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Biomedical subjects

A Guffanti

Publications and source records attributed to A Guffanti.

At least 37 records · Page 2Linked to original sources
PubMed1994

Uncommon clinical presentation of a lymphocytic lymphoma of intermediate differentiation in a patient with systemic sclerosis.

The association of systemic sclerosis (SSc) and non-Hodgkin lymphoma is a rare event and its pathogenetic mechanism remains to be clarified. We describe a previously unreported association of SSc with a lymphocytic lymphoma of intermediate differentiation (IDL), involving the gastrointestinal tract, gallbladder and one salivary gland. Whereas the morphological, immunological and cytogenetic features were typical of IDL, the extensive extranodal involvement and the association with an autoimmune disorder were suggestive of two other lymphomas of mantle lineage: mucosa-associated lymphoid tissue (MALT) lymphoma and monocytoid B-cell lymphoma (MBCL).

Female↗
PubMed1993

Iron status in red cell pyruvate kinase deficiency: study of Italian cases.

We investigated the iron status of 33 pyruvate kinase (PK) deficient patients, most of the cases reported in Italy. Serum ferritin (SF) was higher than the upper limit of the range of matched controls in 15/25 (60%) non-transfused patients (median 228 micrograms/l, range 58-3160 v 43, 22-310). Liver siderosis and fibrosis were found in 8/9, and cirrhosis in two who died at age 39 and 42 of complications of iron overload. SF was independent of age, sex, or severity of haemolysis. The prevalence of HLA-A3 antigen in PK deficient patients was not significantly different from that of our healthy population (29.6% v 23%). The HLA-A3 positive, non-transfused patients had significantly higher SF values than the HLA-A3 negative ones (median 675 micrograms/l, range 340-3160 v 145, 58-400). A pedigree study of six high SF-probands indicated that iron overload has a multifactorial pathogenesis. In particular, the association of PK deficiency-induced haemolysis, splenectomy and an additional factor (heterozygosity for idiopathic haemochromatosis, ineffective erythropoiesis) leads to severe iron accumulation. We suggest that monitoring iron status would be useful in PK deficient patients, particularly in splenectomized and HLA-A3 positive ones, to identify those at risk of iron overload and prevent the clinical consequences of iron accumulation.

Adolescent↗
PubMed1987

[Statistical survey of the hourly incidence of acute myocardial infarction: reduction of frequency during the nighttime hours].

The time of onset of acute myocardial infarction was analysed in 245 patients admitted to the Fatebenefratelli Hospital in Milan over 18 months. A significant decrease in the incidence of this pathology (P less than 0.01) was noted between midnight and 6 am. No significant difference was noted over the rest of the day. These results suggest the existence of a period of relative protection against the onset of myocardial infarction during the day.

Humans↗
PubMed1984

Serotonergic regulation of cortisol secretion in dogs.

The role of serotonin (5-HT) in the control of serum cortisol secretion was studied in 50 conscious beagle dogs. A significant rise in corticosteroids was observed after 1.5 and 3 mg/kg (P less than 0.01) iv fenfluramine, an indirect serotonergic agonist, as well as after 2 (P less than 0.05) and 3 mg/kg (P less than 0.01) iv quipazine, a direct agonist of 5-HT receptors. Both drugs exhibited a dose-related effect. A lower dose of fenfluramine, 0.5 mg/kg, was ineffective when administered iv, but raised serum cortisol (P less than 0.05) after direct injection into a lateral cerebral ventricle, through a chronically implanted brain cannula. The marked increases in corticosteroid concentration produced by the highest fenfluramine and quipazine doses were completely abolished by pretreatment with ketanserin, an antagonist of 5-HT2 receptors, which did not affect cortisol secretion when administered alone. These data suggest that brain serotonergic system plays a role in the control of cortisol secretion in conscious dogs.

Animals↗
PubMed1983

[Difference in the behavior of T-lymphocyte populations in heroin and methadone addicts].

