Osteosarcoma of the limb. Amputation or limb salvage in patients treated by neoadjuvant chemotherapy.
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Adolescent↗
Biomedical subjects
S Ferrari
Publications and source records attributed to S Ferrari.
Mutations of CD40 gene cause an autosomal recessive form of immunodeficiency with hyper IgM.
CD40 is a member of the tumor necrosis factor receptor superfamily, expressed on a wide range of cell types including B cells, macrophages, and dendritic cells. CD40 is the receptor for CD40 ligand (CD40L), a molecule predominantly expressed by activated CD4(+) T cells. CD40/CD40L interaction induces the formation of memory B lymphocytes and promotes Ig isotype switching, as demonstrated in mice knocked-out for either CD40L or CD40 gene, and in patients with X-linked hyper IgM syndrome, a disease caused by CD40L/TNFSF5 gene mutations. In the present study, we have identified three patients with an autosomal recessive form of hyper IgM who fail to express CD40 on the cell surface. Sequence analysis of CD40 genomic DNA showed that one patient carried a homozygous silent mutation at the fifth base pair position of exon 5, involving an exonic splicing enhancer and leading to exon skipping and premature termination; the other two patients showed a homozygous point mutation in exon 3, resulting in a cysteine to arginine substitution. These findings show that mutations of the CD40 gene cause an autosomal recessive form of hyper IgM, which is immunologically and clinically undistinguishable from the X-linked form.
CD40 Antigens↗
Acf1, the largest subunit of CHRAC, regulates ISWI-induced nucleosome remodelling.
The chromatin accessibility complex (CHRAC) was originally defined biochemically as an ATP-dependent 'nucleosome remodelling' activity. Central to its activity is the ATPase ISWI, which catalyses the transfer of histone octamers between DNA segments in cis. In addition to ISWI, four other potential subunits were observed consistently in active CHRAC fractions. We have now identified the p175 subunit of CHRAC as Acf1, a protein known to associate with ISWI in the ACF complex. Interaction of Acf1 with ISWI enhances the efficiency of nucleosome sliding by an order of magnitude. Remarkably, it also modulates the nucleosome remodelling activity of ISWI qualitatively by altering the directionality of nucleosome movements and the histone 'tail' requirements of the reaction. The Acf1-ISWI heteromer tightly interacts with the two recently identified small histone fold proteins CHRAC-14 and CHRAC-16. Whether topoisomerase II is an integral subunit has been controversial. Refined analyses now suggest that topoisomerase II should not be considered a stable subunit of CHRAC. Accordingly, CHRAC can be molecularly defined as a complex consisting of ISWI, Acf1, CHRAC-14 and CHRAC-16.
Adenosine Triphosphatases↗
Insulin-stimulated protein kinase B phosphorylation on Ser-473 is independent of its activity and occurs through a staurosporine-insensitive kinase.
Full activation of protein kinase B (PKB, also called Akt) requires phosphorylation on two regulatory sites, Thr-308 in the activation loop and Ser-473 in the hydrophobic C-terminal regulatory domain (numbering for PKB alpha/Akt-1). Although 3'-phosphoinositide-dependent protein kinase 1 (PDK1) has now been identified as the Thr-308 kinase, the mechanism of the Ser-473 phosphorylation remains controversial. As a step to further characterize the Ser-473 kinase, we examined the effects of a range of protein kinase inhibitors on the activation and phosphorylation of PKB. We found that staurosporine, a broad-specificity kinase inhibitor and inducer of cell apoptosis, attenuated PKB activation exclusively through the inhibition of Thr-308 phosphorylation, with Ser-473 phosphorylation unaffected. The increase in Thr-308 phosphorylation because of overexpression of PDK1 was also inhibited by staurosporine. We further show that staurosporine (CGP 39360) potently inhibited PDK1 activity in vitro with an IC(50) of approximately 0.22 microm. These data indicate that agonist-induced phosphorylation of Ser-473 of PKB is independent of PDK1 or PKB activity and occurs through a distinct Ser-473 kinase that is not inhibited by staurosporine. Moreover, our results suggest that inhibition of PKB signaling is involved in the proapoptotic action of staurosporine.
