PubMed Health⌕ Search

Biomedical subjects

P Musiani

Publications and source records attributed to P Musiani.

At least 19 recordsLinked to original sources
PubMed1992

Distribution and phenotype of immune cells in normal human gingiva: active immune response versus unresponsiveness.

The oral cavity, and particularly the gingival mucosa, is continuously exposed to numerous food and bacterial plaque antigens, though evident immunologic reactions are uncommon. It is therefore possible that the mucosal associated lymphoid tissue (MALT) of this region is preferentially biased towards unresponsiveness, rather than immune cell activation. The distribution and phenotype of immune cells in normal human gingiva were examined. Their distribution varied, and high and low cellularity areas could be distinguished in the same specimen. The number of CD3 positive (CD3+) T lymphocytes was more than thrice higher in a high cellularity area. In both types of area, intraepithelial T lymphocytes were not activated. Moreover, they showed chromatin condensation and cell shrinkage characteristic of apoptosis. In the stroma of high cellularity areas, foci of cell activation and numerous B cells were present, suggesting a localized active immune response. The vast majority of intraepithelial and stromal T lymphocytes expressed the "memory" CD45RO+ phenotype. The absence of an immune response within the epithelium and the localized response in the stroma (probably due to the binding of memory T cells to antigens in a low affinity, cross-reactive fashion) may be a part of a protective mechanism against indiscriminate stimulation by a multitude of external antigens.

Adult↗
PubMed1979

FC receptor for IgM: factors influencing detection on human T lymphocytes.

This paper is concerned with technical standardization in detecting Fc-IgM receptors on human T lymphocytes. We have investigated a number of factors of critical importance in obtaining easily reproducible and reliable estimates of the numbers of TM cells among human peripheral T lymphocytes. A point of major importance is optimal coating of erythrocytes by IgM molecules. For this condition to be met, particular attention is required when erythrocytes from animals other than the one used for obtaining antiserum are used to prepare EA-IgM. Determination of the agglutinating titer of IgM preparation is useful in determing optimal sensitizing dilutions. Full expression of Fc receptors is favoured when human cord serum is added to the medium. The influence of incubation period of EA-lymphocytes mixtures on TM counts has also been investigated.

Animals↗
PubMed1979

T-cell nature of leukaemic cells in a case of Sézary's syndrome with 'null-cell' features.

alpha-naphthyl acetate esterase (ANAE) activity has been investigated in leukaemic cells from peripheral blood in a typical small-cell Sézary syndrome (SS) case in which cerebriform mononuclear cells failed to form E rosettes. The 'dot-like' ANAE positivity found in the majority of these neoplastic cells strongly supports a T-cell origin. In addition, a non-monocytic, non-B-cell nature of Sézary cells is indicated by the lack of Ia-like antigens. Finally, there is evidence of a distinct portion of Sézary cells simultaneously expressing ANAE activity and Fc IgM receptors.

Esterases↗
PubMed1979

Structural and functional characteristics of hairy cells.

Morphological, cytochemical, immunological and ultrastructural studies were performed on peripheral blood mononuclear cells from a patient with hairy-cell leukemia. Immunofluorescence studies showed a very strong intensity of fluorescence and indicated that hairy cells had monoclonal surface-membrane immunoglobulins (SmIg) actively produced by the cells. An unusual spontaneous SmIg redistribution induced by antibodies was also noted. Immunoultrastructural studies demonstrated that antibody-induced redistribution of SmIg on hairy cells is in form of a singular polar cap and that the cell membrane is rapidly cleaned of the complexes by endocytosis. The behavior of hairy cells regarding several membrane markers, mitogen stimulation and antibody-induced cytotoxicity suggests that hairy projections could represent the expression of a functional stage common to different lymphocyte subpopulations, or alternatively, a marker of a peculiar subset of B lymphocytes.

Antibodies, Neoplasm↗
PubMed1979

Subpopulations of T lymphocytes in myasthenia gravis patients.

Subpopulations of human peripheral blood T lymphocytes were examined in twenty-three myasthenic patients. T lymphocytes bearing receptors for the Fc portion of IgG (T gamma) were significantly increased in a third of the patients examined. T lymphocytes bearing receptors for the Fc portion of IgM (Tmu) were within normal values in all but two patients. Possible implications of these cells in the pathogenesis of myasthenia gravis are discussed.

