PubMed Health⌕ Search

Biomedical subjects

F Benazzo

Publications and source records attributed to F Benazzo.

At least 19 recordsLinked to original sources
PubMed2001

Muscle transplant in the rabbit's Achilles tendon.

UNLABELLED: Achilles tendinopathy (AT) is a degenerative disorder resulting from functional overload, especially during running and jumping, with some inflammatory features at the insertions, bursae, and paratenon. The Achilles tendon is poorly vascularized, especially in the middle third, and the consequent slow metabolic rate allows it to work at very low oxygen tensions but prevents on the other hand a rapid healing. PURPOSE: To create an animal model to study a novel surgical technique employed in AT: transplanting some fibers of the soleus muscle into the tendon in order to improve its vascularization and healing and to study the histological appearance of the soleus graft incorporated in the tendon. METHODS: We operated on 10 white New Zealand rabbits (eight rabbits underwent the procedure, two rabbits the sham operation with incision of the tendon without graft). Two animals were euthanized at 1 wk, 1, 2, and 3 months. RESULTS: Histology showed that after 3 months the muscle fibers were still viable within the tendons, interspersed within connective tissue fibers. Tendon and muscle tissues were intimately fused. CONCLUSIONS: The persistence of the soleus muscle pedicle graft within the Achilles tendon tissue is an index of sound blood supply. This surgical model is suitable for application in further studies on tendon healing.

Achilles Tendon↗
PubMed1997

B7.2 expressed by T cells does not induce CD28-mediated costimulatory activity but retains CTLA4 binding: implications for induction of antitumor immunity to T cell tumors.

The B7 family of costimulatory molecules provides the second signal necessary for activation of T cells. In the absence of the second signal, responding T cells become anergic. Although predominantly expressed on professional APCs, recent evidence shows that the B7 molecules are also expressed on T cells. To study the functions of B7 molecules on T cells, we transfected murine B7.1 (CD80) and B7.2 (CD86) cDNAs into the EL4 T cell thymoma cell line and examined the transfectants for their ability to costimulate T cell proliferation in vitro and to induce antitumor immunity in vivo. Here we show that although EL4-B7.1 cells costimulate T cells and induce tumor regression, EL4-B7.2 transfectants failed to costimulate T cell proliferation or induce tumor regression. To understand the cellular basis for this difference, we examined the binding of EL4-B7.1 and EL4-B7.2 to CTLA4 and CD28. Whereas EL4-B7.1 cells bound both CTLA4-Ig and CD28-Ig, EL4-B7.2 transfectants preferentially bound CTLA4-Ig, but not CD28-Ig. Similar binding data were obtained with freshly isolated murine T cells, which have been shown to constitutively express B7.2. Our data suggest, therefore, that B7.2 expressed on T cells may not costimulate but instead inhibit the T cell response by preferential binding to CTLA4.

Abatacept↗
PubMed1996

Achilles and patellar tendinopathies in athletes: pathogenesis and surgical treatment.

In the period from 1985 to 1992, 136 athletes underwent 148 surgical exploration of Achilles (98 operations in 90 patients) and patellar (50 operations in 46 patients) tendons for persistent pain. The morphology and the biochemistry of tendon samples taken at operation were investigated. A marked increase of glycosaminoglycans, especially chondroitin sulphate, was present. The complete alleviation of pain and the return to full activity were obtained in 79% of the athletes, while the remaining 21% were not able to return to their sports activities. Generally, successful outcome after surgery was experience by younger patients who had tendon pain of short duration--which was correlated to a lesser degree of tendon degeneration.

Achilles Tendon↗
PubMed1995

Use of capacitive coupled electric fields in stress fractures in athletes.

The authors report the results of an open study on the treatment of stress fracture in athletes by capacitive coupling, a bone healing stimulation method promoting bone formation by application of alternating current in the form of a sinusoidal wave. Twenty-five lower-limb (navicular, 2nd and 5th metatarsal, tibia, fibula, and talus) stress fractures in 21 athletes (mean age, 21.8 years old) were treated. The mean stimulation time was 52 days (navicular fractures, 60 days). Twenty-two fractures were healed, 1 was not healed, and 2 were improved. This preliminary report shows that capacitive coupling can be used safely in the treatment of these stress fractures.

Adolescent↗
PubMed1994

Pathogenesis of uncus deformation and vertebral artery compression: histologic investigations of the uncus and dynamic angiography of the vertebral artery in the cadaveric cervical spine.