Animals↗
Expression and purification of human recombinant GST-FGF receptor-1.
When tumors undergo the angiogenic switch, cell growth and tissue invasion is facilitated by the formation of new capillaries from preexisting blood vessels, a process known as angiogenesis. Growth factors such as vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) and fibroblast growth factor (FGF) trigger the process of angiogenesis. Here we describe a protocol for the expression and one-step purification of human recombinant GST-FGF receptor type 1 (FGFR-1) from Sf9 cells. This protocol allows generating an active kinase as indicated by its reactivity with a monoclonal antibody to phosphorylated tyrosine. The purified enzyme displays a specific activity of 1.2 x 10(4) pmol mg(-1) min(-1), which is in the range of activities reported for homogeneously purified recombinant kinases. We have employed a number of compounds to show that the GST-FGFR-1 preparation is suitable to the identification of tyrosine kinase inhibitors. Considering that inhibitors of angiogenesis may represent an attractive tool in therapeutic strategies targeting invasive metastatic tumors the results presented here, along with available data on the structure of the ATP-binding pocket of FGFR-1, should facilitate the rational design of specific FGFR-1 inhibitory compounds.
Adenosine Triphosphate↗
Different brain correlates for watching real and virtual hand actions.
We investigated whether observation of actions reproduced in three-dimensional virtual reality would engage perceptual and visuomotor brain processes different from those induced by the observation of real hand actions. Participants were asked to passively observe grasping actions of geometrical objects made by a real hand or by hand reconstructions of different quality in 3D virtual reality as well as on a 2D TV screen. We found that only real actions in natural environment activated a visuospatial network including the right posterior parietal cortex. Observation of virtual-reality hand actions engaged prevalent visual perceptual processes within lateral and mesial occipital regions. Thus, only perception of actions in reality maps onto existing action representations, whereas virtual-reality conditions do not access the full motor knowledge available to the central nervous system.
Adult↗
Pattern of relapse in patients with osteosarcoma of the extremities treated with neoadjuvant chemotherapy.
570 patients with osteosarcoma of the extremities were treated with five different protocols of neoadjuvant chemotherapy at Rizzoli Institute between 1983 and 1995. Surgery consisted of limb salvage in 83% rotation plasty in 5% and amputation in 12%. The 5-year event-free survival (EFS) was 60% which varied according to the protocol followed, ranging from 47.6% to 66.4%. 234 patients relapsed. The pattern of relapse was analysed. The mean relapse time was 23.8 months (range: 2-96). The first site of systemic relapse was the lung in 88% (32% of these had less than three pulmonary metastases and 68% three or more), bone in 9%, lung and bone in 2% and other sites in 3%. The relapse time and the number of pulmonary metastases were strictly correlated with the efficacy of the protocol of chemotherapy used. Patients treated with the three protocols that gave a 5-year EFS of more than 60% relapsed later and had fewer pulmonary lesions than patients treated with the two protocols that gave a 5-year EFS of 47.6% and 52.5%. The rate of local recurrence was relatively low (6%). This was not correlated with the protocol or the type of surgery used: limb salvage (6.4%), rotation plasty or amputation (4.1%). However, the rate of local recurrence was very high (21.9%) in the few patients (7%) that had less than wide surgical margins. We conclude that for patients with osteosarcoma of the extremities treated with neoadjuvant chemotherapy: (a) the pattern of systemic relapse changes according to the efficacy of the protocol of chemotherapy used. This should be always considered when evaluating the preliminary results of new studies as well as in defining the time of follow-up; (b) limb salvage procedures are safe and do not jeopardise the outcome of the patient, provided that wide surgical margins are achieved.
Adolescent↗
Neoadjuvant chemotherapy for osteosarcoma of the extremity: long-term results of the Rizzoli's 4th protocol.
