Metastatic myocardial abscess on the posterior wall of the left ventricle: a case report

<p>Abstract</p> <p>Introduction</p> <p>Myocardial abscess is a rare and potentially fatal condition. Metastatic myocardial abscess in the setting of infective endocarditis has been infrequently reported in the medical literature. To the best of the authors' knowledge no case of myocardial abscess affecting the free wall of the left ventricle secondary to infective endocarditis of a right-sided heart valve has been reported previously.</p> <p>Case presentation</p> <p>We report a case of tricuspid valve endocarditis caused by <it>Staphylococcus aureus </it>and resulting in a myocardial abscess on the posterior wall of the left ventricle, far from the active valvular infection. We also briefly discuss the role of different investigation modalities including cardiac magnetic resonance imaging in diagnosing myocardial abscess.</p> <p>Conclusion</p> <p>Myocardial abscess is a life-threatening illness. A high index of clinical suspicion is required to make a prompt diagnosis. Final diagnosis may need multi-modality imaging. An early diagnosis, aggressive medical therapy, multidisciplinary care and timely surgical intervention may save life in this otherwise fatal condition.</p

Secondary and higher secondary school chemistry teachers’ misconceptions of chemical bonding : Comparison across regions in Pakistan

Chemical bonding is a fundamentally important concept that makes a foundation for further studies in the discipline. Therefore, a better conceptual understanding of teachers can be considered a mediating factor for students\u27 better understanding. This cross-sectional survey study aimed to explore secondary and higher secondary chemistry teachers\u27 misconception of the selected concepts of chemical bonding (i.e., solubility and conductivity, bonding, lattices, intermolecular and intramolecular forces, and polarity and geometry). Chemical Bonding Diagnostic Tool (CBDT) was adapted and found to be reliable for the sample of this study (α = 0.84). CBDT was administered online to 124 secondary and higher secondary school chemistry teachers of GB (n = 58) and Karachi (n= 66) of Pakistan. The findings of this study indicated that, regardless of region, Chemistry Teachers (CTs) hold various misconceptions in all five areas of CBDT. The overwhelming misconceptions of CTs in five constructs of CBDT revealed that they: (i) generalized the metal conductivity model to ionic compounds, (ii) confused the concept of ionic and covalent bonds/ bonding, (iii) mixed up covalent and molecular lattices, (iv) found difficulty in differentiating \u27inter\u27 and \u27intra,\u27 and (v) muddled with the concept of polarity and geometry. The study concludes that participant CTs were found to have similar misconceptions as held by students of grade 9 to 12 in different contexts of the world. This provides significant insight into the existing patterns of misconceptions of CTs for policy, practice, and further research. Keeping the findings in view, it could be suggested that teacher education institutions may need to reflect on existing patterns of misconception and develop professional content development programs for science teachers. The results of this study would make an essential contribution to indigenous literature

Effect of the knockdown of death-associated protein 1 expression on cell adhesion, growth and migration in breast cancer cells

Death-associated protein 1 (DAP1) is a highly conserved phosphoprotein involved in the regulation of autophagy. A previous clinical study by our group suggested an association between low DAP1 expression and clinicopathological parameters of human breast cancer. In the present study, we aimed to determine the role of DAP1 in cancer cell behaviour in the context of human breast cancer. We developed knockdown sublines of MCF7 and MDA-MB‑231, and performed growth, adhesion and invasion assays and electric cell-substrate impedance sensing (ECIS) studies of the post-wound migration of cells. In addition, we studied the mRNA expression of caspase 8 and 9, DELE, IPS1, cyclin D1 and p21 in the control and knockdown sublines. Knockdown was associated with increased adhesion and migration, significantly so in the MDA-MB-231DAP1kd cell subline (p=0.029 and p=0.001, respectively). Growth in MCF7 cells showed a significant suppression on day 3 (p=0.029), followed by an increase in growth matching the controls on day 5. While no change in the apoptotic response to serum starvation could be attributed to DAP1 knockdown, the expression of known components of the apoptosis pathway (caspase 8) and cell cycle (p21) was significantly reduced in the MCF7DAP1kd cell subline (p≤0.05), while in MDA-MB-231DAP1kd the expression of a pro-apoptotic molecule, IPS1, was suppressed (p≤0.05). DAP1 may have an important role in cell adhesion, migration and growth in the context of breast cancer and has significant associations with the apoptosis pathway. Furthermore, we believe that delayed increase in growth observed in the MCF7DAP1kd cell subline may indicate activation of a strongly pro-oncogenic pathway downstream of DAP1

Changing Characteristics and Mode of Death Associated With Chronic Heart Failure Caused by Left Ventricular Systolic Dysfunction

Background— Therapies for patients with chronic heart failure caused by left ventricular systolic dysfunction have advanced substantially over recent decades. The cumulative effect of these therapies on mortality, mode of death, symptoms, and clinical characteristics has yet to be defined. Methods and Results— This study was a comparison of 2 prospective cohort studies of outpatients with chronic heart failure caused by left ventricular systolic dysfunction performed between 1993 and 1995 (historic cohort: n=281) and 2006 and 2009 (contemporary cohort: n=357). In the historic cohort, 83% were prescribed angiotensin-converting enzyme inhibitors and 8.5% were prescribed β-adrenoceptor antagonists, compared with 89% and 80%, respectively, in the contemporary cohort. Mortality rates over the first year of follow-up declined from 12.5% to 7.8% between eras ( P =0.04), and sudden death contributed less to contemporary mortality (33.6% versus 12.7%; P &lt;0.001). New York Heart Association class declined between eras ( P &lt;0.001). QTc dispersion across the chest leads declined from 85 ms (SD, 2) to 34 ms (SD, 1) and left ventricular end-diastolic dimensions declined from 65 mm (SD, 0.6) to 59 mm (SD, 0.5) (both P &lt;0.001). Conclusions— Survival has significantly improved in patients with chronic heart failure caused by left ventricular systolic dysfunction over the past 15 years; furthermore, sudden death makes a much smaller contribution to mortality, and noncardiac mortality is a correspondingly greater contribution. This has been accompanied by an improvement in symptoms and some markers of adverse electric and structural left ventricular remodeling. </jats:sec