Traumatic left shoulder fracture masking aggressive granuloblastic sarcoma in a CML patient.
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The ideal microbicide must fulfill a number of criteria including a broad and potent activity against transmission of HIV and other sexually transmitted agents in the absence of toxicity and inflammation. We have described that derivatives of K5 polysaccharide from Escherichia coli inhibit HIV entry in target cells. K5 derivatives have a structure that resembles that of heparin, but they are devoid of the anticoagulant activity typical of heparin. Moreover, in contrast to heparin, they inhibit a broad spectrum of HIV-1 laboratory-adapted and primary isolates that use either CCR5 or CXCR4 or both coreceptors in terms of their infection and replication in primary CD4+ lymphocytes and monocytes-derived macrophages (MDM). Therefore, these compounds could be developed as candidate microbicides for preventing sexual HIV transmission, a predominant modality of HIV spreading in both the developed and underdeveloped world.
Mucormycosis infections, caused by fungi of the families Rhizopus, Mucor or Absidia, are typically rapidly progressive and often fatal. We report a 27-year-old male with acute myeloid leukemia (AML) developing an invasive pulmonary-CNS mucormycosis during the neutropenic period after salvage induction chemotherapy; the infection was successfully controlled with surgery and antifungal therapy. The patient received two courses of consolidation chemotherapy and underwent autologous stem cells transplantation (ASCT) while receiving secondary antifungal systemic prophylaxis with liposomal Amphotericin B (L-AMB, Ambisome). There was no clinical, radiological or microbiological evidence of mycotic reactivation during the bone marrow transplantation (BMT) procedure.
The angiogenic basic fibroblast growth factor (FGF2) interacts with tyrosine kinase receptors (FGFRs) and heparan sulfate proteoglycans (HSPGs) in endothelial cells. Here, we report the FGF2 antagonist and antiangiogenic activity of novel sulfated derivatives of the Escherichia coli K5 polysaccharide. K5 polysaccharide was chemically sulfated in N- and/or O-position after N-deacetylation. O-Sulfated and N,O-sulfated K5 derivatives with a low degree and a high degree of sulfation compete with heparin for binding to 125I-FGF2 with different potency. Accordingly, they abrogate the formation of the HSPG.FGF2.FGFR ternary complex, as evidenced by their capacity to prevent FGF2-mediated cell-cell attachment of FGFR1-overexpressing HSPG-deficient Chinese hamster ovary (CHO) cells to wild-type CHO cells. They also inhibited 125I-FGF2 binding to FGFR1-overexpressing HSPG-bearing CHO cells and adult bovine aortic endothelial cells. K5 derivatives also inhibited FGF2-mediated cell proliferation in endothelial GM 7373 cells and in human umbilical vein endothelial (HUVE) cells. In all these assays, the N-sulfated K5 derivative and unmodified K5 were poorly effective. Also, highly O-sulfated and N,O-sulfated K5 derivatives prevented the sprouting of FGF2-transfected endothelial FGF2-T-MAE cells in fibrin gel and spontaneous angiogenesis in vitro on Matrigel of FGF2-T-MAE and HUVE cells. Finally, the highly N,O-sulfated K5 derivative exerted a potent antiangiogenic activity on the chick embryo chorioallantoic membrane. These data demonstrate the possibility of generating FGF2 antagonists endowed with antiangiogenic activity by specific chemical sulfation of bacterial K5 polysaccharide. In particular, the highly N,O-sulfated K5 derivative may provide the basis for the design of novel angiostatic compounds.
