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Biomedical subjects

A Salerno

Publications and source records attributed to A Salerno.

At least 127 records · Page 7Linked to original sources
PubMed1985

Infection of mice with Newcastle disease virus inhibits the T suppressor afferent cell circuit which regulates contact sensitivity to picryl chloride.

The interaction between Newcastle disease virus (NDV) and the suppressor cell circuit which regulates the induction phase of contact sensitivity reaction to picryl chloride (Pcl) was investigated. NDV infection impairs the activity of the T suppressor afferent cells (Ts-aff) which inhibit DNA synthesis in the draining lymph nodes of mice specifically sensitized with Pcl and the development of contact sensitivity. The inhibitory effect of NDV was evident when the virus was administered up to 2 days before or at the same time as the injection of picrylsulfonic acid; this effect required infectious virus, as NDV inactivated by ultraviolet irradiation failed to inhibit Ts-aff activity. Taken together with the previous finding that the T suppressor efferent cell is unaffected by NDV, the present results support the view that contact sensitivity reaction to picryl chloride is regulated by two distinct T-suppressor-cell circuits.

Animals↗
PubMed1985

Histopathological aspects of tissue reactivity to suture materials in microsurgical arterial, anastomosis.

In order to assess tissue reactivity to synthetic suture material in microsurgery, a histological study was carried out in 20 rabbits divided into two groups: "A" and "B". The aorta of the animals was sectioned and subsequently anastomosed using polyglycolic acid in the first group and monofilament nylon in the second group. The animals were sacrificed at 10, 20, 40, 60 and 90 days after surgery, and the specimens were studied both macroscopically and microscopically. Tissue reactivity during the initial 40 days had similar histological characteristics in both groups evidentiating a perisuture granuloma with macrophages and giant cells. The second period, 40 to 90 days after surgery, was characterized by a tissue reactivity specific for each type of suture. In group "A", the inflammatory process diminished in parallel to the absorbtion of polyglycolic acid with "restitutio ad integrum" of the vessel wall. In group "B", the inflammatory process persisted due to the presence of non absorbable monofilament nylon, thus causing a fibrosclerotic transformation of the vessel wall. The results of this study suggest that the most suitable suture material for anastomosing living tissues are absorbable sutures.

Animals↗
PubMed1985

OKT4+ and OKT8+ cell subset values and HLA-DR phenotypes.

Blood levels of T cell subsets evaluated by use of monoclonal antibodies OKT4 and OKT8 were analyzed according to HLA-DR phenotypes. The results suggest that gene(s) associated with HLA-DR could be one of the factors which affects blood levels of T cell subsets, modulating the absolute values of T cell population.

Adult↗
PubMed1984

Complement activation by cell-associated immune complexes in contact sensitivity.

Lymph node cells collected 4 days after painting the skin with picryl chloride activate the first components of the classical pathway of complement cascade, as shown by consumption of C4 of rabbit complement with total sparing of C5 and factor B activity. In contrast, lymph node cells collected 1 or 6 days after sensitization fail to do so. The ability of "4-day" cells to activate complement is inhibited by treating the cells with specific low-molecular-weight hapten, which is known to dissociate the immune complex present on the cell surface. When mouse serum was used as source of complement, a different behavior in complement activation between CBA/J and B10.D2-New/SnJ serum was observed: "4-day" cells failed to consume CBA/J serum whereas a normal complement activation was detected when B10.D2-New/SnJ serum was used. Using these two sera which differ in the level of C4, an inverse relationship between the ability of "4-day" cells to activate complement and their capacity to induce contact sensitivity when injected into the footpad of normal recipients was reported. Experiments performed using sera from C5 genetically deficient mice demonstrate that only the early complement components are involved, suggesting that membrane immune complexes are solubilized as a result of complement activation; on the other hand, membrane bound activated complement components could alter the immunizing potential of "4-day" cells.

