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Biomedical subjects

A Giorgio

Publications and source records attributed to A Giorgio.

At least 55 records · Page 3Linked to original sources
PubMed1990

Decreased in vivo survival of hydrogen peroxide-damaged baboon red blood cells.

In this study we attempt to establish the consequence of in vitro hydrogen peroxide (H2O2)-induced membrane damage as manifested by spectrin-hemoglobin (Sp-Hb) complex formation and decreased red blood cell (RBC) deformability to in vivo RBC survival in baboons. After exposure to 135 to 581 mumols/L H2O2 and reduction with dithiothreitol (DTE), baboon RBCs were infused into the animal, and the fraction of cells remaining in circulation after 24 hours and the lifespan of surviving cells were quantitated. In a dose-dependent fashion, a positive correlation was observed between in vitro membrane alterations and the 24-hour in vivo survival. While 12% of the control cells were removed from circulation in 24 hours, 23% were removed after treatment with 339 mumols/L H2O2, and 36% following exposure to 581 mumols/L H2O2. Pretreatment with carbon monoxide before exposure with H2O2 increased the survival of oxidized RBCs. RBCs not removed from circulation in the first 24 hours had a normal lifespan. Moreover, by selectively isolating biotin-labeled, peroxide-treated cells that survived the first 24-hour posttransfusion period, a significant decrease in Sp-Hb crosslinking was observed in these cells. These results suggest that a subpopulation of cells sensitive to oxidation were removed during the first 24 hours. To identify this population, the survival of density-fractionated RBCs exposed to oxidant stress was quantitated. No differences in either the 24-hour survival or RBC life span were observed between untreated low-density (MCHC less than or equal to 32g/dL) and high-density cells (MCHC greater than or equal to 37g/dL). However, striking differences were noted after treatment with 339 mumols/L H2O2, with the 24-hour survival of high-density cells showing a marked decrease compared with low-density cells. These data support our hypothesis that during peroxidative membrane damage, Hb oxidation initiates a sequence of events resulting in skeletal changes that lead to membrane alterations and, eventually, in vivo destruction, and that the dense, dehydrated cells are more susceptible to oxidant damage.

Animals↗
PubMed1989

Morphologic and motility changes of the gallbladder in response to acute liver injury. A prospective real-time sonographic study in 255 patients with acute viral hepatitis.

In 255 patients with acute viral hepatitis and in 50 healthy controls, wall thickness, volume, and percentage of maximal contraction of the gallbladder were prospectively evaluated using real-time ultrasonography. A hypotonic, hypokinetic gallbladder was shown in 58.4% of the cases, expressed by normal parietal thickness, larger volume, and lower response to fat stimulation than the controls. In the remaining patients, wall thickening, decreased volume, and reduced contraction were compatible with a hypertonic gallbladder. Because the latter pattern was never observed in patients with disease onset dating back more than 9 days, it is conceivable that gallbladder hypertonicity in the early phase of the illness is followed by depression of tone and motor activity. However, such sonographic features turned out to be short-lived and reversible as they disappeared in all patients within 3 weeks of the first ultrasound examination. Moreover, none of the sonographic abnormalities correlated with either biochemical indices of acute disease or the patients' long-term outcomes.

Acute Disease↗
PubMed1989

Detection of microorganisms in clinical specimens using slides prestained with acridine orange (AOS).

Slides prestained with acridine orange (AOS) were used for direct examination of microorganisms in clinical specimens. The method is simpler than a commonly used acridine orange stain (AO) and has the advantage of being a supravital stain. Results indicate that the AOS method is sensitive, and allows rapid detection of microorganisms, even in the specimens containing few microorganisms, e.g. cerebrospinal fluid. Moreover AOS may be the choice method for detection of Trichomonas vaginalis.

Acridine Orange↗
PubMed1989

A simple and rapid method to evaluate lymphocyte response to mitogens.

A new method to evaluate lymphocyte response to mitogens is proposed. The method is based on the observation in fluorescence of the stimulated cells after their supravital staining on slides prestained with acridine orange in alcoholic solution. The results are expressed as Blast Index (IB). The method is very practical, easy to reproduce and shows a good correlation with 3H-thymidine uptake.

Acridine Orange↗
PubMed1988

Echo-guided percutaneous puncture: a safe and valuable therapeutic tool for amebic liver abscess.

To clarify the therapeutic role of echo-guided percutaneous puncture (EPP) in management of amebic liver abscess, 20 patients (24 abscesses) received metronidazole plus EPP. Fluid was aspirated through Chiba needles under real-time sonographic guidance so as to reduce cavity size to less than 3 cm. Not more than two EPPs were necessary in the majority of cases and no complication followed the procedure. This scheme resulted in a shortening of time of both hospitalization (less than or equal to 20 days) and liver lesion healing as assessed by ultrasound (less than or equal to 4 months). It is concluded that EPP is a valuable and safe therapeutic tool for hepatic amebic abscess.

Adult↗
PubMed1988

A new primate model for the study of intravenous thrombotic potential and its modification.

