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Biomedical subjects

G Santini

Publications and source records attributed to G Santini.

At least 73 records · Page 4Linked to original sources
PubMed1995

Hepatitis C virus within a malignant lymphoma lesion in the course of type II mixed cryoglobulinemia.

Hepatitis C virus (HCV) has been implicated as the major etiologic factor sustaining B-cell clonal expansion in type II mixed cryoglobulinemia (MC). A putative pathogenetic role of HCV in the development of MC-associated B-cell malignancies has also been speculated. We report for the first time the localization of HCV within a parotid non-Hodgkin's lymphoma (NHL) lesion in the course of HCV-related type II essential MC, an important step to implicate any infectious agent in the lymphomagenesis. Plus and minus strand HCV RNA was first demonstrated by polymerase chain reaction on the whole RNA from the lesion. Further immunohistochemical studies localized HCV c22 proteins in the residual ductal or acinar parotid structures, which also abnormally expressed HLA-DR antigens. Weak c22 signals were inconstantly detected in cells strictly confined around the residual epithelium, while all the remaining infiltrating cells in the parotid lesion stained c-22-negative. Staining for c33 and c100 HCV antigens was negative. In situ hybridization (ISH) studies again identified the residual parotid epithelial cells as the site of HCV infection and replication in the NHL lesion. Sialotropic viruses previously involved in lymphoproliferation, ie, Epstein-Barr virus and human herpesvirus-6, were absent in the same tissue lesion. According to the current models of B-cell lymphomagenesis, a role of HCV as an exogenous antigenic stimulus should be considered for NHL development in the present case, whereas malignant B cells do not appear permissive of active HCV replication. Further efforts would be worthwhile to clarify a role of HCV infection in the development of some B-cell malignancies.

Aged↗
PubMed1995

Interferon therapy in chronic hepatitis C virus: evidence of different outcome with respect to different viral strains.

The aim of the study was to assess the role of different viral strains of hepatitis C virus (HCV) in determining the outcome of the alpha-interferon (IFN) therapy. Fifty-seven patients (34 from Italy and 23 from Japan) with HCV-positive liver disease were enrolled in the study. The NS4 region of HCV was amplified in sera by "nested" polymerase chain reaction (PCR) using a primer pair synthesized according to the sequence of JK-1. The NS4 region was positive in 14 (41%) Italian and in 13 (56%) Japanese patients. In positive patients the sequence of the NS4 region was also obtained. Subsequently, HCV genotype was determined in all patients by PCR amplification of the core region. All patients received recombinant alpha 2a-interferon (IFN), 6 million units 3 times a week for 1 month followed by 3 million units 3 times a week for 5 months. The patients were followed for 1 year after the end of treatment. At the end of the follow-up, 17 (30%) had sustained normal levels of serum alanine aminotransferase (ALT). The outcome of treatment was not correlated with race, age, sex, histology, and pretreatment ALT level, but was significantly (P < 0.00001) associated with the presence of both the NS4-JK-1 region and HCV type II. Among the 27 NS4-positive patients, only 1 patient (3.7%) achieved a complete response, whereas the remaining 26 patients (95.3%) either were non-responders or relapsed after IFN was discontinued.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Time-dependent efficacy of bacterial filters and infection risk in long-term epidural catheterization.

