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Biomedical subjects

C Pini

Publications and source records attributed to C Pini.

71 records · Page 4Linked to original sources
PubMed1983

Circulating immune complexes in sera of patients infected with Echinococcus granulosus.

Circulating immune complexes (CIC) were investigated by the C1q binding assay in sera of 23 patients infected with Echinococcus granulosus. For the 23 sera studied, nine were found to be positive in the test. When the samples were grouped according to the cyst localization, the highest rate of CIC positively was found in the group of sera from patients with pulmonary cyst; in this group, double diffusion (DD) and indirect haemagglutination (IHA) tests gave a low rate of positivity for antibodies directed against parasitic antigens. Rheumatoid factor, anti-nuclear and anti-mitochondrial autoantibodies were not detectable in patients' sera by indirect immunofluorescence technique (IIF). Anti-smooth muscle autoantibodies, detectable by IIF, were present in 56% of the sera and this positivity was higher in the hepatic (83%) than in the pulmonary form (40%).

Antibodies, Antinuclear↗
PubMed1982

Isolation and preliminary characterization of electrophoretic variants of copper, zinc superoxide dismutase.

Three electrophoretic variants of superoxide dismutase can be detected in bovine erythrocytes by gel electrophoresis and electrofocusing. The two major forms, having isoelectric points at pH 5.2 and 4.9, were isolated by preparative focusing or chromatography. No differences were found in molecular weight, metal content, antigenicity, electron spin resonance spectrum, visible and ultraviolet optical spectra. In contrast, holo- and apo-superoxide dismutase, which have an electrophoretic mobility similar to that of the two major forms, showed unresolved isoelectric points but significantly different antigenicity. This result suggests that their different electrophoretic mobility is mainly conformation-related. The variant with pI 5.2, corresponding to the protein purified by ordinary procedures, was found to be inactivated by heat treatment faster than the other form. The latter one, on the other hand, gave rise to a multiple pattern of electrophoretic bands after incubation at 75 degrees C. It is suggested that superoxide dismutase multiplicity in erythrocytes is not genetically determined, but may be related to segregation of subunits, made non-identically by post translational asymmetrical modification.

Animals↗
PubMed1982

T-cell-dependent oscillations of IgM antibody affinity during the immune response to DNP-Dextran to low or high epitope density.

Anti-hapten IgM antibody response and affinity were evaluated by haemolytic plaque inhibition assay on spleen cells from mice immunized with 2,4, dinitrophenyl (DNP)1.3-Dextran or DNP13-Dextran. Regardless of epitope density, affinity was found to mature with time after immunization and to be characterized by rapid oscillations independent of changes in anti-hapten plaque-forming cell (PFC) response and antibody secretion rate. Injection of the lower epitope density immunogen not only elicited higher PFC responses and higher affinity antibodies but also induced more pronounced affinity oscillations mainly confined to the higher affinity PFC subpopulation. Immunization of athymic nude mice with DNP1.3-Dextran elicited PFC responses comparable to those observed in similarly immunized euthymic mice. However, affinity oscillations were drastically reduced in athymic mice and the restricted variation of antibody affinity observed shortly after immunization was followed by no oscillations in any of the affinity PFC subpopulations. Athymic mice did not produce high affinity PFC which account to a large extent for the affinity oscillations observed in euthymic mice. These findings demonstrate the important role of T cells in the appearance of rapid changes in IgM antibody affinity. The generation of T-cell-dependent oscillations of high affinity antibody-producing cell subpopulations is discussed in terms of interactions among cells and soluble factors involved in regulatory circuits of the immune network.

Animals↗
PubMed1982

[Microsurgical blood vessel sutures using the so-called fibrin adhesive].

Since the development of microvascular surgery by Jacobson and Suarez, adaptation of vessel ends of less than 1 mm diameter has been performed by means of 8-10 interrupted sutures. Even the finest suture material, however, produces a foreign body reaction. In addition, necrosis of the media can be seen after insertion of interrupted sutures. After the initial demonstration in 1940 that divided nerves could be successfully rejoined by means of factors from the blood coagulation system, this technique was introduced to microsurgery in 1977. The present investigation was carried out on 50 end-to-end anastomoses in rat common carotid arteries. Subsequently, the healing process was studied by light and electron microscopy. The adhesive used was fibrinogen cryoprecipitate (Fibrinkleber-Human-Immuno), which polymerises after simultaneous application of thrombin. Electron microscopy shows no basic difference between the healing after this technique and the healing process after trauma to the vessel wall. This method, however, prevents regional necrosis of the vessel wall and reduces intimal thickening. The condition of the intimal lining appears better than in sutured anastomoses. The question, whether this change is due only to the absence of sutures or due also to application of fibrinogen, cannot be answered, however.

Animals↗
PubMed1980

Enzyme-linked immunosorbent assay (ELISA) in the serodiagnosis of hydatid disease.

