Evidence that muscle cells do not express the histidine-rich glycoprotein associated with AMP deaminase but can internalise the plasma protein

Histidine-rich glycoprotein (HRG) is synthesized by liver and is present at relatively high concentration in the plasma of vertebrates. We have previously described the association of a HRG-like molecule to purified rabbit skeletal muscle AMP deaminase (AMPD). We also provided the first evidence for the presence of a HRG-like protein in human skeletal muscle where a positive correlation between HRG content and total determined AMPD activity has been shown. In the present paper we investigate the origin of skeletal muscle HRG. The screening of a human skeletal muscle cDNA expression library using an anti-HRG antibody failed to reveal any positive clone. The RT-PCR analysis, performed on human skeletal muscle RNA as well as on RNA from the rhabdomyosarcoma (RD) cell line, failed to show any mRNA specific for the plasma HRG or for the putative muscle variant. When the RD cells were incubated with human plasma HRG, a time-dependent increase of the HRG immunoreactivity was detected both at the plasma membrane level and intracellularly. The internalisation of HRG was inhibited by the addition of heparin. The above data strongly suggest that skeletal muscle cells do not synthesize the muscle variant of HRG but instead can actively internalise it from plasma

Digital radiology with storage phosphors in cephalometric study in orthodontics

Conventional radiology is continually modified with the development of digital systems which can be used for several types of radiologic examinations. Our study was aimed at evaluating the advantages of these new technologies in the orthodontic field, where the problems associated with image quality and radiation protection are major especially in young patients; the latter goal is achievable by dramatically reducing radiation dose and by avoiding repeating the exam. In our study, we compared lateral teleradiographs of the skull for cephalometric analysis obtained using conventional and digital diagnostic methods. The preliminary results demonstrated that the two imaging techniques did not differ relative to bone structure representation, even though the digital system provided better visualization of soft tissue structures. Computed radiography also allowed a marked reduction in the number of repeats and reduced radiation dose. The current disadvantages of this imaging method are the high initial cost of the equipment, reduced work rate, and the need of frequent technical assistance

The small peptide OGP(10-14) reduces proliferation and induces differentiation of TPO-primed M07-e cells through RhoA/TGFbeta1/SFK pathway

Background: Osteogenic growth peptide (OGP) is a 14-mer peptide found in relevant concentration in blood, and its carboxy-terminal fragment [OGP(10-14)] represents the active portion of the full-length peptide. In addition to stimulating bone formation, OGP(10-14) shows hematological activity. In fact, it highly enhances hematopoiesis-affecting stem progenitors. Moreover, OGP(10-14) reduces the growth and induces the differentiation of the hematological tumour cell line trombophoietin(TPO)- primed M07-e by interfering with RhoA and Src kinase pathways. In the present report, we went deeper into this mechanism and evaluated the possible interference of the OGP(10-14) signal pathway with TGFß1 and TPO receptor Mpl. Material/Methods: In OGP(10-14)-treated M07-e cells cultured with or without RhoA and Src kinases inhibitors (C3 and PP2), expression of TGFß1, Mpl, and Src kinases was analyzed by immunoperoxidase technique. Activated RhoA expression was studied using the G-LISA™ quantitative test. Results: In M07-e cells, both OGP(10-14) and PP2 activate RhoA, inhibit Src kinases, reduce Mpl expression and increase TGFß1 expression. OGP(10-14) and PP2 show the same behavior, causing an additive effect when associated. Conclusions: OGP(10-14) induces TPO-primed M07-e cells differentiation through RhoA/TGFß1/SFKs signaling pathway. In particular OGP(10-14) acts as a Src inhibitor, showing the same effects of PP2

Thymus alterations and systemic sclerosis.

OBJECTIVES: The pathogenesis of systemic sclerosis (SSc) includes complex alterations to the immune system, possibly responsible for diffuse microvasculature and fibroblast dysfunction. Previous anecdotal observations suggest a possible role for thymus alterations in some autoimmune rheumatic diseases, including SSc. This study aimed to investigate the prevalence of radiological thymus alterations in SSc patients. METHODS: Thirthy-four unselected patients [28 female and 6 male, mean age (+/- S.D.) 49.7 +/- 9.5 yr, range 33-67 yr] and 34 age- and sex-matched controls were included in the study. The presence of major radiological thymus alterations, i.e. an abnormally enlarged or nodular thymus, were blindly investigated by means of unenhanced multidetector computed tomography. RESULTS: Abnormally enlarged or nodular thymuses were detected in a statistically significant percentage of SSc patients compared with controls (21 vs 0%, P = 0.011). More interestingly, radiological thymus alterations were invariably observed in patients with shorter disease duration (5 yr, 0%; P = 0.007), frequently associated with serum anti-Scl70 antibodies (P = 0.017). Among patients with thymus alterations one developed myasthenia gravis while two others showed thymus hyperplasia at histopathological evaluation after thymectomy. CONCLUSIONS: The present study suggests a possible role of thymic disorders, mainly thymus hyperplasia, in a significant number of SSc patients. Due to the limitations of radiological evaluation, the actual relevance of such an association might be underestimated. The relationship of thymus alterations with shorter disease duration, as well as with serum anti-Scl70, suggests that thymic dysfunction could play a pathogenetic role mostly in the early phases of the disease, and possibly in specific SSc patient subsets

High resolution Computed Tomography (HRCT) in the detection of “early asbestosis”.

Two radiologists reviewed in masked fashion 144 standard chest radiographs, previously judged as normal by other readers, within a cohort of asymptomatic shipyard workers exposed to amosite. Among the 144 workers we selected subjects (n = 72) who fitted the folowing criteries: (1) documented occupational exposure to asbestos; (2) absence of any clinical symptomatology suggestive of asbestosis or of any other lung disease. Thirty-eight of them had standard chest radiographs that were confirmed as normal by both our radiologists, while 34 showed suspected pleural plaques or a very slight parenchymal involvement. These 72 subjects underwent high-resolution CT (HRCT): pleural plaques were shown in 33, parenchymal alterations in 7, and both pleural and parenchymal involvement in 13. HRCT findings were strictly correlated to the duration of amostite exposure. Sensitivity, specificity and diagnostic accuracy values of standard chest radiographs were calculated with respect to HRCT and found to be, for pleural and parenchymal findings respectively: sensitivity 53% and 19%; specificity 72% and 94%; accuracy 60% and 72%. In conclusion, pleural and/or plumonary involvement in asbestos-exposed workers can be shown by HRCT before the appearance of any symptomatology and abnormality on chest radiography. Furthermore the HRCT findings are correlated to the duration of exposure and latency time