Franco Giorgi - Academia.edu (original) (raw)

Papers by Franco Giorgi

Development

The role played by the vitellogenic oocytes of Drosophila melanogaster in relation to the elabora... more The role played by the vitellogenic oocytes of Drosophila melanogaster in relation to the elaboration of material taken from the haemolymph is examined by ultrastructural cytochemistry. As revealed by the Gomori procedure, acid phosphatase occurs widely over the forming yolk platelets of the cortical and central ooplasm. A number of Golgi apparatuses in the cortical ooplasm are also positively stained with lead precipitates. With the proceeding of the ovarian development it becomes progressively more difficult to demonstrate cytochemically the enzyme over the yolk platelets. In stage 9-10 chambers the acid phosphatase is restricted to the so-called associated body, while the rest of the yolk platelet appears devoid of lead deposits. By using a osmium zinc iodide (OZ1) complex as a preferential staining method for the Golgi apparatus, it has been shown that, apart from the apparatus itself, a number of OZI deposits occur over the superficial layer of the forming yolk platelets. When ...

Acta embryologiae experimentalis, 1976

Biosemiotics, Oct 20, 2020

The biopsychosocial model was initially proposed to overcome the normative assumption that human ... more The biopsychosocial model was initially proposed to overcome the normative assumption that human diseases are exclusively due to disordered biochemical and/or neurophysiological processes. The model attempts to explain how expectations, thoughts and feelings modify the patient's motivations to deal with illness and recovery. By considering the physical health in this perspective, healthcare professionals may test the importance of socially and culturally shared principles in alleviating illness experience. The entire biopsychosocial hierarchy may thus appear as a complex network of relationships between the strict logic of scientific explanations and the emotional sustainability with which beliefs may either be defended, changed or even refused. In this paper, we aim at reviewing some of the evidence-based biomedical and psychological findings that provide a unified framework for the biopsychosocial model as a multilevel integrative process. To tackle this objective, we propose to approach the model in biosemiotic terms. It is our contention that the entire biopsychosocial hierarchy could be better understood if approached biosemiotically and the multilevel interconnection of this hierarchy reexamined in the light of a collaborative meaningmaking process.

Tissue & Cell, 1989

The fat body of the stick insect Bacillus rossiw was studied with a view to clarifying the metabo... more The fat body of the stick insect Bacillus rossiw was studied with a view to clarifying the metabolic pathway leading to secretion of vitellogenin (VG). Electrophoretic analysis of ovarian follicles and hemolymph from egg-laying females showed that the two tissues shared a common polypeptide composition consisting of five major pal peptides with molecular weights ranging from a180 Kd. Following in viva exposure to [ 35y S]-methionine for up to 24 h, these polypeptides were labeled in a stage-and time-dependent manner, suggesting that they were transferred from the hemolymph to the oocyte during vitellogenesis. Fat body pulselabeled with [%]-methionine for up to 240min and immunoprecipitated with an anti-yolk serum was labeled only in a fraction containing high molecular weight polypeptides. We presume these polypeptides to be VG precursors bearing a precursor-product relationship with the live major polypeptides of the hemolymph and developing ovarian follicles. Fat body exposed in viva to ('HI-leucine for time intervals ranging from 20-240 min were processed for EM autoradiography. The results of this analysis showed that incorporated radioactivity was progressively transferred from the endoplasmic reticulum to the Golgi apparatus and from there to the composite granules. The data provided in this study are consonant with previous findings by which composite granules were shown to contain two compartments differing both in content and origin. In addition, the autoradiographical data of in viva labeled fat body demonstrate that only the material partitioned into the electron-dense compartment of these granules is exocytosed.