Adolescent↗
PubMed1979

Subpopulations of lymphocytes in human thymomas.

Lymphocyte populations in six normal thymuses and ten thymomas were examined. The majority of lymphocytes from both thymus and thymoma differ from peripheral T lymphocytes in their capacity to form E-rosettes resistant to incubation at 37 degrees C. Low percentages of T lymphocytes bearing receptors for the Fc portion of IgG (TG) and IgM (TM) were found in normal thymus. In contrast, lymphocytes from five out of nine thymomas showed remarkable percentages of TM cells. Compared with normal thymocytes, lymphocytes from seven out of ten thymomas responded vigorously to mitogens. The possible origin and nature of thymoma lymphocytes are discussed.

Adult↗
PubMed1979

Specificities of rabbit anti-human insulin receptor antibodies.

Human insulin receptors obtained from normal human placentae were highly purified by affinity chromatography and used to immunize rabbits. The immunological response was evaluated in order to reveal the presence of antibodies blocking the binding of insulin to monocytes of normal subjects. Since no blocking activity was found IgG from rabbits were coupled to agarose in order to evaluate the presence of antibodies directed to determinant(s) other than the insulin binding site. One rabbit was found to produce antibodies binding the insulin receptor on a site different from the insulin binding site.

Animals↗
PubMed1978

Inhibitory activity of alpha-1-antitrypsin bound to human IgA.

Complexes between alpha-1-antitrypsin (alpha 1AT) and monoclonal IgA are regularly demonstrable in the plasma of myeloma patients. These alpha 1AT-IgA complexes, free of contamination by unbound alpha 1AT, are purified from 5 myeloma patients sera using salt-mediated hydrophobic chromatography. The complexes have a molecular weight greater than or equal to 400 000: this suggests that alpha 1AT is bound to di- or polymeric IgA. The alpha 1AT bound to IgA constitutes the 3.2, 3.5, 7.2, 8.5, and 24.6 per cent of the total alpha 1AT present in the 5 myeloma serum samples. There is a linear correlation between bound alpha 1AT concentration and IgA level in the range of the IgA concentrations considered (r = 0.988; p less than 0.05). Similar values are obtained quantitating bound alpha 1AT by radioimmunodiffusion technique or by determination of the trypsin-inhibiting capacity; this demonstrates that the bound alpha 1AT fully retains its inhibitory capacity. The biological significant of this binding phenomenon is discussed.

Chromatography, Gel↗
PubMed1978

Alpha-1-antitrypsin in umbilical cord serum: pi phenotypes and relationships with idiopathic respiratory distress syndrome.

The concentrations and phenotypes of serum alpha-1-antitrypsin (alpha1AT) were determined in 650 newborn infants. The distribution of these 650 subjects among the various Pi phenotypes confirms the higher frequency reported for the PiS allele in Latin populations. Serum alpha1AT levels vary between one phenotype and the other. Besides, at birth, infants weighing more than 2,500 g have alpha1AT levels significantly higher (P less than 0.001) than infants weighing less than 2,500 g; this difference in serum alpha1AT concentrations is due to the low alpha1AT levels found in preterm infants. The significantly lower alpha1AT concentrations found in preterms is associated with a higher risk of developing IRDS and with a mean birth weight under 2,000 g. Infants who develop IRDS frequently have lower alpha1AT levels than those who do not develop the syndrome, independently from body weight. On the basis of serum alpha1AT quantitation, newborn infants may be separated into two groups, characterized respectively by concentrations above or below 150 mg%. From our data, it appears that if the group with an alpha1AT concentration lower than 150 mg% is phenotyped, it is possible to differentiate infants with a high risk of fatal IRDS from individuals with a "pathological" phenotype.

Birth Weight↗
PubMed1978

Echinococcus granulosus: specific quantification of the two most immunoreactive antigens in hydatid fluids.

