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Biomedical subjects

G Mazzoni

Publications and source records attributed to G Mazzoni.

At least 19 recordsLinked to original sources

Indium-labeled presensitized T cells for diagnosis of graft rejection.

The aim of this experiment was to test a safe, noninvasive method for necessary, accurate diagnosis of early allograft rejection. Heart-lung allograft was performed heterotopically using Brown Norway (BN) rats as the donor and Lewis (LEW) rats as the recipient. T cell suspensions were prepared from lymphnodes of specifically sensitized LEW rats that had acutely rejected full-thickness BN skin graft. Cell count was adjusted 50 x 10(6) cells/ml. The suspension was incubated in vitro with 111I oxide (1 m Ci-ml). An aliquot of labeled cell suspension containing 40 x 10(6) cells and a total radioactivity of 200 mCi was administered intravenously to each animal 3 and 6 days after heart-lung transplant. The traffic of T cells was followed in vivo and in isolated organs under large field view gamma camera. The gamma camera revealed radioactivity on the graft starting Postoperative Day 5 when the heart was actively beating; no radioactivity was revealed at the site of the isografted organs. The histology showed mild to moderate cellular infiltration parallel to the grade of radioimaging intensity. The injection of indium-labeled presensitized T cells was able to detect the rejection process in an early phase when there are no clinical symptoms of rejection and/or the rejection cascade can be reversed. These results suggest that a similar method can be used in human organ transplantation for early diagnosis of rejection.

Animals

Do memorability ratings affect study-time allocation?

This research addresses the relation between predicting future memory performance (judgment of learning, or JOL) and subsequent self-paced study-time allocation. The results of three experiments support the main hypotheses: (1) recall increases with increasing JOL, (2) restudy increases JOL accuracy, and (3) study time is related to JOL. This last relation depends on the length of initial presentation time of the items. When the initial exposure trials were short, the most restudy time was allocated to the items judged hard to recall, but when the initial exposure times were long, the most restudy time was allocated to the uncertain items. Items studied longer were recalled equally well (Experiments 1 and 3) or to a lesser extent (Experiment 2) than items studied for a shorter time. It is hypothesized that during study time, subjects refine their JOLs for the items initially less well discriminated.

Adult

Nonfamilial intestinal polyposis and brain tumor in a 5-year-old girl.

A 5-year-old girl with glioblastoma multiforme and simultaneous adenocarcinoma in one of multiple colonic polyps is the youngest reported case of Turcot's syndrome. A literature survey and a classification based on family pedigree and pattern of inheritance are proposed.

Adenocarcinoma

Reversibility of graft rejection following a short cyclosporin-A administration 5 days after grafting.

The aim of this research was to investigate whether cyclosporin-A (Cy-A) could exert its action on graft rejection in progress. For this purpose, heart-lung grafting was performed in a strong histoincompatible combination of rats (BN/LEW). In one group of animals, Cy-A was administered at the dose of 15 mg/kg daily for 10 days starting on the 5th day after grafting. In a control group only olive oil was administered. Five of six animals treated with Cy-A showed a graft survival over 4 weeks and in two cases it was over 2 months when they were killed.

Animals

[Esophageal atresia associated with a subglottal stenosis. Apropos of a case].

The authors report a case of a 3 kg newborn with oesophageal atresia and congenital subglottic stenosis. The literature is reviewed and the management of our case reported. As in many cases the subglottic stenosis outgrows within a year of age, though tracheostomy is not justified even if general anesthesia is needed in case of major surgery.

Esophageal Atresia

Growth-stimulating factor in regenerating canine liver.

Extracts from dog livers which had been regenerating for 24, 48, and 72 h after hepatectomy were infused for 6 h into the left portal vein of animals which had fresh portacaval shunts (Eck fistula) and which were killed 2 and 3 days later. The brief exposure to the 48-h and especially the 72-h regenerating liver extracts induced a delayed proliferative response predominantly in the left liver lobes, with a slight spillover effect to the right liver lobes but none to the kidney. The response reached its peak 3 days later. In the left but not the right liver lobes, both the 48-h and the 72-h regenerating liver extract reversed the atrophy ordinarily caused by Eck fistula in 3 days and partly prevented the ultrastructural hepatocyte deterioration characteristic of Eck fistula. The active liver extracts apparently contained a growth-control factor or factors which is (are) not insulin or glucagon.

Animals

Acute neurological complications after liver transplantation with particular reference to intraoperative cerebral air embolus.

Nine of 48 adult patients who underwent orthotopic liver transplantation developed significant clinical neurological abnormalities recognized shortly after operation. Decrease in consciousness occurred with resultant coma, focal and generalized seizures and the occasional appearance of a state of akinetic mutism. Neuropathological abnormalities consisted of multifocal areas of infarction in cerebral cortex and basal ganglia in five patients, central pontine myelinolysis in five (often more extensive than usually reported), Wernicke's encephalopathy in three, glial nodules in two, and fungal abscesses in one. Alzheimer II astrocytosis was found in all brains available for retrospective study. There was direct evidence in two of the patients that air embolization from the homografts had occurred. Correlation of this with the brain infarcts in these and other cases seems reasonable. The ease with which air passed to the systemic circulation is explicable by the right to left venous--arterial shunts that are common in chronic liver disease. With the delination of this cause for the neurologic complications, measures to prevent it in future cases have been described.

Adolescent

Renal homotransplantation with venous outflow or infusion of antigen into the portal vein of dogs or pigs. Transplantation at portal site.

Kidneys were transplanted in mongrel dogs so that renal venous drainage was into the portal system of the hosts. Thirty-one recipients were not treated, 11 were given one dose of 3 mg of azathioprine per kg, and 11 were given 2 mg of azathioprine per day. Survival was not statistically increased compared with that in three comparable series in which renal venous drainage was into the vena cava, nor were the histopathological findings favorably altered in the "portal" kidneys. The injection of semisoluble antigen into the portal vein at the same time as renal transplantation at the caval site, had an effect no different from that if the antigen were given systemically during caval site transplantation. The conclusion that drainage of grafts into the portal vein was not beneficial was reached in 20 pigs evenly divided between the portal and vena caval sites, and in 12 pairs of dog to pig or pig to dog xenografts. Thus, none of these experiments has identified an advantage of antigen delivery into the portal as opposed to the systemic venous system.

Animals