Twenty-one cervical spines were collected from fresh cadavers (12 male, nine female), their ages ranging from 10 to 90 years (mean 49.47). After removing muscle debris from the spines, they were mounted and tested on a device to passively reproduce the main movements of the spine. The degree of motion in flexion-extension and lateral bending significantly decreased from group A (ages 10-49 years) to group B (51-90 years) (p < 0.005) and was directly correlated with the amount of cervical spine degenerative alterations. The incidence of these alterations, classified according to Lysell (1969), was highest at C5-6. On the testing machine, dynamic angiography of the vertebral artery showed an impingement with extrinsic compression of the vessels in four of 28 successful injections. The histologic serial sections of the uncus showed a characteristic pattern of ossification-deformation: a newly formed cartilaginous tissue tipping the apex of the uncus, forming a double protruding contour of the apex, rapidly ossifying, and appearing to deform outward together with the disk degeneration and consequently decreasing in height.

Adolescent↗
PubMed1994

The statics of cervical traction.

The statics of a sliding body was used to study the distribution of forces during the application of cervical traction in supine patients. This theoretical analysis was completed using a dynamometer to determine the static friction between bed surface and patient head. Therefore, we measured the head weight in 12 inpatients and the minimum force that causes impending motion of the head on the bed surface. The static friction coefficient was calculated from the ratio of the two quantities. The forces acting on the cervical spine were determined by inserting the former data into a specifically designed algorithm that forecasted a progressively increasing traction angle. The coefficient of static friction was 0.62, whereas the maximum available force acting on the cervical spine was obtained with a 35 degrees traction inclination. In contrast, the forces dissipated by the plane progressively decreased with larger angles.

Aged↗
PubMed1993

[Shoulder instability and pain. Computerized arthro-tomography assessment].

The growing interest in shoulder joint imaging comes from the ever-increasing demand for such an examination in orthopedics. Since more complete and detailed imaging of bone, capsuloligamentous and musculotendinous compartments is always needed, CT arthrography has necessarily become a widely used method. In this study, 282 patients were investigated with CT arthrography. Seventy per cent of them had anatomical instability, 17.3% had functional instability and the extant 12.7% had shoulder pain. In traumatic instability, the most often injured structures were the glenoid labra (91%) and the capsule (82%). Lesions in the two structures were nearly always associated. Moreover, high incidence (65.8%) of Hill-Sachs lesions of the humeral head was observed. In atraumatic instability, abnormal anteversion of the scapular glenoid was always detected. In the patients with shoulder pain, the most common causes were the impingement syndrome (30.5%), superior labrum lesions (16.7%), adhesive capsulitis (16.7%) and synovial osteochondromatosis (13.7%). With CT arthrography, labial abnormalities (detachments, tears, amputations, eversions and degeneration) can be identified, as well as capsular lesions (insertional detachment and laxity), rotator cuff conditions (bursitis, tendinitis and partial/complete tears), biceps tendon abnormalities and glenoid rim and humeral head fractures. Moreover, CT arthrography is minimally invasive and well tolerated. It exhibits 97.7% specificity, 91% sensitivity and 96% accuracy. Furthermore, it has been proven to be extremely useful in treatment and surgical planning.

Adolescent↗
PubMed1992

Atraumatic patellofemoral joint disorders. Long-term results of surgery.

Clinical and radiographic follow-up was done on a group of patients with atraumatic patellofemoral joint disorders who had been treated surgically by realignment of the extensor apparatus at the authors' institution from 1985 to 1989. The preoperative radiographic examination in the 65 patients treated (for a total of 74 realignments) evaluated the following parameters: sulcus angle, Insall-Salvati index, and congruence angle. The 46 patients who returned for follow-up (after an average of 2 years and 3 months) were evaluated clinically according to a classification system proposed by the authors which is based on objective clinical data and a multi-factorial assessment of pain. Moreover, radiographic follow-up of the same 46 patients made it possible to quantify the degree of realignment achieved with each type of surgical technique. The clinical and radiographic data made it possible to determine more precise indications for each type of surgical procedure in relation to the disease involved, using a correct diagnostic approach and making a thorough evaluation of the clinical, anatomical and pathological features.

Adolescent↗
PubMed1991

Osteochondroma of the cervical spine.

The localization of an osteochondroma in the spine is considered a rare occurrence. The authors describe the case of a 37 year-old woman with osteochondroma of the C2 neural arch involving the C1 spinous process. The woman came under observation because of severe loss of neck mobility and was subsequently diagnosed with osteochondroma. Of the preoperative examinations, MRI was more valuable than CT scan for defining the nature and extent of the tumor. Treatment consisted of complete posterior excision of the tumor, including the C1 spinous process and the C2 laminae up to the facets.