From January 1993 to March 1995, 162 patients with osteosarcoma of extremities were treated according to the IOR/OS-4 protocol. 133 patients had localised disease, while 29 had metastases at diagnosis. These last patients were simultaneously operated upon for their primary and metastatic lesions. Chemotherapy consisted preoperatively of two cycles of high dose methotrexate (HDMTX) and one cycle each of cisplatin (CDP)-doxorubicin (ADM), CDP/ifosfamide (IFO) and IFO/ADM. After surgery, patients were treated with the aforementioned drugs used as single agents. The mean follow-up of all patients was 6.5 years (5.5-8 years). Surgery was a limb salvage in 94% of cases, and the 5-year event-free survival (EFS) and overall survival (OS) rates were 56 and 71% for patients with localised disease, and 17 and 24% for patients with metastases at diagnosis. These results did not differ from those achieved in our previous study (IOR/OS-3) in which IFO was used only postoperatively in poor responders.
Adolescent↗
Predictive factors of disease-free survival for non-metastatic osteosarcoma of the extremity: an analysis of 300 patients treated at the Rizzoli Institute.
BACKGROUND: To identify predictive factors of disease-free survival (DFS) in patients with non-metastatic osteosarcoma of the extremity, treated with primary chemotherapy and delayed surgery. PATIENTS AND METHODS: The relationship between patient-related and treatment-related factors and prognosis was evaluated in 300 patients treated from 1986 to 1992 according to chemotherapy protocols based on high-dose methotrexate, cisplatin and doxorubicin, with the addition of ifosfamide in the post-operative phase. Univariate and multivariate analyses of prognostic factors for disease-free survival were performed. RESULTS: With a median follow-up of 9.2 (4.4-12) years, eight-year DFS was 59% (95% confidence interval (95% CI): 54-64.9). Univariate analyses showed that tumor volume > or = 150 ml (P = 0.002), histologic subtype (P = 0.028), age > 12 years (P = 0.044), high serum lactate dehydrogenase (P = 0.044) and alkaline phosphatase (P = 0.064) levels adversely affected DFS. Gender of patients and site of tumor did not influence DFS. No differences in DFS were found among the three chemotherapy protocols, whereas the use of limb-sparing surgery vs. amputation or rotation plasty (P = 0.006) and a good histologic response to primary chemotherapy (P = 0.014) positively correlated with DFS. After multivariate analyses, tumor volume > or = 150 ml (P = 0.028), age > 12 years (P = 0.051), and histologic subtype (P = 0.052) retained prognostic significance. CONCLUSIONS: In patients with non-metastatic osteosarcoma of the extremity treated with neoadjuvant chemotherapy, the disease-free survival is significantly influenced by tumor volume, age, and histologic subtype.
Adolescent↗
Pharmacokinetics help optimizing mycophenolate mofetil dosing in kidney transplant patients.
BACKGROUND: Mycophenolic acid (MPA), the active metabolite of mycophenolate mofetil (MMF), is now routinely used as immunosuppressant in solid organ transplantation in a fixed daily dose regimen (2 g/d) in association with cyclosporine (CsA) and steroids. However, no correlation has been shown between fixed MMF dose and clinical outcome. METHODS: Here we examined the possibility of optimizing MMF dosing by drug pharmacokinetic monitoring in 46 stable kidney transplant recipients. MPA plasma concentration profiles were measured by a reverse-phase high-performance liquid chromatography method 6-9 months after transplantation and related with routine laboratory analysis tests. Since MPA is extensively bound to serum albumin and only the free fraction is pharmacologically active, in a subgroup of 23 patients free plasma MPA was also determined. RESULTS: Despite a comparable MMF dose, a large interindividual variability in both MPA area under the curve (AUC) from 0 to 12 h (range 10.1-99.8 microg/mL. h) and in trough levels (range 0.24-7.04 microg/mL) was found. Patients with AUC >40 microg/mL. h showed a better (p<0.05) renal function than patients with lower AUC (creatinine clearance 85.7+/-23.2 versus 64.5+/-17.5 mL/min), despite no difference in CsA dose, CsA AUC and blood CsA trough level. The percentage of free plasma MPA but not total MPA correlated with the red blood cell and leukocyte count. CONCLUSIONS: Therapeutic MMF drug monitoring might contribute to a better management of kidney transplant recipient with the goal of optimizing drug dosing and limiting the risk of MMF-related toxicity.
