PubMed HealthSearch

Biomedical subjects

A S Kong

Publications and source records attributed to A S Kong.

16 recordsLinked to original sources

Subdural block.

Explore the source record for details and available documents.

Adult

Rupture of membranes before the onset of spontaneous labour increases the likelihood of instrumental delivery.

We studied obstetric outcome in 350 consecutive nulliparous women in spontaneous labour and term pregnancy. Women who presented with rupture of membranes before the onset of contractions were more likely to deliver by forceps compared with those in whom contractions preceded rupture of membranes. This increased likelihood of instrumental delivery was significant with and without the use of extradural analgesia in labour (P less than 0.05 and P less than 0.001, respectively). Furthermore, significantly more women with premature rupture of membranes received extradural analgesia in labour (P less than 0.01). We conclude that any study which aims to examine the influence of extradural analgesia on the outcome of delivery should include premature rupture of membranes as a bias factor.

Adolescent

An audit of induction of anaesthesia in neonates and small infants using pulse oximetry.

The frequency and severity of hypoxaemia during induction of anaesthesia in neonates and small infants at the Norfolk and Norwich Hospital, a district general hospital, was compared, using pulse oximetry, with that of the nearest specialist hospital, the Queen Elizabeth Hospital for Sick Children in London. There were differences in staffing and the choice of anaesthetic techniques between the hospitals. One third of the patients in both hospitals experienced desaturation of more than 5% (moderate or severe hypoxaemia) at one or more recordings during induction. The highest incidence of hypoxaemia was associated with awake intubation. There was no statistical difference in the incidence or severity of hypoxaemia between the hospitals. In the district general hospital, moderate or severe hypoxaemia of greater than 30 s duration was more likely if an anaesthetist with a regular paediatric operating list was not present at induction (p < 0.01).

Anesthesia, Inhalation

Longitudinal study of serum antibody response to bovine corneal protein (BCP 54) in Behçet's disease.

Serum samples from a patient diagnosed as having active Behçet's syndrome with iritis were evaluated by the enzyme-linked immunosorbent assay for antibodies against a purified bovine corneal protein, molecular weight 54,000 daltons (BCP 54). Significantly elevated antibody levels to BCP 54 were found in all serum samples collected over a 2-year period. Anti-BCP 54 antibody levels remained within a very narrow range, at least twofold higher than those of controls. In contrast, no antibody to retinal S antigen was detected. These results indicate the presence of specific anti-BCP 54 autoantibodies in sera from a Behçet's patient and suggest that autoantibodies may play a role in the etiopathogenesis of uveitis.

Adolescent

Studies on a new lymphocyte mitogen from Bordetella pertussis. I. Induction of proliferation and polyclonal antibody formation.

Pertussis B mitogen (PBM), isolated from culture supernatant fluids of Bordetella pertussis, is a potent mitogen for mouse and human lymphocytes. In mice, > 95% of the blast cells recovered from PBM cultures bear surface immunoglobulins. Therefore, PBM seems to induce proliferation of mouse B lymphocytes, but not T cells. The proliferative response observed is nonspecific because cells from all mouse strains tested, including germfree animals, are responsive. Moreover, the mitogenic activity of PBM is independent of T lymphocytes, macrophages, or serum factors. When human peripheral blood or cord blood lymphocytes are cultured in the presence of PBM, a high level of thymidine incorporation by these cells is detected. Furthermore, PBM can induce polyclonal antibody formation by both mouse and human lymphocytes. Despite similar methods of isolation, PBM is distinct from the lymphocytosis-promoting factor of B. pertussis, a previously described T cell mitogen.

Animals

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes. IV. Generation, characterization, and specificity of cytotoxic lymphocytes.

Cytotoxic effector lymphocytes were induced in cultures of mouse spleen or lymph node cells by lymphocytosis promoting factor (LPF). The LPF-activated cytotoxic cells: (a) were not generated unless proliferation occurred; (b) sedimented in the lighter density fraction of a bovine serum albumin gradient; (c) were large, blast-like cells; and (d) were lysed by Thy-1.2 antiserum plus complement and, therefore, were T cells. Neither LPF alone nor supernates from stimulated cultures were cytotoxic. Unlike the situation with concanavalin A and phytohemagglutinin P, LPF-stimulated cytotoxic effector lymphocytes required no further addition of mitogen for maximal cytotoxicity. The effector cells displayed specificity, destroying only allogeneic but not syngeneic normal cells; in the case of tumor cells, both allogeneic and syngeneic cells werelysed in the absence of added mitogen. The reason for differentiated cytotoxicity toward syngeneic tumor and normal cells is not clear but may have some relevance to in vivo tumor rejection initiated by Bordetella pertussis.

