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Biomedical subjects

G Squadrito

Publications and source records attributed to G Squadrito.

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

Tumor necrosis factor induces E-selectin production in splanchnic artery occlusion shock.

Splanchnic arteries were clamped for 45 min to induce splanchnic artery occlusion (SAO) shock in anesthetized rats. Sham-operated animals were used as controls. Survival time, serum tumor necrosis factor-alpha (TNF-alpha), white blood cell (WBC) count, mean arterial blood pressure, myeloperoxidase (MPO) activity, and serum levels of soluble E-selectin (sE-selectin) were investigated. SAO-shocked rats exhibited decreased survival time (95 +/- 11 min, whereas sham-shocked rats survived for > 5 h), reduced mean arterial blood pressure, increased serum levels of TNF-alpha (185 +/- 8 U/ml) and MPO activity in the ileum (0.11 +/- 0.03 U x 10(-3)/g tissue) and lung (1.5 +/- 0.4 U x 10(-3)/g tissue), leukopenia, and enhanced serum levels of sE-selectin. Furthermore SAO-shocked rats showed histological alterations in the ileum and lung. Administration of cloricromene (2 mg/kg i.v.), an inhibitor of TNF-alpha, significantly increased survival time (225 +/- 10 min), decreased serum levels of TNF-alpha and sE-selectin, reduced leukopenia and MPO activity in the ileum (0.035 +/- 0.003 U x 10(-3)/g tissue) and lung (0.3 +/- 0.005 U x 10(-3)/g tissue), improved the cardiovascular changes, and reduced the histological changes in the ileum and lung. Finally, an anti-E-selectin antibody protected rats against SAO shock. Our findings are consistent with an involvement of E-selectin, "in vivo," in the pathogenesis of SAO shock.

Animals↗
PubMed1995

Chronic hepatitis in patients with active hepatitis B virus and hepatitis C virus combined infections: a histological study.

OBJECTIVES: To evaluate whether peculiar histological changes are present in liver tissue of patients with chronic hepatitis by hepatitis B and hepatitis C (HBV and HCV) virus combined infections. METHODS: We studied liver biopsy specimens from 14 HB surface antigen/anti-HCV-positive patients consecutively admitted to hospital because of chronic liver disease from 1987 to 1992. Alcohol abusers, drug addicts, hepatitis delta virus- and HIV-infected subjects were excluded from the study. All of them were positive for serum HBV-DNA and/or intrahepatic HB core antigen and for serum HCV-RNA. Histological examination showed mild or moderate chronic hepatitis in nine cases and severe chronic hepatitis with cirrhosis in five cases. Two additional sets of liver biopsy specimens were also included in the study, consisting of liver samples from 14 patients with chronic liver disease due to active HBV infection alone (group B) and from 14 patients with active HCV infection alone (group C). Cases from group B and C matched for age, sex, and histological diagnosis with those from group B + C. Histological patterns of all the liver specimens of the three groups were re-examined by two authors who scored the found features using a scale from 0 to 3. RESULTS: No peculiar histological pattern was revealed in group B + C, and most of the detected microscopic features were similarly present in all three groups. Bile duct lesions and well defined lymphoid follicles were found only in liver samples of patients from groups C and B + C. Ground-glass hepatocytes were observed only in cases from the groups B and B + C. CONCLUSIONS: Histological examination of liver tissue from patients with chronic HBV and HCV combined infection does not show either typical patterns or evidence that this subgroup of chronic viral hepatitis is a more severe form of liver disease than that caused by a single virus infection. The observation in liver samples of peculiar lesions by HBV or HCV infection does not exclude a combined infection by both viruses.

Adult↗
PubMed1994

Antibodies against intercellular adhesion molecule 1 protect against myocardial ischaemia-reperfusion injury in rat.

In this study we have assayed the pathophysiological role of intercellular adhesion molecule (ICAM-1), a cytokine-inducible adhesion molecule, in a model of ischaemia reperfusion in the rat. Anaesthetized rats were subjected to occlusion (1 h) of the left main coronary artery followed by reperfusion (1 h). Sham myocardial ischaemia-reperfusion rats (Sham MI/R) were used as controls. Myocardial ischaemia plus reperfusion in untreated rats decreased survival rate, produced a marked myocardial necrosis, increased serum creatine phosphokinase activity, and cardiac myeloperoxidase activity (a marker enzyme commonly used to assess polymorphonuclear leukocyte accumulation). Furthermore, rats subjected to myocardial ischaemia-reperfusion showed an increased pressure rate index, studied as a quantitative means for assessing myocardial oxygen demand. Treatment with monoclonal anti-rat ICAM-1 (1 mg/kg i.v.), 3 h before occlusion of the left main coronary artery, significantly lowered serum creatine phosphokinase activity, blunted leukocyte accumulation and protected the myocardium from injury subsequent to ischaemia and reperfusion injury. These investigations have revealed that ICAM-1 is a critical adhesion molecule in the pathogenesis of ischaemia-reperfusion injury. In addition these results suggest that the use of monoclonal antibodies raised against ICAM-1 can represent a useful tool for the prevention of ischaemia-reperfusion damage.