Adult↗
A functionally active RARalpha nuclear receptor is expressed in retinoic acid non responsive early myeloblastic cell lines.
Although all-trans retinoic acid (ATRA) can restore the differentiation capacity of leukemic promyelocytes, early leukemic myeloblasts are conversely not responsive to ATRA induced granulocytic differentiation. To assess whether this resistance to ATRA is related to an impaired function of the Retinoic Acid Receptor alpha (RARalpha), we performed an analysis of RARalpha expression and transactivation activity, in several myeloid leukemic cell lines, representative of different types of spontaneous acute myeloid leukemias. Our results indicate that a functionally active RARalpha nuclear receptor is expressed in all the analyzed cell lines, regardless of their differentiation capacity following exposure to ATRA. The observation that ATRA treatment is able to induce the expression of retinoic acid target genes, in late- but not in early-myeloblastic leukemic cells, raises the possibility that the differentiation block of these cells is achieved through a chromatin mediated mechanism. Acetylation is apparently not involved in this process, since the histone deacetylase inhibitor trichostatin A, is not able to restore the differentiation capacity of early leukemic myeloblasts. Further investigation is needed to clarify whether myeloid transcription factors, distinct to RARalpha, play a role in the resistance of these cells to ATRA treatment.
Alkaline Phosphatase↗
Mucus altering agents as adjuncts for nonviral gene transfer to airway epithelium.
Nonviral vectors have been shown to be a safe and valid alternative to recombinant viruses for gene therapy of cystic fibrosis (CF). Nevertheless, gene transfer efficiency needs to be increased before clinical efficacy is likely in man. One barrier to increased efficacy is normal airway mucus. Using an ex vivo model of sheep tracheal epithelium, we show that this barrier can, in part, be overcome by treatment with the mucolytic agents, Nacystelyn or N-acetylcysteine using either a cationic lipid or a cationic polymer as the gene transfer agent. Further, in vivo application of either Nacystelyn or the anticholinergic glycopyrrolate, both clinically used agents, resulted in increased reporter gene expression in the mouse lung, but no significant correction of the bioelectric defect in CF null mice. These results, whilst unlikely to be sufficient in themselves to achieve clinically relevant gene therapy, may be a further useful step in the attainment of this goal.
Acetylcysteine↗
Effects of vitamin D on the growth of normal and malignant B-cell progenitors.
As the effects of vitamin D3, 1,25-dihydroxyvitamin D3 (1,25-(OH)2-D3) (VD, calcitriol) on the proliferation and differentiation potential of normal and leukaemic cells in vitro of myeloid lineage are known, we investigated the response to VD on the growth of both normal and malignant lymphoid progenitors. Effects of vitamin D on normal human lymphoid progenitors and B lineage acute lymphoblastic leukaemia (ALL) progenitors were assessed by using an in vitro cell colony assay specific for either B or T cell lineages. The expression of VDR on B untreated malignant progenitors at diagnosis was investigated by RT-PCR analysis. VD induced a significant inhibition of normal lymphoid cell progenitors growth of both T and B lineage. VD inhibited significantly also the growth of malignant B cell lineage lymphoid progenitors, without inducing cytotoxic effect. As it has been reported that VD effects on activated lymphocytes are mediated by 1,25-(OH)2-D3 nuclear receptor (VDR), we investigated VDR expression on malignant B cell progenitors. We did not detect VDR expression on these cells examined at diagnosis. We demonstrated that VD inhibited in vitro the clonogenic growth of both normal and malignant lymphoid B cell progenitors and that this inhibitory effect on malignant B cell progenitors was not related to VDR. Our work contributes to understanding of the mechanism of action of this hormone in promoting cellular inhibition of clonal growth of malignant lymphoid B cell progenitors, suggesting that the regulation of some critical growth and differentiation factor receptors could be a key physiological role of this hormone.
