PubMed Health⌕ Search

Biomedical subjects

G Gessoni

Publications and source records attributed to G Gessoni.

17 recordsLinked to original sources
PubMed2004

Biological qualification of blood units: considerations about the effects of sample's handling and storage on stability of nucleic acids.

BACKGROUND: In transfusional setting introduction of nucleic amplification technique (NAT) for HBV-DNA, HCV-RNA and HIV-RNA in biological qualification of blood units suggest some problems. At first the opportunity to operate on mini-pool, at second the need to store the samples at +4 degrees C. The authors therefore have tried to estimate the impact of these conditions on the operativity of NAT testing in the transfusional setting. METHODS: The following parameters has been estimated: distribution of viral-load in untreated subjects, stability of nucleic acids during storage at +4 degrees C, stability of nucleic acids after repeated cycles of freezing and defrosting, robustness of the test to the cross-contamination, definition of the detection-limit (95%). Quantitative tests has been performed by using the following kits: Cobas Amplicor HBV Monitor, Cobas Amplicor HCV Monitor, Cobas Amplicor HIV Monitor; the qualitative tests has been performed by using the following kits: Ampliscreen HBV, Ampliscreen HCV 2,0, Ampliscreen HIV 1,5 all supplied by Roche Molecular System (Brancburg, NJ). RESULTS: Viral load in untreated subjects showed wide variation for HBV, HCV and HIV. HBV has been demonstrated much stable to the conservation +4 degrees C also until 168 h while for HCV and HIV a greater decrease of the viral-load was observed. For all and three virus the conservation to +4 degrees C until 72 h does not seem to involve meaningful fall in the viral-load. A remarkable reduction of the viral-load has been observed after five cycles of freezing and defrosting. All the tests showed a good robustness to cross-contamination. The detection-limit (95%) was 8 U/ml for HBV, 21 U/ml for HCV and 27 copy/ml for HIV. CONCLUSIONS: Samples for NAT testing, can be stored until 72 h to +4 degrees C without appreciable lowering of the viral-load. Repeated cycles of changes of state should be avoided. The tests showed a good robustness to cross-contamination. NAT tests for biological qualification of blood units had a minimal sensibility around 50 (copy/unit/ml). In our experience the detection-limit (95%) was 21 U/ml for HCV, 27 copies/ml for HIV, 8 U/ml for HBV. The availability of NAT test for HBV-DNA, HCV-RNA e HIV-RNA, sensitive and reliable, together with epidemiological data, suggest the opportunity to place side by side, in the biological qualification of the blood units, to add the tests for HBV-DNA and HIV-RNA to the test for HCV-RNA mandatory by low, in Italy in the biological qualification of blood units.

Blood Preservation↗
PubMed2004

Haemoglobin E in pregnancy. A case report. Diagnosis, familiar study and counselling, follow up until delivery and new-born observation.

Haemoglobin E is a beta chain variant quite common in Southeastern Asia. The case of a gravid Thai woman with a microcytic anaemia is reported. The diagnosis of homozygous haemoglobin E was suspected on the basis of ethnic considerations when analysis of her haemoglobin showed the absence of normal HbA1 and about 100% of a variant Hb with electrophoretic mobility with HbC and HbA2. Identification of the haemoglobin variant was performed by using an association of alkaline electrophoresis on agarose gel, acid electrophoresis on agarose gel, haemoglobin isoelectrofocusing, high performance liquid chromatography. A study of haemoglobin pattern in the partner, parents and siblings was also performed. Pregnancy continued without any problems until the 40th week when a caesarean section was performed due to a difficult labour with foetal distress. The haemoglobin pattern of the new-born was studied at birth and after 1 year; as expected, it was quite normal at birth and a heterozygous condition for HbE was observed after 1 year. HbE, in even heterozygous and homozygous states, gives a mild clinical picture but its association with other haemoglobinopathies, such as a double heterozygous state (i.e. HbE/beta Thalassaemia) gives rise to a severe transfusion dependent thalassaemia syndrome. It is the authors' opinion that only a strict interaction between obstetricians and pathologists is the possible correct answer to the new diagnostic question proposed by a rapidly evolving inter-ethnic society.

Adult↗
PubMed2003

Assessment of in vitro platelet activation by Advia 120 platelet parameters.

