do Hospital Santa Cruz. Resultados: Dos 588 pacientes internados na UTIN do Hospital Santa Cruz no período de 01/01/2013 a 31/12/2015, 123 recém-nascidos (RNs) preencheram os critérios para sepse neonatal tardia. Destes, 59 (47,97%) apresentaram hemocultura positiva, o que foi mais frequente em RNs prematuros (39,84%) e de baixo peso (43,90%), embora não tenha havido associação estatisticamente significativa entre estes fatores e hemocultura positiva. Dentre os possíveis fatores de risco para o desenvolvimento de sepse neonatal, o uso de ventilação mecânica (p=0,005), realização de cirurgia (p=0,019) e permanência no hospital por mais de um mês (p=0,001) apresentaram associação estatística com hemocultura positiva. Os microrganismos presentes em maior frequência nas hemoculturas foram os estafilococos coagulase negativa (S. epidermidis, S. saprophyticus e S. haemolyticus), encontrados em 35,71% das hemoculturas analisadas. Conclusão: O estudo evidenciou maior prevalência de sepse neonatal tardia em RNs prematuros e de baixo peso, que necessitaram de maiores cuidados e foram submetidos a maior manipulação durante a permanência na UTIN. Procedimentos invasivos e longa permanência hospitalar se associaram significativamente com hemocultura positiva, corroborando com o descrito na literatura.

Angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and diabetes: a meta-analysis of placebo-controlled clinical trials

BACKGROUND

To determine whether the administration of angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) on top of standard cardiovascular (CV) therapies may reduce the incidence of new onset diabetes (NOD) in placebo-controlled clinical trials. The effects of these drugs on CV and non-CV mortality were also tested.

METHODS

We performed a meta-analysis of all randomized clinical trials (11 trials, n = 84,363 patients, aged 64.2 ± 5.86 years), published until 14 March 2010, in which ACE inhibitors or ARBs were compared with placebo and NOD incidence, CV, and non-CV mortality were reported.

RESULTS

Over an average follow-up of 4.0 ± 1.0 years, there were 1,284/15,142 (8.5%) cases of NOD in active-treated and 1,411/15,130 (9.3%) cases in placebo-treated patients in the ACE inhibitor trials, and 2,330/18,756 (12.4%) cases in active-treated and 2,669/18,800 (14.2%) cases in placebo-treated patients in the ARB trials. Overall, active therapy reduced NOD compared to placebo (odds ratio (OR) 95%, confidence interval (CI): 0.8 (0.8-0.9); P < 0.01). Both ACE inhibitors (OR 95%, CI: 0.8 (0.7-1.0); P = 0.07) and ARBs (OR 95%, CI: 0.8 (0.8-0.9); P < 0.01) reduced NOD as compared to placebo. Active treatment reduced CV mortality (OR 95%, CI: 0.9 (0.8-1.0); P < 0.01) and had a favorable impact on non-CV mortality (OR 95%, CI: 0.7 (0.9-1.0); P = 0.2) as compared to placebo.

CONCLUSIONS

Our findings demonstrated that ACE inhibitors or ARBs should be preferred in patients with clinical conditions that may increase risk of NOD, since these drugs reduced NOD incidence. In addition, these drugs have favorable effects on CV and non-CV mortality in high CV risk patients.

Defective fatty acid uptake in the spontaneously hypertensive rat is a primary determinant of altered glucose metabolism, hyperinsulinemia, and myocardial hypertrophy

