Search PubMed⌕ Search

Biomedical subjects

G Russo

Publications and source records attributed to G Russo.

At least 127 records · Page 7Linked to original sources
PubMed1997

Construction of a 5-Mb YAC contig from the putative 10q25 tumor-suppressor region for glioblastomas.

During the final step of the malignant progression to glioblastoma multiforme (GBM), the most frequent and malignant of primary brain tumors, more than 90% of the cases exhibit loss of genetic material on chromosome 10. We previously identified a 4-cM deletion interval in the 10q24-qter region that is common to all the GBM we have examined. A contig of 20 YACs spanning the 5 Mb of chromosomal DNA in the region has been assembled. Overlaps between YACs have been verified by STS content, fingerprinting analysis, and/or Alu-Alu PCR. The contig contains 17 known microsatellite markers, 15 new STSs derived from the insert ends of YACs, 9 ESTs, and 11 others STSs, for a total of 52 STSs (average marker density 1/100 kb). The physical map of this region will facilitate the search for a candidate tumor-suppressor gene(s) that is inactivated during the information of GBM.

Base Sequence↗
PubMed1997

Different domains cooperate to target the human ribosomal L7a protein to the nucleus and to the nucleoli.

The human ribosomal protein L7a is a component of the major ribosomal subunit. We transiently expressed in HeLa cells L7a-beta-galactosidase fusion proteins and studied their subcellular localization by indirect immunofluorescence staining with anti-beta-galactosidase antibodies. We have identified three distinct domains responsible for the nuclear targeting of the protein: domain I, amino acids 23-51; domain II, amino acids 52-100; domain III, amino acids 101-220, each of which contains at least one nuclear localization signal (NLS). Through subcellular localization analysis of deletion mutants of L7a-beta-galactosidase chimeras, we demonstrate that domain II plays a special role because it is necessary, although not sufficient, to target the chimeric beta-galactosidase to the nucleoli. In fact, we demonstrate that the nucleolar targeting process requires the presence of domain II plus an additional basic domain that can be represented by an NLS or a basic stretch of amino acids without NLS activity. Thus, when multiple NLS are present, each NLS exerts distinct functions. Domain II drives nucleolar accumulation of a reporter protein with the cooperative action of a short basic amino acid sequence, suggesting a mechanism requiring protein-protein or protein-nucleic acid interactions.

Amino Acid Sequence↗
PubMed1997

Stable expression and purification of a secreted human recombinant prethrombin-2 and its activation to thrombin.

A human prothrombin cDNA has been engineered to obtain a cDNA coding for a secreted form of human prethrombin-2. The secreted prethrombin-2 has been produced in a mammalian expression system using DXB11 cells, a mutant strain of CHO cells in which the dihydrofolate reductase gene has been deleted, and an expression vector carrying the dihydrofolate reductase cDNA. Methotrexate-induced gene amplification favored an efficient production of the recombinant protein which accumulated in the culture medium of the DXB11 cells. Growth in suspension of the stable transformants in an airlift fermenter resulted in the production of 25 mg/L recombinant prethrombin-2. The recombinant protein was purified using single-step affinity chromatography on a recombinant-hirudin column and activated by agarose gel-immobilized ecarin. All purified recombinant prethrombin-2 was activated and the generated recombinant thrombin showed catalytic properties identical to those of plasma-derived alpha-thrombin. This expression system can be used to prepare mutants of prethrombin-2 for structure-function studies investigating thrombin interactions with substrate proteins, inhibitors, and cell membranes.

Animals↗
PubMed1997

Improvement in establishing the period of rubella virus primary infection using a mild protein denaturant.

