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Biomedical subjects

V Pavone

Publications and source records attributed to V Pavone.

At least 19 recordsLinked to original sources
PubMed2006

Poor mobilization is an independent prognostic factor in patients with malignant lymphomas treated by peripheral blood stem cell transplantation.

Haemopoietic stem cell therapy is an increasingly adopted procedure in the treatment of patients with malignant lymphoma. In this retrospective analysis, we evaluated 262 patients, 57 (22%) with Hodgkin's and 205 (78%) with non-Hodgkin's lymphomas (NHL), and 665 harvesting procedures in order to assess the impact of poor mobilization on survival and to determine the factors that may be predictive of CD34(+) poor mobilization. The mobilization chemotherapy regimens consisted of high-dose cyclophosphamide in 92 patients (35.1%) and a high-dose cytarabine-containing regimen (DHAP in 87 patients -(33.2%), MAD in 83 (31.7%)). The incidence of poor mobilizers (<2 x 10(6) CD34(+) cells/kg) was 17.9% overall, with a 10% of very poor mobilizers (< or = 1 x 10(6)/kg). Refractory disease status and chemotherapeutic load (>3 regimens) before mobilization played a negative role and were associated with poor mobilization. Survival analysis of all harvested patients showed an overall survival at 3 years of 71% in good mobilizers vs 33% in poor mobilizers (P=0.002). The event-free survival at 3 years was 23% in poor mobilizers and 58% in good mobilizers (P=0.04). We conclude that in NHL patients, poor mobilization status is predictive of survival.

Adult↗
PubMed2004

VEPEMB in elderly Hodgkin's lymphoma patients. Results from an Intergruppo Italiano Linfomi (IIL) study.

BACKGROUND: In advanced age the prognosis of Hodgkin's lymphoma (HL) is poor, but, as a consequence of the low incidence of HL in the elderly, prospective studies are lacking and the best treatment strategy is difficult to define. PATIENTS AND METHODS: One-hundred and five HL patients over 65 years of age were treated homogeneously with an original reduced-intensity regimen designed for HL in the elderly containing vinblastine, cyclophosphamide, procarbazine, etoposide, mitoxantrone and bleomycin (VEPEMB). Forty-eight early stage (IA-IIA) patients received three courses of VEPEMB followed by involved field irradiation. Fifty-seven advanced stage (IIB-IV) patients received six courses followed by radiotherapy limited to the areas of bulky disease. RESULTS: Mean age was 71 years (range 66-83). Co-morbidities were present in 39 patients (37%). A treatment plan modification for poor tolerance or toxicity was needed in 18 patients. Results were satisfactory, even if they were better in early rather than in advanced stage disease: complete response rate 98% versus 58% (P <0.01); 5-year failure-free survival 79% versus 34% (P <0.01). The results were affected by advanced stage, systemic symptoms and co-morbidity but they were not influenced by age itself. CONCLUSIONS: VEPEMB is an effective and low toxic regimen for HL in the elderly. Co-morbidity is a prognostic factor more important than age itself.

Age Distribution↗
PubMed2002

Mobilization of peripheral blood stem cells with high-dose cyclophosphamide or the DHAP regimen plus G-CSF in non-Hodgkin's lymphoma.

Our study analyzes the mobilization of hematopoietic stem cells after two chemotherapeutic regimens in non-Hodgkin's lymphoma (NHL) patients. The study included 72 patients with NHL (42 follicular and 30 large cells). The mean age was 37 years (range 17-60). Sixty-four patients (88.9%) had stage III-IV disease. Forty-eight patients (66.7%) had bone marrow involvement. Systemic B symptoms were present in 42 patients (58.3%). Mobilization chemotherapy regimens were randomly assigned as DHAP in 38 patients (52.7%) or cyclophosphamide (CPM) (5 g/m(2)) in 34 (47.2%) and the results of 132 procedures were analyzed. At the time of PBSC mobilization, 46 patients (63.9%) were considered to be responsive (complete remission, partial remission or sensitive relapse) and 26 (36.1%) not responsive (refractory relapse or refractory to therapy). Pre-apheresis CD34+ blood cell count and number of previous chemotherapy treatments were used to predict the total number of CD34+ cells in the apheresis product. The mobilizing regimens (CPM or DHAP) were similar in achieving the threshold CD34+ cell yield, for optimal engraftment. Since DHAP was very effective as salvage treatment, we suggest using DHAP as a mobilizing regimen in patients with active residual lymphoma at the time of stem cell collection.