Animals↗
PubMed1984

Effects of dextran sulphate (DXS) on lymphocyte localization in complement-deficient mice: evidence that the fifth component of complement is not implicated in the DXS activity.

The effects of subcutaneously or intraperitoneally administered dextran sulphate (DXS) (50 mg/Kg) on the subsequent 1 h localization of intravenously injected radiolabelled lymph node cells was investigated in complement deficient mice which lack C5. DXS proved to be equally as potent in depressing cell localization in deficient as compared to normal mice. These findings indicate that the terminal complement components are not essential for DXS activity.

Animals↗
PubMed1984

Comparison of the effects of polyglycolic acid and monofilament nylon sutures in the common bile duct of pigs.

The tissue reaction and involvement of cells in the common bile duct of young pigs after surgery with two suture materials, polyglycolic acid and monofilament nylon, have been described. By comparing the different tissue reactions to the suture materials the authors observe that the use of non-absorbable polymer sutures and their long lasting presence in living tissues, may interfere with the healing process, since the sutures tend to migrate within the common duct wall and be expelled into the lumen owing perhaps to the delayed immuno-allergic reaction which develops in the common duct wall. In contrast polyglycolic acid seems to be biologically well tolerated and well integrated as a suture material, which is reabsorbed with the help of cell enzymes producing a complete restitutio ad integrum of the wall.

Animals↗
PubMed1984

Analysis of the T suppressor cell circuit which regulates contact sensitivity in mice infected with the virus of Newcastle disease.

The interaction between the virus of Newcastle disease (NDV) and the different cellular elements involved in the T suppressor cell circuit which regulates the expression phase of contact sensitivity has been investigated. NDV does not interfere with the production of the antigen-specific T suppressor factor (TsF) but inhibits its binding to T acceptor cells (Tacc). This cell when armed with TsF and exposed to the antigen corresponding to TsF releases a non-specific inhibitor of the transfer of contact sensitivity. More detailed analysis of the effect of NDV on the Tacc system showed that not only Tacc activity is impaired by NDV, but also the ability of antigen presenting cells (APC) to trigger Tacc armed with TsF is inhibited. The impairment of APC activity by NDV has been also investigated using another system, such as the induction of contact sensitivity by footpad cell transfer. The possibility that a virus-induced membrane modification might be responsible for the effect of NDV on the regulation of contact sensitivity is discussed.

Animals↗
PubMed1984

Reversible inhibition of mononuclear cell Fc receptors by sera from breast cancer patients.

The number of circulating mononuclear cells (MNC) expressing Fc receptor for IgG (Fc gamma R) was evaluated in 65 breast cancer patients and 37 normal controls by EAG rosette technique. The percentage (mean +/- SD) of Fc gamma + cells in patients (15.5 +/- 7.8) was significantly decreased (p less than 0.001) when compared to controls (20.4 +/- 5.6). The MNC of patients with low basal rosette values recovered their rosetting capacity when incubated in vitro at 37 degrees C. This effect was not related to detectable immune complexes (ICs). Some of the sera of breast cancer patients were also able to reversibly inhibit the capacity to form rosettes by MNC from healthy subjects. Our data suggest that serum factor(s), different from detectable ICs, might be responsible for this inhibiting effect.

Adult↗
PubMed1984

Enumeration of TG lymphocytes in B-chronic lymphocytic leukaemia (B-CLL) by a rapid double-rosetting technique.

T lymphocytes bearing the Fc receptors for IgG (E+ F c gamma + or TG cells) in 38 patients with B-cell chronic lymphocytic leukaemia (B-CLL) were quantified by a simple one-step double-rosette technique. This assay detects the TG lymphocytes from total peripheral blood mononuclear cells (MNC) on the basis of their capacity to bind simultaneously sheep red cells and chicken erythrocytes sensitized with anti-CRBC rabbit IgG. The data obtained were comparable to those evaluated by the more elaborate conventional two-step method, which requires initial T-cell purification. The double-rosette technique is specific for T cells and it may be adapted as a routine clinical laboratory assay for TG cells in B-CLL patients who have very low T/B cell ratio owing to clonal expansion of B cells.