A more precise determination of the date of primary rubella infection in pregnancy is obtained by application of the urea denaturation method. Two denaturation buffers containing 6 and 8 M urea were compared for the detection of rubella IgG avidity by enzyme immunoassay. The results demonstrate that IgG avidity detected by 6M urea increases more rapidly, from 16% on the third day to 51% on the 46th day after the rash, than that obtained by 8 M urea, from 13 to 36%. The specific rubella IgG avidity detected by 6 M urea denaturation buffer increased significantly in paired sera obtained at an interval of 15 days. The same samples did not show any significant increase of IgG avidity when an 8 M urea denaturation buffer was used. The use of a mild denaturant such as 6 M urea indicates the presumptive date of primary rubella infection in pregnancy within 2 months of sampling.

Acute Disease↗
PubMed1997

Immune status and the immune response to hepatitis B virus vaccine in thalassemic patients after allogeneic bone marrow transplantation.

We evaluated the immune status with respect to HBV and the immune response to readministration of HBV vaccine in a series of 20 patients with homozygous beta-thalassemia, aged 6-23 years (mean age: 13.0 +/- 4.2) who had undergone allogeneic bone marrow transplantation (BMT). Thirteen of them (group A), had received three doses of plasma-derived HBV vaccine from 7 to 5 years before BMT and 4-5 weeks after the last dose of vaccine, they had had high serum levels of HBV antibodies (anti-HBs). The remaining seven patients (group B) had had clinical symptoms and laboratory evidence of HBV infection in childhood with markedly elevated serum of anti-HBs. Before revaccination, a significantly lower percentage of patients (P < 0.005) with seropositive levels of anti-HBs was observed in group A than in group B. After administration of the second dose of HBV vaccine the percentage of subjects with protective levels of anti-HBs rose to 100% in both groups of patients even if the geometric mean of titers of anti-HBs increased more significantly in group B patients than in group A. We conclude that the serum levels of anti-HBs afforded by HBV vaccine administered from 7 to 5 years previously are very low and probably non-protective in most beta-thalassemic patients after allogeneic BMT, and that at least two doses of HBV vaccine should be readministered from 18 to 24 months after BMT to achieve adequate and long-term protection from HBV.

Adolescent↗
PubMed1997

An alternative to continuous subcutaneous infusion of desferrioxamine in thalassaemic patients.

Sixteen patients with thalassaemia major were treated with subcutaneous desferrioxamine (DF) 50 mg/kg/d, 5 consecutive days a week, for 8 weeks. Every other week the total dose was administered by 12 h infusion pump or by rapid injection of the same dose (25 x 2 mg/kg) twice a day. The two methods of DF administration produced no significant differences in urinary iron excretion. No significant changes in serum ferritin levels were observed at the end of the study. Compared with continuous infusion, rapid injection is equally efficacious, does not induce serious side-effects, is better accepted by the patients, and can improve their compliance to the iron-chelating therapy.

Adolescent↗
PubMed1997

Human leucocyte interferon-alpha in chronic hepatitis C resistant to recombinant or lymphoblastoid interferon-alpha: a randomized controlled trial.

Patients with biopsy-proven chronic hepatitis C, who failed to respond to a previous course of either recombinant (rIFN-alpha) or lymphoblastoid (Ly IFN-alpha) interferon-alpha, were randomized to receive either leucocyte (Le) IFN-alpha (patients) or a second course of the same IFN-alpha (controls), to compare the efficacy and safety of these treatment schedules. All patients received the same dose of IFN-alpha as was used during their previous treatment (3 million units (MU) or 6 MU three times weekly) for 6 months. Patients with a normal alanine aminotransferase (ALT) value at month 6 were treated for a further 6 months. All patients were followed-up for 12 months after treatment. A total of 69 patients were enrolled, 44 in the Le IFN-alpha group and 25 in the control group. At the end of the treatment period, 13 of the 44 patients (29.5%) in the Le IFN-alpha group had a biochemical response (normal ALT) and six of 44 (13.6%) patients had undetectable serum hepatitis C virus (HCV) RNA. At the end of the follow-up period, 10 patients (22.7%) had normal ALT values and serum HCV RNA was undetectable in three (6.8%). None of the patients in the control group showed normal ALT values at any time. Genotype 1b tended to be more frequent among non-responders (61 vs 45%): basal gamma-glutamyl transpeptidase (gamma-GT) values were lower in responders than in non-responders (33.3 +/- 11.70 Ul-1 vs 58.4 +/- 33.04; P = 0.01). Le IFN-alpha was well tolerated by all patients. These results support the use of Le IFN-alpha in patients with chronic hepatitis C who are non-responders to a previous treatment with recombinant or lymphoblastoid IFN-alpha.