Animals

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes. III. B-cell dependence for T-cell proliferation.

The nature of the helper lymphocytes in lymphocytosis-promoting factor (LPF)-induced proliferation was explored. Removal of macrophages from adherent splenocytes by either carbonyl-iron incubation or passage through Sephadex G-10 columns did not affect their synergistic function. Nor did cytolysis with Thy-1.2 antiserum and complement. The helper cells were found to be surface immunoglobulin-positive (sIg+) because they are retained by anti-Ig columns, susceptible to lysis by rabbit anti-mouse immunoglobulin and complement, and occurred in the sIg+ fractions of splenocytes after separation on the fluorescence-activated cell sorter. Further delineation of the surface markers on helper cells showed that complement receptors are not the determining marker for synergistic function. The requirement for B-helper cells in the stimulation of T lymphocytes by LPF is unique for a mouse of T-cell mitogen.

Animals

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes. I. Proliferative response.

The lymphocytosis-promoting factor of Bordetella pertussis is a potent mitogen for murine lymphocytes in vitro. The stimulatory response was not the result of specific antigen stimulation. Spleen and lymph node cells were responsive, whereas normal thymocytes were unresponsive. However, DNA replication was induced in cortisone-resistant thymocytes by lymphocytosis-promoting factor (LPF). Bone marrow cells were not stimulated by LPF.

Animals

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes: II. Nature of the responding cells.

The mitogenic response of murine lymphocytes to the lymphocytosis-promoting factor of Bordetella pertussis has been shown to be due to activation of T cells. The selectivity of responsiveness to LPF with respect to the population of T cells which is stimllated, differs from that of PHA as well as Con A, and the surface receptors are different. A population of adherent cells, which does not appear to consist of macrophages or other phagocytic cells, is required for the T-cell response.

Animals

The mitogenic effect of the lymphocytosis promoting factor from Bordetella pertussis on human lymphocytes.

The purified lymphocytosis promoting factor (LPF) from Bordetella pertussis was found to be a potent mitogen for peripheral blood lymphocytes (PBL) from normal adults as well as for cord blood lymphocytes. Proliferation occurred in autologous plasma or fetal calf serum, regardless of previous exposure to pertussis infection or immunization. Only one adult human serum, from a physician constantly working with B. pertussis, inhibited the mitogenic response to LPF and this serum was shown to contain precipitating antibody against LPF. The proliferative effect of LPF was characteristic of a "nonspecific" mitogen and not of antigen stimulation of sensitized cells.LPF, phytohemagglutinin, and concanavalin A were approximately equal in potency although variation occurred depending upon the cell donor. Experiments with lymphocyte subpopulations obtained by rosetting techniques employing sheep erythrocytes, mouse erythrocytes, and sheep erythrocytes coated with antibody and complement suggested the requirement of a multicellular system for LPF mitogencity.PBL from most patients with chronic lymphatic leukemia and lymphosarcoma cell leukemia were even less responsive to LPF than to phytohemagglutinin, whereas PBL from patients with lymphosarcoma usually responded to both mitogens. It can be inferred from the results of experiments with both normal and leukemic cells that LPF, which is a murine thymus-derived (T)-cell mitogen, is also a T-cell mitogen for human PBL. The exact cell requirement and mode of action, however, are as yet unknown.

Adult

The effect of Bordetella pertussis on the antibody response in mice to type III pneumococcal polysaccharide.

The effect of an i.p. injection of Bordetella pertussis on the primary humoral immune response in mice to the thymus-independent antigen SIII has been studied. Suppression of the antibody response occurred when pertussis cells were injected at the same time as an optimal immunizing dose of SIII. In contrast, the antibody response to high doses of SIII was enhanced by B. pertussis. When SIII alone was injected, only 19S antibody was detected. However, when B. pertussis was administered with either optimal or high doses of SIII, 7S as well as 19S antibody against SIII was produced.

Animals