Cell and Tissue Research, Nov 1, 1979

Progress in Biophysics & Molecular Biology, Dec 1, 2015

In this article we challenge the pervasive notion of hierarchy in biological and cognitive system... more In this article we challenge the pervasive notion of hierarchy in biological and cognitive systems and delineate the basis for a complementary heterarchical approach starting from the seminal ideas of Warren McCullock and Gregory Bateson. We intend these considerations as a contribution to the different scientific disciplines working towards a multilevel integrative perspective of biological and cognitive processes, such as systems and integrative biology and neuroscience, social and cultural neuroscience, social signal transduction and psychoneuroimmunology, for instance. We argue that structures and substrates are by necessity organized hierarchically, while communication processes - and their embeddedness - are rather organized heterarchically. Before getting into the implications of the heterarchical approach and its congeniality with the semiotic perspective to biology and cognition, we introduce a set of notions and concepts in order to advance a framework that considers the heterarchical embeddedness of different layers of physiological, behavioral, affective, cognitive, technological and socio-cultural levels implicit in networks of interacting minds, considering the dynamic complementarity of bottom-up and top-down causal links. This should contribute to account for the integration, interpretation and response to complex aggregates of information at different levels of organization in a developmental context. We illustrate the dialectical nature of embedded heterarchical processes by addressing the simultaneity and circularity of cognition and volition, and how such dialectics can be present in primitive instances of proto-cognition and proto-volition, giving rise to our claim that subjectivity and semiotic freedom are scalar properties. We collate the framework with recent empirical systemic approaches to biology and integrative neuroscience, and conclude with a reflection on its implications to the understanding of the emergence of pathological conditions in multi-level semiotic systems.

Cell and Tissue Research, 1978

Intercellular bridges have been detected in ovarian follicle cells of Drosophila melanogaster. Th... more Intercellular bridges have been detected in ovarian follicle cells of Drosophila melanogaster. These bridges occur widely between follicle cells of previtellogenic chambers, while, in vitellogenic chambers, they become restricted to the columnar follicle cells. Usually, only one bridge is detectable between adjacent follicle cells, but a single cell may form two cytoplasmic continuities. The fine structure of the intercellular bridges is similar to that previously described in the development of Drosophila. The bridge wall consists of two layers of which the more external is more electron dense and thinner than the inner one. The role played by the intercellular bridges in the determination of a synchronous differentiation of the linked follicle cells is discussed in relation to the known behaviour of these cells in the secretion of the egg covering precursors.

Journal of Virology, Nov 15, 2000

ZAM is an env-containing member of the gypsy family of retrotransposons that represents a possibl... more ZAM is an env-containing member of the gypsy family of retrotransposons that represents a possible retrovirus of invertebrates. In this paper, we traced ZAM mobilization to get information about a potential path a retroelement may take to reach the germ line of its host. In situ hybridization on whole-mount tissues and immunocytochemistry analyses with antibodies raised against ZAM Gag and Env proteins have shown that all components necessary to assemble ZAM viral particles, i.e., ZAM full-length RNAs and Gag and Env polypeptides, are coexpressed in a small set of follicle cells surrounding the oocyte. By electron microscopy, we have shown that ZAM viral particles are indeed detected in this somatic lineage of cells, which they leave and enter the closely apposed oocyte. Our data provide evidence that the vesicular traffic and yolk granules in the process of vitellogenesis play an important role in ZAM transfer to the oocyte. Our data support the possibility that vitellogenin transfer to the oocyte may help a retroelement pass to the germ line with no need of its envelope product.