BACKGROUND: Epidural infection represents a serious albeit infrequent complication of long-term epidural catheterization. The catheter hub is regarded as the main point of entry for microorganisms among the three possible routes (hematogenous, insertion site, hub) of microbial colonization of the inserted catheter. The current study was aimed at evaluating whether frequent changing of antimicrobial filters carries an increased risk of catheter hub contamination and the time-dependent efficacy of commonly used antimicrobial filters after prolonged use. METHODS: In the first part of the study, a microbiologic survey (skin, filter, hub, and catheter tip) was performed weekly in a group of 47 patients with cancer bearing subcutaneously tunneled catheters managed at home. Subsequently, the time-dependent efficacy of 96 micropore filters (32 Portex, 32 Sterifix-Braun, 32 Encapsulon TFX-Medical) differing in surface areas and/or composition of the filtering membrane was evaluated in a laboratory study. Filters were perfused, under the usual conditions of clinical use (flow resistance, injection pressure, temperature), every 8 h up to 60 days, with 5 ml of two different analgesic solutions, either sterile or containing 1.5 x 10(5)/ml of Streptococcus milleri I. Eight filters of each type subsequently were flushed with a S. milleri suspension (0.5 McFarland) after 7, 14, 28, and 60 days of continuous perfusion, and the resulting filtrates were cultured. RESULTS: In 16 of 19 positive hub cultures, the same microorganisms (species, biotype, antibiotype) were cultured from skin and filters. A statistically significant positive trend was found between the number of filter changes and the rate of positive hub cultures (chi 1(2) trend 5.11; P = 0.02). A high correlation coefficient was found between number of positive skin cultures and number of positive filtrates (r = 0.88; P = 0.01) and between number of positive filtrates and number of positive hub cultures (r = 0.93; P = 0.003). Cultures obtained from Portex and Sterifix-Braun filters yielded no bacterial growth (64/64) throughout the study period. Cultures from Encapsulon TFX-Medical filters showed bacterial growth 2/8 at seventh day, 7/8 at the 14th day, and 16/16 from the 28th day onward. CONCLUSIONS: Our data indicate significant correlation between the incidence of catheter hub colonization and the filter-change frequency, when the skin close to the filter-hub connection is contaminated. Our results also show that Portex and Sterifix-Braun bacterial filters, when perfused with reduced volumes at low injection pressures, maintain an unmodified antimicrobial function for at least 60 days. Based on these data, it appears clinically feasible to reduce the frequency of filter changes during long-term epidural catheterization, with a consequent possible decrease of epidural catheter colonization.

Ambulatory Care↗
PubMed1995

Effects of the novel anti-inflammatory compounds, N-[2-(cyclohexyloxy)-4-nitrophenyl] methanesulphonamide (NS-398) and 5-methanesulphonamido-6-(2,4-difluorothio-phenyl)-1-inda none (L-745,337), on the cyclo-oxygenase activity of human blood prostaglandin endoperoxide synthases.

1. We have evaluated the selectivity of ketoprofen and two novel nonsteroidal anti-inflammatory drugs, N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulphonamide (NS-398) and 5-methanesulphonamido-6-(2,4-difluorothiophenyl)-1-indano ne (L-745,337), in inhibiting the cyclo-oxygenase activity of prostaglandin endoperoxide synthase-2 (PGHS-2) vs PGHS-1 in human blood monocytes and platelets, respectively. 2. Heparinized whole blood samples were drawn from healthy volunteers pretreated with aspirin, 300 mg 48 h before sampling, to suppress the activity of platelet PGHS-1 and incubated at 37 degrees C for 24 h with increasing concentrations of the test compounds in the presence of lipopolysaccharide (LPS, 10 micrograms ml-1). Immunoreactive PGE2 levels were measured in plasma by a specific radioimmunoassay as an index of the cyclo-oxygenase activity of LPS-induced monocyte PGHS-2. 3. The effects of the same inhibitors on platelet PGHS-1 activity were assessed by allowing whole blood samples, drawn from the same subjects in aspirin-free periods, to clot at 37 degrees C for 1 h in the presence of the compounds and measuring immunoreactive thromboxane B2 (TXB2) levels in serum by a specific radioimmunoassay. 4. Under these experimental conditions, ketoprofen enantioselectively inhibited the cyclo-oxygenase activity of both PGHS-1 and PGHS-2 with equal potency (IC50 ratio: approx. 0.5 for both enantiomers), while L-745,337 and NS-398 achieved selective inhibition of monocyte PGHS-2 (IC50 ratio: > 150). L-745,337 and NS-398 did not affect LPS-induced monocyte PGHS-2 biosynthesis to any detectable extent. 5. We conclude that L-745,337 and NS-398 are selective inhibitors of the cyclo-oxygenase activity of human monocyte PGHS-2. These compounds may provide adequate tools to test the contribution of this novel pathway of arachidonate metabolism to human inflammatory disease.

Adult↗
PubMed1995

Intravenous immunoglobulins suppress the recurrences of genital herpes simplex virus: a clinical and immunological study.