Genetic linkage studies implicated deficiency of CD36, a membrane fatty acid (FA) transporter, in the hypertriglyceridemia and hyperinsulinemia of the spontaneously hypertensive rat (SHR). In this study we determined whether loss of CD36 function in FA uptake is a primary determinant of the SHR phenotype. In vivo, tissue distribution of iodinated, poorly oxidized beta-methyliodophenyl pentadecanoic acid (BMIPP) was examined 2 h after its intravenous injection. Fatty acid transport was also measured in vitro over 20 to 120 s in isolated adipocytes and cardiomyocytes obtained from SHR and from a congenic line (SHRchr4) that incorporates a piece of chromosome 4 containing wild-type CD36. SHR heart and adipose tissue exhibited defects in FA uptake and in conversion of diglycerides to triglycerides that are similar to those observed in the CD36 null mouse. However, a key difference in SHR tissues is that fatty acid oxidation is much more severely impaired than fatty acid esterification, which may underlie the 4-5-fold accumulation of free BMIPP measured in SHR muscle. Studies with isolated adipocytes and cardiomyocytes directly confirmed both the defect in FA transport and the fact that it is underestimated by BMIPP. Heart, oxidative muscle, and adipose tissue in the SHR exhibited a large increase in glucose uptake measured in vivo using [(18)F]fluorodeoxyglucose. Supplementation of the diet with short-chain fatty acids, which do not require CD36-facilitated transport, eliminated the increase in glucose uptake, the hyperinsulinemia, and the heart hypertrophy in the SHR. This indicated that lack of metabolic energy consequent to deficient FA uptake is the primary defect responsible for these abnormalities. Hypertension was not alleviated by the supplemented diet suggesting it is unrelated to fuel supply and any contribution of CD36 deficiency to this trait may be more complex to determine. It may be worth exploring whether short-chain FA supplementation can reverse some of the deleterious effects of CD36 deficiency in humans, which may include hypertrophic cardiomyopathy.

The impact of nutritional status on the outcome of lung volume reduction surgery: a prospective study

OBJECTIVES

To study the incidence and clinical significance of nutritional deficiencies in patients with emphysema undergoing lung volume reduction surgery (LVRS).

DESIGN

Prospective observational study.

SETTING

University-based teaching hospital.

PATIENTS

Fifty-one consecutive patients with end-stage emphysema undergoing video-assisted thoracoscopic surgery for LVRS.

INTERVENTIONS

All patients had their body mass index (BMI) and serum nutritional indexes (albumin, transferrin, total protein, cholesterol) measured preoperatively and postoperatively. Various clinical parameters were also compared between two groups.

RESULTS

The BMI was normal in 24 patients (47%), and 27 patients (53%) had a below normal BMI. A preoperative analysis of the serum nutritional indexes revealed no clinically significant differences between the two groups, but postoperative levels were significantly lower in the low BMI group. Anthropometric measurements supported the designation of nutritional status by BMI. Clinically, 26% of the patients in the low BMI group required prolonged ventilatory support (> 24 h), compared to only 4% of the patients with a normal BMI. The hospital length of stay (LOS) also differed, averaging 15.9 days in the low BMI group, compared to an average of 11.8 days in the normal BMI group.

CONCLUSION

Approximately 50% of patients undergoing LVRS for emphysema have a deficient nutritional status identifiable by BMI, but not by standard nutritional indexes. This impaired nutritional status is associated with increased morbidity following LVRS. We suggest that BMI is an accurate determinant of nutritional status in this patient population, and we speculate that preoperative repletion of nutritional deficiencies may decrease hospital morbidity, hospital LOS, and overall costs in the malnourished population undergoing LVRS.

A genetic linkage map of the laboratory rat, Rattus norvegicus

We report the construction of the first complete genetic linkage map of the laboratory rat. By testing 1171 simple sequence length polymorphisms (SSLPs), we have identified 432 markers that show polymorphisms between the SHR and BN rat strains and mapped them in a single (SHR x BN) F2 intercross. The loci define 21 large linkage groups corresponding to the 21 rat chromosomes, together with a pair of nearby markers on chromosome 9 that are not linked to the rest of the map. Because 99.5% of the markers fall into one of the 21 large linkage groups, the maps appear to cover the vast majority of the rat genome. The availability of the map should facilitate whole genome scans for genes underlying qualitative and quantitative traits relevant to mammalian physiology and pathobiology.