An assessment of T-lymphocyte populations was performed in two groups of drug addicts by the technique of monoclonal antibodies. Group I was composed of 11 asymptomatic heroin addicts, group II being in heroin withdrawal program from at least six months. Homosexual subjects, partners of patients with AIDS and patients with liver abnormalities or with recent infectious diseases were excluded from the present study. In all the examined subjects the antibody pattern to Toxoplasma gondii, Epstein-Barr virus, Cytomegalovirus was either negative or slightly positive as after old infections. All subjects were HBsAg negative and HBsAb positive. Group I patients showed a significant inversion of OKT4/OKT8 ratio (p less than 0.01), due to a reduction in T helper lymphocytes (p less than 0.05) and an increase in T suppressors (p less than 0.05). Both groups showed a not significantly different proliferative response to Phytohemagglutinin (PHA) and Concanavalin A (Con A), although 8 out of 11 patients of group I exhibited a reduced proliferative response to PHA. Group I patients also showed a reduced proliferative response to Pokeweed mitogen (PWM). These results might suggest an involvement of B-lymphocytes in immunological changes of heroin addicts. In group II patient all the examined variables, OKT4/OKT8 ratio, absolute number as well as percentage of T-lymphocytes subpopulations and proliferative responses to the employed mitogens, resulted in the normal range. These data seem to exclude that methadone, in contrast with heroin, may induce a cell-mediated immunodepression.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1976

Transport of maltose by Pseudomonas fluorescens W.

The system for uptake of maltose in Pseudomonas fluorescens W was inducible. Using a mutant strain unable to hydrolyze maltose, it was shown that maltose was taken up unaltered against a concentration gradient. Uptake of 14C maltose was only significantly inhibited by nonradioactive maltose or maltotriose. These were the only sugars that could displace accumulated radioactive maltose in the strain unable to hydrolyze maltose. Uptake exhibited saturation kinetics and was inhibited by energy poisons, indicating that this system was one of active transport. Sulfhydryl-binding reagents reversibly inhibited maltose uptake. No transport ability was lost when cells were subjected to osmotic shock. Using the protein-binding dye 7-diazonium-1, 3-naphthalene disulfonate a protein or proteins located in or external to the cell membrane was implicated in maltose transport. The hydrolysis of p-nitrophenyl-alpha-D-glucoside (PNPG) was used as an indirect measure of transport ability since penetration of PNPG, not its hydrolysis, was the rate-limiting step.

Biological Transport, Active↗
PubMedDate not supplied

Use of IgM monoclonal reagents licensed for tube tests in column agglutination technology.

BACKGROUND: Red cell (RBC) phenotyping using column agglutination technology (CAT) is currently limited by the reagents formulated in the system. To overcome this limitation, it was investigated whether monoclonal IgM reagents licensed for use with tube tests produced valid results with CAT. STUDY DESIGN AND METHODS: Commercial CAT, does not contain antisera, was used to evaluate Procedures A (40 microL of reagent and 10 microL of 4% RBCs) and B (50 microL of reagent and 50 microL of 0.8% RBCs) with or without incubation at room temperature. In Study 1, reagents were tested to determine whether potentiators inhibit the passage of antigen-negative RBCs through the column. In Study 2, CAT sensitivity was measured by the use of potency titrations to define a procedure for each reagent that matched or exceeded that of the tube method. In Study 3, the specificity of each reagent was determined in parallel with the CAT and tube tests. Typing of 1644 samples was performed. RESULTS: Study 1: Free passage was obtained with all reagents. Study 2: Immediate-spin methods using CAT produced the same results as the tube method. Study 3: With 8048 comparisons made, discrepant results were found in 32 transfused patients and in 6 cord blood samples, mainly with Lewis reagents. With comparison of CAT and the standard tube method, complete agreement was obtained with Kell reagents, 99.9-percent agreement with Kidd reagents, and 98.9-percent and 99.4-percent agreement with Lewis reagents. CONCLUSION: Most examined reagents seem suitable for use with CAT.

Aged↗