Effect of etoposide on experimental testicular teratoma in 129/SvJ mice

To study the effects of etoposide on experimental testicular teratoma in 129/SvJ mouse we analysed the tumour growth, differentiation, apoptosis and the localisation of mdr₁ P-glycoprotein (mdr₁-Pgp). In this model the implanted gonadal ridges developed into testicular teratomas in 17 out of 56 implanted testes (30%) and in 14 out of 28 mice (50%). The tumour-bearing mice were treated with etoposide on 4 successive days either 4 weeks or 6 weeks after implantation, and killed 7 days after the last dose. The mice in the control groups did not receive etoposide. The teratomas consisted mainly of neural tissue. The etoposide-treated 4-week teratomas, but not the 6-week teratomas, were significantly smaller than those in the corresponding control groups. The density of apoptotic cells and the distribution of the mdr₁-Pgp were not altered by etoposide. The decreased proportion of immature neuroectodermal tissue components was observed in all treated teratomas, converting the histology towards that of a mature teratoma. In addition, a low proportion of immature tissue components was frequently combined with a low density of apoptotic cells. In conclusion, etoposide decreased the immature tissue components of teratomas, while mature tissues remained unaffected. These results may have clinical relevance in man, since they confirm that postchemotherapy mature teratomas cannot be treated with chemotherapy. Despite benign histology, the human residual tumours have a significant malignant potential and require complete surgical excision and close surveillance. Received: 20 August 1999 / Accepted: 20 January 2000     

Influence of genetics and non-genetic factors on acenocoumarol maintenance dose requirement in Moroccan patients

What is known and Objective: Coumarin derivatives such as acenocoumarol represent the therapy of choice for the long‐term treatment and prevention of thromboembolic diseases. Many genetic, clinical and demographic factors have been shown to influence the anticoagulant dosage. Our aim was to investigate the contribution of genetic and non‐genetic factors to variability in response to acenocoumarol in Moroccan patients. Methods: Our study included 114 adult Moroccan patients, receiving long‐term acenocoumarol therapy for various indications. Tests for VKORC1 ‐1639G>A promoter polymorphism (rs9923231), CYP2C9*2 rs1799853, CYP2C9*3 rs1057910, and CYP4F2 rs2108622 alleles were undertaken using Taq Man^® Pre‐Developed Assay Reagents for allelic discrimination. The statistical analysis was performed using the SAS V9 statistical package. Results and Discussion: Genotyping showed that the allele frequencies for the SNPs studied were no different to those found in Caucasians population. A significant association was observed between the weekly maintenance dose and the VKORC1 (P = 0·0027) and CYP2C9 variant genotypes (P = 0·0082). A final multivariate regression model that included the target International Normalized Ratio, VKORC1 and CYP2C9 genotypes explained 36·2% of the overall interindividual variability in acenocoumarol dose requirement. What is new and Conclusion: Our study shows large interindividual variability in acenocoumarol maintenance dose requirement in our population. VKORC1 and CYP2C9 variants significantly affected acenocoumarol dose, in‐line with results in other populations. For the Moroccan population, the SNPs that have the largest effect on acecoumarol dose are CYP2C9 rs1799853, CYP2C9 rs1057910 and VKORC1 rs9923231.     

Apoptosis in the pattern formation of the ventricular wall during mouse heart organogenesis.

