Antonio Duca

Constrained Spherical Deconvolution Tractography Reveals Cerebello-Mammillary Connections in Humans.

According to the classical view, the cerebellum has long been confined to motor control physiology; however, it has now become evident that it exerts several non-somatic features other than the coordination of movement and is engaged also in the regulation of cognition and emotion. In a previous diffusion-weighted imaging-constrained spherical deconvolution (CSD) tractography study, we demonstrated the existence of a direct cerebellum-hippocampal pathway, thus reinforcing the hypothesis of the cerebellar role in non-motor domains. However, our understanding of limbic-cerebellar interconnectivity in humans is rather sparse, primarily due to the intrinsic limitation in the acquisition of in vivo tracing. Here, we provided tractographic evidences of connectivity patterns between the cerebellum and mammillary bodies by using whole-brain CSD tractography in 13 healthy subjects. We found both ipsilateral and contralateral connections between the mammillary bodies, cerebellar cortex, and dentate nucleus, in line with previous studies performed in rodents and primates. These pathways could improve our understanding of cerebellar role in several autonomic functions, visuospatial orientation, and memory and may shed new light on neurodegenerative diseases in which clinically relevant impairments in navigational skills or memory may become manifest at early stages.

Three-dimensional volume rendering of the ankle based on magnetic resonance images enables the generation of images comparable to real anatomy

We have applied high‐quality medical imaging techniques to study the structure of the human ankle. Direct volume rendering, using specific algorithms, transforms conventional two‐dimensional (2D) magnetic resonance image (MRI) series into 3D volume datasets. This tool allows high‐definition visualization of single or multiple structures for diagnostic, research, and teaching purposes. No other image reformatting technique so accurately highlights each anatomic relationship and preserves soft tissue definition. Here, we used this method to study the structure of the human ankle to analyze tendon–bone–muscle relationships. We compared ankle MRI and computerized tomography (CT) images from 17 healthy volunteers, aged 18–30 years (mean 23 years). An additional subject had a partial rupture of the Achilles tendon. The MRI images demonstrated superiority in overall quality of detail compared to the CT images. The MRI series accurately rendered soft tissue and bone in simultaneous image acquisition, whereas CT required several window‐reformatting algorithms, with loss of image data quality. We obtained high‐quality digital images of the human ankle that were sufficiently accurate for surgical and clinical intervention planning, as well as for teaching human anatomy. Our approach demonstrates that complex anatomical structures such as the ankle, which is rich in articular facets and ligaments, can be easily studied non‐invasively using MRI data.

In Vivo CT Direct Volume Rendering: A Three-Dimensional Anatomical Description of the Heart.

Summary Background Since cardiac anatomy continues to play an important role in the practice of medicine and in the development of medical devices, the study of the heart in three dimensions is particularly useful to understand its real structure, function and proper location in the body. Material/Methods This study demonstrates a fine use of direct volume rendering, processing the data set images obtained by Computed Tomography (CT) of the heart of 5 subjects with age range between 18 and 42 years (2 male, 3 female), with no history of any overt cardiac disease. The cardiac structure in CT images was first extracted from the thorax by marking manually the regions of interest on the computer, and then it was stacked to create new volumetric data. Results The use of a specific algorithm allowed us to observe with a good perception of depth the heart and the skeleton of the thorax at the same time. Besides, in all examined subjects, it was possible to depict its structure and its position within the body and to study the integrity of papillary muscles, the fibrous tissue of cardiac valve and chordae tendineae and the course of coronary arteries. Conclusions Our results demonstrated that one of the greatest advantages of algorithmic modifications of direct volume rendering parameters is that this method provides much necessary information in a single radiologic study. It implies a better accuracy in the study of the heart, being complementary to other diagnostic methods and facilitating the therapeutic plans.

Diffusion Tensor Imaging (DTI) in Head and Neck Oncology; a new method of Virtual Biopsy

The objective of our study is to explore the feasibility and utility of Diffusion Tensor Imaging (DTI) in the non invasive evaluation of any lesion [1] in Head and Neck structure. We would reach a verified and certified step of Virtual biopsy. Ten patients with different histological lesions were recruited for this study. Morphological and diffusion weighted images were acquired with a 3T scanner during last 3 months. Probabilistic tensor-based tractography reconstruction of any lesions was performed and mean fractional anisotropy (FA) values for everyone were extracted [2]. The results showed that the Diffusion Tensor Imaging (DTI) was able to identify the lesion geometrical morphology and diffusion microstructural changes. The patient with a benign lesion reported a significant improvement in ADC mean values. We have evidence that pushes us to continue with this method. We are at the beginning of this work. We had to recruits more patients to get meaningfully significant data.

