Blockade of the interleukin-2 receptor by anti-Tac antibody inhibits the generation of antigen-nonspecific suppressor T cells in vitro.

The role of interleukin 2 (IL-2) in the activation of suppressor T cells was investigated by using the monoclonal antibody anti-Tac, which blocks the binding of IL-2 to the 55-kDa peptide of the high-affinity IL-2 receptor. Anti-Tac was added to an antigen-nonspecific suppressor system in which Con A-induced suppressor T cells were generated during a preculture period, and their effects on immunoglobulin production were assessed in second, indicator cultures containing pokeweed mitogen and peripheral blood mononuclear cells. Anti-Tac added during the preculture period inhibited Con A-induced suppressor T-cell generation.

25- to 30-nm virus particle associated with a hospital outbreak of acute gastroenteritis with evidence for airborne transmission.

Between November 1 and 22, 1985, an outbreak of acute, nonbacterial gastroenteritis occurred in a 600-bed hospital in Toronto, Ontario, Canada. Illness in 635 of 2,379 (27%) staff was characterized by fatigue, nausea, diarrhea, and vomiting and had a median duration of 24-48 hours. The finding of virus-like particles measuring 25-30 nm in six stool specimens and low rates of seroresponse to Norwalk virus (3/39) and Snow Mountain agent (1/6) suggest that a Norwalk-like virus was responsible for the outbreak.

Effects of a patient education program in the treatment of schizophrenia.

Two groups of schizophrenic patients were compared to determine the effects of educating patients about schizophrenia and its treatment. One group completed a three-week educational program while the other was involved in the usual ward activities. Comparison of the groups' pretest and posttest scores on three instruments (the Experiential World Inventory, the Scale for the Assessment of Negative Symptoms, and the Knowledge of Illness and Resources Inventory) revealed the experimental group had a significant increase in knowledge of the illness and a significant decrease in the negative symptoms of schizophrenia.

Flow cytometric resonance energy transfer measurements support the association of a 95-kDa peptide termed T27 with the 55-kDa Tac peptide.

Two monoclonal antibodies (OKT27 and OKT27b) have been produced that react with distinct epitopes of a 95-kDa peptide. The T27 antigen is widely distributed, being expressed on B lymphocytes, monocytes, and adult T-leukemic cells but not on polymorphonuclear leukocytes or platelets. There was a low level of T27 expression on resting T cells that increased on T-cell activation.

The p75 peptide is the receptor for interleukin 2 expressed on large granular lymphocytes and is responsible for the interleukin 2 activation of these cells.

There are at least two interleukin 2 (IL-2) binding peptides: one is the Mr 55,000 peptide (p55) reactive with the anti-Tac monoclonal antibody, and the other is a Mr 75,000 non-Tac IL-2 binding peptide (p75). Independently existing Tac or p75 peptides represent low-affinity IL-2 receptors, whereas high-affinity IL-2 receptors are expressed when both peptides are present and associated in a receptor complex. It has long been known that normal large granular lymphocytes (LGL) or leukemic cells from the patients with abnormal expansions of LGL can be activated by IL-2 not only to more-potent natural killer cells but also to effectors of lymphokine-activated killer (LAK) activity, although they do not express the Tac peptide.

Cimetidine and neonatal small bowel adaptation: an experimental study.

Histamine2-blockers are being used more extensively in the pediatric short gut patient as an agent to accelerate small bowel adaptation. Reversal of lipid malabsorption and a direct trophic effect on the intestinal crypt cells have been postulated as the mechanism for the salutary influence of cimetidine. Weanling Sprague-Dawley rats underwent 85% small bowel resection.

Contribution of a p75 interleukin 2 binding peptide to a high-affinity interleukin 2 receptor complex.

There are at least two forms of cellular receptors for interleukin 2 (IL-2); one with a very high affinity and the other with a lower affinity. We identified a non-Tac IL-2 binding peptide with a relative molecular weight of 75,000 (p75). Cell lines bearing either the p55 Tac or the p75 peptide alone manifested low-affinity IL-2 binding, whereas a cell line bearing both peptides manifested both high- and low-affinity receptors.

Expression of functional IL 2 receptors by lipopolysaccharide and interferon-gamma stimulated human monocytes.