Effective treatment is not currently available for suppressing the recurrence of genital herpes simplex virus (HSV) infections. Since intravenous immunoglobulins (IVIG) proved useful against HSV in experimental models, we treated patients with very high frequency of HSV genital recurrences (more than 15 episodes per year) with IVIG (400 mg/Kg every fourth week). The control group was treated with intermittent oral acyclovir (800 mg twice a day for one week every month). Both groups were treated for six months and, then, patients were followed-up to further six months. Both IVIG and acyclovir were effective in reducing the frequency of HSV genital recurrences as compared to base-line. However, patients treated with IVIG had a more striking reduction in the frequency of recurrences as well as both a shorter mean duration and a minor severity of the lesions as compared to acyclovir-treated patients. Furthermore, we found a trend indicating IVIG as more effective in reducing the viral load. Since in IVIG-recipients we found a strong increase of peripheral blood lymphocytes with natural killer (NK) surface phenotype, we suggest that the clinical effectiveness of IVIG treatment is probably mediated via the expansion of NK cell populations. Our study indicates that the treatment with IVIG is an effective and safe tool for suppressing the recurrences of genital HSV infections.

Acyclovir↗
PubMed1995

[Non-surgical treatment of pseudoaneurysm of the hepatic artery and its branches].

The transcatheter embolization of hepatic artery pseudoaneurysms and of its branches is now considered the most effective tool for their treatment. These lesions are caused by abdominal traumas or inappropriate surgical treatment. These pseudoaneurysms must be treated promptly because they are at high risk for rupture, with subsequent complications such as hematemesis, hemobilia and hemoperitoneum. We treated 7 patients with pseudoaneurysms: 4 of them were in the right hepatic artery, 1 in a right hepatic artery branch, 1 in the common hepatic artery and 1 in the suprahilar hepatic artery. Two pseudoaneurysms were treated with Gianturco coils, 2 with Ivalon particles, 1 with Contour particles, 1 with fibrin particles and 1 with transcatheter occlusion with Bucrylat. Six of 7 patients recovered completely after embolization and in 1 patient only subsequent surgery was required. The success rate of transcatheter embolization was 85%. In our personal experience and from international literature reports, percutaneous embolization emerges as the safest therapeutic approach to hepatic artery pseudoaneurysms, yielding optimal results. In particular, percutaneous embolization is indicated for intrahepatic pseudoaneurysms and extraparenchymal saccular pseudoaneurysms of the common hepatic artery. Moreover, this technique exhibits a lower complication rate than surgery, whose mortality rate ranges 15-20%.

Adult↗
PubMed1995

[Deterministic chaos in biology].

Higher physiological organisms are characterised by a complex interaction of multiple control systems. This interaction permits man to adapt those unexpected demands given by experimental changes. The idea of complexity results basically from the non linearity of dynamic systems that are correlated to each other through feedback cycles. These systems fluctuate in an apparent chaos. The improvidence and the non uniformity of biological systems are basic qualities that define the state of health. It is anyhow possible to discriminate in them a certain repeatability of interaction that succeeded each other; this repeatability makes the system fit for a fractal interpretation.

Biology↗
PubMed1994

Stimulation of endogenous ADP-ribosylation by brefeldin A.

Brefeldin A (BFA) is a fungal metabolite that exerts profound and generally inhibitory actions on membrane transport. At least some of the BFA effects are due to inhibition of the GDP-GTP exchange on the ADP-ribosylation factor (ARF) catalyzed by membrane protein(s). ARF activation is likely to be a key event in the association of non-clathrin coat components, including ARF itself, onto transport organelles. ARF, in addition to participating in membrane transport, is known to function as a cofactor in the enzymatic activity of cholera toxin, a bacterial ADP-ribosyltransferase. In this study we have examined whether BFA, in addition to inhibiting membrane transport, might affect endogenous ADP-ribosylation in eukaryotic cells. Two cytosolic proteins of 38 and 50 kDa were enzymatically ADP-ribosylated in the presence of BFA in cellular extracts. The 38-kDa substrate was tentatively identified as the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase. The BFA-binding components mediating inhibition of membrane traffic and stimulation of ADP-ribosylation appear to have the same ligand specificity. These data demonstrate the existence of a BFA-sensitive mono(ADP-ribosyl)transferase that may play a role in membrane movements.