The Advia 120 Hematology System provides new platelet parameters that have been proposed as useful markers of platelet activation. The aim of this study was to investigate platelet parameter variations after adenosine diphosphate (ADP) activation of platelet-rich plasma (PRP) in vitro, with particular interest in the mean platelet component (MPC), which was compared with two well-known degranulation antigens. Changes in platelet parameters that were induced by the activation of PRP with different concentrations of ADP were examined first. The time course of parameter values up to 60 minutes after maximal ADP activation and the relationships between the MPC and P-selectin and granulophysin expression as determined by flow cytometry were then investigated. After 10 minutes of ADP stimulation, the MPC presented a dose-dependent increase. At the maximal ADP concentration, the initial increase of the MPC was followed by a progressive decrease, leading the MPC to become significantly lower with respect to the baseline after 60 minutes of incubation. Significant variations in other parameters are also described. Finally, a negative correlation was found between the MPC change with respect to time 0 and both P-selectin and granulophysin expression. The present study suggests that platelet parameter variation, particular in the MPC, may be used to assess platelet activation in PRPs stimulated by ADP.

Adenosine Diphosphate↗
PubMed2002

Field evaluation of a second-generation cytometer UF-100 in diagnosis of acute urinary tract infections in adult patients.

AIMS: The authors evaluated the analytical performance of the Sysmex UF-100 cytometer vs. the diagnosis of urinary tract infections (UTI). METHODS: We considered 2010 subjects, aged between 18 and 78, 870 males and 1140 females. The majority (90.2%) of the samples were voided urine specimens collected by using the midstream technique. Each sample was subjected to microbiological evaluation (culture + residual antibacterial activity), dipstick tests, UF-100 examination and microscopic observation. In order to obtain a final diagnosis of UTI these laboratory results were taken into consideration together with clinical data and patients' characteristics. The analytical performance of the laboratory tests was obtained by adopting this diagnosis as standard practice. RESULTS: Out of the total 2010 subjects considered a clinical diagnosis of UTI was obtained in 529 cases (26.32%). The UF-100-based screening had sensitivity, 0.94; specificity, 0.93; positive predictive value, 0.83; negative predictive value, 0.98; and correctly classified incidence, 0.93. CONCLUSIONS: In our experience the results of the UF-100-based screening show a very good correlation with the diagnosis of acute UTI in adults patients.

Acute Disease↗
PubMed2002

[Foetal-maternal alloimmunizations in the South-East area of the Venice province].

BACKGROUND: This study report the results obtained in a retrospective analysis of the foetal-maternal alloimmunizations observed from 1993 to 1999 in the South-East area of the Venice province. METHODS: The data concerning 17,000 pregnancy observed in this area from 1993-1999 have been collected. For each pregnancy data concerning maternal ABO, Rh, Kk and IAT as well as foetal ABO, Rh, Kk and DAT were available. Further data (mainly antibodies concentration and specificity) were available if a foetal-maternal alloimmunization was detected and if transfusional support was given after the birth. RESULTS: The authors observed 465 alloimmunizations (prevalence 2.7%): 381 (82%) of these were due to an ABO foetal-maternal incompatibility, 23 due to D incompatibility and the other 61 due to other blood groups antigens. Only 6 cases needed transfusional support: 5 exchange transfusion (a patient needed 2 exchanges) and a delayed transfusion. CONCLUSIONS: Foetal-maternal alloimmunizations are today a rare but not exceptional event (about 3% of pregnancy), the great majority of these alloimmunizations are due to an ABO incompatibility. Despite the prevention of alloimmunization in D negative women by using Rh immune globulin, anti-D alloimmunization is still observed. A great number of other blood groups antigens are involved in foetal-maternal alloimmunization mainly within the Rh system (CcEe, etc.). In the authors' experience the great majority of foetal-maternal alloimmunizations were clinically silent, only 6 cases (1.3% of patients with a positive DAT) needed transfusional therapy.

ABO Blood-Group System↗
PubMed2001

Platelet count and parameters determined by the Bayer ADVIA 120 in reference subjects and patients.

In order to study the behaviour of traditional and new platelet parameters determined by the ADVIA 120 Hematology System, five hundred samples from reference subjects, divided for sex and age, were processed. Significant variations on the basis of sex and age were found. Reference ranges as 95% confidence limits were therefore calculated for each age class, and platelet parameters proved to have specific variations during lifetime. Moreover, one hundred samples from thrombocytopenic patients were processed by the ADVIA 120 System. When compared with those of reference subjects matched for sex and age, all platelet parameters, except mean platelet component (MPC), showed significant differences.