Adolescent↗
PubMed2002

Assessment of skeletal status in patients with congenital disorder of glycosylation type IA.

Congenital disorder of glycosylation (CDG) type IA (phosphomannomutase deficiency) is the most common of a group of inherited metabolic disorders that are due to defective glycosylation of glycoproteins. CDG-IA is clinically characterized by major nervous system involvement and various organs are affected to a variable degree. Common clinical findings are skeletal changes including peculiar thoracic deformity and joint restriction, while a major radiological feature is diffuse osteopenia. The aim of this study was to measure bone density and biochemical markers of bone turnover in three patients with CDG-IA, whose age ranged between 14 and 27 years. We found that bone mass, as judged by standard densitometry, quantitative computed tomography and ultrasonography, was lower in patients than in age- and sex-matched healthy controls. Biochemical indexes of bone resorption including free pyridinoline levels in serum and pyridinoline and deoxypyridinoline urinary excretions were normal, whereas bone formation markers (serum osteocalcin and serum bone-specific alkaline phosphatase) activity were increased. These results suggest that low bone density is a component of CDG-IA, which should be considered among inherited metabolic diseases with decreased bone mass. We hypothesize that hypoglycosylation of noncollagenous bone proteins may contribute to the osteopenia observed in these patients. From a clinical point of view, our observation shows that bone density measurements can provide a quantitative assessment of bone involvement in such diseases.

Adolescent↗
PubMed2001

Toward the de novo design of a catalytically active helix bundle: a substrate-accessible carboxylate-bridged dinuclear metal center.

De novo design of proteins provides an attractive approach to uncover the essential features required for their functions. Previously, we described the design and crystal structure determination of a di-Zn(II) complex of "due-ferri-1" (DF1), a protein patterned after the diiron-dimanganese class of redox-active proteins [Lombardi, A.; Summa, C.; Geremia, S.; Randaccio, L.; Pavone, V.; DeGrado, W. F. Proc. Natl. Acad. Sci. U.S.A. 2000, 97, 6298-6305]. The overall structure of DF1, which contains a carboxylate-bridged dinuclear metal site, agrees well with the intended design. However, access to this dimetal site is blocked by a pair of hydrophobic leucine residues (L13 and L13'), which prevent facile entry of metal ions and small molecules. We have now taken the next step in the eventual construction of a catalytically active metalloenzyme by engineering an active site cavity into DF1 through the replacement of these two leucine residues with smaller residues. The crystal structure of the dimanganous form of L13A-DF1 indeed shows a substrate access channel to the dimetal center. In the crystal structure, water molecules and a ligating dimethyl sulfoxide molecule, which forms a monatomic bridge between the metal ions, occupy the cavity. Furthermore, the diferric form of a derivative of L13A-DF1, DF2, is shown to bind azide, acetate, and small aromatic molecules.

Amino Acid Sequence↗
PubMed2001

Congenital insensitivity to pain with anhidrosis (CIPA): novel mutations of the TRKA (NTRK1) gene, a putative uniparental disomy, and a linkage of the mutant TRKA and PKLR genes in a family with CIPA and pyruvate kinase deficiency.

Congenital insensitivity to pain with anhidrosis is an autosomal recessive hereditary disorder characterized by recurrent episodic fever, anhidrosis (inability to sweat), absence of reaction to noxious stimuli, self-mutilating behavior, and mental retardation. The human TRKA gene (NTRK1), located on chromosome 1q21-q22 encodes the receptor tyrosine kinase for nerve growth factor. We reported that TRKA is the gene responsible for CIPA and we developed a comprehensive strategy to screen for TRKA mutations and polymorphisms, as based on the gene's structure and organization. Here we report eight novel mutations detected as either a homozygous or heterozygous state in nine CIPA families from five countries. Mendelian inheritance of the mutations was confirmed in seven families for which samples from either parent were available. However, non-mendelian inheritance seems likely for the family when only samples from the mother and siblings, (but not from the father) were available. A paternal uniparental disomy for chromosome 1 is likely to be the cause of reduction to homozygosity of the TRKA gene mutation in this family. Interestingly, a Hispanic patient from the USA has two autosomal genetic disorders, CIPA and pyruvate kinase deficiency, whose genetic loci are both mapped to a closely linked chromosomal region. A splice mutation and a missense mutation were detected in the TRKA and PKLR genes from the homozygous proband, respectively. Thus, concomitant occurrence of two disorders is ascribed to a combination of two separate mutant genes, not a contiguous gene syndrome. This finding suggests a mechanism responsible for two autosomal genetic disorders in one patient. All these data further support findings that TRKA defects can cause CIPA in various ethnic groups. This will aid in diagnosis and genetic counseling of this painless but severe genetic disorder.

