Modelling structural colour from helicoidal multi-layer thin films with natural disorder.

A coupled mode theory based on Takagi-Taupin equations describing electromagnetic scattering from distorted periodic arrays is applied to the problem of light scattering from beetles. We extend the method to include perturbations in the permittivity tensor to helicoidal arrays seen in many species of scarab beetle and optically anisotropic layered materials more generally. This extension permits analysis of typical dislocations arising from the biological assembly process and the presence of other structures in the elytra. We show that by extracting structural information from transmission electron microscopy data, including characteristic disorder parameters, good agreement with spectral specular and non-specular reflectance measurements is obtained.

Clinical characteristics and outcomes of patients with inflammatory and autoimmune rheumatological diseases admitted for intensive care in Colombia.

OBJECTIVE: Contemporary studies reporting outcomes of critical care in patients with inflammatory and autoimmune rheumatological diseases are scarce. This study describes 15 years of experience from 2005-2019 in a Colombian referral hospital. METHODS: This observational, descriptive, consecutive case series study was performed on adult patients with inflammatory and autoimmune rheumatic diseases who were admitted to the intensive care unit (ICU) of the San Ignacio University Hospital in Bogotá (Colombia), from January 1, 2005, to December 21, 2019. We describe the sociodemographic characteristics, admission causes and criteria, lengths of stay, immunosuppressive treatment, systemic support, and mortality. RESULTS: The study included 300 patients with a median age of 48 years [interquartile range (IQR) 31-62 years], predominantly female (76%). Disease exacerbations (30%), infections (17.6%), and cardiovascular diseases (15%) were the main causes of admission. Respiratory failure (23%) most commonly caused by septic shock (24%) was the principal indication for intensive care admission. The most frequent infections were community-acquired pneumonia (11.6%) and soft-tissue infections (9%). In 40.3% of patients, inotropic and vasopressor support was required. The median length of stay was 4 days (IQR 2-8), and global mortality was 21.6%. CONCLUSIONS: Rheumatic diseases in the ICU are still associated with high morbidity and mortality. Patients with inflammatory and autoimmune rheumatic diseases require a meticulous clinical approach, strict clinical monitoring, frequent assessment of complications, evaluation of systemic support needs, and specific management.

Pro-proliferative function of the long isoform of PML-RARalpha involved in acute promyelocytic leukemia.

The promyelocytic leukemia (PML) gene codes for a tumor suppressor protein that is associated with distinct subnuclear macromolecular structures called the PML bodies. The PML gene is frequently involved in the t(15;17) chromosomal translocation of acute promyelocytic leukemia (APL). The translocation results in a fusion gene product, PML-RARalpha, in which the PML gene fuses to the retinoic acid receptor alpha (RARalpha) gene. PML-RARalpha has been shown to promote transcriptional repression of genes involved in myeloid terminal differentiation and to disrupt the architecture of PML bodies, a phenotype reversed by treatment with all trans retinoic acid (ATRA). However, there are several alternatively spliced isoforms of PML-RARalpha. Here, we addressed the differences between the short and the long isoforms of PML-RARalpha (L and S) since both are associated with APL. We demonstrate that PML-RARalphaL, but not PML-RARalphaS, can directly promote cell growth by transcriptionally activating the pro-proliferative gene, c-fos, in response to mitogenic stimulation. The activity of the PML-RARalphaL is completely sensitive to ATRA. We further show that this activation is not via direct recruitment of the protein to the c-fos promoter but indirectly by altering the chromosomal environment of the c-fos gene, thereby rendering it more accessible to the signal induced transcriptional activators. Our results suggest that in addition to antagonizing the PML-tumor suppressor or the PML-pro-apoptotic activity, PML-RARalpha proteins can also directly promote cell growth by activating c-fos.

[Results of surgery in mitral valve insufficiency with impaired left ventricular function]. / Résultats de la chirurgie dans les insuffisances mitrales à fonction ventriculaire gauche altérée.

