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Biomedical subjects

C Castaldini

Publications and source records attributed to C Castaldini.

At least 19 recordsLinked to original sources
PubMed1996

In vitro study of gingival fibroblasts from normal and inflamed tissue: age-related responsiveness.

The aim of this study was to characterize some phenotypic expressions of fibroblasts from the human oral mucosa. Gingival and lower forearm fibroblasts from young (20-30 years) and elderly (> 60 years) subjects were analyzed. Gingival fibroblasts were taken from donors with (P) and without (NP) periodontal disease, while skin biopsies were taken from healthy subjects. Cell proliferation was assessed by evaluating the cell multiplication coefficient (C.M.C.). The proliferation potential of gingival fibroblasts from elderly individuals with and without periodontopathy did not differ from that of young subjects in the same condition but differed significantly in the skin samples. Enzyme neutral endopeptidase (EC 3.4.24.11) (NEP) activity, studied as a possible marker of cell ageing, showed an age-related increase in human skin fibroblasts but not consistently in gingival fibroblasts from individuals with or without periodontal disease. Cell area and substrate adhesion were evaluated by morphometric analysis. There were no significant differences between elderly P and NP subjects, while significant differences were observed between young and elderly P subjects. In conclusion, proliferative capacity and NEP activity in gingival fibroblasts did not appear to be age-related, probably because their microenvironment is continually moistened by saliva, which continues to contain growth factors, notably EGF, even into senescence. Tissue reaction and repair are important clinical and therapeutic implications.

Adult↗
PubMed1996

Structural features of latex gloves in dental practice.

The aim of this study was to define from a morpho-structural point of view, using scanning electron microscopy, the features of various types of disposable latex gloves commonly used in Italian dental practice (Biogel D, Trend, Pagni, J&J, Latechnics, Pehasoft, Bantex). None of the brands examined was free from morphological flaws; however, while in some of these only slight depressions were found (Biogel D, Trend), in others (Latechnics, Bantex) there was a marked lack of homogeneity in the latex structure or real holes (Pehasoft). This study emphasizes the current difficulties faced by dentists in the search for safe working conditions.

Biocompatible Materials↗
PubMed1995

The human umbilical vein in normal, hypertensive and diabetic pregnancies: immunomorphological and ultrastructural evidence.

Mother-fetus exchanges at the placental level are found to be altered in women affected by hypertensive or diabetic pregnancies following the onset of microenvironmental, circulatory, trophic or tissue disorders. Our aim was therefore to assess the alterations occurring within the umbilical cord, particularly its venous endothelial component and underlying smooth muscle layer, using transmission (TEM) and scanning electron microscopy (SEM) and immunohistochemical analyses. Immunohistochemical data appear to support the ultrastructural evidence for an activated state of these vascular structures, in both conditions (hypertension and diabetes). Furthermore, mainly during diabetic pregnancies, extracellular matrix molecules such as tenascin and fibronectin also quantitatively increase at the vein wall level. The umbilical cord seems to be a structure capable of responding actively to abnormal microenvironmental conditions which seriously threaten the health of the fetus and also the mother herself.

Cell Adhesion Molecules↗
PubMed1995

Human skeletal muscle mitochondria in aging: lack of detectable morphological and enzymic defects.

We have investigated structural and functional properties of skeletal muscle mitochondria obtained from biopsies from young and old individuals. The morphometric analysis of muscle sections revealed a tendency to an increase of total area, numerical density and volume density of mitochondria in the aged. The enzymatic activities of NADH-Coenzyme Q reductase, succinate cytochrome c reductase, ubiquinol-cytochrome c reductase exhibited a high variability of specific activities without any correlation with age. Expression of the values as enzyme turnovers reduced the variability but was unable to reveal any age-dependent modification.

Adolescent↗
PubMed1994

Fibroblast proliferation over dialysis membrane: an experimental model for "tissue" biocompatibility evaluation.