Frequency of a deletion polymorphism in the gene for angiotensin converting enzyme is increased in African-Americans with hypertension

In white populations, a deletion polymorphism in the gene for angiotensin converting enzyme (ACE) appears to be associated with increased risk for myocardial infarction but not for hypertension. In a population-association study in African-Americans, we compared the frequency of the ACE deletion polymorphism in subjects with hypertension versus those with normal blood pressure. The frequency of the ACE deletion allele was greater in African-Americans with hypertension than in those with normal blood pressure (P < 0.05). These findings raise the possibility that in some patient subgroups, sequence variation in or near the ACE gene may contribute to the risk for hypertension.

Assignment of rat linkage group V to chromosome 19 by single-strand conformation polymorphism analysis of somatic cell hybrids

The rat provides a number of important models of human genetic disease; however, the rat genetic map has not been extensively developed. Although most rat chromosomes carry several gene assignments, some major linkage groups (LG) remain to be mapped. To determine the chromosome location of the largest unmapped linkage group in the rat (LG V containing multiple carboxylesterase loci), we used single-strand conformation polymorphism analysis to identify the rat esterase-10 gene in a panel of rat x mouse somatic cell hybrids. We found that the carboxylesterase gene family and hence LG V are located on rat chromosome 19. We have also confirmed the assignment of the angiotensinogen gene to rat chromosome 19 and have used a large set of recombinant inbred strains to map two anonymous variable number of tandem repeat (VNTR) markers to this chromosome. The current findings bring the total number of genes assigned to rat chromosome 19 from 3 to 19 and provide further evidence of substantial homology between this chromosome and chromosome 8 in the mouse.

The rat renin gene: assignment to chromosome 13 and linkage to the regulation of blood pressure

It has recently been suggested that in the rat, sequence variation in the renin gene or closely linked genes may have the capacity to affect blood pressure and contribute to the pathogenesis of hypertension. To map the chromosomal location of the rat renin gene and to investigate its relationship to the inheritance of increased blood pressure, we studied a panel of rat x mouse somatic cell hybrids and a large set of recombinant inbred (RI) strains derived from spontaneously hypertensive rats (SHR) and normotensive Brown-Norway (BN) rats. We have found that in the rat, the renin gene is located on chromosome 13 and that it belongs to a conserved synteny group located on chromosome 1 in man and mouse. We have also found the median blood pressure of the RI strains that inherited the renin allele of the SHR to be greater than that of the RI strains that inherited the renin allele of the normotensive BN rat. These findings, together with the results of previous studies, suggest that in the rat, sequence variation in the renin gene, or in genes linked to the renin locus on chromosome 13, may have the capacity to affect blood pressure.

[Roentgen morphologic study of arthrosis of the sternoclavicular joint]

X-rays of 102 sternoclavicular joints from post-mortem examination were interpreted systematically. In 89 cases we found an osteoarthrosis. We investigated the correlation between stage of osteoarthrosis and size and form of articular surface, age, sex and right or left preference. We also made a review about anatomy, embryology and pathology of the sternoclavicular joint. The differential diagnosis of sternoclavicular pain is discussed.

Regulation of hepatic inorganic phosphate and ATP in response to fructose loading: an in vivo 31P-NMR study

