Aurelio Bonelli

Segmental vertebral motion in the assessment of neck range of motion in whiplash patients

The purpose of this study was to obtain comparative data concerning the relative contribution of segmental cervical vertebral motion to the cervical range of motion (ROM) in whiplash and healthy subjects in an effort to evaluate the usefulness of X-ray analysis in future forensic and research efforts. Each subject’s neck ROM was measured with an optoelectronic system and also by X-ray measurements of the angular rotation in flexion and extension. The X-rays were examined to calculate the angular movement in the sagittal plane of each of the functional units C2–C3 to C6–C7. The chronic whiplash subjects showed reduced total neck range in all directions as compared to healthy subjects (p<0.001). There was a reduced total angular rotation from flexion to extension between these two groups (p<0.01), but no significant difference, however, between chronic whiplash subjects and controls in the percentage contribution of each of the functional units C2–C3 to C6–C7 to this rotation. This data will now allow a design of trials where healthy subjects are asked to simulate restricted neck ROM while undergoing optokinetic and X-ray evaluation of segmental vertebral motion. We will be able to determine if simulators produce a similar pattern to chronic whiplash and healthy, non-simulating subjects, and thus determine if, at least for forensic and research purposes, this technique is useful in validating reported restricted neck range.

Smooth muscle cells, dendritic cells and mast cells are sources of TNFalpha and nitric oxide in human carotid artery atherosclerosis ☆

INTRODUCTION In atherogenesis, dendritic cells, beside presenting antigens, may be sources of tumour necrosis factor (TNF)alpha and nitric oxide (NO), together with mast cells and smooth muscle cells. MATERIAL AND METHODS We have looked at the expression of TNFalpha and inducible NO synthase (iNOs) by these cells by affinity cytochemistry in autoptical specimens from normal carotid arteries and not ruptured, hemorrhagic or calcified atheromata. RESULTS Round to dendritic, major histocompatibility complex class II molecules (MHC-II+) cells and avidin-labeled mast cells were rare in normal arteries and significantly more numerous in atheromata. Many MHC-II+ cells expressed S-100 antigen; while a few were positive for phalloidin; appreciable fractions of these cells were immunoreactive for TNFalpha and iNOs, both in control specimens and atheromata. The fraction of mast cells labeled for iNOs was significantly lower in atheromata than in controls. Phalloidin positive cells were the most abundant cell type in the normal intima and atheromata; the fractions of these cells labeled for TNFalpha and iNOs were significantly higher in atheromata than in controls. Very few of these cells were also labeled for MHC-II. Computerized image analysis confirmed that the amounts of iNOs and TNFalpha were higher in atheromata than in controls. The increase in TNFalpha in atheromata was also confirmed by western blot. CONCLUSIONS Dendritic cells and mast cells can participate to the generation of TNFalpha and NO in the normal arterial wall and in atheromata, but myointimal cells are candidates as major sources of these molecules.

Immunohistochemical analysis of dendritic cells in skin lesions: correlations with survival time

The response to wounds until healing requires the activity of many cell types coordinate in space and time, so that the types of cells in a wound and their localization may be of help to date lesions with respect to death, which would be useful in forensic pathology. Cells reacting to injury include dendritic cells; the early reaction of these cells to skin wounding has not yet been investigated in humans, which was the aim of this study. Samples of wounded and control skin were taken at autopsy and analyzed by affinity histochemistry. Both epidermal and dermal MHC-II+ cells increased transiently in number within the first hour after wounding, then decreased. In the epidermis the increase affected also CD1a+ cells, i.e. well differentiated Langherhans cells, which however increased less, earlier and for a shorter time period than MHC-II+ cells. Dermal MHC-II+ cells became part of a perivascular mononuclear cell infiltrate visible in the subpapillary dermis by 60 min after wounding, which contained also mast cells. The immediately perivascular MHC-II+ cells were DC-SIGN- and CD11c-, while MHC-II+, DC-SIGN+, CD11c+ dendritic cells were predominantly located at the periphery of infiltrates and some were near the epidermis. Mast cells underwent degranulation, besides increase in number, in the first hours after wounding. The results suggest that skin dendritic cells, including Langerhans cells, participate to the early response to wounding in concert with mast cells, and that subpapillary blood vessels are primary sites of cell infiltration during that response in humans. The results show that the ratio between CD1a positive and MHC-II positive cells in the epidermis, the degranulation index of mast cells and the relative volume of MHC-II positive cells in the dermis can be added to the tools useful to distinguish vital from post mortem lesions and, the first two of them, to estimate the interval between a lesion and death.