Sixty-one cases of Aspergillus infection (35 acute myeloid leukemia, 15 acute lymphoid leukemia, one myelodysplastic syndrome, two aplastic anemia, eight non-Hodgkin's lymphoma) seen in our department between January 1989 and July 1999 were studied retrospectively to evaluate the clinical characteristics, to ascertain the factors that influenced the outcome from mycotic infections, and whether early diagnosis and prolonged therapy permitted completion of scheduled intensive chemotherapy and bone marrow transplantation (BMT) without fungal recurrence. The patients were divided into three diagnostic categories: proven aspergillosis (autoptic or histologic diagnosis) n = 39, probable aspergillosis (radiological diagnosis with positive microbiology) n = 9, and possible aspergillosis (radiological diagnosis alone) n = 13. In the same period among 675 acute leukemia patients the incidence of proven or probable aspergillosis was 7.1%. At onset of infection 92% of patients were neutropenic (< 0.5 x 10(9)/L). The most frequent site of infection was the lung (90%); disseminated disease was present in 20 patients. Among 44 assessable patients, 12 (27%) failed to respond to early antifungal therapy and died. Thirty-two patients were cured with antifungal treatment, three of five nonneutropenic with only itraconazole, the others with amphotericin B 1 mg/Kg/day with or without itraconazole subsequently or with liposomal amphotericin, Ambisome, if renal toxicity occurred. Twenty-four of 29 neutropenic responders, all affected by acute leukemia, continued scheduled intensive chemotherapies. Pulmonary lobectomy was successfully combined with medical treatment in two cases before scheduled BMT. After infection nine patients were submitted to BMT (six allo, one marrow unrelated donor (MUD), two auto) with Ambisome or itraconazole as secondary prophylaxis without fungal relapse (follow-up: 25-99 months). The median time from fungal infection to transplant was five months, range 3-10. Thirteen of 29 surviving patients had leukemia relapse, but only three (23%) of these showed also fungal infection recurrence. In conclusion, a high index of suspicion and careful clinical and radiological examinations are the key to identifying infected patients early and to programming the following therapeutic steps. Above all in leukemia patients, prompt and aggressive administration of antifungal agents seems to improve the outcome of invasive fungal disease and to permit intensive chemotherapy completion and transplant.
A process to generate glycosaminoglycans with heparin- and heparan sulfate-like sequences from the Escherichia coli K5 capsular polysaccharide is described. This polymer has the same structure as N-acetylheparosan, the precursor in heparin/ heparan sulfate biosynthesis. The process involves chemical N-deacetylation and N-sulfation, enzymatic conversion of up to 60% of the D-glucuronic acid to L-iduronic acid residues, and chemical O-sulfation. Because direct sulfation afforded unwanted 3-O-sulfated (instead of 2-O-sulfated) iduronic acid residues, a strategy involving graded solvolytic desulfation of chemically oversulfated C5-epimerized sulfaminoheparosans was assessed using persulfated heparin and heparan sulfate as model compounds. The O-desulfation process was shown to increase the anti-factor Xa activity of oversulfated heparin.
In the period 1973-1998, among 2139 allograft recipients treated with standard immunosuppression, posttransplant lymphoproliferative disorders (PTLD) developed in 19 patients (0.9%): one plasmacytic hyperplasia, two polymorphic PTLD, one myeloma, and 15 lymphomas. PTLD developed 1 year after transplantation (tx) in 14 patients. Five patients were diagnosed at autopsy, 2 were lost to follow up, 3 died before therapy could be instituted, and 1 patient has just started chemotherapy. Of the 8 evaluable patients, 2 received acyclovir and are alive in complete remission (CR) and 6 received chemotherapy +/- surgery. Of these 6, 4 died of lymphoma and/or infection, 1 died of unrelated causes in CR, and 1 is alive in CR. PTLD is a severe complication of tx, usually running an aggressive course which may preclude prompt diagnosis and treatment. Nevertheless, therapy is feasible and must be tailored on the histologic subtype. Seventy-four percent of patients were diagnosed with late-onset PTLD stressing the need for long-term follow up.