Apoptosis is an important mechanism in organogenesis, but its role in heart development has been poorly characterized. We have here studied apoptosis in the developing ventricular wall of mouse embryonic heart. Developing mice hearts on days 11 to 16 of gestation were studied using in situ end-labeling of degraded DNA (TUNEL), immunocytochemistry of regulatory genes Bcl-2 and Bax, and light and electron microscopy. TUNEL end-labeled apoptotic cells were found in the ventricular wall on days 11 to 16 of gestation. The proportions of apoptotic cells of all cells in the ventricular wall differed between the trabecular and compact regions (P = 0.003) and between the days of gestation (P = 0.0001), the calculated apoptotic index was greater in the compact region at all ages except day 14. Ultrastructural analysis showed typical apoptotic shrinkage, chromatin degradation, and apoptotic bodies in several myoblastic and myocardial endothelial cells which were also positive by DNA end-labeling. Immunocytochemical reaction for the apoptosis checkpoint proteins in the ventricular wall showed clearly more Bcl-2 positive cells than Bax positive cells. The numerical densities of all cells in the compact and trabecular regions remained always higher in the compact region (P = 0.04) despite the fact that apoptosis was present in both areas at the same time. In conclusion, apoptosis takes place in the developing myocardial muscle as well as the myocardial endothelium during ventricular morphogenesis on days 11 through 16 and decreases clearly on day 16. We suggest that apoptosis and its regulatory factors are closely involved in the morphogenesis of the ventricular wall of the mammalian heart.     

Apoptosis in the pattern formation of the ventricular wall during mouse heart organogenesis

Apoptosis is an important mechanism in organogenesis, but its role in heart development has been poorly characterized. We have here studied apoptosis in the developing ventricular wall of mouse embryonic heart. Developing mice hearts on days 11 to 16 of gestation were studied using in situ end‐labeling of degraded DNA (TUNEL), immunocytochemistry of regulatory genes Bcl‐2 and Bax, and light and electron microscopy. TUNEL end‐labeled apoptotic cells were found in the ventricular wall on days 11 to 16 of gestation. The proportions of apoptotic cells of all cells in the ventricular wall differed between the trabecular and compact regions (P = 0.003) and between the days of gestation (P = 0.0001), the calculated apoptotic index was greater in the compact region at all ages except day 14. Ultrastructural analysis showed typical apoptotic shrinkage, chromatin degradation, and apoptotic bodies in several myoblastic and myocardial endothelial cells which were also positive by DNA end‐labeling. Immunocytochemical reaction for the apoptosis checkpoint proteins in the ventricular wall showed clearly more Bcl‐2 positive cells than Bax positive cells. The numerical densities of all cells in the compact and trabecular regions remained always higher in the compact region (P = 0.04) despite the fact that apoptosis was present in both areas at the same time. In conclusion, apoptosis takes place in the developing myocardial muscle as well as the myocardial endothelium during ventricular morphogenesis on days 11 through 16 and decreases clearly on day 16. We suggest that apoptosis and its regulatory factors are closely involved in the morphogenesis of the ventricular wall of the mammalian heart. Anat Rec 256:208–217, 1999. © 1999 Wiley‐Liss, Inc.     

Diverticule congénital isolé du ventricule gauche découvert à l’âge adulte : apport de l’imagerie

Cardiac diverticulum is an infrequent congenital malformation, it's even more rare in adulthood. It's often associated with other thoraco-abdominal diverticulums, and rarely isolated. The diagnosis relies on echocardiography. By the way, the magnetic resonance imagery (MRI) allows a finer analysis of the diverticulum, its topography and its situation contributed to vascular and cardiac structures, it has largely replaced the ventriculography. We report in this article the case of a patient of 36 years whose diagnosis of the diverticulum was made by transthoracic echocardiography (TTE) at the time of an assessment of dyspnea, this exam also objectified a mitral insufficiency by deformation and dilatation of the mitral annulus. Radiological assessment was completed by a transoesophageal echocardiography (TOE) and magnetic resonance imagery (MRI). Surgical treatment consisted of surgical closing of the diverticulum and mitral annuloplasty.     

Multi-system inflammatory syndrome in children during the coronavirus disease 2019 in Saudi Arabia: Clinical perspective from a case series