Antiviral Agents↗
PubMed1997

In vitro mimicry of CaMBr1 tumor-associated antigen by synthetic oligosaccharides.

The murine monoclonal antibody (Mab) MBr1, raised against the breast cancer cell line MCF7, recognizes a saccharidic epitope overexpressed on a high percentage of human breast, ovary, and lung carcinomas. This antigen was originally identified on the immunogen as a globo-series glycosphingolipid with an H-like determinant at its terminus (globo-H). We report here the biological characterization of the entire globo-H hexasaccharide and five synthetic oligosaccharides representing fragments of the entire structure and/or different anomeric configurations. Using competitive binding assays on live cells, we identified the residues and the linkages essential for mimicry of the cellular antigens recognized by Mab MBr1 on the breast carcinoma cell line MCF7 and small cell lung cancer cell line POVD. The terminal tetrasaccharidic fragment of globo-H is the oligosaccharide that most resembles the MBr1-defined epitope both on glycolipids and on glycoproteins. This information will help in the rational design of a highly specific reagent for active specific immunotherapy of carcinomas overexpressing the MBr1-defined antigen.

Antibodies, Monoclonal↗
PubMed1997

Persistence of Mediterranean anaemia in Sicily.

We report 40 cases of homozygous beta thalassaemia, aged between 3 and 24 months, who were observed between January 1990 and June 1996 at the Thalassaemia Centre, Paediatric Department, Catania University. A questionnaire was used to find out the parents' knowledge of their risk before the birth of the affected children and showed that the persistence of Mediterranean anaemia in Sicily was mainly because of the following reasons: (1) poor information (62.5%), (2) laboratory error (12.5%), (3) difficulty in the differential diagnosis of beta thalassaemia trait (10%), and (4) not performing prenatal testing or selective abortion of an affected fetus (15%). We conclude that improved preventive measures at various medical and social levels can remove risk factors and so further reduce the incidence of Mediterranean anaemia in Sicily.

Genetic Counseling↗
PubMed1997

In situ evidence of neoplastic cell phagocytosis by macrophages in papillary thyroid cancer.

We evaluated the occurrence, tissue distribution, and prognostic value of tumor-associated macrophages in 121 papillary thyroid carcinomas using immunohistochemical staining with anti-CD68 antibody in archival paraffin-embedded sections. Lymphocytic infiltration and dendritic cell presence were also evaluated. Three groups were identified according to the presence and characteristics of macrophages: 1) tumors without evidence of infiltrating macrophages: (n = 35); 2) tumors with infiltrating macrophages but no evidence of neoplastic cells phagocytosis (n = 68); and 3) tumors with infiltrating macrophages and in situ evidence of active neoplastic cell phagocytosis (n = 18). Neoplastic cell phagocytosis by macrophages was positively correlated with both lymphocytic infiltration and dendritic cells (P = 0.0000), whereas it was negatively correlated with vascular invasion (P = 0.0032). Distant metastases developed in none of the 18 tumors with neoplastic cell phagocytosis, but occurred in 15 of 103 of the remaining tumors (P = 0.0647) and were significantly and negatively associated with lymphocytic infiltration or dendritic cells. The present study indicates, therefore, that immune reaction, involving neoplastic cell phagocytosis by macrophages and lymphocytic infiltration, plays a role in the development of distant metastases in patients with papillary thyroid cancer.

