It has been previously described that Aroclor 1254 can inhibit GJIC in rodent liver cells where it is known to be a tumor promoter, while the possibility that Aroclor 1254 exerts its inhibitory effects on GJIC in human keratinocytes and acts as a human skin tumor promoter, deserves further attention. In the present study the effects of Aroclor 1254 were examined on gap junction channel permeability, on connexin 43 (Cx 43) expression at mRNA and protein level and on ultrastructural modification to add further experimental evidence to its inhibitory effect on GJIC. The results were compared to those induced by 12-O-tetradecanoylphorbol-13 acetate (TPA), a tumor promoter known to be a potent inhibitor of GJIC in human skin cells and to those induced by benzo[a]pyrene (B[a]P) known for its genotoxic activity. Our data show increased Cx 43 protein expression in Aroclor 1254 and TPA-treated cultures compared to controls, decreased Cx 43 protein level in those exposed to B[a]P, while Cx 43 gene expression (Cx 43 mRNA) was unaffected by the treatments. In Aroclor and TPA-treated keratinocytes, the ultrastructural examination showed residues of junctional systems expressed by specular, short tracts of the faced plasma membranes. In contrast, the contacts between plasma membranes of adjacent B[a]P treated keratinocytes were more extended. A clear inhibition of gap junction channel permeability due to Aroclor 1254 and TPA was also manifest by Lucifer yellow dye test compared to B[a]P-treated cultures where dye spreading to the neighbouring cells and to the extracellular space occurred. The present data, in addition to confirming inhibition of GJIC mediated by Aroclor 1254 in human keratinocytes, which were found to be comparable to those induced by TPA, suggest that GJIC inhibition is associated with increased Cx 43 protein expression without significant modification of its gene expression.

Analysis of Variance↗

PubMedDate not supplied

Biomechanics of the spine.

Instability is one of the pathologic conditions of the spine for which surgical treatment is increasingly indicated, even if to-date the definition of instability is controversial. Some aspects of the biomechanics of the spine with particular reference to the viscoelastic characteristics of its elements and the involved loads, are reported. The elasticity of the spine is analyzed with an in-depth consideration of the concept of stability and instability from the biomechanical, clinical and radiographic viewpoint.

Biomechanical Phenomena↗

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Imaging in degenerative disease of the lumbar spine.

Degenerative disease involves all spinal components. Conventional radiology and digital radiology are the procedures of first choice in order to establish the diagnosis. CT and MRI should be considered of second choice, based on precise indications. The physiologic aspects of the spine during aging are differentiated from the degenerative alterations and relative complications specific of arthrosis with modern available imaging procedures.

Aging↗

PubMedDate not supplied

Degenerative disease of the lumbosacral spine: disk herniation and stenosis.

Degeneration of the intervertebral disk complex begins early in life and is a consequence of a variety of environmental factors as well as of normal aging. Degeneration of bone and soft tissue spinal elements is the most common cause of spinal stenosis. The term "degeneration" as commonly applied to the spine covers such a wide variety of clinical, radiological and pathological manifestations that the word is really only a symbol of our ignorance. Computed tomography and myelography have long been used for diagnosing the effects of degenerative diseases' of the lumbar spine. Despite the continuous improvement in magnetic resonance scanning for this purpose, computed tomography can provide excellent screening for disk herniation and spinal stenosis.

Aging↗

PubMedDate not supplied

The lumbar spine: imaging in rheumatic disease.

Seronegative inflammatory spondyloarthropathies include ankylosing spondylitis, psoriatic arthritis, Reiter syndrome, juvenile chronic arthritis and colitic arthritis. These diseases share some characteristics among which the most important is the presence of the histocompatibility antigen HLA B27; moreover the frequent overlapping of the various inflammation patterns have accounted for their classification in a single group. Diagnostic imaging can differentiate among the different forms only if the diagnostic algorithm, based on clinical history and laboratory findings is followed, considering the advantages and limitations of each method. In this respect, it should be kept in mind that the findings relative to the spine and sacroiliac joints allow to establish a definitive diagnosis.

Arthritis↗

PubMedDate not supplied

Imaging of sacroiliac joints.

The early diagnosis of inflammatory and degenerative disease of sacroiliac joints is markedly difficult because the clinical pattern is not dissimilar from that of diseases involving the lumbar spine and sciatic nerve. Furthermore as in inflammations in general, when only structural changes in the synovial membrane and cartilage are involved, the findings of conventional radiology are often nondiagnostic. CT is now considered the gold standard procedure because in spite of its nonnegligible limitations, single lesions in the synovial and ligamentous compartments can be distinctively evidenced. MRI, unlike other procedures, affords the early nonspecific documentation of intrinsic and/or reactive alterations in the subchondral bone, therefore it appears to fill the gap between the onset of symptoms and the imaging visualization of sacroiliitis.

Arthritis↗

PubMedDate not supplied

Combined imaging in spondylodiscitis.

At present, in spite of the advancement in antibiotic therapy no significant decrease in the incidence of spinal infections is observed: most likely, this is correlated to the increased immigration flows, high risk behaviors (drug addiction, alcoholism), immunosuppressive diseases (AIDS, leukemia, lymphoma), interventional procedures (iatrogenic causes). Early diagnosis, at times difficult and often misunderstood, is facilitated by the use of a correct diagnostic algorithm, supported by blood culture, needle aspiration and biopsy. Aim of this report was to evaluate the role of the different imaging procedures, CT and MRI in particular, for prompt correct therapeutic management.

Diagnosis, Differential↗

PubMedDate not supplied

Primary bone tumors and pseudotumors of the lumbosacral spine.