BACKGROUND AND OBJECTIVES: In recent years pulmonary mucormycosis has been reported in patients with leukemia and lymphoma and bone marrow transplant recipients. It carries an extremely poor prognosis. We report our experience of clinical findings, diagnostic procedures, treatment and outcome of mucormycosis diagnosed in neutropenic patients affected by hematologic neoplasms admitted to our Department. DESIGN AND METHODS: From November 1987 to July 1999 we observed 13 cases of Mucor. Their median age was 61 years (range 20-75), and they were predominantly in the aplastic post-chemotherapy period (12/13), affected by acute myeloid leukemia (11 cases ) or non-Hodgkin's lymphoma (2 cases). Six patients (all with leukemia) were receiving inductionEth consolidation therapy, 7 had progressive hematologic disease. At the onset of infection all patients were neutropenic (N < 0.5x10(9)/L). No patients had diabetes mellitus. Two patients had been receiving steroid therapy for 5 and 7 days. RESULTS: The lung was involved in all cases (13/13); disseminated disease was present in 8/13 patients. All cultures (blood, sputum, nasal swabs and bronchoalveolar lavage) were negative. In 3 patients a histologic diagnosis was made in vivo: in 1 patient by percutaneous pulmonary biopsy, in 1 patient by pulmonary lobectomy, and in the last patient by percutaneous pulmonary biopsy confirmed by excision of a cerebellar abscess. In the remaining 10 cases diagnosis was made post-mortem. Five patients were not treated, 2 because of poor clinical condition and 3 because fungal infection was not suspected. Amphotericin B (1 mg/kg/day) was given empirically to 6 patients and 2 responded to treatment. The remaining 2 patients with neurologic symptoms at the onset of infection were treated with liposomal amphotericin, Ambisome, one with 3 and one with 5 mg/kg/day; of these two patients the first died in 4 days; the second, with both pulmonary and cerebellar localizations, was treated successfully with 5 mg/kg/day for 4 weeks and then with 3 mg/kg/day, and excision of a brain abscess at neutrophil recovery (total dose of Ambisome: 12,000 mg). The 3 surviving leukemic patients were able to complete subsequent consolidation therapy using amphotericin B or liposomal amphotericin as secondary prophylaxis during aplasia. INTERPRETATION AND CONCLUSIONS: In neutropenic hematologic patients Mucor is rarely suspected. In our patients infection was often characterized by disseminated disease and a rapidly fatal course; only early aggressive amphotericin B (or Ambisome) treatment together with neutrophil recovery appeared to improve the outcome. Diagnosis is very important for programming antifungal therapy and secondary prophylaxis with amphotericin B, because Mucor is usually resistant to itraconazole.
Tat protein, a transactivating factor of the human immunodeficiency virus type I, acts also as an extracellular molecule. Heparin affects the bioavailability and biological activity of extracellular Tat (Rusnati, M., Coltrini, D., Oreste, P., Zoppetti, G., Albini, A., Noonan, D., D'Adda di Fagagna, F., Giacca, M., and Presta, M. (1997) J. Biol. Chem. 272, 11313-11320). Here, a series of homogeneously sized, (3)H-labeled heparin fragments were evaluated for their capacity to bind to free glutathione S-transferase (GST)-Tat protein and to immobilized GST-Tat. Hexasaccharides represent the minimum sized heparin fragments able to interact with GST-Tat at physiological ionic strength. Also, the affinity of binding increases with increasing the molecular size of the oligosaccharides, with large fragments (>/=18 saccharides) approaching the affinity of full-size heparin. 6-Mer heparin binds GST-Tat with a dissociation constant (K(d)) equal to 0.7 +/- 0.4 microM and a molar oligosaccharide:GST-Tat ratio of about 1:1. Interaction of GST-Tat with 22-mer or full-size heparin is consistent instead with two-component binding. At subsaturating concentrations, a single molecule of heparin interacts with 4-6 molecules of GST-Tat with high affinity (K(d) values in the nanomolar range of concentration); at saturating concentrations, heparin binds GST-Tat with lower affinity (K(d) values in the micromolar range of concentration) and a molar oligosaccharide:GST-Tat ratio of about 1:1. In agreement with the binding data, a positive correlation exists between the size of heparin oligosaccharides and their capacity to inhibit cell internalization, long terminal repeat-transactivating activity of extracellular Tat in HL3T1 cells, and its mitogenic activity in murine adenocarcinoma T53 Tat-less cells. The data demonstrate that the modality of heparin-Tat interaction is strongly affected by the size of the saccharide chain. The possibility of establishing multiple interactions increases the affinity of large heparin fragments for Tat protein and the capacity of the glycosaminoglycan to modulate the biological activity of extracellular Tat.