The present study reports on a biological model based on fibroblast proliferation applied to 3 different types of flat-plate dialysis membrane, in order to ascertain whether the artificial materials currently used in hemodialysis cause in vitro cellular proliferation. The study plan we followed involved plate membrane isolation from non-used dialyzers and used dialyzers, observed through scanning electron microscopy (SEM) both before and after testing with human fibroblasts by means of cell culture. Fibroblast growth was assessed by phase contrast light microscopy examination and cytometric DNA content evaluation. Our investigations proved that the artificial materials we considered interact with fibroblast cultures. Noticeable proliferative response was observed both after contact with unused material and on mediation by the protein layer absorbed on the membrane surface at the end of dialysis sessions. In this last case fibroblast proliferative activity appeared higher than that observed with unused membranes, showing that the soluble molecules entrapped in the protein layer appeared able to exert a biological activity even in vitro tests.

Acrylic Resins↗
PubMed1993

Osteoconduction exerted by methylpyrrolidinone chitosan used in dental surgery.

Surgical wounds from wisdom tooth avulsions were medicated with freeze-dried methylpyrrolidinone chitosan, a gel-forming resorbable biopolymer obtained from crab chitosan by chemical modification. Methylpyrrolidinone chitosan promoted osteoconduction and the space left after avulsion was filled with newly formed bone tissue, which conferred desirable mechanical and physiological characteristics to the healed would site. Morphological evidence obtained from biopsies confirmed the radiographic data. Methylpyrrolidinone chitosan was progressively depolymerized by lysozyme and was no longer detected 6 months after surgery. None of the 10 patients reported adverse effects over one year of observation.

Bone Regeneration↗
PubMed1993

Osteoconductive properties of methylpyrrolidinone chitosan in an animal model.

Bone defects were surgically produced in the tibiae of rabbits and medicated with freeze-dried methylpyrrolidinone chitosan. Histological observations 60 d after surgery showed a considerable presence of neoformed bone tissue, as opposed to controls, originating from the pre-existing bone as well as from the periosteum. The cationic nature and the chelating ability of the methylpyrrolidinone chitosan apparently favoured mineralization. Endosteal-periosteal and bone marrow osteoblast-like precursors, stimulated by growth factors entrapped in the coagulum-polysaccharide mixture, gave rise to intramembranous bone formation. The ultrastructural examination evidenced that bone osteoid was followed by mineralization of the tissue.

Animals↗
PubMed1992

Placental villi-decidua interactions in normal and hypertensive pregnancies: a morphological quantitative study.

The decidual response to the implantation of the embryo is characterized by physical modifications to the uterine wall, with proliferation of the stromal cells which later change into decidual cells. We performed associated morphological and morphometrical studies to assess how the placental villi and decidua intersect, both in normal terminal pregnancy and in hypertensive patients in whom microenvironmental modifications induced by hypertension may cause significant alterations in mother-fetus relationships. In placentas of hypertensive women our morphometric analyses showed a higher number of chorionic villi-decidua interactions (p less than 0.05) with a more clumped distribution (p less than 0.05) and a smaller surface area of single interaction (p less than 0.001), in association with a higher number (p less than 0.005), and greater areas (p less than 0.01) of decidual cells. These data demonstrate how the placenta can enhance mother-fetus contacts impaired as the result of a hypertensive condition.

Chorionic Villi↗
PubMed1990

Effects of chemical pretreatments on dentin bonding.

The aim of this study was to evaluate several chemical pretreatments on the shear bond strength of three dentin bonding agents (DBAs) and to try to correlate dentin morphology with bond strength using scanning electron microscopy (SEM). The DBAs tested were: Gluma Primer in association with Scotchbond DC, Scotchbond DC alone and Clearfil New Bond. Bond strengths of Scotchbond DC and Clearfil New Bond were not significantly modified or reduced by acidic dentin pretreatments. Gluma/Scotchbond adhesion was increased by several treatments but only maleic acid treatment produced shear bond strengths significantly higher than EDTA treatment. SEM evaluation of dentin treatments revealed a wide variety of morphological changes in the dentin surface with partial and complete removal of smear layer by acidic solutions, and only minor modification by amino acid solutions. Only maleic acid was capable of the complete removal of the smear layer and smear plugs coupled with extensive exposure of dentin collagen fibrils.

Acid Etching, Dental↗
PubMed1990

[Our experience in vascular trauma of the limbs].

