Activation of human peripheral blood lymphocytes: effect of concanavalin A and lipopolysaccharide on in vitro synthesis of DNA and immunoglobulins

Role of concanavalin A lectin in recognition of pterygium remnant after surgical excision: preliminary results of a prospective study

Background:

Pterygium is one of the most common conjunctival diseases among ophthalmic pathologies. The frequency of recurrences is high, either after surgical treatment or after treatment combined with mitomycin C or beta-radiation therapy.

Aims:

The purpose of this study was to determine whether concanavalin A (ConA) lectin bound to the pterygial surface can be used to detect recurrence or remnants of pterygium after surgical excision.

Materials and Methods:

This was a prospective study on 20 patients with pterygium, divided in five stages, pre-surgery, early post-surgery (24h), late post-surgery (seven days), very late post-surgery (four weeks) and two months after the procedure.

A drop of fluorescein-marked Con A (35 µg/mL) was instilled in the lower conjunctival eyelid sac and the eye was exposed to the light of a Wood′s lamp for an average of five seconds.

Results:

Out of the 20 patients, eight patients were found to have fluorescent stretch marks over the scar corresponding to residual pterygial tissue at four weeks; two months after the procedure of re-surgery we observed no fluorescent remnants. All residual pterygia were confirmed through histochemistry studies.

Conclusion:

It was possible to detect remnants of pterygium in postoperative patients and recurrences in early pre-clinical stages through the visualization of fluorescent ConA bound to the pterygial surface.

Changes in bovine milk secretion following intramammary infusions of concanavalin A, oyster glycogen, or water

Effects of sterile intramammary infusion of Concanavalin A on milk secretion were contrasted with infusion of oyster glycogen or water. Twenty-four cows were infused intramammary with 100 mg Concanavalin A, oyster glycogen in 20 ml water, or with 20 ml water alone. Concentrations of lactose, somatic cells, immunoglobulins G and A, serum albumin, and activity of N-acetyl-B-D-glucosaminidase were determined in milk. Blood N-acetyl-B-D-glucosaminidase activity and concentrations of blood immunoglobulins G and A and serum albumin were determined. Oyster glycogen and concanavalin A caused inflammation in treated quarters; peak elevations of milk somatic cell counts, serum albumin, immunoglobulin G concentrations, and N-acetyl-B-D-glucosaminidase activity were at 12 to 36 h following treatment. Milk production and lactose concentration were reduced by oyster glycogen and Concanavalin A. Selective indices of relative accumulation of milk immunoglobulins decreased following Concanavalin A and oyster glycogen, whereas the N-acetyl-B-D-glucosaminidase activity selective index generally remained unchanged. Inflammation reduced the selective accumulation of immunoglobulins, and absence of change in the N-acetyl-B-D-glucosaminidase selective index indicated that blood is not a major source of milk N-acetyl-B-D-glucosaminidase.

Lymphocyte subpopulations in the neonate: a subset of HNK-1-, OKT3-, OKT8+ lymphocytes displays natural killer activity

It has been recently reported that cord blood lymphocytes (CBL) contain a subpopulation of OKT8+, sheep erythrocyte-rosetting negative (E-) cells not detectable in adult peripheral blood lymphocytes (a-PBL). The present studies were undertaken to characterize this subset of lymphocytes functionally and phenotypically. OKT8+ cells were purified from E-depleted CBL by negative selection on nylon-wool columns as well as by positive selection on plates coated with rabbit antibody to murine IgG (panning). The purified CBL displayed natural killer (NK) activity against K562 erythroleukemic cells. Although most of these CBL were large granular lymphocytes, they lacked typical NK markers such as HNK-1 and OKM1 surface antigens. Most OKT8+, OKT3- cells were also OKT10+, Ia+ and had the receptor for peanut agglutinin. These CBL may represent a stage along the differentiation pathway leading to mature NK or T cells.