Human immunodeficiency virus type 1 (HIV-1) Tat protein is released from infected cells. Extracellular Tat enters the cell where it stimulates the transcriptional activity of HIV-long terminal repeat (LTR) and of endogenous genes. Heparin modulates the angiogenic (Albini, A., Benelli, R., Presta, M., Rusnati, M., Ziche, M., Rubartelli, A., Paglialunga, G., Bussolino, F., and Noonan, D. (1996) Oncogene 12, 289-297) and transcriptional (Mann, D. A., and Frankel, A. D. (1991) EMBO J. 10, 1733-1739) activity of extracellular Tat. Here we demonstrate that heparin binds specifically to recombinant HIV-1 Tat produced as glutathione S-transferase (GST) fusion protein and immobilized on glutathione-agarose beads. Heparin and heparan sulfate (HS), but not dermatan sulfate, chondroitin sulfates A and C, hyaluronic acid, and K5 polysaccharide, competed with 3H-labeled heparin for binding to immobilized GST-Tat and inhibited HIV-LTR transactivation induced by extracellular GST-Tat. Selective 2-O-, 6-O-, total-O-desulfation, or N-desulfation/N-acetylation dramatically reduced the capacity of heparin to bind GST-Tat. Totally-O-desulfated and 2-O-desulfated heparins also showed a reduced capacity to inhibit the transactivating activity of GST-Tat. Very low molecular weight heparins showed a significant decrease in their capacity to bind GST-Tat and to inhibit its LTR transactivating activity when compared with conventional 13.6-kDa heparin. However, when 3.0-kDa heparin was affinity chromatographed on immobilized GST-Tat to isolate binding and non-binding subfractions, the Tat-bound fraction was >/=1,000 times more potent than the unbound fraction in inhibiting the transactivating activity of GST-Tat. The results demonstrate that Tat interacts in a size-dependent manner with heparin/HS and that high affinity Tat-heparin interaction requires at least some 2-O-, 6-O-, and N-positions to be sulfated. The Tat binding activity of the glycosaminoglycans tested correlates with their capacity to affect the transactivating activity of extracellular Tat, indicating the possibility to design specific heparin/HS-like structures with Tat-antagonist activity.
We compared the clinical and pathological features of 10 HIV+ CD30+ anaplastic large cell lymphoma (ALCL) patients with 28 HIV+ CD30- non-Hodgkin's lymphoma (NHL) patients. The incidence of ALCL among 38 HIV+ systemic NHL patients was 26%. Clinical features were similar in all the HIV-related NHL cases, but ALCL patients seemed to differ from HIV+ CD30- systemic NHL only in the greater frequency of lung tumours (40% v 21%) without concomitant mediastinal mass, bone marrow (75% v 18%) and gastroenteric involvement (40% v 25%). Among the HIV+ ALCL patients, histologic subtypes did not differ in frequency from ALCL in the general population. The B phenotype was predominant (50%) as in other HIV-related NHL. EBV genoma, studied in all HIV+ ALCL patients, was present in 3/10 by in situ hybridization (ISH) and in 5/10 cases using PCR. The clinical course of lymphomas was similar in CD30 positive and negative NHL patients. Overall survival also was short in our series, particularly in HIV+ ALCL (84 v 188 d), probably because of profound immunodepression of the ALCL patients. Our findings suggest that severe immunodepression due to HIV infection determines-more than any other factor-the clinical features of HIV+ ALCL, making them very similar to those of other high-grade systemic HIV+ NHL.