Systems research and behavioral science, Jul 15, 2020

Patient-centred care is an approach intended to include service-users' needs and perspectives as ... more Patient-centred care is an approach intended to include service-users' needs and perspectives as crucial aspects of clinical treatment, superseding any attempt to paternalistic and unilateral attitude in the therapeutic relationship. It is a call to think about persons and not simply of their diseases and implies the adoption of a biopsychosocial perspective and shared decision making. Nonetheless, thinking about persons inevitably means taking the context into due consideration, as individuals are not isolated and any kind of illness experience cannot be thought as a simple matter of inner thoughts and feelings. This perspective article builds on the core tenets of systems thinking and the biopsychosocial approach, with the aim of developing a multilevel approach to patient-centred care. Within this framework, a literature review has been conducted to gather relevant research findings concerning each level of analysis and the interrelations of such levels. Systems thinking is an ideal framework for capturing the multilayered aspects of illness, from the biological processes that lead to a given disease to the social context where people live. From this angle, we can argue that systems-centred care is the framework we actually need to truly accomplish patient-centred goals. This means seeing people as complex dynamical systems and always bearing in mind the ecology of their lives. This also means gearing research and clinical practice towards this direction because complex phenomena like health require adequate methods of inquiry and treatment plans. A multilevel approach is the main road to effective and enduring outcomes. On the contrary, fragmentation of knowledge and excessive specialization without integration can pave the way to short-term solutions and weak or vanishing improvements in the long run, with obvious costs for persons, families and the community.

Journal of Evaluation in Clinical Practice, Nov 28, 2022

Study AimsThe article aims at reiterating the importance of a biopsychosocial approach to mental ... more Study AimsThe article aims at reiterating the importance of a biopsychosocial approach to mental health, taking stock of the critiques that have been raised and moving forward throughout a reconsideration of the theoretical background of systems thinking and emphasizing the relevance of the concept of thick description for the promotion of an adequate reflection on methodology and case formulation.Literature ReviewIt is our opinion that the biopsychosocial approach is still a powerful framework for making sense of the growing data collected in the different fields related to mental health and for designing proper treatment plans. A crucial challenge for mental health is that of surpassing the dichotomies and ideological disputes that still contaminate the field with detrimental effects on the advancement of knowledge and on the integration and continuity of different kind of interventions.ConclusionsThe time is ripe for building bridges among neuroscience, humanities and social sciences, and this can only happen within the umbrella of a biopsychosocial perspective reinstated into its systems thinking background.

Biosemiotics, Apr 15, 2011

Biosemiotics, May 21, 2010

The majority of G protein-coupled receptors (GPCRs) self-assemble in the form dimeric/oligomeric ... more The majority of G protein-coupled receptors (GPCRs) self-assemble in the form dimeric/oligomeric complexes along the plasma membrane. Due to the molecular interactions they participate, GPCRs can potentially provide the framework for discriminating a wide variety of intercellular signals, as based on some kind of combinatorial receptor codes. GPCRs can in fact transduce signals from the external milieu by modifying the activity of such intracellular proteins as adenylyl cyclases, phospholipases and ion channels via interactions with specific G-proteins. However, in spite of the number of cell functions they can actually control, both GPCRs and their associated signal transduction pathways are extremely well conserved, for only a few alleles with null or minor functional alterations have so far been found. This would seem to suggest that, beside a mechanism for DNA repairing, there must be another level of quality control that may help maintaining GPCRs rather stable throughout evolution. We propose here receptor oligomerization to be a basic molecular mechanism controlling GPCRs redundancy in many different cell types, and the plasma membrane as the first hierarchical cell structure at which selective categorical sensing may occur. Categorical sensing can be seen as the cellular capacity for identifying and ordering complex patterns of mixed signals out of a contextual matrix, i.e., the recognition of meaningful patterns out of ubiquitous signals. In this context, redundancy and degeneracy may appear as the required feature to integrate the cell system into functional units of progressively higher hierarchical levels.