Adolescent↗
PubMed2001

A new ultrasound criterion for the diagnosis of polycystic ovary syndrome: the ovarian stroma/total area ratio.

OBJECTIVE: To evaluate whether some ultrasound parameters of ovarian morphology can discriminate between control women and patients with polycystic ovary syndrome (PCOS). DESIGN: Retrospective data analysis. SETTING: Volunteers women in an academic research environment. PATIENT(S): Eighty amenorrheic or oligomenorrheic women and 30 normal ovulatory control participants. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): We evaluated ovarian volume, area, stroma, and the stroma/total area (S/A) ratio by use of transvaginal pelvic ultrasound; and we assayed serum levels of gonadotropin, androgen, and estradiol during the early follicular phase (days 2 to 5) of the menstrual cycle in regularly cycling controls and on a random day in amenorrheic patients. RESULT(S): Patients with PCOS showed significantly higher ovarian volume, area, stroma, and mean S/A ratio when compared to multifollicular and control groups. Cut-off values have been defined for ovarian volume (13.21 mL), area (7.00 cm2), stroma (1.95 cm2), and S/A ratio (0.34). The sensitivity for PCOS diagnosis was 21%, 4%, 62%, and 100%, respectively. The S/A ratio showed the most significant correlation with the androgen levels. CONCLUSION(S): The evaluation of the S/A ratio can differentiate between PCOS and control or multifollicular women with both a sensitivity and a specificity of 100%. Furthermore, this ultrasound parameter is strictly related to hormonal milieu and to anthropometric characteristics.

17-alpha-Hydroxyprogesterone↗
PubMed2001

Structural determinants of CCR5 recognition and HIV-1 blockade in RANTES.

Certain chemokines act as natural antagonists of human immunodeficiency virus (HIV) by blocking key viral coreceptors, such as CCR5 and CXCR4, on the surface of susceptible cells. Elucidating the structural determinants of the receptor-binding and HIV-inhibitory functions of these chemokines is essential for the rational design of derivative molecules of therapeutic value. Here, we identify the structural determinants of CCR5 recognition and antiviral activity of the CC chemokine RANTES, showing that critical residues form a solvent-exposed hydrophobic patch on the surface of the molecule. Moreover, we demonstrate that the biological function is critically dependent on dimerization, resulting in the exposure of a large ( approximately 180 A2), continuous hydrophobic surface. Relevant to the development of novel therapeutic approaches, we designed a retroinverted RANTES peptide mimetic that maintained both HIV- and chemotaxis-antagonistic functions.

Alanine↗
PubMed2001

Total condylar knee arthroplasty: a long-term followup.

Between July 1977 and December 1983, 80 patients underwent 120 arthroplasties using a total condylar knee prostheses. Forty-one patients (68 knees) died and 13 patients were lost to followup. Twenty-six patients with 34 total condylar replacements were available for clinical followup. During the followup, 10 knees in nine patients (8.3%) from the overall 80 patients (120 knees) underwent revision; three (four knees) for aseptic loosening, one for periprosthetic fracture, three for infection, and two patients underwent revision for pain. Three revisions (three patients) occurred in the group of 26 patients available for followup. The average age of this group of patients at followup was 78 years (range, 53-94 years). There were 10 men and 16 women. Considering the high mean age of the patients in the series and patients' overall health status, the clinical results were extremely good. Kaplan-Meier analysis showed a survivorship of 91% at 23 years followup, considering revision as an end point. Although there have been several changes in total knee replacement designs, materials, and implantation techniques, the long-term outcome of the original total condylar knee prosthesis is excellent.

Adult↗
PubMed2000

Miniaturized metalloproteins: application to iron-sulfur proteins.

