Luciana Travan

Suggestive evidence for a microanatomical relationship between mast cells and nerve fibres containing substance P, calcitonin gene related peptide, vasoactive intestinal polypeptide, and somatostatin in the rat mesentery.

A close microanatomical relationship between serotonin-positive mast cells and nerve fibres positive for substance P, calcitonin gene related peptide, vasoactive intestinal polypeptide, and somatostatin has been observed in whole-mount preparations of rat mesentery by an immunofluorescent double-staining procedure. Peptidergic fibres have been shown either to run in close proximity or come in direct contact with mast cells. This supports earlier morphological and immunohistochemical results suggesting an innervation of mast cells and provides a structural foundation for a series of pharmacological studies which outline the influence of various neuropeptides on mast cell secretory activity.

Mast Cells and Basophils: A Potential Link in Promoting Angiogenesis during Allergic Inflammation

Mast cells and basophils are granulated metachromatic cells which possess complex and partially overlapping roles in acquired and innate immunity, including both effector and regulatory activities. Mast cells and basophils cooperate in exacerbating and/or modulating inflammation as well as in mediating subsequent tissue repair. Mast cells release a series of potent proangiogenic molecules during inflammation that stimulate vessel sprouting and new vessel formation. Recent data suggest that basophils may also play a role in inflammation-related angiogenesis, principally but not exclusively through the expression of several forms of vascular endothelial growth factors and their receptors. This review focuses on the potential cooperative link between mast cells and basophils in promoting angiogenesis during allergic inflammation. We discuss the multifaceted roles of mast cells and basophils in inflammatory mechanisms of allergic diseases and whether these cells can be both source and target of proangiogenic mediators.

Apposition of enteric nerve fibers to plasma cells and immunoblasts in the mouse small bowel

Light (LM) and electron microscopy (EM) were used to investigate the structural relationship between enteric nerves and the population of immune cells in the mouse small bowel. By LM, the osmium-zinc iodide procedure was used for visualizing nerve fibers; the incidence of nerve-plasma cell contacts in the mucosa and submucosa was calculated to be approximately 4 times and, respectively, 3 times greater than would be expected by chance alone (P < 0.0001). EM revealed close, synaptic-like contacts between axonal varicosities and plasma cells or B immunoblasts. The results presented here provide systematic quantitative evidence that a structural foundation for communication between nerve fibers and B cells exists in the mouse small bowel.

Bilateral arcuate foramen associated with partial defect of the posterior arch of the atlas in a medieval skeleton: case report and review of the literature. Looking backward to go forward

PurposeWe observed a complex atlas (C1) dysmorphism in a human medieval skeleton dug up from the sixth to the seventh century necropolis located in the north-eastern Italy. We analyzed such a dysmorphism in the light of pertinent literature and discussed the functional and clinical implications related to this type of C1 structural malformation.MethodsMacroscopical and CT-SCAN examinations of the atlas were carried out.ResultsBone findings consisted of partial aplasia of the posterior arch of the C1 accompanied by a bilateral arcuate foramen. In addition, the spinous processes of C7 and T1 were found to be bifid.ConclusionsAlthough such abnormalities are supposed to be clinically inconspicuous, yet they may become challenging or even dangerous in the context of trauma. They may even complicate specific diagnostic or surgical procedures. In addition, they may cause a great number of symptoms, ranging from headache and neck pain to loss of postural muscle tone and consciousness, due to the close and complex relationship of bone structures with nerves, blood vessels, muscles, and ligaments. As a result, radiologists, clinicians, surgeons, and chiropractors should consider in their clinical reasoning the possibility that atlas dysmorphisms may occur.

Identification of P-glycoprotein at the membrane of mast cell secretory granules. An immunofluorescence and protein A-gold electron microscopical investigation

The presence of P-glycoprotein has been investigated in rat peritoneal mast cells by means of immunofluorescence and immunogold electron microscopy, using the specific monoclonal antibody JSB-1. Immunofluorescence studi es showed that the glycoprotein is primarily concentrated in mast cell granules, and little is localized at the plasma membrane. Electron microscope observations revealed a marked accumulation of colloidal gold particles at the granule-coating membranes, whereas decoration of the plasma membrane is much less intense. When mast cells are stimulated to exocytate with compound 48/80, both immunofluorescence and electron microscopy showed concentration of P-glycoprotein reactivity at the plasma membrane level. Indeed, fusion of the granule with the plasma membrane allowed transfer of immunoreactive P-glycoprotein material from the granule-coating membrane to the cell surface membrane. These findings confirmed the presence of P-glycoprotein in mast cells; it is predominantly localized in the granules and is exposed on the cell surface only after exocytosis, suggesting, therefore, a possible physiological role for P-glycoprotein in the secretion of certain mediators.