An enzyme-linked immunosorbent assay (ELISA) was adapted for the indirect serological measurement of anti-Echinococcus antibodies in human hydatid disease. Both the tube method and the microtitration procedure were used successfully. However, the tube test with a purified hydatid fluid fraction appears to be the method of choice. ELISA results are comparable to those found in the indirect hemagglutination test and with the agar gel methods (double diffusion and immunoelectrophoresis), but false positive results were observed with the sera of patients with schistosomiasis or liver cirrhosis. ELISA has proved to be a sensitive quantitative procedure for the serodiagnosis of human echinococcosis, even though it has not been shown in our study to be more sensitive than the classical serological procedures such as indirect hemagglutination. It can be concluded that ELISA should be considered not as an alternative but as a useful addition to the range of immunodiagnostic tests available for serodiagnosis of hydatid disease.

Antibodies↗
PubMed1980

Oscillations of IgM antibody affinity at the level of single immunocytes.

IgM antibody affinity was measured by hemolytic plaque inhibition assays on spleen cells from mice immunized with a single injection of DNP-dextran. Maturation of affinity was found to occur with time after 1 to 1000 microgram of immunogen and to be characterized by rapid oscillations independent from changes inFC number/spleen and in antibody secretion rate. Analysis of affinity heterogeneity showed that such oscillations occur in higher affinity PFC subpopulations. The origin of affinity oscillations was discussed in terms of interactions among antigen and the elements of the immune network.

Animals↗
PubMed1978

Time and antigen dose-dependent variations of IgM antibody affinity.

Affinity of IgM antibodies elicited in mice by a single injection of dinitrophenylated dextran was measured by equilibrium dialysis. Maturation of affinity was found to occur with time, the rate of increase being higher after larger antigen doses. Maturation was followed by a decrease of affinity with time, the fall being more pronounced after lower antigen doses. These findings are more in line with the theory of antigen-induced diversity rather than with the maturation theory.

Animals↗
PubMedDate not supplied

Cholesterol distribution between HDL subfractions. A study of 498 subjects.

In 498 subjects (205 normolipidemics and 293 hyperlipidemics) of both sexes, the cholesterol content of high density lipoprotein (HDL) subfractions has been determined. The serum concentration of total HDL-cholesterol appears to be more strictly related to the cholesterol content of HDL2 than to that of HDL3. This latter one, however, gives a contribution to the variability of HDL-cholesterol so that the value of HDL-cholesterol cannot be assumed as a reliable estimate of the serum level of the more anti-atherogenic HDL2 subfraction. The cholesterol content of HDL and its subfractions is higher in women than in men and decreases with increasing serum VLDL-cholesterol level and body weight. Both HDL2- and HDL3-cholesterol appear to largely depend from the metabolism of triglyceride-rich lipoproteins in accordance with the data of experimental studies.

Adolescent↗
PubMedDate not supplied

Effects of serum storage on the determination of cholesterol.

Cholesterol determined by 4 different enzymatic commercial kits and by the dry chemistry Reflotron system was higher in serum stored at 4 degrees C and at -20 degrees C than in fresh serum. The effects of storage seem to be temperature-dependent. In fact, cholesterol values significantly increased only after 2h of freezing. The prolongation of freezing up to 2 weeks was not followed by further significant changes. In serum stored at 4 degrees C the increase in cholesterol was slower than in frozen serum. Both free and esterified cholesterol underwent an increase after storage. When cholesterol was determined by a chemical method (sulfuric acid-ferric chloride) after extraction with ethyl acetate and ethanol, no difference was observed in fresh and stored serum. Cholesterol, triglycerides and apoproteins A-I and B underwent parallel changes after storage both in whole serum and fractionated lipoproteins. Our findings strongly suggest that in serum stored at positive or negative temperature there is an alteration of the lipoprotein molecules which allows an easier availability of cholesterol for the enzyme-substrate reaction than in fresh serum. Current enzymatic methods underestimate (about 10%) cholesterol when the analysis is performed on fresh serum.

Apolipoproteins↗
PubMedDate not supplied

Relationship of serum triglyceride concentration to lipoprotein composition and concentration in normolipidemic and hyperlipidemic subjects.

In a series of 438 subjects (184 normolipidemics and 254 hyperlipidemics) the relationship among serum concentration of triglycerides, lipoprotein lipids and apoproteins A-I and B has been evaluated. The results show that as serum triglyceride level increases, VLDL rise and become enriched in triglycerides. The increase of VLDL is associated with a reduction of serum levels of LDL and HDL which appear to be rich in triglycerides and poor in cholesterol. The decrease in serum HDL level is mainly due to a reduction in serum concentration of the HDL2 subfraction. The triglyceride content of HDL2 and HDL3 rises with increasing serum triglycerides. The increase in serum triglyceride concentration seems then to be associated with a complex metabolic derangement which involves all the lipoprotein fractions.

Adolescent↗
PubMedDate not supplied

Monoclonal suppressor T-cell factor displaying V H restriction and fine antigenic specificity.