B-Lymphocytes↗
A comparison of methods of loco-regional chemotherapy combined with systemic chemotherapy as neo-adjuvant treatment of osteosarcoma of the extremity.
AIM: Our experience of pre-operative intraarterial (i.a.) vs intravenous (i.v.) infusion of cisplatinum (CDP) in a multiagent neo-adjuvant chemotherapy for osteosarcoma of the extremity is reported. METHODS: Two successive randomized studies were performed. In the first, pre-operatively, CDP i.a. vs CDP i.v. was applied in combination with high-dose methotrexate (HDMTX) and adriamycin (ADM) within a three-drug regimen. In the second, a combination of HDMTX, ADM and IFO, within a four-drug regimen was tested. RESULTS: The rate of responses to chemotherapy (tumour necrosis > or = 90%) was significantly higher (P<0.04) for the 142 patients treated with the four-drug regimen than in the 79 patients treated with a three-drug regimen (76%vs 62%). According to the route of CDP infusion, in the three-drug regimen the rate of responses was significantly higher (P=0.004) in patients treated with i.a. CDP (77%) than in patients treated i.v. (46%); with the four-drug regimen the rate of response was not significantly different in patients treated i.a. (81%) and in patients treated i.v. (71%). No significant differences in the rates of limb salvages, local recurrence and event-free survival (EFS) were seen between the i.a. and the i.v. groups. CONCLUSION: In the treatment of osteosarcoma of the extremity, the i.a. infusion of CDP does not offer any significant advantage when this drug is used within an aggressive, multiagent, pre-operative four-drug regimen.
Adolescent↗
Suppression of bile acid synthesis, but not of hepatic cholesterol 7alpha-hydroxylase expression, by obstructive cholestasis in humans.
Regulation of bile acid synthesis, a key determinant of cholesterol homeostasis, is still incompletely understood. To elucidate the feedback control exerted on bile acid biosynthesis in humans with obstructive cholestasis, 16 patients with bile duct obstruction were studied. In vivo 7alpha-hydroxylation, reflecting bile acid synthesis, was assayed in 13 of them by tritium release analysis. Serum 27-hydroxycholesterol was determined by gas chromatography-mass spectrometry. In a subgroup, hepatic cholesterol 7alpha-hydroxylase mRNA was assayed by real-time polymerase chain reaction (PCR), enzyme activity was determined by isotope incorporation, and microsomal cholesterol content was assayed by gas chromatography-mass spectrometry. Age-matched control subjects were studied in parallel. Hydroxylation rates were lower in cholestatic patients (108 +/- 33 mg of cholesterol per day, mean +/- SEM; controls: 297 +/- 40 mg/d; P <.01). The reduction was proportional to the severity of cholestasis, and synthetic rates were normalized in 4 subjects restudied after resolution of biliary obstruction. Consistent findings were obtained by analysis of serum 7alpha-hydroxycholesterol levels. On the other hand, hepatic cholesterol 7alpha-hydroxylase mRNA, microsomal enzyme activity, and cholesterol content tended to be increased in cholestasis. Finally, serum 27-hydroxycholesterol levels were slightly reduced in cholestatic subjects and were not related with the severity of the disease. Suppression of in vivo bile acid synthesis with no corresponding reduction in tissue 7alpha-hydroxylase expression and activity is consistent with nontranscriptional, posttranslational levels of regulation; these may play a role in the feedback control of bile acid synthesis in particular conditions. Alteration of the alternate biosynthetic pathway seems unlikely according to the present data.
Aged↗
Telangiectatic osteosarcoma of the extremity: neoadjuvant chemotherapy in 24 cases.