O-Sulfation of sulfaminoheparosan SAH, a glycosaminoglucuronan with the structure-->4)-beta-D-GlcA(1-->4)-beta-D-GlcNSO3(-)-(1-->, obtained by N-deacetylation and N-sulfation of the capsular polysaccharide from E. coli K5, was investigated in order to characterize the sulfation pattern eliciting heparin-like activities. SAH was reacted (as the tributylammonium salt in N,N-dimethylformamide) with pyridine-sulfur trioxide under systematically different experimental conditions. The structure of O-sulfated products (SAHS), as determined by mono- and two-dimensional 1H and 13C NMR, varied with variation of reaction parameters. Sulfation of SAH preferentially occurred at O-6 of the GlcNSO3- residues. Further sulfation occurred either at O-3 or at O-2 of the GlcA residues, depending on the experimental conditions. Products with significantly high affinity for antithrombin and antifactor Xa activity were obtained under well-defined conditions. These products contained the trisulfated aminosugar GlcNSO3-3,6SO3-, which is a marker component of the pentasaccharide sequence through which heparin binds to antithrombin.
Heparins from bovine mucosa and lung, and chemically modified heparins were assayed for their capacity to: (i) protect human recombinant basic fibroblast growth factor (bFGF) from tryptic cleavage; (ii) prevent 125I-bFGF binding to heparan sulphate proteoglycans present in the extracellular matrix and on the cell surface of fetal bovine aortic endothelial GM 7373 cell cultures; (iii) affect 125I-bFGF binding to high-affinity tyrosine kinase FGF receptors present on the cell membrane of GM 7373 cells; (iv) inhibit the mitogenic activity exerted by bFGF in the same cells. The results demonstrate that the potency shown by mucosal heparins in the different assays is a direct function of size, very-low-molecular-mass heparin (2.0 kDa) being significantly less effective on a molar basis than unfractionated heparin (13.6 kDa). Increased flexibility of the backbone structure, as observed in reduced/oxidized heparins of different size, does not affect the capacity of the polysaccharide to interact with bFGF. In contrast, selective 2-O-desulphation, but not 6-O-desulphation, drastically reduced the capacity of heparin to protect bFGF from proteolytic cleavage, to affect its interaction with low- and high-affinity sites, and to inhibit its mitogenic activity. Two preparations of bovine lung heparin, differing in molecular mass, were as effective as mucosal heparin in the bFGF-tryptic-digestion assay and the endothelial-cell proteoglycan-binding assay, but they were highly inefficient at inhibiting the capacity of bFGF to interact with its tyrosine kinase receptors. Bovine lung heparins were also less effective than mucosal heparin as bFGF antagonists in GM 7373-cell-proliferation assays. N-Desulphated/N-acetylated bovine lung heparin retained only a significant capacity to protect bFGF from tryptic cleavage. The results demonstrate that different chemical features of the heparin molecule, including decrease in molecular mass, selective desulphation, disaccharide composition and clustering, affect differently the capacity of the glycosaminoglycan to interact with bFGF and to influence its biological behaviour in different assays in vitro and in endothelial cell cultures. Our findings should aid the design of synthetic oligosaccharides aimed at improving the bioavailability of bFGF when administered in vivo as a therapeutic agent.