Analysis of Variance↗
PubMed1994

TCV-309, a novel platelet activating factor antagonist, inhibits leukocyte accumulation and protects against splanchnic artery occlusion shock.

The aim of this study was to evaluate: (1) the accumulation of leukocytes in the ileum and the lung during splanchnic artery occlusion (SAO) shock; (2) the role of platelet-activating factor (PAF) and tumor necrosis factor (TNF-alpha) in this phenomenon. Untreated anesthesized rats subjected to total occlusion of the celiac, superior and inferior mesenteric arteries for 45 min, followed by reperfusion, uniformly died within 90 min after reperfusion. The mean survival time was 93 +/- 7 min. The neutrophilic infiltrate was quantitated in the ileum and in the lung using a myeloperoxidase (MPO) assay. MPO activity in the ileum and in the lung averaged 0.05 +/- 0.03 and 0.4 +/- 0.02 U x 10(-3)/g protein in animals killed before occlusion. MPO activity did not change in rats killed immediately before reperfusion and was significantly elevated (0.11 +/- 0.02 and 1.7 +/- 0.6 U x 10(-3)/g protein in the ileum and the lung, respectively) in those killed 80 min after the beginning of the reperfusion. The histological examination confirmed the accumulation of leukocytes in the mucosa of the ileum and the lung over the 80 min. SAO shocked rats exhibited leukopenia and increased serum levels of TNF-alpha. In order to evaluate the role of PAF and TNF-alpha in SAO shock, a powerful PAF receptor antagonist, TCV-309 (5 micrograms/kg i.v.), was injected 5 min after reperfusion. TCV-309 increased survival time, lowered serum TNF-alpha, reduced MPO activity in both the ileum and the lung and ameliorated leukopenia induced by SAO shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Contribution of intercellular adhesion molecule 1 (ICAM-1) to the pathogenesis of splanchnic artery occlusion shock in the rat.

1. It has been suggested that leukocytes play a key role in the pathogenesis of splanchnic artery occlusion shock. Intercellular adhesion molecule 1 (ICAM-1) is an adhesion molecule of crucial importance in the phenomenon of leukocyte accumulation. 2. We investigated the involvement of ICAM-1 in the pathogenesis of splanchnic artery occlusion shock. Splanchnic artery occlusion (SAO) shock was induced in anaesthetized rats by clamping splanchnic arteries for 45 min. Sham-operated animals were used as controls. Survival time, serum tumour necrosis factor-alpha (TNF-alpha), white blood cell (WBC) count, mean arterial blood pressure, myeloperoxidase activity (MPO; studied as a quantitative means to assess leukocyte accumulation) and the responsiveness to acetylcholine of aortic rings were investigated. SAO shocked rats had a decreased survival time (90 +/- 9.5 min, while sham-shocked rats survived more than 4 h), reduced mean arterial blood pressure, increased serum levels of TNF-alpha (201 +/- 10 mu ml-1) and MPO activity in the ileum (0.15 +/- 0.03 mu x 10(-3) per g tissue) and in the lung (1.9 +/- 0.8 mu x 10(-3) per g tissue), leukopenia and reduced responsiveness to acetylcholine (ACh, 10 nM-10 microM) of aortic rings. 3. Administration of monoclonal antibody raised against rat ICAM-1 significantly increased survival time (225 +/- 9 min), reduced leukopenia and MPO activity both in the ileum (0.031 +/- 0.003 mu x 10(-3) per g tissue) and in the lung 0.23 +/- 0.03 mu x 10(-3) per g tissue), improved the cardiovascular changes and restored the responsiveness to ACh of aortic rings. 4. Our findings are consistent with an involvement of adhesion mechanisms in vivo in the pathogenesis of SAO shock and suggest that specific adhesion mechanisms, which support leukocyte accumulation,may represent potentially important therapeutic targets in circulatory shock.

