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OBJECTIVES: The study objective was to compare patient satisfaction after thyroid lobo-isthmectomy under hypnoanesthesia versus general anesthesia. METHODS: A retrospective study included 100 patients undergoing lobo-isthmectomy. A group of 50 patients under hypnoanesthesia was compared to a control group of 50 patients under general anesthesia. Satisfaction was assessed on questionnaire between three and six months after surgery. We also compared secondary criteria: procedure time, blood loss, intraoperative comfort, postoperative pain, postoperative complications and time to resumption of daily activities. RESULTS: Our study showed good overall satisfaction in patients operated under hypnoanesthesia, for equivalent operative safety and complications rate compared to general anesthesia. For comparable analgesia, postoperative pain was lower, but not significantly, in the Hypnosis group, while the rate of nausea and vomiting was significantly lower (p<0.05). Postoperative convalescence was shorter in the Hypnosis group: 3.7 versus 9.2 days (p<0.001). CONCLUSION: In thyroid surgery, hypnoanesthesia has real advantages over general anesthesia in that it places the patient at the center of the care team's attention. His or her active participation is essential during the process, bringing a new dimension to care, beneficial for the patient. However, it must be reserved for minimally invasive procedures in which organization is anticipated in full collaboration within teams that are willing and experienced.

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A 14-year-old boy presenting headache crisis, sweating and palpitation was observed. On ultrasound scan, a 3 × 2.5 cm hypoechoic mass, highly vascularized, was observed arising from the left bladder wall. Magnetic resonance imaging confirmed the mass situated close to the ureteral orifice, with intense peripheral enhancement and a central non-enhanced portion. Left partial cystectomy was performed. Large clear cells, presenting cytoplasmatic granules positive for S100 and chromogranin, were observed at histology. Bladder paraganglioma derives from chromaffin tissue of the sympathic system and it is uncommon in children. The estimated prevalence is very low (0.06% of bladder tumors). Symptomatology is related to the catecholamine production. In pediatrics, prognosis is usually good but long-term follow-up is required.

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Tendons transmit forces generated from muscle to bone making joint movements possible. Tendon collagen has a complex supramolecular structure forming many hierarchical levels of association; its main functional unit is the collagen fibril forming fibers and fascicles. Since tendons are enclosed by loose connective sheaths in continuity with muscle sheaths, it is likely that tendon sheaths could play a role in absorbing/transmitting the forces created by muscle contraction. In this study rat Achilles tendons were passively stretched in vivo to be observed at polarized light microscope (PLM), scanning electron microscope (SEM) and transmission electron microscope (TEM). At PLM tendon collagen fibers in relaxed rat Achilles tendons ran straight and parallel, showing a periodic crimp pattern. Similarly tendon sheaths showed apparent crimps. At higher magnification SEM and TEM revealed that in each tendon crimp large and heterogeneous collagen fibrils running straight and parallel suddenly changed their direction undergoing localized and variable modifications. These fibril modifications were named fibrillar crimps. Tendon sheaths displayed small and uniform fibrils running parallel with a wavy course without any ultrastructural aspects of crimp. Since in passively stretched Achilles tendons fibrillar crimps were still observed, it is likely that during the tendon stretching, and presumably during the tendon elongation in muscle contraction, the fibrillar crimp may be the real structural component of the tendon crimp acting as shock absorber. The peritendinous sheath can be stretched as tendon, but is not actively involved in the mechanism of shock absorber as the fibrillar crimp. The different functional behaviour of tendons and sheaths may be due to the different structural and molecular arrangement of their fibrils.

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Following anterior cruciate ligament (ACL) reconstruction with the middle third part patellar tendon, the graft undergoes histological rearrangement due to biomechanical action, which transforms it into a structure similar to the normal ACL. The purpose of our study was to make a qualitative and quantitative histological evaluation, by transmission electron microscopy (TEM), of the neoligamentization process of a bone-patellar tendon-bone (BTPB) graft used as pro-ACL at different follow-up times. We analysed the ultrastructure of collagen fibrils by focusing on their size and distribution with respect to a normal patellar tendon and a normal ACL used as controls. Our results showed that up to 24 months follow-up, progressive ultrastructural changes towards the normal ACL were observed. At longer times after surgery (48 and 120 months) no further changes were evident and the ultrastructure showed a marked reduction in large fibrils, which was typical of the control patellar tendon, and a significant increase in small fibrils. The ultrastructure seemed to combine fibrils from two different morphological units. The BPTB graft used as ACL underwent a transformation process for up to two years. After that period the transformation ceased and for ten years failed to reach the ultrastructural aspect of a normal ACL. However, from an architectural point of view the graft was slowly transformed into a structure similar to ACL with respect to the different mechanical stresses the ligament has to sustain.