This cooperative study (8 French Cardiology Departments) was undertaken to determine the postoperative outcome of patients with pure, chronic, non-ischemic mitral regurgitation and poor left ventricular function (ejection fraction less than 50%). Seventy-three patients, 48 males and 25 females with a mean age of 55.5 +/- 12.1 years were included. Fifty-eight patients were in Class III or IV of the NYHA Classification. The average cardiothoracic ratio was 0.59 +/- 0.07. Forty-six patients were in atrial fibrillation. The average ejection fraction was 43 +/- 5 per cent (end systolic volume: 97.8 +/- 37.9 ml/m2; end diastolic volume: 175.2 +/- 67.6 ml/m2). Sixty-one patients underwent prosthetic mitral valve replacement and 12 had a Carpentier valvuloplasty. Two patients died after the operation and 20 died during follow-up (average 48.1 +/- 27.6 months), giving a 5 year actuarial survival rate of 69.6 per cent. In the long-term, fifteen per cent of patients were in NYHA Class III or IV. A multivariate Cox analysis showed that the only predictive factors of a poor outcome were age and female sex. These results of surgery for mitral regurgitation with moderate to severely altered left ventricular function were relatively good, but this study does not allow evaluation of the evolution of patients with mitral regurgitation and very poor left ventricular function (no patients with ejection fraction less than 25%).

Mitral valve replacement with St Jude Medical prosthesis. Incidence of thromboembolic events in 349 patients.

This study reports incidence of thromboembolic episodes in a series of 349 patients where the St. Jude Medical (SJM) valve was implanted in the mitral position (252 isolated mitral, 91 mitral and aortic, 4 triple valve and 2 mitral and tricuspid valve replacements). The mean follow up was 28 months (range 6 to 57 months) which represents 784 patient-years. Overall operative mortality was 15 patients (4.3%). There were no valve-related deaths. Late post-operative prosthetic thrombosis occurred in 3 poorly anticoagulated patients (0.4% patient-years). A further 4 patients had a thromboembolic episode (0.5% patient-years). The overall frequency of thromboembolic episodes was 0.9 events per 100 patient-years. Per- and post-operative anticoagulation methods are described. The frequency of thromboembolism was studied with respect to the performance of SJM valve analyzed by echocardiography regardless the positioning of the prosthesis in the mitral ring. Our experience indicates that the SJM valve offers an excellent alternative in the choice of mechanical valve.

[Endomyocardial biopsy as a method of surveilling adriamycin cardiac toxicity. 28 biopsies in 26 patients]. / Place de la biopsie endomyocardique comme méthode de surveillance de la toxicité cardiaque de l'adriamycine. 28 biopsies chez 26 patients.

The aim of this study was to evaluate the role of endomyocardial biopsy in the surveillance of toxic, latent cardiomyopathy secondary to adriamycin (ADM) therapy, and to assess its value by comparison with non-invasive investigations such as echocardiography. Twenty six patients underwent endomyocardial biopsy and echocardiographic measurement of the fractional shortening of the left ventricular internal diameter after a total dose of 150 to 520 mg/m2 of ADM. Interstitial fibrosis was observed in 8 of the 20 interpretable cases on light microscopy (6 moderate, 2 severe). There were no cellular changes. Slight focal myofibril degeneration was observed in 8 cases, and vacuolisation corresponding to mild dilatation of the sarcoplasmic reticulum was observed in 9 cases out of the 22 technically interpretable cases on electron microscopy. In contrast to the findings of interstitial fibrosis, cellular degeneration correlated significantly with the total dose of ADM (p less than 0,01). We conclude that this histological study confirms the fact that myocardial changes are rare and slight with doses of less than 520 mg/m2 of ADM and that non-invasive techniques are adequate for follow-up until this dose is reached.

Echocardiography and left ventricular function on recovery from anaesthesia in patients with coronary artery disease.

Eight patients with coronary artery disease and eight age-matched patients without coronary artery disease undergoing noncardiac surgery were submitted to M-mode echocardiography and haemodynamic measurements. In the patients with coronary artery disease, but not in the controls, recovery from anaesthesia was associated with echocardiographic and haemodynamic changes suggestive of impaired cardiac pump function. This impairment seems to result from an imbalance between myocardial oxygen availability and demand in patients with coronary artery disease.

[Complications of myocardial infarction between the 2d and 4th week]. / Complications de l'infarctus du myocarde de la 2e à la 4e semaine.