Fructose loading results in hepatic accumulation of fructose 1-phosphate (Fru1 P). The goals of the present experiments were: first, to distinguish between ATP, intracellular inorganic phosphate (Pi), and extracellular Pi as sources of phosphate for the phosphorylation of fructose, and second, to examine the influence of ATP and Fru1 P on movement of phosphate into and out of these three pools. To achieve these goals, 31P-NMR was used to monitor the response of hepatic ATP, Pi and Fru1 P to two consecutive injections of fructose. The first was administered with ATP at the control level, and the second, 1 h after the first, with ATP at 65% of the control level. Changes in intra- and extracellular Pi were distinguished by correlating measurements of total NMR-detectable phosphorus and NMR-detectable Pi with measurements of plasma Pi. The initial fructose injection resulted in rapid accumulation of Fru1 P, small decreases in plasma and NMR-detectable Pi and a dramatic decrease in ATP. Total NMR-detectable phosphorus did not change, suggesting that phosphate did not enter or leave the liver. Therefore, accumulation of Fru1 P was initially balanced by an equivalent decrease in ATP, without large changes in Pi. Following the second injection, when ATP was at 65% of control. Fru1 P accumulated at approximately the same rate and to the same level as achieved following the first injection. There was little further change in ATP and a marked decrease in NMR-detectable Pi, while plasma Pi was higher than after the first injection. Therefore the greater decrease in NMR-detectable Pi following the second injection represented a significant decrease in intracellular Pi. Return of Fru1 P to control coincided with a dramatic increase in plasma Pi, and a decrease in total NMR-detectable phosphate. This suggests that phosphate released from Fru1 P entered the extracellular space. These data suggest the mechanisms by which intracellular Pi is regulated. When sufficient ATP is available, ATP hydrolysis supplies phosphate for the synthesis of Fru1 P, and prevents a significant decrease in intracellular Pi. When ATP is reduced, accumulation of Fru1 P depletes intracellular Pi. Therefore, decreased availability of ATP correlates with increased utilization of intracellular Pi. When Fru1 P returns to control, the increase in intracellular Pi is limited by release of Pi into the plasma.

Prolonged continuous versus intermittent oral acyclovir treatment in normal adults with frequently recurring genital herpes simplex virus infection

In Year 1 of this two-year trial, patients with six or more genital herpes recurrences in the past year received suppressive treatment with either acyclovir, 400 mg, or placebo, orally twice daily for one year, and physician-documented recurrences were treated with open-labeled acyclovir, 200 mg, orally five times per day for five days (acute treatment). In Year 2, patients received open-labeled acyclovir treatment either with daily suppressive therapy or intermittent acute therapy. Among 683 patients who completed two years of treatment, 348 received continuous suppressive treatment for two years, 276 received acute treatment in Year 1 and suppressive treatment in Year 2, 24 received suppressive treatment in Year 1 and acute treatment in Year 2, and 35 received acute treatment for two years. Patient groups receiving intermittent acute acyclovir treatment experienced means of 7.0 to 12.6 recurrences/year during treatment as compared with 1.4 to 1.9 recurrences/year among groups receiving continuous suppressive treatment. No patients who received acute treatment remained recurrence-free for two years as compared with 29 percent of patients receiving continuous acyclovir suppression for two years. There was no evidence of cumulative toxicity detected by clinical, hematologic, or blood chemistry evaluations performed monthly in Year 1 and quarterly in Year 2. Suppressive oral acyclovir therapy remained effective and well-tolerated in this two-year trial.

[Long-term course of syphilitic aortic insufficiency with ostial stenosis following surgical treatment]

Syphilitic aortic insufficiency and coronary ostial stenosis is a rare condition. It was diagnosed in 8 patients referred for surgery. The infection, acknowledged in 3 cases, was contracted over 15 years prior to admission! The operative indication was aortic valve replacement in 6 cases (Stage II to IV dyspnoea) and coronary insufficiency in 2 cases (Stage III angina pectoris). Two cases of ostial stenosis were not identified at coronary angiography, illustrating the potential diagnostic pitfall of a disease which is often unrecognised nowadays. Preoperative echocardiography of the left main coronary artery, especially its intra-aortic segment, may be of value but was not performed in these old cases. Surgery consisted in aortic valve replacement and coronary revascularisation by decortication of the ostia or coronary bypass (1 case). The evolution was excellent in the 6 survivors, especially with respect to the anginal syndrome which was completely cured without associated treatment. A protocol of echocardiographic surveillance of the left main coronary artery has been instituted in these patients to detect any late postoperative changes after ostial decortication.