Pulmonary Cement Embolism After Kyphoplasty

Pulmonary polymethylmethacrylate (PMMA) cement embolism after kyphoplasty (KP) surgery is a quite frequent event as well as the pulmonary embolization of central venous catheter fragment. This report shows the case of a subject who, after KP, developed pulmonary embolism and who underwent thoracic surgery. After hospital discharge, the subject advanced a claim for damages toward the hospital where he was operated, complaining sensation of tenderness at the chest surgical scar and esthetic damage. To understand the nature of the embolism (either central venous catheter fragment or cement), chemical investigations were then ordered. Spectrometry identified the PMMA cement used for KP. When doubts rise about the origin of the embolized material, chemical investigations may reveal important data not only for clinical but also for forensic purposes.

Hemidiaphragm Paralysis after Robotic Prostatectomy: Medical Malpractice or Unforeseeable Event?

The authors present a case of suspected malpractice linked to the onset of hemidiaphragm paralysis after robot-assisted radical prostatectomy (RARP). The approach to the case is shown from a medico-legal point of view. It is demonstrated how, after a thorough review of the literature, this was not a case of medical malpractice but an unforeseeable event. This paper aims at contributing to the very few reports dealing with the onset of hemidiaphragm paralysis after RARP, thus fostering clinical knowledge of these rare events and meanwhile providing useful data for the medico-legal handling in case of alleged negligence of surgeons.

Dendritic cells: a candidate cell in injury response to myocardial infarction and a possible diagnostic tool for sudden death

Dendritic cells and mast cells are involved in the organization of inflammatory cell infiltrates in general, and in vascular wall in particular. The behaviour of these cells in myocardial infarction is still to be studied in detail. Myocardial samples were taken at autopsy from the left ventricle of subjects respectively affected by (1) acute myocardial infarction, (2) previous myocardial infarction, (3) coronary artery disease and (4) traumatic death assumed as controls. Tissue sections were stained with haematoxylin and eosin and immunohistochemistry; organ sections were also stained with triphenyltetrazolium. Loss of acidophilia and disappearance of nuclei and intercalated disks were found in acute infarction. Massive infiltration of dendritic cells was found in acute and previous infarction, while mast cell numbers were similar to controls. Localized lack of reactivity with triphenyltetrazolium, indicating lack of viable tissue, was observed only when autopsy was conducted within 48 h from death. The results indicate that: dendritic cells react early to myocardial injury; they may be regulators of the inflammatory and scarring response in this tissue; their increase may be a useful marker of acute myocardial infarction.

Dendritic cells infiltrate the cardiac muscle fibers during myocardial infarction

Myocardial infarction (MI) consists in myocardial cell death due to prolonged ischemia. Partial ischemia at the periphery at the necrotic area may lead to “hibernating” myocardium, which may eventually recover. Upon necrosis an inflammatory a process starts [1], leading to healing through formation of a fibrous scar. Dendritic cells (DC) are involved in the regulation of immune responses and in the organization of inflammatory cell infiltrates in vascular wall, even independent of immune reactions. Another cell type involved in acute reaction to tissue injury are mast cells. The behaviour of DC and mast cells in myocardial infarction is still to be studied. To address this issue myocardial samples were taken at autopsy from the left ventricle of subjects respectively affected by (1) coronarosclerosis, (2) acute MI, (3) previous MI, and (4) traumatic lesions assumed as controls. Cryosections were stained with haematoxilin heosin and by immunohistochemistry. Fiber alterations consisting in loss of acidophilia and disappearance of nuclei and intercalar disks were found only in acute MI, while a cell infiltrate was found both in acute and previous MI. Massive infiltration of DC was found only in acute MI, while mast cells were similar to controls. These preliminary results suggest that DC react early to myocardial injury and therefore may be candidate regulators of the inflammatory and scarring response in this tissue and markers of acute myocardial infarction.