Hippotherapy improves gait and balance in Down Syndrome

Patients with Down syndrome (DS) present delays in motor development, showing a unique pattern of locomotion in clinical settings. Hippotherapy (HBR) is a field of rehabilitation therapy to achieve physical, social, and psychological well-being through therapeutic horse riding, providing a new stimulus related to gait and may helping balance and postural control [1], [2]. Herein, we have enrolled fifteen male individuals affected by DS, aged from 19 to 36 years old. All patients were vaccinated for tetanus and previously screened for any contraindications to practice HBR. The HBR protocol included a six-months period of horseback riding exercise, performed weekly. Before, during and after the study period, functional mobility, strength and performance in balance were assessed by Time Up and Go Test (TUG), 30s Chair-Stand-Test (30CST), MRC-scale and the Berg-Balance-Scale (BBS). Furthermore, the OPTO-Gait for dynamic analysis and the Diasu Ultrasensor systems for static analysis were applied at the same timepoints, in order to assess the HBR effects on movement reaction time, muscle activation, functional mobility, muscle strength and balance in DS. In conclusion, we provided objective clinical data on the role of HBR to determine a functional improvement on gait speed, rhythm, width, bilateral symmetry, gross motor function and balance in DS.

Sarcoglycans and mucin in epithelial tissues of digestive and respiratory tracts: an immunofluorescence study

Sarcoglycans are transmembrane glycoproteins which play a key role in maintaining sarcolemma stabilization during muscle contraction. Several studies have demonstrated that this complex is not muscle specific and that it is also expressed in epithelial tissues as gingival, breast and prostatic epithelia. In the present study we investigated sarcoglycans expression in the epithelia of digestive and respiratory tracts. We performed immunofluorescence reactions using antibody against a-, b-, g-, d-, e- and z-sarcoglycans and against mucin 4 and 16. Mucins are a superfamily of proteins which serve to protect the underlying epithelia against a wide range of injuries (bacteria, virus, parasites, toxins, pH). This protection leads to coordinate cell proliferation, differentiation and apoptosis among other cellular responses; in fact, mucins are promising biomarkers and therapeutic targets in cancer and inflammatory diseases. Our results show the expression of sarcoglycans in the basal, lateral, and apical epithelial cell’s surface; moreover, sarcoglycans show to colocalize with mucins in the cell’s apical surface of bronchi and bronchioles, stomach and intestine but no apical localization has been detected in the esophageal epithelium. These results support the role of sarcoglycans in cell-cell and cell-matrix interaction. Moreover, the colocalization between sarcoglycans and mucins at apical level of epithelia which have high mucosecretory activity suggest that sarcoglycans could interact with mucus, maybe involving in maintainig omeostasis of gastro enteric epithelia. It will be necessary to demonstrate the hypothetical correlation between sarcoglycans and the maintaining epithelial homeostasis.

Effects of mini screw placement in mandibular bone of rats treated with low dose zoledronate

Bisphosphonates are a category of drugs that are commonly used in dentistry and orthopedics to treatment of several bone disorders. The two most potent and widely used nitrogen-containing BPs are zoledronate and alendronate, which inhibit the intracellular mevalonate pathway. In recent years it has been observed Biphosphonate-associated osteonecrosis of the jaws which is a real complication of intravenous biphosphonates therapy in patients with cancer or osteoporosis. In our previous studies, performed on rat model, we observed mandibular bone characteristics after long term of low dose zoledronate treatment without tooth extraction or trauma; results showed several areas of bone with empty osteocyte lacunae, absence of matrix and presence of unorganized fibrillar structures but no spontaneous bone exposure has been observed. In the present study we have treated 20 rats with intraperitoneal injections of zoledronate at the lower dose for three times a week. After 30 days of treatment we applied trauma on mandibular bone by application of screw. Specimens were analysed by histological staining, immunofluorescence techniques and scanning electron microscopy. Our results show that the bone area of screw application is characterized of empty osteocyte lacunae, empty Volkmann’and Havers’canals and some inflammatory cells. Although the presence of small necrotic areas no bone exposure has been observed after low dose zoledronate treatment and trauma application. These results suggest us that the bisphosphonates-associated osteonecrosis of jaw is strictly correlated to drug’s dose. It will be necessary to perform the same study using the highest dose of drugs.