[Emboligenic abscess of the aortic ring disclosing gonococcal endocarditis. Value of echocardiography]

Echocardiography has become a valuable diagnostic modality in bacterial endocarditis and of even more importance in following the subsequent course of the infection while on medical therapy. It can play an extremely important role in certain clinical circumstances, even before blood culture results are available or hemodynamic or auscultatory abnormalities appear. Nevertheless, in spite of this usefulness, the limitations of echocardiography should be recognized. The examination lacks absolute specificity and sensitivity which could result in inaccurate or delayed information in diagnosing a lesion or in recognizing local or regional complications. These advantages and limitations are well illustrated in an unusual case due to Neisseria gonorrhoeae, a causative agent whose incidence may increase over the years to come.

[Aortic and mitral monovalvular replacements. Comparison of the ball prosthesis of Starr-Edwards (1260-6120) and the tilting disc prosthesis of Bjork-Shiley. Series of 390 patients]

The evaluation of short and long term replacement by the Björk-Shiley tilting disc prosthesis (BS) and by the Starr-Edwards ball and cage prosthesis (SE) was carried out on a series of 390 consecutive patients. In mitral replacement, operative mortality rate (SE 5.9 P. 100 - BS 4.8 P. 100), 5 year actuarial survival (SE 79.8 P. 100 +/- 3.8 P. 100 - BS 86.3 P. 100 +/- 9 p. 100) incidence of thromboembolic complications and valvular thrombosis (SE 1.6 P. 100 - BS 1.3 P. 100) as well as the degree of post-operative improvement were virtually identical in both types of prosthesis. Likewise, in aortic valve replacement, operative mortality rate (SE 4 p. 100 - BS 3.2 p. 100), 5 year survival (SE 82 +/- 7.8 P. 100 - BS 86 +/- 3.3 p. 100) incidence of thromboembolic complications (SE 2.2 p. 100 - BS 1.8 p. 100) and the degree of post-operative improvement were not statistically different. However, the incidence of sudden death was statistically smaller with a BS prosthesis than with a SE prosthesis (respectively 1.6 p. 100 and 6.9 p. 100).

[Massive pulmonary embolism Apropos of 26 embolectomies with definitive survival, 10 of them by Trendelenburg's operation]

The authors report 26 pulmonary embolectomies carried out successfully, 10 of them having been Trendelenberg procedures and 16 having been carried out under extracorporeal circulation. The latter method gives better results, and appears to be the procedure of choice. The haemodynamics before operation were always abnormal, and there were 4 cardiac arrests, 11 cases of severe shock, and 6 cases with less severe hypotension. In the other cases, cyanosis, respiratory distress and signs of acute cor pulmonale were the clinical features of the massive embolus. It was possible to carry out arteriography in 14 cases, and this showed extensive pulmonary vascular obstruction in between 70 and 90%. In 4 cases this procedure was followed by an exacerbation, and extremely urgent treatment became neccessary. This examination is important for diagnosis and for assessment of the prognosis. It seems clear to the authors that surgery has a certain place, alongside medical fibrinolysis of a severe prognosis. It seems clear to the authors that surgery has a certain place, alongside medical fibrinolysis of a severe pulmonary embolus. The essential indications for surgery are moribund patients, those in whom fibrinolysis is contraindicated or unsuccessful, and those with massive obstruction of the pulmonary arterial tree.

[Post-traumatic interventricular communication. Closure under extracorporeal circulation]

Report of one case of acquired traumatic interventricular septal defect due to a stab injury of the right ventricle by a knife. The highly-placed penetrating injury involved the muscular septum and very probably resulted in a right bundle-branch block of the His system. Surgical operation performed in view of a starting clinical intolerance with moderately increased right cardiac pressures, was done under ECC with easy suture of the septal wound. The post-operative course was normal and a quick clinical cure was noted, which persisted for 8 months after surgery. The interest of this case, in addition to the very severe condition of the patient who had sustained 11 stab-knife wounds, lies in the high localization of the septal wound, which explains the involvement of the intracardiac conduction pathways.