Skin dendritic cells increase in number during early response to wounding

Among the cells that may participate to wound response and wound healing, coordinate with other cell types, dendritic cells have been little studied until now and the least so in humans. This issue has been addressed on samples of wounded and control skin taken at autopsy and analyzed by immunohistochemistry and morphometry. Langerhans cell number in the epidermis and the relative volume of MHC II+ cells in the dermis increased transiently upon wounding, with a significant peak in the first and the second half hour after wounding respectively. Dermal MHC II+ cells became part of a perivascular mononuclear cell infiltrate visible in the subpapillary dermis since between 30 and 60 after wounding and which contained also MC. Cells at the periphery of the infiltrates were also DC-SIGN+ and CD11c+, i.e. were well differentiated connective tissue dendritic cells. Mast cells underwent degranulation associated to an increase in number in the first hours after wounding. These modifications of dendritic cells and mast cells and the respective tissue course suggest that epidermal and dermal dendritic cells participate to the early response to wounding in humans, coordinately with mast cells and possibly stimulating the recruitment and activation of the cells involved in injury response at later time points.

Cell interactions between mast cells and dendritic cells in human skin wounds.

The response to wounding passes through different phases and mast cells (MC) respond to injury since early [1]. These cells can interact with dendritic cells (DC) and lymphocytes in vitro to control immune responses [2], but possible interactions between MC and DC in the early response to wounding in vivo have not yet been investigated. To address this issue, cryosections of skin wounded since 0-24 h taken at autopsy were stained with fluorescent avidin (MC) and UEA-1 (Ulex europaeus-1 lectin: endothelium), and immunolabeled for MHC-II (DC), CD1a (Langerhans cells, i.e. epidermal DC) and PDGF (endothelium). Fluorescence microscopy was followed by computerized image analysis. Intact neighbor skin was used as control. Langerhans cells number increased significantly with a peak 5 min after wounding. The intensity of MHC-II expression and the relative volume of MHC-II+ cells in the dermis increased significantly since 5 min after wounding and remained high for several hours. These cells became part of a perivascular mononuclear cell infiltrate visible in the subpapillary dermis since 60 min after wounding, which contained also MC strictly close to MHC-II positive cells. Upon wounding the number of capillaries labeled by UEA-1 and for PDGF increased markedly. The results suggest that: immature cells residing in the epidermis may come to express CD1a quickly; DC recruitment and redistribution in the dermis may occur quite fast upon injury; the latter cells participate to the response to wounding since the early steps, coordinately with MC and close to capillaries. Therefore DC, together with MC, may be candidate to regulate early injury response in human skin. [1] Bacci et al. J. Forensic. Sci. 2011 (in press) [2] Dudeck et al. Eur. J. Immunol. 2011; doi: 10.1002/eji.201040994.

Early perivascular clustering of dendritic cells and mast cells in human skin wounds

Skin wounds determine a cascade of chemical and morphological events directed at hemostasis, prevention or arrest of infection, removal of damaged tissue and eventually repair. We could show that mast cells modify in number [Bonelli et al., Int. J. Leg. Med. 117; 14-18, 2003] and change their content in TNFalpha [Bacci et al., Int. J. Leg. Med. 120: 38-42, 2006] at the border of a wound since early after injury. Dendritic cells can be at play in natural immune responses, besides antigen presentation, therefore their behavior in wounded skin deserves attention. We have investigated on the presence and intercellular relationships of mast cells and dendritic cells in human skin wounds suffered from no more than 60 min; control specimens were taken at least 20 cm from a wound. Cryosections, fixed in cold acetone, were fluorescent stained with avidin (mast cells) and Ulex europaeus-1 lectin (UEA-1: endothelium) and immunolabeled for MHC-II (dendritic cells), CD1a (Langerhans cells) and PDGF. In the epidermis, Langerhans cells were found to undergo transient increase in number and labeling intensity, while dermal dendritic cells continued to increase in number and labeling intensity until 60 min. In control skin, mast cells and dendritic cells were sparse and only exceptionally close to each other; upon wounding, cell clusters formed progressively along blood vessels and included a majority of MHC-II positive cells and several mast cells, often strictly close to MHC-II positive cells. Isolated MHCII positive cells and mast cells outside these clusters were exceptional. The binding of UEA-1 and the labeling for PDGF in control skin was limited to the spinous and granular epidermal layers and dermal capillaries. In wounded skin the intensity of epidermal labeling was increased and, most relevant, the number of labeled capillaries increased markedly. The results suggest that: immature cells residing in the epidermis may come to express CD1a quickly; dendritic cell recruitment and redistribution in the dermis may occur quite fast upon injury; the latter cells participate to the response to wounding since the early steps, coordinately with mast cells and capillary endothelium. Therefore, dendritic cells are candidate to regulate injury response in human skin, together with mast cells.