Adolescent↗
PubMed2000

The stability of hepatitis C virus RNA after storage at +4 degrees C.

One of the major issues in nucleic acid testing is how to store blood samples to obtain reliable results. We therefore studied hepatitis C virus (HCV) RNA concentration in samples after storage at +4 degrees C or freezing and thawing. Six HCV RNA-positive, untreated subjects were studied. Blood samples were collected from these subjects in plasma preparation tubes. The HCV RNA concentration was analysed after storage at +4 degrees C for 168 h or after five freeze-thaw cycles. For HCV RNA quantification we used a qualitative and a quantitative commercial test. After 168 h of storage at +4 degrees C, the HCV RNA concentration was similar to that observed at time-point 0 (5.025 log vs 5.492 log). In one sample we observed a significant fall in HCV RNA concentration. After five freeze-thaw cycles, the HCV RNA concentration was lower than that observed at time-point 0 (4.454 log vs 5.492 log) and in four samples we observed a significant fall in HCV RNA concentration. Our data suggest that HCV RNA is stable in whole blood samples stored at +4 degrees C for 168 h. Based on our results, we conclude that the standard procedures for transport of blood samples (at room temperature for a maximum of 5 h) and storage schedules (+4 degrees C for a maximum of 48 h) can be maintained without compromising the quality of results.

Blood Donors↗
PubMed1998

In subjects with antibody to hepatitis C virus a high serum level of interleukin-2 soluble receptor suggests activity of liver disease.

The hepatitis C virus (HCV) is an RNA virus without apparent cytopathic effects, and hepatocellular damage in chronic infection is generally believed to be immune-mediated by cytotoxic T lymphocytes. Activated T cells release the soluble form of the interleukin-2 (IL-2) receptor (sIL-2R) and its concentration is correlated with the degree of lymphocyte activation. We measured sIL-2R in 69 subjects: 24 healthy repeat blood donors (group I), 17 HCV carriers without liver damage (group II) and 28 patients with HCV-related chronic active hepatitis (group III). There was no significant difference between sIL-2R levels in patients of group I (36.5 +/- 14.6 U ml-1) and group II (46.8 +/- 17.4 U ml-1), and the levels for both of these groups were significantly lower than those observed in the patients with active HCV, group III (176.9 +/- 59.5 U ml-1). Hence, among HCV-infected subjects (HCV RNA positive) with persistently normal alanine aminotransferase (ALT) levels, the plasma levels of sIL-2R are normal, but, in patients (HCV RNA positive) with HCV-related chronic active hepatitis there are increased plasma levels of sIL-2R. We conclude that in HCV infection high levels of sIL-2R are related to activity of the disease rather than to virus replication. In patients with HCV-related chronic liver disease, the sIL-2R concentration may be a useful marker of disease activity.

Adolescent↗
PubMed1996

Hepatitis E virus infection in north-east Italy: serological study in the open population and groups at risk.

Developed western countries are considered to be relatively free from endemic foci of hepatitis E virus (HEV) infections. The aim of this study was to assess the seroepidemiology of HEV in north-east Italy. Of the 2361 individuals studied 1889 were representative of the general population and 472 were from groups at high risk for viral infections: 279 drug users and 193 patients on chronic haemodialysis. All sera were tested for hepatitis C virus antibody (HCVAb), human immunodeficiency virus antibody (HIVAb) and for hepatitis B virus (HBV) serology. Two solid-phase enzyme-linked immunosorbent assays (ELISA) were used to study the seroepidemiology of HEV IgG, the first (using recombinant antigens) for confirmation of initially reactive samples. The prevalence of circulating hepatitis E virus antibody (HEVAb) was 2.6% in the open population, 5.4% among drug users and 9.3% among patients on chronic haemodialysis. In the open population a positive relationship between age and prevalence of HEVAb was observed. A relationship between presence of HEVAb and serological evidence of previous HBV or HCV infections was also observed in this study. It was concluded that HEV infections are present in north-east Italy and are more frequent among subjects at risk for blood-borne viral infections. The positive correlation, observed in the open population, between age and prevalence of HEVAb suggests the presence of a cohort effect.

Adolescent↗
PubMed1993

Prevalence of anti-hepatitis C virus antibodies among teenagers in the Venetian area: a seroepidemiological study.