Between April 1990 and December 1994, we treated 24 patients with telangiectatic osteosarcoma (TO) of the extremities with neoadjuvant chemotherapy using 2 protocols. Surgery consisted of limb salvage in 21 patients and amputation or rotation plasty in 3. The histologic response to chemotherapy was good (90% or more tumor necrosis) in 23 patients, of whom 12 had total necrosis. With a mean follow-up of 74 (60-96) months, 20 patients remained continuously free of disease and 4 relapsed with lung metastases. There were no local recurrences. Comparing these results to the ones achieved in 269 contemporary patients with conventional osteosarcoma of the extremities using the same protocols for chemotherapy, we found a significantly better histologic response to chemotherapy (96% vs 68% of good histologic response; p = 0.004) and disease-free survival (83% vs 55%; p = 0.01) in the TO group. We conclude that TO, once considered a lethal tumor, seems to be even more sensitive to chemotherapy than conventional osteosarcoma, and that most of these patients may be cured without amputation.
Adolescent↗
Histologic response of high-grade nonmetastatic osteosarcoma of the extremity to chemotherapy,.
In 510 patients with osteosarcoma of the extremity treated at the authors' institute between March 1983 and June 1995 with different regimens of neoadjuvant chemotherapy, factors that influenced the histologic response were investigated. The rate of total necrosis was not related to the patients' gender, age, site, size of tumor, serum of alkaline phosphatase values, or route of cisplatin administration. The histologic response significantly and independently correlated with the number of drugs administered before surgery and with the histologic subtype of the tumor. According to the number of drugs used, the percentage of total necrosis was 31% for a four-drug regimen, 18% for a three-drug regimen, and only 1.5% for a two-drug regimen. According to the histologic type, the rates of total necrosis were 41% for telangiectatic tumors, 36% for fibroblastic tumors, 15% for osteoblastic tumors, and 3% for chondroblastic tumors. The authors concluded that in neoadjuvant therapy of osteosarcoma, the histologic response to preoperative treatment, which correlates with prognosis, depends on the effectiveness of the chemotherapy regimen and on some features intrinsically inherent to the tumor. These data should be considered when selecting the type of treatment (adjuvant or neoadjuvant) and the combinations of drugs to be used in preoperative treatment of patients with osteosarcoma.
Adolescent↗
Increased expression of the normal cellular isoform of prion protein in inclusion-body myositis, inflammatory myopathies and denervation atrophy.
The cellular isoform of the prion protein (PrPc) is a glycosylphosphatidylinositol-anchored glycoprotein, normally expressed in neural and non-neural tissues, including skeletal muscle. In transmissible spongiform encephalopathies, or prion diseases, PrPc, which is soluble in nondenaturing detergent and sensitive to proteinase K (PK)-treatment, represents the molecular substrate for the production of a detergent-insoluble and PK-resistant isoform, termed PrP(Sc). In human prion diseases, PrP(Sc) accumulation occurs only in brain tissues, with the exception of new variant Creutzfeldt-Jakob disease, where PrP(Sc) is also detected in lymphoid tissues. Increased amounts of prion protein expression and deposition have been described in pathological muscle fibers of two human muscle disorders, called sporadic inclusion-body myositis (s-IBM) and hereditary inclusion-body myopathy, but it is unknown whether accumulated prion protein reflects normal PrPc or PrP(Sc). We investigated the biochemical characteristics of prion protein in normal human muscle, s-IBM, other inflammatory myopathies and denervation atrophy. We report that 1) both the glycoform profile and size of the normal muscle PrPc are different from those of human brain PrPc; 2) in addition to s-IBM, increased PrPc expression is seen in polymyositis, dermatomyositis and neurogenic muscle atrophy, but PrPc glycoforms are unchanged; 3) only the normal PrPc isoform, and not PrP(Sc), is detected in s-IBM. The present results exclude that s-IBM is a prion disease.
Adult↗