Primary tumors of the spine are relatively infrequent lesions compared with metastatic disease, multiple myeloma, and lymphoma which are the more frequent neoplasms of the spine and usually manifest with multifocal lesions and thus pose little diagnostic dilemma. However, in the presence of a solitary spinal lesion, the more uncommon primary tumors of the spine represent an important group of entities for diagnostic consideration. The most common benign and malignant primary tumors of the spine are enostosis, osteoid osteoma, osteoblastoma, giant cell tumor, aneurysmal bone cyst, osteochondroma, chordoma, chondrosarcoma, Ewing sarcoma, primitive neuroectodermal tumor, and osteosarcoma. The imaging features of these lesions are often characteristic. Radiologists should be aware of the appearance of these unusual tumors in order to provide a complete differential diagnosis.

Diagnosis, Differential↗

PubMedDate not supplied

Postoperative lumbar spine.

The differentiation between normal sequelae and complications of any surgical treatment of the lumbar spine is of the utmost importance. Clinical and radiological diagnosis is often difficult. Certainly the introduction of computed tomography (CT) and magnetic resonance imaging (MRI) has improved and refined the diagnostic possibilities, however not all problems have been resolved. For example, the frequent resort in vertebral surgery to metal implants which may limit or even prevent the interpretation of CT or MR images, should be kept in mind. The main types of surgical procedures involving the lumbar spine are briefly reviewed, focusing on CT and MRI appearance of normal sequelae of early or late complications and the recurrence of the lesion that necessitated the first procedure.

Diskectomy↗

PubMedDate not supplied

[Promoter effect of mercury chloride and methyl-mercury on human keratinocytes in culture].

Mercury has received considerable media focus because it is present in dental amalgams and seafood. There is potential exposure in gas meters, thermometers and fluorescent lamps workers. To evaluate its possible epigenetic carcinogen effect, cultures of human keratinocytes were treated with increasing doses of HgCl2 for 30 min, 24 h and of CH3HgCl for 24 h, respectively. The red neutral method was used to evaluate the doses of HgCl2 and CH3HgCl which had no cytotoxic effect. Then, the dye transfer method was used to investigate the gap junctions-mediated intercellular communication (GJIC). Cells were microinjected with Lucifer Yellow CH by using the Eppendorf Apparatus and the Leica inverted microscope. After 30 min incubation at the concentration of 10 microM, HgCl2 did not exert inhibition of GJIC. Conversely, after 24 h at the concentration of 10 nM, HgCl2 inhibited GJIC. Incubation with CH3HgCl at the concentration of 250 nM for 24 h reduced the number of fluorescent cells, thus denoting a inhibition of GJIC. Taken together our data demonstrated that: i) HgCl2 and CH3HgCl exerted an inhibitory effect upon GJIC; ii) HgCl2 resulted to inhibit GJIC at concentrations 25 folds lower than CH3HgCl. Further studies will be addressed to evaluate whether the reversal of GJIC inhibition could be obtained by withdrawal of toxic substance, or by the addition of a GJIC activator like the retinoic acid. Finally to shed light on the possible effect of mercury derivates at the transcriptional or translational levels, the expression profile of the connexin 43 gene after HgCl2 and CH3HgCl exposure of cultured human keratinocytes will be investigated.

Cell Communication↗

PubMedDate not supplied

Expression and modification of NO synthase in human dental pulps during orthodontic treatment.

In the last few years our histology laboratory has worked in collaboration with Winchmore Hill Dental Practice in London in studying nitric oxide synthase (NOS) protein expression by the use of immunohistochemistry in dental pulps following orthodontic treatment (A. Gerbino et al. 2000; A. Gerbino et al 2001; A. Gerbino et al 2001.) The study has been carried out on samples taken from orthodontically treated and non-orthodontically treated teeth. The results suggest a close correlation between the duration of the orthodontic traction and the expression of the above-mentioned neurotransmitter (NO).

Adolescent↗

PubMedDate not supplied

Sonographic study of painful shoulder.

OBJECTIVE: To identify sonographically the site and entity of alterations in a high number of patients with shoulder pain. METHODS: Two different experienced operators (both rheumatologists), who were blinded to the clinical data, performed sonographic examinations on 528 shoulders of 425 consecutive patients with painful shoulder and in both shoulders of 198 control subjects. They carried out ultrasound examinations separately using a 7.5 MHz linear transducer. Investigation included the long head of the biceps tendon, the supraspinatus tendon, infraspinatus tendon, subscapularis tendon, acromioclavicular joint, glenohumeral joint, subacromial-subdeltoid bursa, subscapularis bursa, and finally identification of calcifications. Before the ultrasonographic exam, a third experienced rheumatologist performed a physical examination in all patients using specific tests of movement for evaluation of the long head of biceps tendon, the supraspinatus tendon, infraspinatus tendon, subscapularis tendon, and acromioclavicular joint. RESULTS: Sonographic alterations were found in a total of 94.1% of patients. The structure most frequently involved was the supraspinatus tendon (64.6%). The long head of the biceps tendon (48.1%) and the acromioclavicular joint (51.5%) were also frequently involved. Different types of alterations in the various structures were detected. Significant differences were found with respect to controls. A high sensitivity and specificity of sonography was demonstrated compared to physical examination. CONCLUSIONS: Sonography evaluates accurately the single anatomic structures of the shoulder and identifies both the site and type of changes in patients with painful shoulder. The high sensitivity/specificity, non-invasiveness and low costs of this technique justify its routine utilisation in clinical rheumatological practice.

Adolescent↗