ADP Ribose Transferases↗
PubMed1994

Different genotypes of hepatitis C virus are associated with different severity of chronic liver disease.

The presence of the "Japanese type" NS4 region was investigated in two series of patients (53 from Italy and 58 from Japan) with hepatitis C virus (HCV)-related chronic liver disease. The two populations were homogeneous as regard to age, male/female ratio, histological diagnosis, and serum aminotransferase activities. Genomic amplification was carried out by "nested" polymerase chain reaction (PCR) with a pair of primers synthesized according to the sequence of JK-1 isolated in Japan. The presence of viral replication was confirmed further by PCR amplification of the 5'NC region. The NS4 region of the Japanese strain was detected in 24 sera (45%) from Italy and in 44 (71%) from Japan. NS4-positive patients were significantly older and showed an ALT serum level significantly lower (P < 0.01) than NS4 negative cases in each group. Cirrhosis was significantly (P < 0.0007) more common in NS4-positive than in NS4-negative patients. The HCV genotype was subsequently obtained according to Okamoto. All the NS4-positive patients were infected by Type II, whereas in NS4-negative patients all four genotypes were present though Type II still constituted the majority. Cirrhosis was associated exclusively with Type II both in NS4-positive and -negative subjects. These data indicate that, although the positivity for NS4 "Japanese" region seems to be associated with a more aggressive liver disease, the most prevalent Type II predicts more specifically those who are likely to develop cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1994

A multicentre study: Staphylococcus and Enterococcus susceptibility to antibiotics.

A multicentre study to evaluate the susceptibility of Gram-positive cocci isolated from clinical samples, was performed by six centres working in different areas of Italy. We examined 4,544 strains of Staphylococcus aureus, 4,381 strains of coagulase-negative staphylococci and 2,478 strains of enterococci. The following antibiotics were tested: penicillin G, ampicillin, amoxicillin, piperacillin, imipenem, oxacillin, ofloxacin, pefloxacin, ciprofloxacin, gentamicin, tobramycin, amikacin, netilmicin, rifampicin, clindamycin, tetracycline, cotrimoxazole, erythromycin, chloramphenicol, vancomycin and teicoplanin. Oxacillin-susceptible staphylococci confirmed their susceptibility to many other antimicrobial agents while oxacillin-resistant strains confirmed their multiple and frequent resistance to antibiotics. Resistance to oxacillin, cotrimoxazole and chloramphenicol was more frequent in coagulase-negative staphylococci than in Staphylococcus aureus. Aminoglycosides, rifampicin and quinolones were more active against coagulase-negative staphylococci than against Staphylococcus aureus. Enterococci were susceptible to penicillins and imipenem, and moderately susceptible to ciprofloxacin. Susceptibility of 70-79% was observed with high levels of aminoglycosides. Excellent results against staphylococci and enterococci were observed with vancomycin and teicoplanin.

Anti-Bacterial Agents↗
PubMed1994

High-dose therapy and autologous bone marrow transplantation for adult patients with lymphoblastic lymphoma: results of the European Group for Bone Marrow Transplantation.

PURPOSE: To investigate the results of treatment and factors that affect prognosis in adult patients undergoing high-dose therapy and autologous bone marrow transplantation (ABMT) for lymphoblastic lymphoma (LBL). PATIENTS AND METHODS: The study was a retrospective analysis of 214 patients reported to the Lymphoma Registry of the European Group for Bone Marrow Transplantation (EBMT) between January 1981 and December 1992, including 105 patients undergoing marrow transplantation in first complete remission (CR). Data on all patients were reviewed, and analysis of prognostic factors conducted. RESULTS: The actuarial overall survival rate at 6 years for the entire group is 42%. Disease status at ABMT was the major determinant of outcome: 6-year actuarial overall survival was 63% for patients transplanted in first CR, compared with 15% for those with resistant disease at the time of transplantation. Transplantation in second CR resulted in a 31% rate of actuarial overall survival at 6 years. For patients transplanted in first CR, univariate analysis failed to identify any factors at presentation that predicted for outcome after transplantation. CONCLUSION: These results suggest that ABMT is effective therapy for adults with LBL, even in patients with disease that is resistant to conventional-dose therapy. Results for patients transplanted in second CR are superior to those reported for conventional-dose salvage regimens. The results in first CR require verification in a prospective randomized clinical study.

