Single photon emission computed tomography: An alternative imaging modality in left ventricular evaluation

Various diagnostic imaging modalities have been used for quantitative left ventricular (LV) parameters. Because of the suboptimal value of the most widely used technology, two-dimensional (2D) echocardiography, 3D ultrasonographic imaging has improved accuracy for LV volume and function. Single photon emission computed tomography (SPECT) is another diagnostic method where LV volumetric and functional parameters can be accurately provided by gated myocardial perfusion tomographic slices. First pass radionuclide venticulography is another imaging modality which has some practical limitations. Despite lower ejection fraction (EF) values compared with invasive approach, noninvasive techniques are accurate in determination of normal and depressed EF. Noninvasive techniques with 3D approach including gated SPECT are beneficial for not only global but also regional LV evaluation. It has been mentioned that the slight difference between echocardiography and SPECT could be caused by the diverse population studied. The results of diagnostic stress tests support that SPECT is feasible to use in evaluation of LV volume and functional analysis. Magnetic resonance imaging is an expensive modality to use routinely, but it preserves its importance in selected patients for providing precise LV geometric data

A Long View of Shareholder Power: From the Antebellum Corporation to the Twenty-First Century

For most of the twentieth century, the conventional wisdom held—probably correctly—that shareholders in America’s large, public corporations were passive and powerless and that managers wielded the real power. Beginning in the 1980s, however, shareholders in the form of institutional investors started to push for a greater say in corporate decision-making. In the twenty-first century, hedge funds have upped the ante, fighting for major changes in corporations whose shares they own. Once-imperial CEOs have now become embattled as they fight, but often lose, against activist shareholders demanding policy changes, new dividends, board representation, and even the sale or break-up of corporations. In short, things have changed. This Article situates the present-day rise of shareholder power by taking a long view of the previous two centuries, moving beyond traditional accounts to reach all the way back to the beginnings of the American business corporation in the early nineteenth century, then following the story of shareholder power up to the present day. Its long view reveals the complicated and shifting nature of shareholder power, documenting how periods of greater shareholder power were interspersed with periods where shareholders had little power, how the focus of shareholder power has moved from controlling shareholders to autonomous managers, and how shareholder power has ebbed and flowed across the last two centuries. This Article not only provides the backstory to present-day developments, but also suggests that what has appeared as a hallmark of American corporate capitalism—the relative powerlessness of shareholders—may only have been typical of a few decades in the middle of the twentieth century.\u3c.p\u3

Atypical fibroxanthoma in scalp

Atypical fibroxanthoma is an uncommon neoplasm generally found in elderly patients on sun-exposed areas. Both clinical, histopathological and immunohistochemical features of this fibroblastic process should be assessed in order to be able to diagnose and differentiate it from a number of malignant entities such as carcinoma, melanoma and malignant fibrous histiocytoma. The majority of cases of atypical fibroxanthoma are benign, and metastasis is a rare phenomenon. In this report a 75 year old male patient complaining of a parietally located, painless, mildly hemorrhagic, hard nodular lesion for 1,5 month diagnosed as atypical fibroxanthoma is presented with its clinical and histopathological findings. There was no metastatic lesion, lymphovascular and deep invasion areas microscopically. In the discussion part, the diagnosis was compared with some other entities in histopathological and immunohistochemical manner with regard to differential diagnosis. Lastly the adequacy of the chosen surgical method for the case is discussed and commented.Atipik fibroksantom nadir görülen, düşük dereceli bir neoplazm olup, sıklıkla güneşe maruz kalan yaşlı hastalarda görülmektedir. Fibroblastlardan kaynaklanan bu hastalığın tanısında klinik, histopatolojik ve immünokimyasal özelliklerinin incelenmesi ve böylece karsinom, melanom, malign fibröz histiyositom gibi malign bazı tanılardan ayrılması gerekmektedir. Olguların büyük çoğunluğu benign olup metastaza nadir olarak rastlanmaktadır. Çalışmamızda 75 yaşında bir erkek hastada 1,5 ay önce parietal alanda ortaya çıkan, başvuru sırasında palpasyonla sert üzeri hafif kanamalı ağrısız nodüler lezyon ile prezente olan atipik fibroksantom olgusu klinik ve patolojik bulgular eşliğinde sunulmuştur. Olgunun metastatik lezyonu, lenfovasküler veya derin invazyonu bulunmamaktadır. Tartışma bölümünde vaka ayırıcı tanı açısından diğer bir takım hastalıklarla histopatolojik ve immünokimyasal olarak karşılaştırılmıştır. Son olarak seçilen cerrahi tedavi yöntemin yeterliliği değerlendirilmiştir

Current cardiac imaging techniques for detection of left ventricular mass

Estimation of left ventricular (LV) mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE) is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR) and cardiovascular computed tomography (CCT) are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test

Hemodynamic stress and microscopic remodeling.

BackgroudHeart responds to physiologic and pathologic conditions and sympathetic drive plays an important role. It has been documented that LV base is more dominantly affected by sympathetic drive compared to the other regions. LV base is more dominantly exposed to wall stress in the initial period of remodeling due to pressure-overload, since LV cavity is the largest at base. Basal septal hypertrophy (BSH) in cross-sectional data is associated with the early phase of hypertensive heart disease. BSH was confirmed by 3rd generation microscopic ultrasound in small animals. BSH as the closest location to increased afterload could be detected in variety of stress stimuli and result in a huge septal hypertrophy in advance cases possibly related to earlier exposure of hemodynamic stress to septal wall.ConclusionEffective geometric and functional evaluation of initial remodeling due to hemodynamic stress is important according to both human and animal data. These findings possibly contribute to early recognition of adaptive phase of hypertensive remodeling and more effective management in a timely fashion