Adult↗
PubMed1997

Negative/low expression of the Met/hepatocyte growth factor receptor identifies papillary thyroid carcinomas with high risk of distant metastases.

To investigate the clinical impact of Met/hepatocyte growth factor receptor (HGF-R) expression in thyroid cancer we studied 163 thyroid carcinomas (129 papillary, 21 follicular, and 13 anaplastic) from patients followed-up for 25-147 months postthyroidectomy. Forty-nine thyroid adenomas were also studied. Met/HGF-R expression was evaluated by semiquantitative immunohistochemistry, measuring both the proportion (scale of 0-5) and the intensity (scale, 0-5) of stained cells and calculating a total score (scale of 0-10). Met/HGF-R was absent in the normal thyroid tissue, absent or focally expressed in follicular and anaplastic tumors, and expressed at various levels in most papillary carcinomas, including microcarcinomas. Papillary carcinomas were thus categorized as having negative/low Met/HGF-R (n = 50; total score, < or = 5) or high Met/HGF-R expression (n = 70; total score, > 5). High Met/HGF-R was inversely associated with vascular invasion (P = 0.0308), but not with other prognostic factors. Negative/low Met/HGF-R expression was the most effective predictor by multivariate Cox analysis of distant metastases (hazard ratio = 9.71; P = 0.0036), higher than extrathyroid invasion (hazard ratio = 4.25; P = 0.0181), age (< or = 45 vs. > 45 yr; hazard ratio = 3.99; P = 0.0099), and vascular invasion (hazard ratio = 3.19; P = 0.0358). These findings suggest a role for Met/HGF-R in papillary thyroid cancer and its clinical use to select patients with a high risk of distant metastases.

Adenocarcinoma, Follicular↗
PubMed1997

A mechanical model of human spinal motion segments.

A modular mechanical model of the spine was developed which can be adapted to approximate the mechanical properties of various spinal levels and pathologic conditions in single- or multi-segmental forms. The characteristics of the model were compared with those of human L4-5 specimens in flexion and extension, axial rotation and lateral bending. The model showed comparable ranges of motion to those of human specimens in all directions and likewise was characterized by increasing stiffness with increasing load as well as hysteresis. This model can be used as a standard for the comparison of different spine testers. As a substitute for cadaveric specimens in implant testing, these models provide the advantages of availability, consistent properties, and adaptability, and avoid the risks associated with handling human tissue.

Adult↗
PubMed1997

[Spontaneous bacterial peritonitis in patients with liver cirrhosis. Differential aspects with portal thrombosis].

In a series of 155 patients with decompensated liver cirrhosis spontaneous bacterial peritonitis (SBP) was diagnosed in 15 cases (9.7%) and portal thrombosis (PT) in 8 (5.1%) by mean of standard criteria. The main clinical and laboratory characteristics were similar in the two groups of patients; fever was more frequently recorded in the SBP patients. Cytological examination of the ascites showed an increase in total cell count and in neutrophils count higher in SBP group than in PT. The diagnosis of PT was confirmed by ultrasonography. The data suggest that a cytological examination of the ascites should be performed in all patients with decompensated cirrhosis and may contribute to the differential diagnosis of SBP or PT.

English Abstract↗
PubMed1996

Dual action of retinoic acid on human embryonic/fetal hematopoiesis: blockade of primitive progenitor proliferation and shift from multipotent/erythroid/monocytic to granulocytic differentiation program.

