Helical Structure of the Cardiac Ventricular Anatomy Assessed by Diffusion Tensor Magnetic Resonance Imaging With Multiresolution Tractography

Introduction and objectives

Deeper understanding of the myocardial structure linking the morphology and function of the heart would unravel crucial knowledge for medical and surgical clinical procedures and studies. Several conceptual models of myocardial fiber organization have been proposed but the lack of an automatic and objective methodology prevented an agreement. We sought to deepen this knowledge through advanced computer graphical representations of the myocardial fiber architecture by diffusion tensor magnetic resonance imaging.

Methods

We performed automatic tractography reconstruction of unsegmented diffusion tensor magnetic resonance imaging datasets of canine heart from the public database of the Johns Hopkins University. Full-scale tractographies have been built with 200 seeds and are composed by streamlines computed on the vector field of primary eigenvectors at the diffusion tensor volumes. We also introduced a novel multiscale visualization technique in order to obtain a simplified tractography. This methodology retains the main geometric features of the fiber tracts, making it easier to decipher the main properties of the architectural organization of the heart.

Results

Output analysis of our tractographic representations showed exact correlation with low-level details of myocardial architecture, but also with the more abstract conceptualization of a continuous helical ventricular myocardial fiber array.

Conclusions

Objective analysis of myocardial architecture by an automated method, including the entire myocardium and using several 3-dimensional levels of complexity, reveals a continuous helical myocardial fiber arrangement of both right and left ventricles, supporting the anatomical model of the helical ventricular myocardial band described by F. Torrent-Guasp.     

Bone mineral density in healthy Tunisian women

Interpretation of densitometric results requires a comparison with reference bone mineral density (BMD) values of normal age and sex-matched persons. Thus the aim of this study was to determine these values for healthy Tunisian women, to estimate the prevalence of osteoporosis and to compare our findings with other populations. A cross-sectional study of 1378 Tunisian women aged between 20 and 96 years was carried out using DXA (GE-Lunar Prodigy). Subjects with suspected conditions affecting bone metabolism were excluded. Measurements were taken at the lumbar spine and femoral neck. These values were expressed at T-scores, with reference to the mean BMD values of the group aged 20–40 years. The peak bone mass, estimated in this age group was 1.174 + 0.127 g/cm² at the lumbar spine and 1.016 ± 0.118 g/cm² at the femoral site. It was attained respectively within the age of 25 years and 36 years. For both sites, the expected decline in BMD was shown when the successive age groups [40–49 years] and [50–59 years] were compared. Bone loss was rapid during the first 5 years after menopause. Thereafter BMD declined slowly but continually. The prevalence of osteoporosis in the women over 50 years of age, taking account of peak bone mass observed in our cohort, was 23.3% at the spine and 17.3% at the femoral neck with a combined prevalence of 23.4%. These rates attained respectively 30.4%, 11.8% and 32.9% when we considered the Italian values, which demonstrate the variability of osteodensitometric depending to the reference population adopted.     

Generalized cutis laxa and fibrillar glomerulopathy resulting from IgG Deposition in IgG‐lambda Monoclonal Gammopathy: pulmonary hemorrhage during stem cell mobilization and complete hematological response with bortezomib and dexamethasone therapy

The case of a 52‐years‐old man with generalized acquired cutis laxa associated with IgG‐lambda monoclonal gammopathy and nephrotic syndrome with renal failure (due to fibrillar glomerulopathy resulting from IgG deposition) is reported. A peripheral blood autologous stem cell transplant was planned, but the procedure was complicated by severe pulmonary hemorrhage during stem cells mobilization with granulocyte colony‐stimulating factor (G‐CSF). Treatment with bortezomib and dexamethasome was subsequently started and a complete hematological response was achieved. Finally, the complete hematological response with the disappearance of the toxic M‐protein allows the possibility of a long‐term benefit with a kidney transplant followed by an autologous bone marrow transplant.     

Carcinoma de ovario: enfermedad tras citorreducción y quimioterapia adyuvante. Importancia e implicaciones terapéuticas

Ovarian cancer is often diagnosed in the advanced stages. Primary cytoreduction still retains its central prognostic value. We have witnessed a general in treatment results since the appearance of the taxanes and the development of the intraperitoneal therapies. However, the latter has not been incorporated into routine clinical practice, given the difficulties it poses. After adjuvant chemotherapy the majority of our patients will recur. If we could identify high risk patients, we could study and develop better strategies for these patients.     

Molecular Analysis of a Multistep Lung Cancer Model Induced by Chronic Inflammation Reveals Epigenetic Regulation of p16 and Activation of the DNA Damage Response Pathway

The molecular hallmarks of inflammation-mediated lung carcinogenesis have not been fully clarified, mainly due to the scarcity of appropriate animal models. We have used a silica-induced multistep lung carcinogenesis model driven by chronic inflammation to study the evolution of molecular markers and genetic alterations. We analyzed markers of DNA damage response (DDR), proliferative stress, and telomeric stress: γ-H2AX, p16, p53, and TERT. Lung cancer-related epigenetic and genetic alterations, including promoter hypermethylation status of p16(CDKN2A), APC, CDH13, Rassf1, and Nore1A, as well as mutations of Tp53, epidermal growth factor receptor, K-ras, N-ras, and c-H-ras, have been also studied. Our results showed DDR pathway activation in preneoplastic lesions, in association with inducible nitric oxide synthase and p53 induction. p16 was also induced in early tumorigenic progression and was inactivated in bronchiolar dysplasias and tumors. Remarkably, lack of mutations of Ras and epidermal growth factor receptor, and a very low frequency of Tp53 mutations suggest that they are not required for tumorigenesis in this model. In contrast, epigenetic alterations in p16(CDKN2A), CDH13, and APC, but not in Rassf1 and Nore1A, were clearly observed. These data suggest the existence of a specific molecular signature of inflammation-driven lung carcinogenesis that shares some, but not all, of the molecular landmarks of chemically induced lung cancer.     

Design and In-line Raman Spectroscopic Monitoring of a Protein Batch Crystallization Process

Raman spectroscopy was used to design and monitor a lysozyme protein batch crystallization process in a lab scale study to facilitate the design of a pharmaceutical protein manufacturing process. A D-optimal design that consisted of 18 experiments was performed to elucidate the effect of temperature, concentration of the precipitating agent, time of crystallization, and possible interactions between these three factors on the Raman scattering changes. A polynomial mathematical model was calculated relating the scattering of the lysozyme solutions measured at individual Raman shifts to the significant factors obtained in the previous crystallization experiment. The 2,940-cm⁻¹ band provided the highest correlation values indicative of small prediction errors and good predictive ability for the crystallization model. Raman scattering signals obtained during the experiments were used as input to obtain a response surface for the factors studied and elucidate the relationship between the crystallization process conditions and the crystals obtained. The main factors affecting the crystallization process were the sodium chloride concentration and temperature.     

Granulocytic sarcoma (chloroma): rare extramedullary tumors associated with acute non-lymphoblastic leukemia

The authors report 5 new cases of pediatric granulocytic sarcomas. These rare extramedullary tumors are composed of immature granulocytic cells, usually associated with an acute non lymphoblastic leukemia, but may appear several months before. Their characteristics are exposed (epidemiology, clinical features, cytology and cytogenetics), and therapeutic rules are discussed, especially for the granulocytic sarcomas without evidence of bone marrow involvement. The prognosis is known to be poor.