Progress in the management of complex vascular injuries of the limbs has not eliminated the necessity for amputations. Physicians' failure to suspect vascular injury on admission in traumatized patients causes delay in the diagnosis and management of arterial injury that ultimately leads to limb loss. High index of suspicion, early recognition by clinical evaluation, routine use of Doppler flowmeter and broad indication of preoperative angiography result in prompt repair of these lesions in the majority of cases. In managing the lower popliteal or trifurcation vessels, distal radial and ulnar artery as well as nerve injuries, the Authors believe microsurgical techniques should always be employed.

Accidents, Occupational↗
PubMed1989

Reconstruction of parodontal tissue with chitosan.

Chitosan ascorbate, obtained by mixing chitosan with ascorbic acid and sodium ascorbate, was produced in a gel form suitable for the treatment of periodontitis according to current dental surgery. While chitosan ascorbate underwent degradation in vitro, especially in the presence of atmospheric oxygen and at pH 6.0, the protection from oxygen offered by the surgical cements and the physiological pH value permitted chitosan ascorbate to play an important biological role in vivo, where it kept a honeycomb structure, as indicated by SEM on biopsies taken on 10 patients. The proliferation and organization of the cells were thus favoured with a subsequent enhanced capability of reconstructing a histoarchitectural tissue. Chitosan was progressively reabsorbed by the host, with very satisfactory clinical recoveries of the 52 defects treated, for which tooth mobility and pocket depths were significantly reduced.

Adult↗
PubMed1989

[Hypertension and syncytiotrophoblast: morpho-structural aspects].

Hypertension is a pathological condition that involves maternal fetal relationship. In hypertension placenta displays a syncytiotrophoblast plasmalemma with aspects of anomalous behaviour concerning Intramembranous Particles (IMP) and actin content of microvilli cytoskeleton. Decrease of syncytiotrophoblast microvilli IMP and microvilli actin further sustain the tendency of hypertensive placenta to show some features of immaturity that might deeply influence fetal-maternal exchanges during pregnancy associated with pathological status.

Calcium↗
PubMed1989

[Intrinsic potential of the gingival interdental epithelium and its "therapeutic" induction using brushing. Clinico-morphologic aspects].

Toothbrushing technique may represent an important tool to improve gingival keratinization. Our experience evidenced a close relationship between this endoral therapy and interdental epithelial recovery of gingiva, after two months of treatment. Mechanical or microenvironmental stimuli and genetically determined potentialities are the main factors involved in this clinical-therapeutical recovery to modulate structural epithelial behaviour.

Chronic Disease↗
PubMed1988

Root curettage and gingival repair in periodontitis.

Twelve patients, aged 35 to 60, having adult periodontitis were treated with scaling and root planning performed with ultrasonic and hand scalers. Biopsies were taken, gingival crevicular fluid and clinical parameters were analyzed at different times, and the healing process was monitored. Findings showed a clear correlation between the amount of crevicular fluid and the histological inflammatory pattern, whereas no relationship between crevicular fluid and gingival pocket depth was apparent. In this study, no differences were found in the histological features of the repair process triggered by either type of scaler.

Adult↗
PubMed1988

Cytoskeleton and extracellular matrix of cutaneous vessels in inflammatory processes: immunomorphological study.

In pathological conditions, vascular modifications occur in various stages involving both vessel structure and adjacent extracellular matrix. The relationships between vascular cells and surrounding microenvironmental stroma are mediated by cytoskeleton. Our investigation showed a high number of vimentin- and actin-positive cells in the vascular cutaneous bed, mainly related to reactive vascularization phenomena, whereas vessel cells with a desmin-positive reaction were barely detectable. Furthermore, in newly formed vessels ultrastructure showed that basement membrane synthesis strictly depends on close contact between the endothelium and extracellular matrix. Our data give structural evidence of the close morphofunctional interactions existing between vascular cells and extracellular matrix.

Actin Cytoskeleton↗
PubMed1986

Fibronectin distribution during lymph node development in guinea pig: an immunohistochemical study.

We carried out an immunohistochemical study on mesenteric guinea pig lymph nodes, from the 10th day prepartum till the 26th day postpartum, to assess the role of fibronectin in their organization during development. This glycoprotein is diffusely distributed in embryonic lymph nodes, suggesting a primer function during organogenesis. After birth, in fact, it is less widespread and is mainly localized around sinuses and vessels. Our data, supporting the important role of this glycoprotein during lymph node organization, are in agreement with the results obtained in other tissues and organs.

Animals↗