Advances from probabilistic tractography in connections of the limbic system with the cerebellum

The limbic system is a complex set of brain structures located on both sides of the thalamus, right under the cerebrum. It is not a separate system but a collection of structures from the telencephalon, diencephalon, and mesencephalon, including the hippocampus, amygdala, anterior thalamic nuclei, fornix, columns of fornix, mammillary body, septum pellucidum, habenular commissure, cingulate gyrus, parahippocampal gyrus, limbic cortex, pars of olfactory system and limbic midbrain areas. Nevertheless, recent studies showed that the definition of anatomical structures considered part of the limbic system is a controversial subject. Although the role of the cerebellum was traditionally considered mainly associated to motion control, it has been recently suggested a cerebellar involvement in emotions control, cognitive processes and social behavior. In this regard, we have previously demonstrated that the cerebellum is interconnected with the hippocampus [1]. In this work, a wider sample of normal subjects was examined by using probabilistic Constrained Spherical Deconvolution (CSD) tractography, which represents a method able to overcome many limitations of other Diffusion Tensor Imaging (DTI) techniques, providing more accurate data [2]. We found evidences in the human brain that the cerebellum is widely linked with limbic-related structures and provided a more reliable demonstration of direct cerebello-limbic pathways. In addition, we further extendend our analysis to the other limbic connections including uncinated fasciculus, cingulate fasciculus, inferior longitudinal fasciculus, anterior thalamic connections and fornix. Although these pathways have been already described in the tractographic literature we provided reconstruction and quantitative analysis, which could be potentially useful to explore pathological conditions damaging this system. Finally, the demonstration of the existence of cerebello-limbic connections could constitute an important step in the knowledge of the anatomic substrate of non-motor cerebellar functions.

Three-dimensional analysis for the evaluation of left ventricular aneurysm and pseudo-aneurysm after myocardial infarction

Myocardial Infarction (MI) is an ischemic heart disease representing one of the main causes of death for acute cardiac pathologies. Two important consequences of MI are left ventricular (LV) aneurysm and pseudo-aneurysm. The aim of the present study is to highlight anatomical and functional changes in LV undergoing post-ischemic remodeling by means of three dimensional-Magnetic Resonance Imaging (MRI) and three dimensional-Computed Tomography (CT), which are useful techniques for the diagnosis and evaluation of accurate clinical and surgical approaches. In this way the surgeon can evaluate pro and counter of the classical approach or the parachute implant with possible promotion of mininvasive surgery [1]. Although to date MI consequences can be assessed with bidimensional technique (e.g. echocardiography and ventriculography), we want to suggest the use of three dimensional Direct Volume Rendering (DVR), which is a direct technique for visualizing primitive volumes without any intermediate conversion of the volume data to surface presentation [2]. DVR allows to better discriminate between aneurysm and pseudoaneurysm and to do a better evaluation of inclusion and exclusion criteria for the implant of a parachute device.

Sarcoglycan sub-complex and Satellite cells in masseter muscle of crossbite patients

Crossbite is a lateral misalignment of the dental arches. Subjects with unilateral posterior crossbite exhibit different kinematics of the mandible during mastication when chewing on the affected side, resulting in an increased frequency of reverse chewing cycles; moreover, the masseter of the affected side results less active than the counterpart (Piancino et al., 2006). An our immunofluorescence study on masseter muscle of crossbite patients has shown that in the affected side there is a lower expression of muscle specific integrins than the counterpart (Cutroneo et al., 2012). So, we hypothesized that integrins could be correlated with contraction activity in mastication, maybe promoting the production of new muscle fibers. Another our tractography study on crossbite patients has shown an increment of muscle fibers number in non affected side. On this basis in the present work we investigated the number of satellite cells in masseter muscle of crossbite patients, both in affected and non affected side. Since the existence of a bidirectional signaling between integrins and sarcoglycans we have also investigated the expression of the sarcoglycan subcomplex. Results show that the number of satellite cells in non affected side is higher than affected side. Moreover, in according with our previous results about integrins, even the sarcoglycan sub-complex show to be less expressed in the affected side than the counterpart. These data support that in non affected masseter muscle a new fibers production activity takes place which, in turns, determines a muscular hyperplasia. Based on our results, the myogenesis in masseter muscle could be regulated by sarcoglycan and integrin protein systems.