Interaction of basic fibroblast growth factor (bFGF) with heparan sulfate proteoglycans (HSPGs) plays an important role in the binding of bFGF to its tyrosine kinase receptor (FGFR). The molecular bases of this interaction were investigated by evaluating the capacity of conventional and selectively desulfated heparins i) to affect the binding of bFGF to FGFR and HSPGs of NIH 3T3 cells transfected with FGFR-1/flg cDNA, ii) to facilitate the interaction of bFGF with a recombinant soluble form of the extracellular domain of FGFR-1/flg (xcFGFR-1), and iii) to protect xcFGFR-1 from tryptic cleavage. 6-O-desulfated (6-O-DS) heparin, but not 2-O-desulfated (2-O-DS) and N-desulfated/N-acetylated (N-DS/N-Ac) heparins, retains the capacity to bind bFGF, as assessed by its ability to inhibit bFGF-binding to cell-associated FGFR-1 and HSPGs. On the other hand, at variance with conventional heparin, 2-O-DS, N-DS/N-Ac, and 6-O-DS heparins are all ineffective in potentiating the binding of bFGF to xcFGFR-1 and protecting xcFGFR-1 from tryptic cleavage. The data indicate that 6-O-sulfate groups are not essential for the interaction of heparin with bFGF but are involved in the interaction with xcFGFR-1. Our findings support the hypothesis that HSPGs modulate the binding of bFGF to FGFR through the formation of a ternary complex in which the glycosaminoglycan chains interact with bFGF via 2-O- and N-sulfate groups and with FGFR also via 6-O-sulfate groups.
GAGs were purified from urine of dogs after intranasal administration of 40 mg/kg ITF 1300. The electrophoretic patterns of urine GAGs in acidic buffer showed the presence of heparin together with chondroitins, heparan sulfate, and hyaluronic acid. The heparin present in urines was purified using chondroitinase ABC, and its purity was tested by electrophoresis in acidic buffer. The sample obtained was characterized by 13C-NMR, showing the same characteristic signals of the heparin starting material.
We report nasopharyngeal angiofibroma in a 13 year old boy treated with embolization, surgical excision and radiotherapy, which recurred 13 years later. No features of sarcomatous transformation were found, but the tumor had a locally aggressive course, possibly due to the HIV-positivity of the patient who then died of AIDS. The relations between the clinical course of the tumor and severe immunodeficiency are discussed.
In the present study we have attempted a characterization of the biochemical bases of the interaction of human basic fibroblast growth factor (bFGF) with glycosaminoglycans (GAGs) in solution. This interaction has been evidenced as the capacity of different GAGs and various sulfated compounds to protect bFGF and different bFGF mutants from tryptic cleavage. Heparin protects bFGF from trypsin digestion in a dose-dependent fashion. Substitution by site-directed mutagenesis of two or more basic residues with neutral glutamine residues in the amino-terminal region bFGF(27-32) or in the carboxyl-terminal region bFGF(118-129) does not significantly affect the protective effect exerted by heparin. In contrast, heparin protection is abolished when the full region bFGF(27-32) is deleted. The capacity of different GAGs to protect bFGF from proteolytic cleavage decreases in the following order: heparin > heparan sulfate > dermatan sulfate = chondroitin sulfates A and C > hyaluronic acid = K5 polysaccharide, indicating that both the degree of sulfation and the backbone structure of GAG modulate its interaction with bFGF. This is confirmed by the different capacity of various sulfated compounds (including dextran sulfates, suramin, trypan blue, and sulfate ion) to protect bFGF from tryptic digestion. Moreover, tryptic digestion studies performed with various heparin molecules and dextran sulfates of different size, ranging from 2.0 kDa to 500 kDa, indicate that the number of bFGF molecules which interact with a single molecule of polysaccharide is related to the molecular mass of the GAG and that six hexose residues are sufficient to protect 1-2 molecules bFGF. In conclusion, our findings indicate that the capacity of GAGs to protect bFGF from tryptic cleavage depends upon their size, sulfation, distribution of the anionic sites along the chain, and structural requirements of the bFGF molecule. These studies will help to design synthetic oligosaccharides endowed with different bFGF agonist and/or antagonist activities.
A sensitive method has been developed for extracting and analyzing heparin from plasma after intravenous and subcutaneous administration in humans and rabbits. The glycosaminoglycans are precipitated from the biological fluid as cetylpyridinium salt, and heparin is cleaved with heparinase. The reaction products are analyzed by polyacrylamide gel electrophoresis and visualized by staining with Azure A/ammoniacal silver. With this method 12 ng of heparin can be detected.