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The structure of periodontal tissues is still far less understood than their clinical relevance would demand. Here the periodontal ligament and radicular cementum in healthy human teeth were studied by light microscopy, transmission and scanning electron microscopy. These observations showed that the extracellular matrix of periodontal ligament is composed of a loose plexus of wavy collagen fibrils immersed in a highly hydrated interfibrillar matrix. Only close to their cemental insertion do these fibrils gather in thick, parallel fascicles (Sharpey's fibres). As these cross the mineralization front, they become infiltrated by the mineral phase and continue directly with the cementum matrix. Sharpey's fibres, "extrinsic" and "intrinsic" fibres all appear to be the same fibres, which bend and branch repeatedly during their course within the thickness of the cementum. Because of its physical continuity with the cementum, a limited portion of the periodontal ligament approximately corresponding to the length of Sharpey's fibres remains unaffected by enzymatic digestion of the interfibrillar matrix while the rest of the ligament is completely dissolved. The findings here indicate that the periodontal ligament and dental cementum join by a continuity rather than a contiguity of structures; that the collagen-mineral relation in cementum has distinctive features in comparison to other hard tissues; that extrinsic and intrinsic fibres of cementum and the adjoining portion of periodontal ligament form a structural, mechanical and metabolic unit distinct from the central, more metabolically active portion of the periodontal ligament.

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Biomaterials may initiate several and complex biological reactions in host tissues, and the cell-biomaterial interactions can determine the release of mediators including monocytes and lymphocytes chemotactic factors. The present work was aimed to investigate in vitro the macrophage biological reactions of a natural apatite obtained by heat treatment at 400 degrees C of bovine bone, compared to other ceramics usually used for dental and orthopedic applications, using synthetic apatite and three types of alumina as controls. Particles chemotactic activity and powders oxidative burst evidenced no monocyte macrophages sensitivity reaction for natural and synthetic hydroxyapatite powders at great granulometry (> 50 microm); data were confirmed by ultrastructural observations; electron microscopy analysis showed macrophages with the features of healthy cells in the presence of both natural and synthetic apatites while macrophages grown in the presence of alumina seemed to be negatively affected. In conclusion, among all ceramics tested, natural apatite displayed a good compatibility with living cells, being better tolerated than synthetic hydroxyapatite which in turn is better tolerated than alumina.

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We had carried out a detailed morphological study on the human acellular extrinsic fiber cementum (AEFC) in order to support the exclusively extrinsic origin of matrix collagen bundles. Mesial and distal cervical third of fresh premolars from young individuals were examined. Semi-thin and thin section clearly show the Sharpey fibres entering in the cementum at right-angle to the root surface and coursing throughout the cementum to the cemento-dentinal junction. On their way to the dentin the Sharpey fibres divide into smaller bundles which, coursing obliquely or tangentially, intersect with others deriving from neighbouring Sharpey fibres. Both de-proteinated and decalcified samples observed at SEM present Sharpey fibres along the fractured surfaces entering and running trough the cementum perpendicularly to the root surface. Fibril bundles are seen branching out from the main body of a single Sharpey fibre and coursing obliquely or perpendicularly to the original fibre. These morphological evidences obtained both at TEM and SEM further confirm that in AEFC fibril bundles running parallel or obliquely to the root surface are branches of Sharpey fibres and not intrinsic cementum fibres.

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Collagen fibre organisation and fibril size were studied in the buccal gingival and hard palate mucosa of Macacus rhesus monkey. Light and electron microscopy analysis showed connective papillae exhibiting a similar inner structure in the different areas examined, but varying in distribution, shape and size. Moving from the deep to surface layers of the buccal gingival mucosa (free and attached portions), large collagen fibril bundles became smaller and progressively more wavy with decreasing collagen fibril diameter. This gradual diameter decrease did not occur in the hard palate mucosa (free portion, rugae and interrugal regions) where the fibril diameter remained constant. A link between collagen fibril diameter and mechanical function is discussed.

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Glaucomatous optic neuropathy is a multifactorial disease, whose most important risk is high intraocular pressure. Filtering surgery, i.e. trabeculectomy, is the operation of choice to lower pressure, allowing the aqueous to outflow from the anterior chamber under the conjuctiva and Tenon's capsule. Failure to establish a filtration bleb is due in most cases to subconjunctival fibrosis, leading to bleb encapsulation (Tenon's cyst). Our study aimed to locate the best cleavage plane for aqueous drainage. Based on histological data, the subtenonian space appears to satisfy this requirement, due to low scarring aptitude and low resistance.