Acetylcholine↗
PubMed1994

Participation of tumour necrosis factor and nitric oxide in the mediation of vascular dysfunction in splanchnic artery occlusion shock.

1. Splanchnic artery occlusion (SAO) shock is characterized by irreversible circulatory failure. Tumour necrosis factor (TNF-alpha) may affect the L-arginine/nitric oxide (NO) pathway, thus contributing to the cardiovascular derangements of circulatory shock. 2. We investigated the contribution of both TNF-alpha and the L-arginine/nitric oxide pathway to the vascular dysfunction of SAO shock. Anaesthetized rats, subjected to total occlusion of the superior mesenteric artery and the coeliac trunk for 45 min developed a severe shock state (SAO shock) resulting in a fatal outcome within 75-90 min after the release of occlusion. Sham operated animals were used as controls. SAO shocked rats had also a marked hypotension and enhanced macrophage and serum levels of TNF-alpha. Furthermore, aortic rings from shocked rats showed a marked hyporeactivity to phenylephrine (PE 1 nM-10 microM) and reduced responsiveness to acetylcholine (ACh 10 nM-10 microM). Endothelium-denuded aortic rings had also a marked hyporeactivity to phenylephrine, which was restored to control values by in vitro administration of NG nitro-L-arginine-methyl ester (L-NAME 10 microM). 3. In vivo administration of cloricromene (2 mg kg-1, i.v.), an inhibitor of TNF-alpha biosynthesis, increased survival, enhanced mean arterial blood pressure and reduced macrophage and serum levels of TNF-alpha. Furthermore, aortic rings from shocked rats treated with cloricromene exhibited a greater contractile response to phenylephrine and improved responsiveness to ACh when compared to aortic rings from vehicle-treated SAO shocked rats. 4. Our results suggest that TNF-alpha alters both endothelial and muscular L-arginine/nitric oxide pathways which in turn produce vascular dysfunction in SAO shock.

Acetylcholine↗
PubMed1994

Beneficial effects of BAY u3405, a novel thromboxane A2 receptor antagonist, in splanchnic artery occlusion shock.

Splanchnic artery occlusion shock was induced in male anaesthetized rats by clamping the splanchnic artery for 45 min. The arteries were then released and survival rate, mean survival time, mean arterial blood pressure, plasma levels of thromboxane B2 and 6-keto-PGF1 alpha, macrophage phagocytosis activity and plasma levels of myocardial depressant factor were evaluated. In addition, the neutrophilic infiltrate was quantified in the ileum and lung using a myeloperoxidase (MPO) assay. Sham splanchnic-artery-occlusion-shocked rats were used as controls. Splanchnic-artery-occlusion-shocked rats died within 93 +/- 7 min, while all sham-shocked animals survived more than 3 h. Splanchnic artery occlusion shock caused changes in mean arterial blood pressure, significantly increased the plasma levels of thromboxane B2 (7.5 +/- 1.3 ng/ml; p < 0.001 vs. sham), 6-keto-PGF1 alpha (8.9 +/- 1.7 ng/ml; p < 0.001 vs. sham) and myocardial depressant factor (114 +/- 11 U/ml), and reduced macrophage phagocytosis. Furthermore, MPO activity was significantly elevated (0.12 +/- 0.03 x 10(-3) and 1.8 +/- 0.5 x 10(-3) U/g protein in the ileum and lung, respectively) 70 min after starting reperfusion. Administration of BAY u3405, a novel thromboxane A2 receptor antagonist (30 mg/kg i.v., 30 min before occlusion), significantly increased survival time (187 +/- 3.7 min) and survival rate, improved mean arterial blood pressure, reduced the plasma levels of myocardial depressant factor (54 +/- 3 U/ml), partially restored macrophage phagocytosis and lowered MPO activity in both the ileum and the lung. Our data are consistent with an involvement of thromboxane A2 in splanchnic artery occlusion shock and suggest that BAY u3405 might be of benefit in low-flow states such as circulatory shock.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Inapparent "wild-type" and "e-minus variant" HBV infection in patients with HCV-related chronic hepatitis.