A keyhole-shaped sternal defect in an ancient human skeleton

We observed a sternal foramen contiguous with a small sternal cleft in a human skeleton coming from North-Eastern Italy and dating back to between the sixteenth and seventeenth century AD. Both of these types of anomalies result from a defective midline fusion of the developing sternum. Sternal foramen is a relatively common bony defect that usually comes to light as an incidental finding. Sternal cleft is a rarer morphological anomaly that can have a wide spectrum of clinical manifestations and outcomes, depending on the extent of the bony defect as well as on the presence and severity of other abnormalities. The coexistence of a sternal foramen and a sternal cleft has very rarely been described in the literature. We report here one such unusual association and discuss its potential practical implications. In most cases, sternal foramina and small sternal clefts are clinically uneventful; yet, lack of awareness about the existence of these subtle anatomical variations can sometimes lead to misinterpretation of radiological and pathological findings or make sternal biopsy and acupuncture unsafe.

Serotoninergic fibres form dense synaptic contacts with Purkinje cells in the mouse cerebellar cortex — An immunohistochemical study

The distribution of serotonin immunoreactivity in the mouse cerebellar cortex was studied using the indirect antibody peroxidase-antiperoxidase (PAP) technique of Sternberger (1979) on epoxy embedded semithin sections. The great majority of serotonin-positive afferents distribute throughout the Purkinje cell layer and form dense synaptic contacts with the somata of the Purkinje neurons. Only a sparse immunostaining of serotoninergic fibres could be detected at the granular cell and molecular layers. The microanatomical organization of the serotoninergic projections to the mouse cerebellar cortex is quite different from that observed in other animal species. These findings suggest that in the mouse cerebellar cortex, the Purkinje cell population represents the main target for serotoninergic afferents. Our histochemical data provide morphological support for a series of electrophysiological observations which indicate serotonin as a potential modulatory neurotransmitter for Purkinje cell firing activity.

Ultrastructural evidence of a vesicle-mediated mode of cell degranulation in chicken chromaffin cells during the late phase of embryonic development

In the present investigation, we attempted to determine whether ultrastructural features indicative of a vesicle‐mediated mode of cell secretion were detectable in chick chromaffin cells during embryo development. The adrenal anlagen of domestic fowls were examined at embryonic days (E) 12, 15, 19 and 21 by electron microscopy quantitative analysis. Morphometric evaluation revealed a series of granule and cytoplasmic changes highly specific for piecemeal degranulation (PMD), a secretory process based on vesicular transport of cargoes from within granules for extracellular release. At E19 and E21 we found a significant peak in the percentage of granules exhibiting changes indicative of progressive release of secretory materials, i.e. granules with lucent areas in their cores, reduced electron density, disassembled matrices, residual cores and membrane empty containers. A dramatic raise in the density of 30–80‐nm‐diameter, membrane‐bound, electron‐dense and electron‐lucent vesicles – which were located either next to granules or close to the plasma membrane – was recognizable at E19, that is, during the prehatching phase. The cytoplasmic burst of dense and clear vesicles was paralleled by the appearance of chromaffin granules showing outpouches or protrusions of their profiles (‘budding features’). These ultrastructural data are indicative of an augmented vesicle‐mediated transport of chromaffin granule products for extracellular release in chick embryo chromaffin cells during the prehatching stage. In conclusion, this study provides new data on the fine structure of chromaffin cell organelles during organ development and suggests that PMD may be part of an adrenomedullary secretory response that occurs towards the end of chicken embryogenesis. From an evolutionary point of view, this study lends support to the concept that PMD is a secretory mechanism highly conserved throughout vertebrate classes.

Unusual case of occipital vertebra in a medieval skeleton.

The craniovertebral junction (CVJ) is a transitional region of the spine that exhibits extensive structural variability. Developmental defects include a vast array of anatomical anomalies that result, from remnants of the proatlas and are grouped under the term ‘occipital vertebra’. The purpose of the present paper is to describe the case of a medieval skeleton, which was found to display a previously unreported manifestation of occipital vertebra. It consisted of two large basilar processes that articulated with the anterior arch of the atlas. In addition, the left process exhibited a supplementary contact zone with the dens of the axis. These structural defects were associated with an accessory canal situated posterior to the right hypoglossal canal.

Congenital axis dysmorphism in a medieval skeleton

PurposeWe describe here the axis dysmorphism that we observed in the skeletal remains of a human child dug up from a fifteenth century cemetery located in north-eastern Italy. This bone defect is discussed in the light of pertinent literature.MethodsWe performed macroscopical examination and CT scan analysis of the axis.ResultsAxis structure was remarkably asymmetric. Whilst the left half exhibited normal morphology, the right one was smaller than normal, and its lateral articular surface showed horizontal orientation. In addition, the odontoid process appeared leftward deviated and displayed a supplementary articular-like facet situated on the right side of its surface.ConclusionsThese findings suggest a diagnosis of unilateral irregular segmentation of atlas and axis, a rare dysmorphism dependent upon disturbances of notochordal development in early embryonic life. Likewise other malformations of the craniovertebral junction, this axis defect may alter the delicate mechanisms of upper neck movements and cause a complex series of clinical symptoms. This is an emblematic case whereby human skeletal remains may provide valuable information on the anatomical defects of craniovertebral junction.