OBJECTIVES: To establish the prevalence of circulating anti-hepatitis C virus antibodies and investigate hepatitis B virus serology, in adolescents in Chioggia (Venitia), Italy. METHODS: We conducted a population based survey of 1,015 fourteen-year-old school children, 529 boys and 486 girls. All were testing for hepatitis C antibodies with second generation enzyme-linked immunosorbent assay (ELISA). Four immunoblotting tests were used to confirm positive ELISA tests. Hepatitis B (HB) markers, HBs, anti-HBs and anti-HBc, were tested with commercial ELISA kits. RESULTS AND COMMENTS: Fourteen children were positive for anti-HCV antibodies, after confirmation with four immunoblotting tests. No significant difference was seen between the prevalence rate in males (0.41%) and females (0.38%) or between urban (0.43%) or rural (0.31%) dwellers. A significant variation of rate (12.5% to 0.2%) was seen in subjects with or without previous HBV infection. A positive relationship between age and prevalence of antibodies to HCV was noted, suggesting a late acquisition of infection in our district. Nine subjects had had a history of apparent parenteral exposure and only 1 was anti-HCV positive. Among HCV positive subjects only 25% had a history positive for parenteral exposure.

Adolescent↗
PubMed1993

[Modifications induced on thrombin and plasmin activity by voluntary interruption of pregnancy].

Pregnancy is characterized by plasmatic variations of coagulative factors' concentration and by different haemostatic-fibrinolytic balance. At present it is possible, with EIA methods, to measure fibrinogen (FgDP) and fibrin (FbDP) degradation products with precision and accuracy, as direct indexes of fibrinolysis and the thrombin-antithrombin III complex (TAT) as indirect index of thrombophilia. We have considered the course of those indexes in 61 pregnant women within the tenth week of gestation, before and after voluntary pregnancy interruption (VPI) resulted without complications. The results don't show any peculiar variation of the examined parameters between the pregnant women before VPI and a control group. Comparing the basal data with those obtained three hours after VPI, all indexes are increased, particularly FbDP. After 24 hours the concentration of FgDP, FbDP and TDP decreased in comparison with the three hours control drawing, nevertheless staying higher than the values obtained in the basal drawing. The evolution of FDP and of TAT, in our study, points out that, in the first weeks of pregnancy, the haemostatic-fibrinolytic balance does not differ significantly from the physiological balance. Three hours after VPI fibrinolytic mechanisms prevail as regards the fibrinogenolytic ones. TAT increases after 3 hours and returns to the rules after 24 hours, proposing itself as an indirect index of thrombinic activation and as a direct index of antithrombinic activity.

Abortion, Induced↗
PubMed1992

Antibodies to non-structural hepatitis C virus antigens: a link with liver disease activity?

OBJECTIVES: The aim of our study was to evaluate the aetiopathogenetic role of hepatitis C virus (HCV) in the genesis of chronic liver disease and hepatocellular carcinoma and the relationship between presence of circulating antibodies against non-structural HCV antigens and disease activity. METHODS: Using a new enzyme-immunoassay capable of detecting, either separately or together, circulating antibodies to structural and non-structural hepatitis C virus antigens, we tested 208 chronic hepatitis B surface antigen (HBsAg) carriers and 144 patients suffering from chronic liver disease. RESULTS: Among the chronic HBsAg carriers with normal transaminase activity, there were 4% who proved to be anti-HVC positive, compared with 14.5% among those with high serum transaminase. Among subjects with chronic liver disease, 20% of patients with chronic persistent hepatitis, 54% with chronic active hepatitis, 35% with liver cirrhosis and 47% with hepatocellular carcinoma proved to be anti-HCV positive. With regard to the aetiology of liver disease, 13% and 25% of chronic HBV infected patients, with or without anti-delta virus superinfection respectively, had anti-hepatitis C virus antibody. This prevalence was 22% among alcoholic liver disease and 89% among patients with cryptogenic liver diseases. The percentage of subjects with circulating antibodies against non-structural HCV proteins was higher among HBsAg chronic carriers with raised alanine aminotransferase and among patients with chronic active hepatitis and hepatocellular carcinoma. CONCLUSIONS: Many subjects with chronic liver disease have circulating anti-HCV antibodies. Anti-HCV positive subjects, especially those with antibodies to non-structural antigens, are more frequently found among patients with aggressive liver diseases. Among HBsAg chronic carriers the prevalence of anti-HCV was lower in "healthy carriers" and HBeAg positive rather than in HBeAg negative subjects with high alanine aminotransferase. We therefore suggest that there may be a relation between HCV replication, activeness of the liver disease and presence of antibodies to non-structural viral antigens.

Carcinoma, Hepatocellular↗