Mesenchymal Stem Cell Transplantation Has a Regenerative Effect in Ischemic Myocardium: An Experimental Rat Model Evaluated by SPECT-CT Assessment.

Translational perspective: Ischemic heart disease remains a major medical problem with high mortality rates. Beside the great efforts devoted to research worldwide and the use of numerous experimental models, an absolute understanding of myocardial infarction and tissue loss has not yet been achieved. Furthermore, the regeneration of myocardial tissue and the improvement of myocardial activity after ischemia is one of the major areas of interest in the medical (and especially cardiovascular) community. In a novel experimental rat model, the beneficial effect of mesenchymal stem cell transplantation (MSCT) in a surgically induced ischemic myocardium was documented. From a clinical perspective, this work supports the surgical administration of MSCT in the infarcted area during coronary artery bypass surgery. AIMS: The regeneration of myocardial tissue and the improvement of myocardial activity after ischemia is one of the major areas of interest in cardiovascular research. We developed a novel experimental rat model and used it to examine the effect of mesenchymal stem cell transplantation (MSCT) on myocardial ischemia evaluated by SPECT-CT and immunohistochemistry. METHODS AND RESULTS: An open thoracotomy took place for forty adult female Wistar rats with (n = 30) or without (n = 10) surgical ligation of the left anterior descending coronary artery (LAD) in order to cause myocardial ischemia. Myocardial viability was evaluated via SPECT/CT 7 days before surgery, as well as at 7 and 14 days post-surgery. At day 0, 15 animals received homologous stem cells injected at the ischemic myocardium area. A SPECT/CT evaluation showed decreased activity of the myocardial cells in the left ventricle one week post-infarction. Regeneration of the ischemic myocardium fifteen days post-infarction was recorded only in animals subjected to stem cell transplantation. These findings were also confirmed by histology and immunohistochemical analysis, with the significantly higher expression of GATA4 and Nkx2.5. CONCLUSIONS: The positive effect of mesenchymal stem cell transplantation in the ischemic myocardium was recorded. The application of SPECT-CT allowed a clear evaluation of both the quality and quantity of the living myocardium post-infarction, leading to a new approach in the research of cardiovascular diseases. From a clinical perspective, MSCT may be beneficial when accompanied by myocardial revascularization procedures.

A Novel Experimental Rat Model for the In Vivo Assessment of Myocardial Ischemia Based on Single Photon Emission Computed Tomography.

BACKGROUND/AIM: Myocardial infarction, an acute medical situation with a high mortality rate worldwide, has been extensively studied in modern cardiovascular research, using different experimental models. However, a deep understanding of myocardial activity loss has not been fully investigated. We have developed a novel experimental rat model for noninvasive assessment of myocardial ischemia based on single photon emission computed tomography (SPECT/CT), in order to further understand and evaluate myocardial activity before and after surgical induction of myocardial ischemia. MATERIALS AND METHODS: Thirty adult female Wistar rats underwent open thoracotomy with (n=20) or without (n=10) surgical ligation of the left anterior descending coronary artery (LAD). The myocardial ischemia was confirmed with ECG and myocardial viability was evaluated via SPECT/CT at 7 days before as well as at 7 and 14 days post-surgery, after which animals were sacrificed and myocardial ischemic injury was further assessed histologically. RESULTS: All animals were evaluated with anatomical and functional criteria based on the SPECT/CT imaging results. A successful surgical technique causing ischemia and loss of myocardial function in all animals undergoing a LAD ligation was established. Furthermore, evaluation of the viable myocardium with SPECT/CT confirmed the reduction of functional myocardial cells of the left ventricle post-infarction, which was also documented histologically. CONCLUSION: Using our technique, the validity of this animal model to induce and evaluate myocardial ischemia was demonstrated. Our choice to apply SPECT-CT qualitative and quantitative evaluation of myocardial function leads to a new approach in experimentation with an anticipated significant impact in the ongoing cardiovascular laboratory research.

Recurrent Struma Ovarii Presented with High Levels of Thyroglobulin.