The production of stable T-cell clones is essential for the study of T-cell-derived, specific immunoregulatory products and of specific T-cell receptors. T-cell clones have been established by radiation leukaemia virus (RadLV)-induced transformation of suppressor T lymphocytes specific for hen egg white lysozyme (HEL). We report here that culture supernatant obtained from these T-cell clones can, when injected into mice, specifically suppress the anti-HEL antibody response. This monoclonal T-cell product suppresses the antibody response induced by HEL and human lysozyme, but not that induced by ring-necked pheasant egg white lysozyme (REL), thus displaying fine antigenic specificity probably restricted to an epitope involving phenylalanine at amino acid residue 3, present in the N-terminal region of HEL and shared by human lysozyme but absent in REL. The suppression induced by this monoclonal T-cell product is restricted by both H-2 and Igh-1 genes whereas anti-HEL antibodies bearing a predominant idiotype are induced in all mice strains tested, irrespective of their H-2 haplotype or Igh-1 allotype.

Animals↗
PubMedDate not supplied

[Comparison of preschool children's performance using the Denver developmental test, before and after nutritional intervention].

UNLABELLED: Psychomotor and development analysis must be emphasized when studying institutionalized children. Many previous investigations have been showing deleterious effects of day care centers over developmental performance in children. OBJECTIVE: This study is aimed at comparing the performance in the Development Screening Test (Denver) in children attending day care centers, before and after nutritional intervention with an energetic supplement enriched with iron. METHOD: 130 children from 2 to 6 years old, attending three municipal day care centers, were evaluated by means of the application of the Denver test; by trained psychologists, comparing the collected data according to sex and age group, before and after six months intervention with iron enriched protein energetic supplement. RESULTS: Most of the children had normal performance, both in first application (70.80%), and in the second one (80.80%). When comparing these results, 76.92% of the children had not altered their performance and 18.46% improved it substantially. As to sex, no significant differences were found and as to age group, there was significant improvement among children aged 4 to 6 years of age. CONCLUSIONS: Besides the nutritional aspects, factors such as learning readiness, family organization, and psychopedagogic orientation to the day care centers, must have fostered development, even if the low socioeconomic level of the studied population is considered.

Child↗
PubMedDate not supplied

Identification of factors interacting with a subset of T8+ cells.

In a previously work we have reported that T8+ lymphocytes decrease can be obtained by incubation of lymphocytes from normal blood donors with serum taken from patients in the acute phase of the disease. In this paper is described a partial characterization of the masking serum factor present in the acute phase of the disease. It displays a m.w. of approximately 640,000 d and its effect disappears either after heating 60 min. at 37 degrees C or 30 min. at 56 degrees C, after dialysis against 1M NaCl or lyophilization. Another serum factor, insoluble at 50% ammonium sulphate final saturation, resistant to heating and lyophilization, able to remove (in vitro) the former masking factor from the T8+ cells, is present in the remission phase.

Humans↗
PubMedDate not supplied

Detection of phosphatidylcholine-specific phospholipase C in NIH-3T3 fibroblasts and their H-ras transformants: NMR and immunochemical studies.

Although evidence supports constitutive activation of phosphatidylcholine specific phospholipase C (PC-plc) in rastransformed fibroblasts, no studies have been devoted to measure the basal activity levels of this enzyme, its molecular characteristics and subcellular localization. This paper reports for the first time measurements of the activity of different enzymes responsible for PC hydrolysis (PC-plc; phospholipases A2 (pla2) and A1 (pla1)) in homogenates of murine NIH-3T3 fibroblasts (3T3) and their transformants obtained by human H-ras transfection (3T3ras). To this end, 31P NMR analyses were carried out on total cell homogenates, incubated in the presence of mixed diheptanoylphosphatidylcholine: sphingomyelin (DHPC:SM) unilamellar vesicles (SLUV), in which DHPC acts as a suitable substrate for water-soluble lipolytic enzymes. The basal PC-plc activity levels (0.66 +/- 0.14 and 0.38 +/- 0.10 nmol/10(6) cells.hour in 3T3 and 3T3ras fibroblasts, respectively),were substantially higher (over 30-50x) than those reported in the literature for normal mammalian cells (dog heart myocytes). Moreover the PC-plc activity was about 15-30 times lower than the overall PC deacylation activity in both clones. The use of high titer polyclonal antibodies, raised in a rabbit against bacterial PC-plc, allowed identification of one cross-reactive mammalian PC-plc component (M(r) 66 kD) in cell lysates of both 3T3 and 3T3ras fibroblasts, and detection, by indirect immunofluorescence, of its subcellular localization. In control 3T3 fibroblasts (in the late log-phase of growth) the enzyme was exclusively located in the cytosol, while in H-ras transformed cells it was massively exposed on the external side of the membrane. This new finding strongly suggests that the oncogenic product p2Iras is able to induce (or mediate) translocation of PC-plc across the plasma membrane of ras transformed cells, with possible implications not only on cell biochemistry (enhancement of PC-plc activity, and consequent production of intra- and extracellular PCho and accumulation of neutral lipids) but also on cell-cell interaction mechanisms which facilitate tumour invasion and metastasis of oncogene-transformed cells.

3T3 Cells↗