Adult↗
PubMed1990

Degenerative arthritis of the adjacent spinal joints following anterior cervical spinal fusion: clinicoradiologic and statistical correlations.

On the premise that cervical intersomatic spinal fusion in the treatment of traumatic or spondylolytic myelopathy and post-traumatic instability provokes degenerative arthritis due to functional overloading of the spaces adjacent to the fusion, 37 patients (average age 57, range 25-80) who had undergone spinal fusion by Cloward's technique were subjected to radiographic study and clinical evaluation. The average follow-up was 11.5 years (range 7-16 years). In comparison with a control group of the same age who had not undergone this operation, these patients' C3-C4 and C6-C7 spaces (adjacent to the most commonly fused vertebrae) were smaller by 16.7% and 15.9%, respectively. In spite of the worsening of the radiographic situation, from a clinical standpoint there was a significant improvement in the symptomatology of 86.5% of the patients. Thus the degenerative arthritis is both less evident and, as far as the long-term clinical outcome is concerned, less influential than could be expected. This finding is confirmed by the lack of statistical correlation between the clinical results and the radiographic evidence.

Adult↗
PubMed1990

[The role of echotomography in sports traumatology of the lower extremity].

Sonography, which is commonly used in the evaluation of muscular traumas following exercise, quite often provides the radiologist with normal findings. One hundred and fifty-nine athletes were considered (170 US examinations), and the clinical diagnoses the patients had been referred for were compared with US findings: the pathologic condition was confirmed in 59% of the cases, while the extant 41% had normal findings. The highest percentage of positive findings was observed in the Achilles tendon region (75%), while the figure dropped to 38% in the thigh. In the latter location, muscular ruptures were confirmed in 69% of the cases, versus 17% in case of muscular distraction. As for the Achilles tendon, pathologic conditions both along the axis and in the insertion of the tendon were confirmed in 20% of the cases, but clinical accuracy was improved by US in 47% and 20% of the patients, respectively, and the diagnosis was changed in 10% and 20% of the cases, respectively. Therefore, clinical accuracy was demonstrated to depend on the pathologic condition as well as on the anatomical region involved.

Athletic Injuries↗
PubMed1988

Early alteration of synovial membrane in osteoarthrosis.

Biopsy specimens of the synovial membrane were obtained during arthroscopy and surgical meniscectomy from the knees of 20 patients with meniscus lesions. The aim of this study was to identify the morphological and immunological changes which appear in the synovium during the earliest phase of osteoarthrosis. Interstitial deposits of IgG and, in some cases, C3 were found not only in patients with evident arthrotic degeneration (cartilaginous lesions and synovitis), but also in patients who showed no overt arthrotic changes. Furthermore, light and electron microscopy showed an increased number of mast-cells with peculiar semilunar or piecemeal aspects of their secretory granules. These ultrastructural modifications are characteristic of slow, chronic release of mediators in response to a constant, moderate degranulatory stimulus. Our findings suggest that synovial changes may occur before the advent of cartilage degeneration and that the latter may be directly influenced by early pathological changes in the synovial membrane.

Adolescent↗
PubMed1987

Pathogenesis of membranous lipodystrophy. Case report and review of the literature.

Membranous lipodystrophy occurred in a 35-year-old woman and membrane-like material was found in her epiphyses and short bones. Electron microscopy allowed a study of the relationship between the pathologic tissue and normal fat, suggesting that the membrane-like material is derived from degenerated cells. Nucleation of hydroxyapatite crystals was also observed in the membranous material. Because basal ganglia calcifications were demonstrated with the use of computed tomography, brain and bone lesions may be assumed to share the same pathogenesis. Lipid and mucopolysaccharide metabolism was found to be normal.

Adipose Tissue↗
PubMed1981

Differences in the microfibrillar arrangement of collagen fibrils. Distribution and possible significance.

The microfibrillar arrangement of collagen fibrils has been studied on replicas of freeze-fractured specimens and on thin sections of specimens treated with a 4.0 M guanidinium chloride solution. Collagen fibrils with straight arrangement of their microfibrils usually have a variable diameter and correspond in their distribution to genetical type I and type II collagens. Collagen fibrils with helicoidal arrangement of their microfibrils present a relatively small and uniform diameter and show a tissue distribution similar to that of the genetical type III collagen. The corneal stroma, although predominantly composed of type I collagen, displays collagen fibrils with a helicoidal microfibrillar arrangement, and small uniform diameter. This exception can be explained in consideration of the function of the collagen of the corneal stroma. A close correlation between all the different microfibrillar patterns of the collagen fibrils and their function in the anatomical sites we examined is evident.

Animals↗