Aged↗
PubMed1983

Double-rosetting technique for the detection of Fc gamma receptor-positive T lymphocytes.

Lymphocyte populations that bear Fc receptors for immunoglobulin G (IgG) (Fc gamma R) seem to be important in a variety of human diseases and have been studied extensively with several techniques to assess their status in human pathologic conditions. The immunologic role of these cells is quite important as they appear to contain the majority of T lymphocytes with suppressor activity and thus may have important regulatory functions. The Fc gamma R+ T lymphocytes are altered in several immunologic diseases and in some neoplastic conditions. We have studied FcR+ lymphocytes by a new method employing E-rosetting techniques in conjunction with a rosetting technique with chicken erythrocytes sensitized with rabbit antichicken erythrocyte IgG. In this fashion we have been able to define T lymphocytes and identify Fc gamma R+ lymphocytes in one simple step. This technique has been compared to other well-accepted methodologies and has given identical results. We have applied this technique to the examination of a group of women with nonmetastasized mammary carcinoma at different stages during their disease as compared with a group of normal, age-matched subjects. Our results indicate that Fc gamma R+ T lymphocytes detected by our mixed-rosette technique are significantly reduced in mammary carcinoma patients.

Animals↗
PubMed1981

Chicken buffy coat leucocytes (BCL) as indicator cells for human leucocytes migration inhibitory factor (LIF).

Human leucocyte migration inhibiting factor (LIF) form Con A stimulated lymphoid cells inhibited the migration of human and chicken peripheral blood leucocytes. The evaluation of human LIF activity on chicken cells is easy to perform as a routine test and has the advantage that large quantities of indicator cells are readily available. The chicken cell LIF test can be performed in the absence of serum, so avoiding effects due to plasminogen activator, and does not require the use of concentrated supernatants. LIF activity against both human and chicken targets was absent in supernatants from lung cancer subjects.

Animals↗
PubMed1981

Depression of contact sensitivity to oxazolone by the paramyxovirus of Newcastle disease. Impairment by infectious virus of effector T cells which mediate the response to contactant.

The paramyxovirus of Newcastle disease (NDV) impairs the contact sensitivity to oxazolone in CBA/J mice: in vitro treatment with the infectious virus inhibits the passive transfer of contact sensitivity. Experiments performed with three different virus preparations demonstrate that only the infectious virus is able to inhibit the hypersensitivity reaction while treatment of virus by heat or ultraviolet irradiation wipes out its inhibitory activity. These results suggest that I-NDV depresses the response to oxazolone by its action on T immunoblasts which mediate the response to contactant.

Animals↗
PubMed1979

Depression of contact hypersensitivity to oxazolone in mice exposed to Newcastle disease virus.

The effect of Newcastle disease virus (NDV) on delayed hypersensitivity to oxazolone in CBA mice was studied. There was a significant impairment of the ability of mice to develop cutaneous hypersensitivity shortly after injection of the virus. The effect was evident when NDV was administered up to 2 days before or within 24 h after sensitization, suggesting that NDV interferes with the process of sensitization. The degree of depression was related to the dose of virus inoculated. NDV inactivated by UV irradiation or heat did not depress contact sensitivity to oxazolone. These data are considered to support the hypothesis that the depression is mediated by a direct interaction between lymphocytes and NDV.

Animals↗
PubMed1977

Delayed-type skin reactions in bursectomized or thymectomized chickens.

Chickens can easily be induced to develop delayed-type skin reactions to oxazolone when animals are sensitized 7 days before the challenge. The reaction is quantitated by assessing the increase in wattle thickness: maximum reactions occur 24 h after challenge. The reaction is inhibited by neonatal thymectomy or bursectomy; these findings therefore suggest also an important B-derived component in delayed hypersensitivity to oxazolone.

Animals↗