The miniaturization process applied to rubredoxins generated a class of peptide-based metalloprotein models, named METP (miniaturized electron transfer protein). The crystal structure of Desulfovibrio vulgaris rubredoxin was selected as a template for the construction of a tetrahedral (S(gamma)-Cys)(4) iron-binding site. Analysis of the structure showed that a sphere of 17 A in diameter, centered on the metal, circumscribes two unconnected approximately C(2) symmetry related beta-hairpins, each containing the -Cys-(Aaa)(2)-Cys- sequence. These observations provided a starting point for the design of an undecapeptide, which self assembles in the presence of tetrahedrally coordinating metal ions. The METP peptide was synthesized in good yield by standard methodologies. Successful assembly of the METP peptide with Co(II), Zn(II), Fe(II/III), in the expected 2:1 stoichiometry, was proven by UV-visible and circular dichroism spectroscopies. UV-visible analysis of the metal complexes indicated the four Cys ligands tetrahedrally arrange around the metal ion, as designed. Circular dichroism measurements on both the free and metal-bound forms revealed that the metal coordination drives the peptide chain to fold into a turned conformation. NMR characterization of the Zn(II)-METP complex fully supported the structure of the designed model. These results prove that METP reproduces the main features of rubredoxin.

Circular Dichroism↗
PubMed2000

Retrostructural analysis of metalloproteins: application to the design of a minimal model for diiron proteins.

De novo protein design provides an attractive approach for the construction of models to probe the features required for function of complex metalloproteins. The metal-binding sites of many metalloproteins lie between multiple elements of secondary structure, inviting a retrostructural approach to constructing minimal models of their active sites. The backbone geometries comprising the metal-binding sites of zinc fingers, diiron proteins, and rubredoxins may be described to within approximately 1 A rms deviation by using a simple geometric model with only six adjustable parameters. These geometric models provide excellent starting points for the design of metalloproteins, as illustrated in the construction of Due Ferro 1 (DF1), a minimal model for the Glu-Xxx-Xxx-His class of dinuclear metalloproteins. This protein was synthesized and structurally characterized as the di-Zn(II) complex by x-ray crystallography, by using data that extend to 2.5 A. This four-helix bundle protein is comprised of two noncovalently associated helix-loop-helix motifs. The dinuclear center is formed by two bridging Glu and two chelating Glu side chains, as well as two monodentate His ligands. The primary ligands are mostly buried in the protein interior, and their geometries are stabilized by a network of hydrogen bonds to second-shell ligands. In particular, a Tyr residue forms a hydrogen bond to a chelating Glu ligand, similar to a motif found in the diiron-containing R2 subunit of Escherichia coli ribonucleotide reductase and the ferritins. DF1 also binds cobalt and iron ions and should provide an attractive model for a variety of diiron proteins that use oxygen for processes including iron storage, radical formation, and hydrocarbon oxidation.

Amino Acid Sequence↗
PubMed2000

Prognosis of follicular lymphoma: a predictive model based on a retrospective analysis of 987 cases. Intergruppo Italiano Linfomi.

Patients (n-987) with a histologically confirmed diagnosis of follicular lymphoma were studied with the aim of developing a prognostic model specifically devised for this type of lymphoma. We collected information on age, sex, Ann Arbor stage, number of extranodal disease sites, bone marrow (BM) involvement, bulky disease, B symptom criteria (fever, night sweats, and weight loss), performance status (PS), serum lactate dehydrogenase (LDH) level, serum albumin level, hemoglobin level, and erythrocyte sedimentation rate (ESR). In the training sample of 429 patients with complete data, multivariate analysis showed that age, sex, number of extranodal sites, B symptoms, serum LDH level, and ESR were factors predictive for overall survival. Using these 6 variables, a prognostic model was devised to identify 3 groups at different risk. The 5- and 10-year survival rate was 90% and 65% for patients at low risk, respectively; 75% and 54% for patients at intermediate risk; and 38% and 11% for those at high risk (log-rank test, 86.62; P <. 0001). The model was also predictive (P =.0001) in the validation sample of 265 patients with complete data only for the 6 variables used in the development of the model and even in the group of 210 patients from the validation sample uniformly treated with doxorubicin-containing regimens (P =.0001). The prognostic model appears to be very useful in identifying patients with follicular lymphoma at low, intermediate, or high risk.