Actuarial Analysis↗
PubMed1994

MACOP-B versus ProMACE-MOPP in the treatment of advanced diffuse non-Hodgkin's lymphoma: results of a prospective randomized trial by the non-Hodgkin's Lymphoma Cooperative Study Group.

PURPOSE: The aim of our study was to compare in a multicentric randomized trial two regimens widely used in the treatment of advanced-stage intermediate- to high-grade non-Hodgkin's lymphoma and to assess whether a third-generation regimen (methotrexate with leucovorin, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin [MACOP-B]) was superior to a second-generation regimen (procarbazine, methotrexate with leucovorin, doxorubicin, cyclophosphamide, and etoposide [ProMACE-MOPP]). PATIENTS AND METHODS: Between January 1987 and August 1991, 221 patients with diffuse intermediate- to high-grade non-Hodgkin's lymphoma (Working Formulation groups F, G, H, and K), stage II bulky (> 10 cm), III, or IV, were randomized by the Non-Hodgkin's Lymphoma Cooperative Study Group (NHLCSG) to receive ProMACE-MOPP for six cycles or MACOP-B for 12 weeks. Survival, progression-free survival, and disease-free survival were determined, and multivariate analysis of prognostic factors was performed. RESULTS: In the two groups of patients, there was no significant difference in terms of complete remission (CR) rate (49.1% with ProMACE-MOPP and 52.3% with MACOP-B), 3-year overall survival rate (45.2% with PROMACE-MOPP and 52.3% with MACOP-B), and 3-year progression-free survival rate (36.4% with ProMACE-MOPP and 36.1% with MACOP-B). In terms of toxicity, no significantly greater toxicity occurred in either arm. Overall toxicity was acceptable. The most frequent side effects were grade II through IV leukopenia, infection, mucositis, and anemia. Treatment-related deaths were equally distributed. CONCLUSION: No significant differences in terms of efficacy and/or toxicity between ProMACE-MOPP and MACOP-B are evident. These results are consistent with recent randomized trials showing that the new-generation aggressive regimens are no better than previous ones.

Adolescent↗
PubMed1994

Serum levels of intercellular adhesion molecule 1 in patients with HIV-related Kaposi's sarcoma.

Infection with the human immunodeficiency virus type 1 (HIV-1) in man is associated with an increase in the incidence of Kaposi's sarcoma (KS). The biological and clinical characteristics of these patients differ from those of subjects with other HIV-associated diseases. Here we report that levels of serum-soluble intercellular adhesion molecule 1 (sICAM 1) are increased in HIV-1-positive patients with KS, but not in patients belonging to other CDC classification groups. KS patients with elevated levels of serum sICAM 1 had a significant lowering of CD4 cell counts during the follow-up period compared with those KS subjects whose sICAM 1 levels were only moderately higher. We suggest that increased sICAM 1 levels may have a pathogenetic role in the development of HIV-associated immunodeficiency in KS patients and may also be considered an important prognostic factor.

Antigens, CD↗
PubMed1993

Receptor and protein kinase C-mediated regulation of ARF binding to the Golgi complex.

The formation of constitutive transport vesicles involves the association of non-clathrin coat proteins to transport organelles. Here we report that IgE receptors and protein kinase C (PKC) regulate the GTP-dependent binding of the two coat proteins ADP-ribosylation factor (ARF) and beta-COP to Golgi membranes in rat basophilic leukaemia cells. Activation of IgE receptors and PKC prevented the ARF and beta-COP dissociation from Golgi membranes that occurs in permeabilized cells in the absence of GTP and potentiated the association-promoting effects of GTP and the G protein activator fluoroaluminate. In contrast, PKC downregulation and PKC inhibition abolished the activity of GTP and fluoroaluminae in promoting ARF binding to the Golgi complex. Studies of ARF binding to isolated Golgi membranes gave similar results. These findings suggest that coat assembly on Golgi membranes, and thus possibly constitutive secretory traffic, is modulated by membrane receptors and second messengers.

ADP-Ribosylation Factors↗