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We examined by light and electron microscopy study a Leeds-Keio ligament removed from a patient 6 years and 4 months after implant following rupture. The new ligament presented an outer capsule made up of bundles of collagen fibres running mainly perpendicular to the long axis of the ligament. Septa were seen emerging from the capsule and composed of bundles of collagen fibres surrounding the bundles of Dacron fibres. Each thread of Dacron was surrounded by a layer of connective tissue containing periodic acid-Schiff (PAS)-positive cells. The bundles of collagen fibres making up the outer capsule, the septa and the layer of connective tissue surrounding the Dacron threads were positive for anti-type I collagen antibody. The rehabitated Leeds-Keio ligament presented a specific organization at the septa zone, showing a layer of collagen fibrils alternating with a layer of cells. Our remodelling findings suggest a shoelace effect of the artificial ligament. On the other hand, the presence of type I collagen could be responsible for the good functional behaviour of this composite system. In conclusion, the factors that play an important role in determining this remodelling process and its mechanical function are unknown.

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The correlation between anterior cruciate ligament (ACL) collagen fibril diameter and aging were studied in subjects aged 15 to 87 years. The samples processed for light and electron microscopy showed statistically significant differences in collagen fibril diameter among young (< 20 years), adult (20-60) and elderly subjects (> 60 years). In the young, the ACL was made up of collagen fibrils which were highly variable in size (range 20-180 nm); the diameter distribution curve was very asymmetrical (mean asymmetry +0.895). In adults and elderly subjects, the maximum diameter had decreased remarkably (120 and 110 nm, respectively) and the diameter distribution curve had become less asymmetrical (mean asymmetry +0.527 and +0.297 respectively). Fibril concentration increased considerably from young (68 fib/mu 2) and elderly subjects (140 fib/mu 2). This reduction in diameter and the relative change in collagen fibril concentration may be related to changes in elastic stiffness. The increase in small collagen fibrils and the marked rise in their concentration may make the ligament more pliable. These findings are similar to those we obtained in Achilles tendon. They demonstrate that both ACL and Achilles tendon, a tissue which responds to unidirectional mechanical forces more than ACL does, show a reduction in diameter value during ageing. These data further suggest that collagen fibril diameter is related to the aging process.

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A kinetic chromogenic limulus test was carried out in order to investigate the possibility of a sensitive and specific detection of circulating endotoxin during the first 24 h of septic shock or severe sepsis in 76 patients. Two commercial kits, Whittaeker (W) and Chromogenix (C), were used. Blood culture was taken as a reference. At 1:10 plasma dilution (a currently used dilution in the end point limulus test) abnormal reaction kinetics were found in 13% and 41% of tests, for C and W respectively (P = 0.0008), resulting in unreliable results. Retesting plasma at a greater dilution, until the reaction kinetic was identical to calibration curve control values, gave similar results between the two kits and a better accuracy. Beyond a 0.5 EU mL-1 endotoxin level, the probability of Gram-negative bacteraemia was high (sensitivity = 0.53 and 0.47; specificity = 0.95 and 0.93 for C and W respectively). This kinetic limulus amoebocyte lysate (LAL) test may be useful in therapeutic decisions for treatment of endotoxaemia.

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The tibial insertion of the patellar ligament of rat was investigated at light microscopy, scanning electron microscopy and transmission electron microscopy. Until the point of insertion, the patellar ligament showed the typical structure of a tendon. In proximity to the insertion, the ligament increased in diameter and was gradually infiltrated by a different, cartilage-like matrix. Its tenocytes became progressively rounded and displayed some characteristics of chondrocytes. Tendon fibres crossed this fibrocartilage and arrived well beyond the mineralization front. Finally, they appeared to interweave with the tibial diaphysis bone. These fibres were always distinct from the interposed extracellular matrix and exhibited a different pattern of mineralization from the matrix. Our observations indicate that fibrocartilage does not supersede tendon but merely infiltrates it. Thus, the tendon does not splay during articular movement and the tensile stress is redistributed across the insertion area by increasing the mechanical coupling among adjacent fibres. At the same time, this mechanism provides a structural, uninterrupted connection from tendon to bone which is consistent with the biomechanical requirements it has to withstand.

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OBJECTIVE: To design an alternative experimental model of ischemia-reperfusion syndrome. Our model mimics the clinical pattern of the syndrome and also assesses the efficacy of therapeutical protocols. EXPERIMENTAL DESIGN: Ischemia was induced under general anaesthesia in the posterior limbs of 10 sheep by occluding the aorta and vena cava by means of two-way balloon catheters. Ischemia was stopped after 4 hours and blood and histologic parameters determined in the first three hours of revascularization. The animals were divided into three groups: a group of 3 sheep in which a sham operation was performed; a control group (5) to assess the efficacy of induced ischemia; the third group (5) to determine the effect of antioxidant and membrane protective drugs to assess the reliability of the model to study the ischemia-reperfusion syndrome. RESULTS: At the end of ischemia, skin temperature was decreased (p < 0.04) both in control and treated groups, pH decreased significantly soon after reperfusion in the control group (p < 0.04). Reperfusion in control sheep, compared with treated animals, was followed by a significant increase in CPK blood levels (p < 0.009), related to marked muscle damage, in particular after reperfusion. Tissue damage detected at TEM was less severe in treated animals. CONCLUSIONS: This model is an effective experimental strategy and a means of assessing preventive treatment.