Struma ovarii are rare ovarian tumors, of monodermal germ cell origin, containing predominantly thyroid tissue. They are typically benign unilateral pelvic masses. Among the rare cases of malignancy, the most common histological type is that of the papillary carcinoma. A definite preoperative diagnosis of these tumors is difficult to achieve since most imaging findings are generally nonspecific. A rare exception is the case of synchronous abnormal thyroid blood tests where an ovarian teratoma should be highly suspected, especially when no pathology of the thyroid gland coexists. Surgical excision is the mainstay of treatment. Taking into account that struma ovarii are mainly encountered in patients of a childbearing age, a conservative surgical approach is a reasonable option. We present the case of a 56-year-old woman who was diagnosed with both a primary and recurrent struma ovarii while investigating the incidental finding of elevated blood laboratory levels of the thyroglobulin (Tg).

Rare Case of Hepatic Endometriosis as an Incidental Finding: Difficult Diagnosis of a Diagnostic Dilemma.

Endometriosis is the abnormal existence of functional uterine mucosal tissue outside the uterus. It is a usual disorder of women in reproductive age which is mainly located in the female genital tract. Hepatic endometriosis is one of the rarest disorders characterized by the presence of ectopic endometrium in the liver. It is often described as cystic mass with or without solid component. Preoperative diagnosis is difficult via cross-sectional imaging and histopathologic evaluation remains the gold standard for diagnosis. We report an asymptomatic 40-year-old female with a large cystic mass involving the left hepatic lobe. She underwent laparoscopic removal of the cyst. The diagnosis of hepatic endometriosis was established by the histopathological analysis of the surgical specimen.

Effect of stress on structural brain asymmetry.

There is a growing body of evidence that stressful events may affect the brain not only as a whole, but also in multiple laterality aspects. The present review is aimed at discussing the effect of stress and stress hormones on structural brain asymmetry. Differences and crossroads of functional and structural asymmetry are briefly mentioned throughout the document. The first part of this review summarizes major findings in the field of structural brain asymmetries in animals and humans from the evolutionary perspective. Additionally, effect of stress on animals is discussed generally. The second part then explores asymmetrical effects of stress on structural changes of principal brain areas - amygdala, hippocampus, neocortex, diencephalon, basal forebrain and basal ganglia from the point of normal lateralization, steroids, trauma and genetic factors. At the end we present hypothesis why stress appears to have asymmetrical effects on lateralized brain structures.

Hippocampal spatial position evaluation on MRI for research and clinical practice.

In clinical practice as well as in many volumetric studies we use different reorientations of the brain position towards x and y axis on the magnetic resonance imaging (MRI) scans. In order to find out whether it has an overall effect on the resulting 2D data, manual hippocampal area measurements and rotation variability of the brain (in two reoriented axes) and the skull were performed in 23 Alzheimer's disease patients and 31 healthy controls. After the MRI scanning, native brain scans (nat) were reoriented into the two different artificial planes (anterior commissure-posterior commissure axis (AC-PC) and hippocampal horizontal long axis (hipp)). Hippocampal area and temporal horn of the lateral ventricle was measured manually using freeware Image J program. We found that 1) hippocampal area of nat images is larger compared to hipp images, area of the nat images is equal to the AC-PC images and area of the hipp images is smaller compared to AC-PC images, 2) hippocampal area together with the area of the temporal horn for nat images is larger compared to hipp images, area of the hipp images is smaller compared to the AC-PC images and area of the nat images is smaller compared to the AC-PC images. The conclusion is that the measured area of the hippocampus in the native MRI is almost the same as the area of MRI reoriented only into the AC-PC axis. Therefore, when performing 2D area studies of the hippocampus or in the clinical practice we recommend usage of not-reoriented MRI images or to reorient them into the AC-PC axis. Surprising finding was that rotation of both AC-PC and hipp line towards x-axis among patients varies up to 35° and the same is true for the skull rotation so that it is not only a matter of the brain position.