Most of the reports about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children reported mild-to-moderate disease manifestations. However, recent reports explored a rare pediatric multisystem syndrome possibly associated with SARS-CoV-2 infection termed multisystem inflammatory syndrome in children (MIS-C).The study prospectively enrolled 5 patients with clinical and laboratory evidence of MIS-C associated with SARS-CoV-2 infection. They were admitted to the pediatric intensive care unit (PICU). Their clinical presentation, laboratory, and outcome were described.All patients shared similar clinical presentations such as persistent documented fever for more than 3 days, respiratory symptoms, gastrointestinal involvement, and increased inflammatory markers (CRP, ESR, and ferritin). Three patients had concurrent positive coronavirus disease 2019 (COVID-19) infection, and the other 2 patients had contact with suspected COVID-19 positive patients. They were all managed in the PICU and received intravenous immunoglobulin, systemic steroid, and hydroxychloroquine. The hospital stays ranged between 3 and 21 days. One patient died due to severe multiorgan failures and shock, and the other 4 patients were discharged with good conditions.Pediatric patients with SARS–CoV-2 are at risk for MIS-C. MIS-C has a spectrum of clinical and laboratory presentations, and the clinicians need to have a high index of suspicion for the diagnosis and should initiate its early treatment to avoid unfavorable outcomes. Long-term follow-up studies will be required to explore any sequelae of MIS-C, precisely the cardiovascular complications.     

Adhesion of Legionella pneumophila on glass and plumbing materials commonly used in domestic water systems

We aimed to investigate the adhesion of Legionella pneumophila serogroup1 and L. pneumophila serogroup2–15 on glass, galvanized steel, stainless steel, copper, Polyvinyl chloride(PVC), Cross-linked polyethylene(PEX-c) and Polypropylene Random Copolymer(PPR). The surface physicochemical properties of both bacterial cells and materials were estimated through contact angle measurements. The roughness and surface topography of the materials were evaluated by Atomic Force Microscopy. The two L. pneumophila serogroups and plumbing materials showed a hydrophobic character, while glass surface was hydrophilic. All strains were adhered to all materials with the exception of copper. The result showed that the adhesion of both L. pneumophila sg1 and sg2–15 was systematically expressed with high intensity on galvanized steel followed by PVC, PEX-c, PPR, stainless steel and the low intensity on glass. The extent of adhesion is in correlation with the surface roughness and acid–bases interactions, while hydrophobicity seems to have no effect in adhesion intensity.     

The role of Fas in the progression of ischemic heart failure: prohypertrophy or proapoptosis

During myocardial ischemia, cardiomyocytes can undergo apoptosis or compensatory hypertrophy. Fas expression is upregulated in the myocardial ischemia and is coupled to both apoptosis and hypertrophy of cardiomyocytes. The role of Fas in apoptosis induction or cardiomyocyte hypertrophy during ischemic conditions is, however, still unclear. Some reports suggested that Fas might induce myocardial hypertrophy. Apoptosis of ischemic cardiomyocytes and Fas expression in the nonischemic cardiomyocytes occurs during the early stage of ischemic heart failure. Hypertrophic cardiomyocytes easily undergo apoptosis in response to ischemia, after which apoptotic cardiomyocytes are replaced by fibrous tissue. In the late stage of ischemic heart failure, hypertrophy, apoptosis, and fibrosis are thought to accelerate each other and might thus form a vicious circle that eventually results in heart failure. In this review, we summarize recent advances in the understanding of the role of Fas in remodeling ischemic myocardial tissues.     

Stem cell therapy in heart diseases: a review of selected new perspectives, practical considerations and clinical applications

Degeneration of cardiac tissues is considered a major cause of mortality in the western world and is expected to be a greater problem in the forthcoming decades. Cardiac damage is associated with dysfunction and irreversible loss of cardiomyocytes. Stem cell therapy for ischemic heart failure is very promising approach in cardiovascular medicine. Initial trials have indicated the ability of cardiomyocytes to regenerate after myocardial injury. These preliminary trials aim to translate cardiac regeneration strategies into clinical practice. In spite of advances, current therapeutic strategies to ischemic heart failure remain very limited. Moreover, major obstacles still need to be solved before stem cell therapy can be fully applied. This review addresses the current state of research and experimental data regarding embryonic stem cells (ESCs), myoblast transplantation, histological and functional analysis of transplantation of co-cultured myoblasts and mesenchymal stem cells, as well as comparison between mononuclear and mesenchymal stem cells in a model of myocardium infarction. We also discuss how research with stem cell transplantation could translate to improvement of cardiac function.