The complications of myocardial infarction after transfer from the Coronary Care Unit on the 6th day were analysed bu a retrospective study of 3,460 computerised case reports (1973-1980). The mortality rate was 6% (1/3 of hospital deaths) in the period from the 7th day to discharge from hospital (14th to 30th day). Cardiac arrest as not uncommon (20% of all cardiac arrests) but the prognosis was better thn during the initial phase (p less than 0.05) as the mechanism was more commonly ventricular fibrillation or tachycardia (p less than 0.05). This series was compared with a similar population from 1970-1973; an improvement was observed in global hospital mortality (27% previously compared to 17%, in the study series, p less than 0.001). As the population were comparable, this phenomenon seems to be related to better treatment of shock and cardiac failure and the advances in cardiac surgery during the initial phase of infarction. Thd commonest mechanical complication was ventricular aneurysm; its occurrence does not influence the vital prognosis during this period. The incidence of cardiac arrest and death due to cardiac failure is not negligible after the first week of myocardial infarction. Therefore, we do not believe that the hospital period should be reduced after myocardial infarction. Special training of the nursing staff is essential for the successful treatment of these complications. The global prognosis could be improved by the rehabilitation of digitalis therapy and the introduction of new sympathomimetic amines in the acute phase of myocardial infarction.

[Cardiac surgery under extracorporeal circulation in patients with chronic renal insufficiency. Apropos of 4 cases and review of the literature]. / Chirurgie cardiaque sous circulation extra-corporelle chez les insuffisants rénaux chroniques. A propos de 4 observations et revue de la littérature.

Four cases of cardiac valve replacement in patients with chronic renal failure are reported. The problem of surgery under cardiopulmonary bypass in these patients are discussed with respect to 36 other previously reported cases. Of this lot of 40 cases, 33 (82,5 p.100) underwent valve replacement (21 aortic, 9 mitral, 1 mitral and aortic, and 2 unspecified), 26 (79 p.100) for valvular lesions due to infective endocarditis. Coronary revascularisation was performed in 6 cases (15 p.100) and pericardectomy in 1 case. Operative mortality was within acceptable limits (4 deaths) ; the overall mortality was 10 cases. Valvular lesions due to endocarditis were the main cause of death (9 cases). A session of haemodialysis is performed 12 hours preoperatively. Post-operative care is directed to the control of the fluid balance, the neutralisation of metabolic acidosis with alkaline fluids (sodium lactate) and the correction of hyperkalaemia by kayexalate. In addition, dialysis is required between the 24 th post-operative hour and the 3 rd day. The main indications for cardiac surgery under cardiopulmonary bypass in patients with renal failure are valve replacement for infective endocarditis where the operative decision should be made early on, and aorto-coronary bypass grafting, the selection criteria for which should be very strict.

[Exercise testing in probable primary hypokinetic cardiomyopathies]. / L'épreuve ergométrique au cours des myocardiopathies hypocinétiques en apparence primitive.

50 patients with primary congestive cardiomyopathy underwent one or several exercise tests at yearly intervals in order to evaluate exercise capacity and to assess the prognosis. Three parameters were studied: the workload, the elevation of the systolic blood pressure (SBP) on exercise and the appearance of premature ventricular beats (PVB) on exercise or during the recovery phase. The results show that when the work loads > 120 watts, an elevation of SBP greater than or equal to 50 mmHg and the appearance of less than 3 PVB per minute were compatible with a moderate degree of physical exertion. On the other hand these same poor prognostic factors were associated with a higher mortality rate after 20 months follow-up.

[The heart and drug poisoning, excluding cardiologic treatments]. / Coeur et intoxications médicamenteuses en dehors des thérapeutiques cardiologiques.

When considered strictly from the viewpoint of actions on the myocardium, the number of drugs falling into this category is limited, but the resulting conditions may be serious. The prototype for cardiac toxicity is the group of antimitotic drugs (adriamycin or daunomycin). If these drugs are used; frequent and careful follow-up is necessary, the dosage at which the drug becomes cumulative must be known; and patients with a pre-existing cardiac condition must be exluded from treatment. Above all, it is essential not to wait until asystole occurs, but to try to prevent such occurrences by monitoring the patient electrocardiographically. A part from these drugs, recent articles in the literature suggest that similar care should be taken when prescribing emetine and lithium salts. There is insufficient information about other drugs which may have a certain degree of cardiotoxicity. For this reason, it is most important to gather information on accidents and reaction during treatment.