We analysed DNA extracted from liver biopsy specimens and serum samples from 42 HCV-RNA-positive/HBsAg-negative subjects with chronic hepatitis. Twenty-eight of them were anti-HBs/anti-HBc-positive (group A), while 14 were negative for all HBV markers (group B). HBV sequences were found in hepatic DNA of 12 cases (11 of group A, one of group B), but in the serum of only two cases of group A. Sequencing analysis of pre-core region of HBV-DNA showed the presence of wild-type HBV in three cases, HBeAg-defective HBV in three cases, and the coexistence of both viral populations in six cases. These results indicate that HBV and HCV infection may coexist in HBsAg-negative chronic hepatitis, particularly in anti-HBs/anti-HBc-positive patients. However, HBV replication appears suppressed in these cases, and this state of latency may involve both wild and HBeAg-defective HBV types.

Adult↗
PubMed1993

Serum levels of 2',5 oligoadenylate synthetase during interferon therapy in patients with B-cell chronic lymphocytic leukemia.

We assayed 2',5 oligoadenylate synthetase (2'5-AS) activity in the serum of eight patients with B-cell chronic lymphocytic leukemia (B-CLL) who were undergoing therapy with alpha interferon (IFN). Mean pretreatment levels of 2'5-AS were normal, but upon treatment the levels rose to higher than normal values. Moreover, the degree of enzyme induction in serum was significantly higher in CLL responders (P < 0.003) whereas no difference was found in non-responders. The lack of serum 2'5-AS induction in non-responder patients might be related to unresponsiveness to treatment with IFN. These results seem to show that the measurement of serum levels of 2'5-AS activity may be a useful tool in monitoring IFN treatment.

2',5'-Oligoadenylate Synthetase↗
PubMed1993

Isodicentric Philadelphia chromosome in accelerated phase of chronic myeloid leukemia.

We describe a case of chronic myeloid leukemia (CML) associated with the finding of an isodicentric Philadelphia chromosome [idic(Ph)] during the accelerated phase of the disease. Chromosome study was carried out on bone marrow aspirate cells, obtained and cultured 5 months after the clinical diagnosis. The presence of an isodicentric Philadelphia chromosome was found in 90% of the analyzed metaphases; among the remaining observed metaphases, 6% showed two idic(Ph) chromosomes, 2% a t(9;22), and 2% a normal karyotype. The patient died 7 months after the clinical diagnosis, and 2 months after our chromosome study. The observation of idic(Ph) during CML has seldom been reported and the few cases studied have been inconsistently correlated with the course of the disease. In the present case, the finding of an idic(Ph) and the short patient survival from the time of clinical diagnosis may suggest the observed chromosome aberration as a factor associated with a poor prognosis.

Aged↗
PubMed1993

[Tumor necrosis factor in myocardial ischemia and reperfusion].

The role of tumor necrosis factor (TNF-alpha) was investigated in an anaesthetized rat model of coronary artery ligation (60 min) followed by reperfusion (60 min; MI/R). Sham operated rats were used as controls (Sham MI/R). Myocardial necrosis, myocardial myeloperoxidase activity (MPO; investigated as an index of leukocyte adhesion and accumulation), serum creatinphosphokinase (CPK) activity and serum and macrophage TNF-alpha were studied. Ischemia and reperfusion produced a marked myocardial injury, with enhancement of serum CPK levels and myocardial MPO activity in the area at risk and in the necrotic area. Furthermore, serum TNF-alpha was undetectable during the occlusion period, but increased significantly after release of the coronary artery. At the end of reperfusion, macrophage TNF-alpha was also enhanced. A passive immunization with a hyperimmune serum containing antibodies against murine TNF-alpha or administration of an inhibitor of TNF-alpha synthesis, such as cloricromene, significantly lowered myocardial necrosis, reduced the increase in serum CPK and decreased MPO activity in the area at risk and in the necrotic area. Finally, the administration of the specific anti-TNF-alpha antibodies neutralized the serum levels of TNF-alpha and the injection of cloricromene reduced both serum and macrophage TNF-alpha. These data are consistent with an involvement of TNF-alpha in myocardial ischemia-reperfusion injury and suggest that drugs capable of reducing TNF-alpha might represent a novel therapeutic approach to the treatment of myocardial reperfusion injury.

Animals↗
PubMed1992

E rosette formation in B cell chronic lymphocytic leukemia.

We describe a patient with B cell chronic lymphocytic leukemia whose B lymphocytes showed the capacity to form rosettes with sheep red blood cells during prolymphocytoid transformation of the disease. In this case, rosette formation was found to be related to the presence of the classic E rosette receptor since the leukemic cells were recognized by the OKT11 monoclonal antibody. This feature was not shown at diagnosis. Evaluation of this phenomenon is discussed.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1992

Intracellular and serum levels of aldolase activity in B chronic lymphocytic leukemia.