In preliminary studies, we have analyzed the hematopoietic growth factor (HGF) requirement of hematopoietic progenitor cells (HPCs) purified from embryonic-fetal liver (FL) and grown in fetal calf serum-supplemented (FCS+) clonogenic culture. The key role of erythropoietin (Epo) for colony formation by early erythroid progenitors (burst-forming units-erythroid [BFU-E]) has been confirmed. Furthermore, in the absence of exogenous HGFs, FL monocytic progenitors (colony-forming unit monocyte [CFU-M]) generate large colonies exclusively composed of monocytes-macrophages; these colonies are absent in FCS- clonogenic culture. On this basis, we have investigated the role of all-trans retinoic acid (ATRA) and its isomer 9-cis RA in FL hematopoiesis. Both compounds modulate the growth of purified FL HPCs, which show a dose-dependent shift from mixed/erythroid/ monocytic to granulocytic colony formation. Studies on unicellular and paired daughter cell culture unequivocally indicate that the shift is mediated by modulation of the HPC differentiation program to the granulopoietic pathway (rather than RA-induced down-modulation of multipotent/ erythroid/monocytic HPC growth coupled with recruitment of granulocytic HPCs). ATRA and 9-cis RA also exert their effect on the proliferation of primitive HPCs (high-proliferative potential colony-forming cells [HPP-CFCs]) and putative hematopoietic stem cells (HSCs; assayed in Dexter-type long-term culture). High concentrations of either compound (1) drastically reduced the number of primary HPP-CFC colonies and totally abolished their recloning capacity and (2) inhibited HSC proliferation. It is crucial that these results mirror recent observations indicating that murine adult HPCs transduced with dominant negative ATRA receptor (RAR) gene are immortalized and show a selective blockade of granulocytic differentiation. Altogether, these results suggest that ATRA/9-cis RA may play a key role in FL hematopoiesis via a dual effect hypothetically mediated by interaction with the RAR/RXR heterodimer, ie, inhibition of HSC/ primitive HPC proliferation and induction of CFU-GEMM/ BFU-E/CFU-M shift from the multipotent/erythroid/monocytic to the granulocytic-neutrophilic differentiation program.

Cell Differentiation↗
PubMed1996

Inactivation of delayed rectifier K+ current in semicircular canal hair cells.

Some properties of the inactivation process of delayed rectifier K+ current (Ik) were investigated in vestibular hair cells of the central region of frog crista ampullaris. These cells were chosen since they exhibited a very large Ik. Experiments were performed on thin slices of sensory epithelium using the whole-cell variant of the patch-clamp technique. Ik showed clear time-dependent inactivation over a period of some seconds, but the current did not completely inactivate even after 30 s depolarizing pulses. Another interesting finding was that inactivation could be well fitted by the sum of two exponentials: at 20 mV depolarization the fast time constant was 291.3 ms and the slow time constant was 2662.3 ms. In addition, an analysis of the steady-state inactivation process of Ik revealed that the inactivation curve was incomplete showing a non-inactivating current at potentials more positive than -50 mV. These results suggested that Ik in hair cells of frog crista ampullaris is composed of more than one component: by at least one inactivating and one non-inactivating component. The possible role of these components in hair cell excitability is discussed.

Animals↗
PubMed1996

Potassium currents of pear-shaped hair cells in relation to their location in frog crista ampullaris.

Voltage-dependent K+ currents in pear-shaped hair cells of the frog crista ampullaris were investigated in thin slice preparations using the whole-cell variant of the patch-clamp technique. Microscopy observation revealed that pear-shaped cells are located in intermediate and peripheral regions of the crista, whereas they are absent in the central region. Voltage-clamp recordings in cells from the peripheral regions revealed that the total outward K+ current could be separated pharmacologically into three distinct components: a A-type K+ current (IA); an inactivating calcium-activated K+ current (IK(Ca)) and a delayed rectifier K+ current (IK). IK and IK(Ca) exhibited similar magnitude and accounted for most of the membrane cell conductance. The same experimental protocol applied to cells from the intermediate regions showed the presence of a large and sustained IK(Ca) which represented 95% of the total outward current. In this region IA was absent. The present results demonstrated that pear-shaped hair cells located in two discrete regions of frog crista ampullaris exhibit a different complement of voltage-dependent conductances, suggesting that they can play a different role in processing the natural stimulus.

Animals↗