Biology of the Cell, Mar 1, 1998

Macromolecular Bioscience, Feb 15, 2019

Nanoparticles Curcumin-loaded collagen cryostructurates have been devised for wound healing appli... more Nanoparticles Curcumin-loaded collagen cryostructurates have been devised for wound healing applications. Curcumin displays strong antioxidant, antiseptic, and anti-inflammatory properties, while collagen is acknowledged for promoting cell adhesion, migration and differentiation. However, when curcumin is loaded directly into collagen hydrogels, it forms large molecular aggregates and clogs the matrix pores. A double-encapsulation strategy is therefore developed by loading curcumin into lipid nanoparticles (LNP), and embedding these particles inside collagen scaffolds. The resulting collagen/LNP cryostructurates have an optimal fibrous structure with ≈100 µm average pore size for sustaining cell migration. Results show that collagen is structurally unaltered and that nanoparticles are homogeneously distributed amidst collagen fibers. Hydrogels soaked in saline buffer release about 20 to 30% of their nanoparticles content within 24 h, while achieved 100% release after 25 days. When exposed to NIH 3T3 fibroblasts, these hydrogels provide a satisfactory scaffold for cell interaction as early as 4 h after seeding, with no cytotoxic counter effect. These positive features make the collagen/lipid cryostructurates a promising material for further use in wound healing.

Journal of Endocrinological Investigation, Jun 21, 2017

ObjectiveDichlorodiphenyltrichloroethane (DDT) is an organochlorine known for its pesticide prope... more ObjectiveDichlorodiphenyltrichloroethane (DDT) is an organochlorine known for its pesticide properties and for its negative effects on human health. It was banned in most countries for its toxicity to the endocrine system, but due to its persistence at clinically relevant concentrations in both soil and animal tissues, DDT is still linked to several health and social problems.MethodsWe have previously shown that DDT exposure is causally related to the extracellular release of vesicular organelles such as microvesicles and/or exosomes by using immunocytochemistry with gold-tagged antibodies and various fluorescent membrane markers. ResultsIt is now well recognized that microvesicles and/or exosomes organelles are implicated in cell-to-cell communication, and that they are fundamental elements for transferring proteins, RNA, DNA, lipids and transcriptional factors among cells. In this short review, we discussed the role of extracellular vesicle formation in the thyroid-disrupting mechanism of DDT. In particular, we described how DDT, by dislodging the thyrotropin hormone (TSH) receptor from the raft containing compartments of the cells, prevents its activation and internalization. ConclusionBased on our earlier finding and on the large body of evidence here reviewed, we propose that DDT-induced formation of extracellular vesicles containing the TSH receptor could be directly involved in the development of autoimmune responses against the TSH receptor and that, therefore, their release could lead to the development of the Graves’ disease.

Springer eBooks, 1985

ABSTRACT

With the onset of vitellogenesis, the follicular epithelium overlying the oocyte in stick insect ... more With the onset of vitellogenesis, the follicular epithelium overlying the oocyte in stick insect ovarioles becomes highly polarized and patent by formation of wide intercellular spaces. The aim of the present study was to provide experimental support to the notion that the follicular epithelium in this insect species may be involved in transcytosis. Data demonstrate that the follicular epithelium carries out sulfo-conjugation of a 85 kDa fat body derived protein by allowing it to transit from one cell pole to another. Along the basal end, follicle cells branch into a number of cytoplasmic finger-like projections. At the opposite end facing the oocyte they taper off into lance-head shapes. Different vesicular elements are evident at both these extremities. In vivo exposure to horseradish peroxidase shows that the vesicular elements present along the apical end provide an endocytic entry. In contrast, those present along the basal end are labeled with sodium [35S]-sulfate, suggesting that they may be exocytic vesicles containing a sulfo-conjugated secretory product. In vivo exposure to sodium [35S]-sulfate caused radioactivity to appear over the Golgi apparatus and some nearby vesicles of the follicle cell cytoplasm, including the exocytic vesicles. The intracellular pathway of the follicle cells was also examined by immunogold labeling using a monoclonal antibody raised against a 85 kDa fat body derived protein. Under these conditions, gold particles were consistently detected over the Golgi apparatus and the vesicular elements lying along both poles of the follicle cell membrane. Based on this evidence, it is concluded that follicular cells in stick insect ovarioles are endowed with the ability to undergo transcytosis by providing an endocytic entry along the apical end and by releasing exocytically a sulfo-conjugated 85 kDa protein along the baso-lateral domain of the follicle cell membrane.

International Journal of Psychophysiology, Sep 1, 2012