Intracellular and serum activities of aldolase (ALS) were biochemically determined in lymphocyte subpopulations from normal subjects and patients with B-chronic lymphocytic leukemia (B-CLL). Aldolase activity was significantly lower in T cells of CLL than in normal T cells (2.9 +/- 1.5 vs. 4.7 +/- 2.1 Sigma Units (SU)/6 x 10(6) cells, p < 0.05). The aldolase activity also was significantly (p < 0.001) lower (3.1 +/- 1.9 SU/6 x 10(6) cells) in CLL B lymphocytes than in normal B lymphocytes (18.1 +/- 6.5 SU/6 x 10(6) cells). Moreover, the serum levels of ALS in all patients with B-CLL were higher than that in normal subjects (8.1 +/- 5.8 vs. 2.2 +/- 0.8 SU/ml, p < 0.02). Our findings demonstrate that T lymphocytes from patients with B-CLL display enzyme activity different from that of normal T cells. This may reflect the abnormal maturity of the residual T cell population in B-CLL.

Adult↗
PubMed1991

Hepatitis B virus variant, with a deletion in the preS2 and two translational stop codons in the precore regions, in a patient with hepatocellular carcinoma.

We analyzed hepatitis B virus (HBV) genomes obtained from serum samples and liver biopsy specimen of a chronic HBsAg/anti-HBe carrier with hepatocellular carcinoma (HCC). Before the liver biopsy, performed at the time of HCC diagnosis, the patient had been followed for 2 years; the serum samples collected in that period resulted negative for HBV-DNA dot blot hybridization. The hepatic DNA was at first examined by Southern blot, but no HBV sequence was detected. Polymerase chain reaction (PCR) amplification revealed the presence of HBV genomes in DNA extracted from the liver tissue and from two serum samples collected, respectively, 1 and 2 years before the biopsy. Direct sequence of the amplified preC/C and preS regions showed that the viral populations present in serum and liver were identical and that they had a 34 nucleotide deletion in the preS2 region, while the preC region presented two mutations each introducing a translational stop codon, one at the carboxy terminal end and the other at the second codon of the region, both able to prevent HBeAg expression. These results identify a new HBV variant which was selected during a chronic infection, and had very low levels of replication as shown by its detection only after PCR amplification.

Base Sequence↗
PubMed1991

HBe antibody unrelated to 'e minus' hepatitis B virus variant infection in patients with chronic type D hepatitis.

The presence of HBV-DNA sequences was evaluated in DNA extracted from serum samples, peripheral blood lymphocytes and liver biopsy specimens of five HBsAg/anti-HBe-positive carriers with chronic HDV infection. DNAs were tested by polymerase chain reaction (PCR) amplification technique using two pairs of oligonucleotide primers specific for the preC/C and S regions of the HBV; viral sequences were found exclusively in liver extracts and only in three out of the five cases. The direct sequencing of the amplified preC/C regions showed wild-type sequences in two cases, while in the third case a combination of 'wild' and 'e minus variant' viral populations was observed. Moreover, liver DNA of one positive case was electrophoresed through a low melting agarose gel and the following amplification, performed on DNA re-extracted from three different fragments of the gel, showed the presence of free HBV genomes but the absence of replicative intermediate forms. These results show that anti-HBe positivity is not constantly related to precore mutant HBV infection and suggest that HDV inhibits HBeAg production. Moreover, as it was observed in 'e minus' HBV variants, also during a chronic HBV wild-type infection, the viral replication might be suppressed to undetectable levels.

Base Sequence↗
PubMed1991

Serum levels of CD8 antigen and soluble interleukin 2 receptors in patients with B cell chronic lymphocytic leukemia.

We assayed the plasma levels of CD8 antigen (CD8Ag) and soluble interleukin 2 receptor (sIL-2R) in 34 subjects with B cell chronic lymphocytic leukemia (B-CLL) and in 15 controls using an immunoenzymatic method. The results showed higher average levels of soluble CD8 (sCD8) and sIL-2R in the leukemic patients compared to the controls (sCD8 = 860 vs. 306 U/ml; sIL-2R = 4,131 vs. 311 U/ml). The two antigen levels were significantly higher in patients with progressive disease than in those with indolent disease, and they also correlated with Rai's stage. sIL-2R levels correlated with lymphocyte count (p less than 0.001), while there was no correlation between sCD8 levels and total number of lymphocytes. These results seem to show that the measurement of serum levels of CD8Ag and sIL-2R may be a useful tool in the prognostic evaluation of patients with B-CLL.

Adult↗