Advances in venous reconstruction have been limited by inherent venous thrombogenicity and the absence of a suitable prosthetic material for use in the venous system. We have designed an in vivo experimental model to evaluate early blood-material interactions within the venous system and to quantitate drug efficacy in the alteration of platelet function and fibrin deposition in the baboon. An 8F catheter was placed percutaneously in the femoral vein of an adult male baboon. Indium 111-labeled autogenous platelets or iodine 125-labeled human fibrinogen was infused before the introduction, into the inferior vena cava, of a linear array of 5 x 15 mm alternating Dacron and polytetrafluoroethylene samples attached to a benzalkonium-heparin-treated guide wire. At 60 or 120 minutes the samples were removed and a 1 ml aliquot of blood was drawn. The materials and blood samples were counted in a gamma well counter, and the material counts were normalized to the circulating label present in the 1 ml blood sample. The experiment was repeated after pretreatment with heparin, aspirin, or dextran. Whole blood clotting times and bleeding times were monitored. The results showed decreased platelet and fibrin deposition on polytetrafluoroethylene when compared with Dacron in the venous system. Aspirin, heparin, and dextran were all found to decrease platelet and fibrin deposition onto intravenously placed graft material samples (p less than 0.05, Student's t test). The data confirm the ability of the model to evaluate quantitatively anticoagulants, antiplatelet agents, and prospective graft materials for use in venous reconstructions.

Animals↗
PubMed1988

[Clinical significance of hyperechogenic focal lesions of the cirrhotic liver].

A review was made of the ultrasonographic (US) examinations performed over the period 1981-1986; 27 cirrhotic patients with hyperechoic liver lesions were identified, whose diagnoses had been made by means of either US-guided percutaneous biopsy, or laparoscopy, or autopsy. In 24 patients hepatocellular carcinomas nodules (HCC) were found, associated with cirrhosis, while in 3 cases only cirrhosis was seen. In the above mentioned 3 cases, a 2-year US follow-up showed no variation in the size of the nodules. These data confirm the importance of US in the screening of risk HCC patients, and point out that--however small--hyperechoic lesions in a cirrhotic liver suggest the cancerization of the substanding cirrhosis.

Biopsy↗
PubMed1988

Ultrasonically-guided percutaneous transcholecystic cholangiography--an alternative approach in cases of biliary obstruction and failure of percutaneous transhepatic cholangiography.

Fourteen ultrasonically-guided percutaneous transcholecystic cholangiographies (PTCC) were performed in subjects with biliary obstruction with different underlying diseases. No complication was observed, and the procedure permitted diagnosis in all cases, although the previously reported difficulty of visualizing proximal bile ducts was confirmed in two cases. PTCC can constitute a valid and safe diagnostic alternative in obstructive jaundice in which no dilation of intrahepatic bile ducts is revealed on US, in cases in which percutaneous trans-hepatic cholangiography fails.

Aged↗
PubMed1987

Survey of delta infection in the Naples basin: a possible epidemiologic model for endemic areas.

The prevalences of delta co-infections and superinfections in 100 randomly selected subjects for each year from 1977 to 1982 and in all the subjects of subsequent years until April 1986, admitted to our Department with acute viral hepatitis B (AVHB), were evaluated and compared with the annual incidence of cases of AVHB reported in Naples during the same period. Moreover, anti-delta antibodies were determined in the sera of 25 consecutive cases of HBsAg-positive chronic active hepatitis and 25 consecutive cases of HBsAg-positive chronic active hepatitis and 25 consecutive cases of HBsAg-positive cirrhosis, respectively, for 1977, 1980, 1983 and 1986. Our data show a high, constant circulation of HDV and a decrease in its incidence in acute forms over the last 3 years, which coincides with the parallel lower incidence of AVHB, but which is not reflected in the delta prevalence in the chronic forms. They also indicate the possible existence of alternate cycles of increase and decrease in the infection, partly dissociated from HBV circulation, which present peculiar epidemiologic characteristics.

Adolescent↗
PubMed1986

Delta infection in the Naples area. Epidemiologic and clinical significance.

To define the epidemiologic and clinical significance of delta infection in the Naples area, we sought anti-delta antibodies in all cases of HBV-associated liver diseases, hospitalized in our department during 1983 (234 acute hepatitis, 9 of which fulminant; 51 chronic hepatitis; 32 cirrhosis; 19 hepatocarcinomas) and in randomly selected acute hepatitis over the previous 6 years. Delta agent in acute forms and IgM anti-HBc in delta-positive acute forms were also tested. The acute cases were controlled for at least 9 months after dismissal. Delta infection showed a high prevalence in the Naples area (20% of all acute cases in 1983; similar prevalences in previous years; high rate of coinfections, 81%; no peculiar modalities of circulation) and a high pathogenicity, as proved by the greater prevalence in fulminant cases (66.7%) and severe chronic forms. Moreover superinfection appears a more dangerous event than coinfection as regards the diseases becoming chronic (77.8% vs 2.5%).

Adolescent↗
PubMed1986

Cirrhosis: value of caudate to right lobe ratio in diagnosis with US.

To verify the value of ultrasound (US) in the diagnosis of cirrhosis, the ratio of transverse caudate lobe width to right lobe width (C/RL) was determined with US in 25 healthy subjects and 156 consecutive patients with either histologically proved acute viral, chronic persistent, or chronic active hepatitis or cirrhosis. The C/RL ratio had a sensitivity of 43%, a specificity of 100%, and an accuracy of 79% in cirrhosis. The sensitivity was very low in alcoholic cirrhosis, low in cryptogenic cirrhosis, and high in hepatitis B virus related cirrhosis. In spite of its fairly low overall sensitivity, the C/RL ratio is a useful measurement in assessing chronic liver disease because of its high specificity in cirrhosis.

Adolescent↗