Adult↗
PubMed2000

The crystal structure of Afc-containing peptides.

A systematic structural analysis of Afc (9-amino-fluorene-9-carboxylic acid) containing peptides is here reported. The crystal structures of four fully protected tripeptides containing the Afc residue in position 2: Z-X(1)-Afc(2)-Y(3)-OMe (peptide a: X = Y = Gly; peptide b: X = Aib, C(alpha, alpha)-dimethylglycine, Y = Gly; peptide c: X = Gly, Y = Aib; peptide d: X = Y = Aib) have been solved by x-ray crystallography. All the results suggest that the Afc residue has a high propensity to assume an extended conformation. In fact, the Afc residue adopts an extended conformation in three peptides examined in this paper (peptides a-c). In contrast, Afc was found in a folded conformation, in the 3(10)-helical region, only in the peptide d, in which it is both preceded and followed by the strong helix promoting Aib.

Amino Acids↗
PubMed2000

Conformational behavior of C alpha,alpha-diphenyl glycine: extended conformation in tripeptides containing consecutive D phi G residues.

Recent studies on the conformational preferences of the Dphig (C(alpha,alpha)-diphenylglycine) residue showed that this C(alpha,alpha)-disubstituted glycine has a structural versatility. In fact, depending on the nature of the following or preceding residue, Dphig can assume either folded or extended conformations. We have carried out the analysis of the conformational preferences of the Dphig residue in tripeptides containing consecutive Dphig residues. The crystal structures of Z-Dphig-Dphig -Dphig-OMe (a; Z = benzyloxycarbonyl; OMe = methyl ester), Z-Aib-Dphig-Dphig-OMe (b; Aib = alpha-aminoisobutyric acid), and Z-Ac(3)c-Dphig-Dphig-OMe (c; Ac(3)c = alpha-amino-cyclopropan carboxylic acid), are here reported. The Dphig residues adopt the fully extended conformation in the three tripeptides examined. Together with our previous findings on Dphig containing peptides, the structures of the peptides here examined, indicate that the presence of adjacent Dphig residue in the sequence further stabilizes the extended conformation.

Crystallography, X-Ray↗
PubMed2000

The crystal structure of a Dcp-containing peptide.

We have investigated the conformational preferences of a newly synthesized C(alpha,alpha) symmetrically disubstituted glycine, namely alpha,alpha-dicyclopropylglycine (Dcp). We report here the crystal structure of a fully protected dipeptide containing Dcp, namely Z-Dcp(1)-Dcp(2)-OCH(3). Both Dcp residues are in a folded conformation. The overall peptide structural organization corresponds to an alpha-pleated sheet conformation, similar to that observed in linear peptides made up of alternating D- and L-residues and in Z-Aib-Aib-OCH(3) (Aib: alpha,alpha-dimethylglycine). These preliminary data suggest that the Dcp could represent an alternative as molecular tool to stabilize folded conformations.

Crystallography, X-Ray↗
PubMed2000

Extraordinary bone involvement in a gaucher disease type I patient.

We report on a 63-year-old patient with Gaucher disease type I who developed severe bone involvement with destructive lesions and huge soft tissue extension in both humeri that appeared to evolve slowly. The clinical course and histopathological findings in our patient suggested a progressive extraosseous extension of the storage cells into the soft tissue, accompanied by a striking increase of fibrotic tissue and resulting in an impressive deformity. The extraordinary bone involvement in this patient expands our knowledge on the most severe skeletal complications of untreated Gaucher disease.

Female↗
PubMed2000

Arthrogryposis multiplex congenita and pituitary ectopia. A case report.

We report a patient with a form of arthrogryposis multiplex congenita who developed seizures at 4 months of age that proved to be hypoglycemic. Further evaluation of the etiology of hypoglycemia led to the discovery of partial anterior hypopituitarism, with normal posterior pituitary function. Neuroimaging revealed an ectopic neurohypophysis with very small anterior pituitary, the presumed anatomic basis for his endocrine dysfunction. A chance association between the pituitary ectopia and the arthrogryposis cannot be ruled out. However, it is more likely that in the present patient a common genetic mechanism may be the basis for both the arthrogryposis and the pituitary dysfunction.

Abnormalities, Multiple↗