Preparations of the two most immunoreactive Echinococcus granulosus antigens (antigens 4 and 5) from sheep hydatid fluid, purified by a simplified method, and monospecific antisera against antigens 4 and 5, prepared by a new procedure, were used to measure the antigenic concentrations of antigens 4 and 5 in swine, sheep, and human hydatid fluids from pulmonary or hepatic cysts. Two bovine samples and two commercial preparations were also tested. The concentration of both antigens was significantly higher in sheep and human hydatid fluids than in swine hydatid fluid. The antigenic content of the two bovine samples and of the two commercial preparations was below the sensitivity level of the method employed. Independently of the species tested, the amount of Echinococcus antigens was greater in hepatic than in pulmonary cysts. The ratio between the concentrations of antigens 4 and 5 was constant at about 1:10 in the samples from various organs and from different species. When there were enough samples for statistical analysis a linear correlation was found between the contents of these two antigenic components but there was none between the amounts of proteins and the antigenic concentrations in the single cysts. Sheep hydatid fluid must therefore be considered the best source of antigenic material for diagnostic purposes even though in human cysts the antigenic fraction is less contaminated by serum proteins. We describe a reliable method of standardising antigenic material for the immunodiagnosis of hydatid disease.

Animals↗
PubMed1978

Alpha-1-antitrypsin phenotypes in newborns from Central and Southern Italy.

The results of Pi typing on 500 infants from Central and Southern Italy are reported. Phenotype determinations were performed on umbilical cord serum. We observed nine different phenotypes; each of these is present in other European populations. The frequencies of the Pi alleles in our group were found to be, on the whole, comparable to those found in other populations widely separated geographically. However, the frequency of the Pi S gene in our sample (0.0670) was greater than that observed in Northern and Central European and American groups. Our Pi S frequency was similar to that found in a French group and lower than that of Spanish and Portuguese groups. Our data thus confirm the higher Pi S gene frequency in Latin populations.

Alleles↗
PubMed1977

Echinococcus granulosus: identification of subunits of the major antigens.

This paper describes a procedure for obtaining the two "major" Echinococcus granulosa antigens (antigens 4 and 5) from sheep hydatid fluid. Purified antigen 4 (m.w. 400,000 and over) and antigens 5 (m.w. 150,000) were separated in order to identify molecular subunits of each. SDS 12.5% polyacrylamide gel electrophoresis of antigen 4 gave a single band for which a m.w. of 67,000 was calculated. When 5% 2-mercaptoethanol was added to the antigen 4 preparation, SDS 12.5% polyacrylamide gel electrophoresis gave two bands (m.w. 47,000 and 20,000). SDS 12.5% polyacrylamide electrophoresis of antigen 5, with or without 2-mercaptoethanol, gave at least three bands with m.w. ranging from 10,500 to 20,000. Low m.w. subunits of both antigens were eluted in a single peak from a preparatory SDS 7.5% acrylamide gel electrophoresis; these subunits were found to be immunogenic and antigenic.

Animals↗
PubMed1976

Isolation, chemical, and physical properties of alpha-1-antitrypsin.

A method of isolation of alpha-1-antitrypsin (alpha-1-AT) in good yield from normal human plasma is described. A key step was affinity chromatography employing an antiserum which had been depleted of alpha-1-AT antibodies. The final preparations were homogeneous by immunological and physicochemical criteria. The specific activity of the purified alpha-1-AT was 0.363 mg of active bovine trypsin inhibited per 1.0 mg of inhibitor. Polyacrylamide gel patterns at both alkaline and acid pH of highly pure preparations frequently, but not invariably, showed multiple hands. Molecular weight studies by sedimentation equilibrium ultracentrifugation in aqueous buffer and in 6 M guanidine as well as sodium dodecyl sulfate polyacrylamide gel electrophoresis suggest that alpha-1-AT is a single polypeptide chain having a molecular weight of 49,500. Other physical and chemical properties of the inhibitor are described. A limited N-terminal sequence (Glu-Asp-Pro-Gln-Gly-Asx-Ala-Ala) was obtained. It was found that alpha-1-AT easily forms polymers and higher aggregates when exposed to denaturing agents such as 8 M urea and 6 M guanidine. The results suggest that aggregation is determined by both covalent and noncovalent forces.

Amino Acid Sequence↗