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Heat-deproteinated bone (calcined bone) is a natural candidate for an osteoreproductive biomaterial. Ultrastructural investigation has pointed out an important aspect of the preparation technique. Treatment of bone at temperatures exceeding 500 degrees C causes complete disruption of the tissue architecture and the reorganization of the mineral phase into tightly packed, dense crystals. At 500 degrees C or less the structure and distribution of the mineral phase remain unaffected, so that cross-banded 'shadows' of collagen fibrils are still readily observable, although collagen is no longer present in the samples. By its excellent structural preservation and natural porosity, low-temperature calcined bone seems to be a promising alternative for osteoreproduction.

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The authors report their experiences using the excimer laser and holmium:YAG laser in arthroscopic meniscal surgery. Histologic and ultrastructural aspects caused by laser irradiation on meniscal tissues are evaluated. Two groups of 10 patients, each suffering from a bucket-handle lesion of the internal meniscus, were used for this study. The histologic results of the study confirm the clinical reliability of the laser even in the presence of different ultrastructural frames.

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Using transmission electron microscopy, patellar tendons that had been autografted to replace the ACL were studied. Follow-up biopsies, performed at 6, 12 and 24 months after reconstructive surgery demonstrated that the autograft patellar tendons had undergone considerable change. After 6 months, the large collagen fibrils were less numerous and more widely spaced. The spaces were occupied by dense colonies of very small, newly-formed collagen fibrils and were rich in glycosaminoglycans. Small elastic fibres, fibrocytes, round cells with abundant rough endoplasmic reticulum and macrophage-like cells were scattered among the collagen fibrils. At 12 months, sporadic clumps of large collagen fibrils were seen between the compact bundles of small, uniform collagen fibrils. Both elastic and oxytalan fibres were observed; round cells with abundant rough endoplasmic reticulum were the most prevalent cell type. At 24 months, the tissue had the appearance of a normal ligament. The small uniform collagen fibrils had formed large, compact bundles that were prevalently arrayed parallel to the long axis. Both elastic and oxytalan fibres were observed and the numerous cells present exhibited the same morphological features as those observed at 12 months after surgery. The appearance of compact collagen bundles, the abundant elastic system and the abundance of active cells observed in the patellar tendon autograft 24 months after implantation, suggest that this type of tissue is a valid functional ACL substitute of a knee required to perform normal mechanical activity.

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In transverse and longitudinal paraffin-embedded sections, the human anterior cruciate ligament (ACL) is made up of wavy bundles of collagen fibres arrayed in various directions, the majority around the axis of the ligament with a few running parallel to it. The fascicles making up the larger bundles are also characterised by this undulating appearance. In thin sections 2 types of collagen fibrils are observed: small (with a single diameter peak at 45 nm) and large (3 peaks at 35, 50 and 75 nm respectively), organised into distinct areas made up of either large or small bundles of fibrils. The numerous fibroblasts that are present appear elongated in the direction of the bundles with branches and short cytoplasmic processes. The elastic system is made up of both elastic and oxytalan fibres. The varied orientation of the bundles in the ACL, the complex ultrastructural organisation and the abundant elastic system make it very different from other ligaments and tendons, providing a structure able to withstand the multiaxial stresses and varying tensile strains imposed upon it.

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The histological aspects of the true vocal cord mucosa change in the anterior third compared with the posterior two thirds. The anterior third is characterized by an epithelium where the ridges, marked in the posterior two thirds, are very slight or even absent. The underlying basement membrane, which is thin in the posterior two thirds, here appears particularly thick. At the ultrastructural level in this area, beneath a normally thickened basal lamina, a thick layer of finely granulated electron-dense material, interspersed with thin and randomly scattered collagen fibrils and proteoglycan filaments, is detectable. Beneath this thickened basement membrane, a layer of small undulated collagen fibril bundles with very numerous interspersed oxytalan fibres is found. The collagen fibrils, small in diameter (30-40 nm), seem to continue with the collagen fibrils of the basement membrane. In this layer numerous blood vessels with a very thick, delaminated basement membrane are also observed. The underlying area is characterized by the vocal cord ligament, composed by large compact collagen fibril bundles with interspersed elastic fibres. The particular features of the thick basement membrane, the thick-walled and delaminated vessels and the modular distribution of the elastic system together may well form the basic structure enabling the functional integration of the vocal ligament into the overlying mucosa and the underlying vocal muscle.

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