Human peripheral blood monocytes were stimulated with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) alone or in combination. Stimulated but not resting monocytes displayed the Tac peptide of the interleukin 2 (IL 2) receptor within 24 hr as measured by immunofluorescence staining and [3H] Tac binding. The total number of anti-Tac binding sites on co-stimulated monocytes was 13,700.

Cytoprotective agents in experimental small bowel volvulus.

An accepted experimental model for midgut volvulus was used to produce small bowel strangulation obstruction of 48 hours duration in Sprague-Dawley rats. A 93% perioperative mortality rate resulted after release of the volvulus. Treatment with three cytoprotective agents at the time of volvulus release resulted in the following mortality rates: superoxide dismutase, 89%; ibuprofen, 50%; prostaglandin E1 (PGE1, 11%.

Demonstration of a non-Tac peptide that binds interleukin 2: a potential participant in a multichain interleukin 2 receptor complex.

The interleukin 2 (IL-2) receptor system plays a key role in the T-cell immune response. Although IL-2 binding was reported to be restricted to the Tac peptide, we have identified an IL-2 binding peptide that does not react with anti-human IL-2 receptor monoclonal antibodies, including anti-Tac on MLA 144, a gibbon ape T-cell line. The MLA 144 cell line expressed 6800 IL-2 binding sites per cell with a low (Kd = 14 nM) affinity for human recombinant IL-2.

Clinical and operative experience with non-Caucasian patients with Crohn's disease.

Fifteen black patients with Crohn's disease were seen during a ten-year period (1975-1985). They represented 11 percent of our experience with Crohn's disease during that time. These patients had an earlier age of onset of Crohn's symptoms than our white patients, and correct diagnosis was delayed for an average of four years.

Management of experimental pneumothorax in weanling rabbits with the use of fibrin glue sclerosant.

Fibrin glue pleurodesis successfully sealed surgically created pneumothoraxes in 12 (92.3%) of 13 New Zealand white rabbits, an animal model chosen for its similarity to the thoracic configuration of the human neonate. All chest tubes were removed at 24 hours; there were no recurrences.

Postsynaptic alpha 2-noradrenergic receptors mediate feeding induced by paraventricular nucleus injection of norepinephrine and clonidine.

This study examines the feeding response induced by hypothalamic noradrenergic stimulation, in terms of the type and synaptic position of its mediating receptor. Tests with norepinephrine or the alpha 2 receptor agonist clonidine, injected into the area of the paraventricular nucleus (PVN), revealed a potent feeding response in satiated animals. This response by either agonist was blocked, in a dose-dependent fashion, by local injection of the alpha 2-noradrenergic antagonists, rauwolscine and yohimbine.

Interleukin 2 receptor (Tac antigen) expression in HTLV-I-associated adult T-cell leukemia.

Interleukin-2 (IL-2) is a lymphokine synthesized by some T-cells following activation. Resting T-cells do not express IL-2 receptors, but receptors are rapidly expressed on T-cells following interaction of antigens, mitogens, or monoclonal antibodies with the antigen-specific T-cell receptor complex. Using anti-Tac, a monoclonal antibody that recognizes the IL-2 receptor, the receptor has been purified and shown to be a Mr 33,000 peptide that is posttranslationally glycosylated to a Mr 55,000 mature form.

Contamination of intravenous fluid with Sporothrix schenckii.

Fungi are known to contaminate intravenous (IV) solutions, particularly when there is a defect in the bottle or bag. On occasion several millilitres of such solutions have been infused into patients before the recognition of clumps in the fluid led to termination of the infusion. We wish to report the case of a patient accidentally infused with 100 ml of a solution that on subsequent culture yielded both Penicillium species, a previously recorded contaminant, and Sporothrix schenckii, a recognised pathogen.

Climatic forcing: effects of el nino on a small, temperate lake.

Temperature profiles measured regularly for 21 years reveal the interannual differences in winter-to-summer heat gain in Castle Lake, California, a small subalpine lake. Year-to-year changes in large-scale climatic surface forcing, especially the amount of snowfall from February through April (which determines the date of thaw) coupled with the early heating and wind mixing after thaw, causes this interannual variation. The seasonal thermal structure for years in which the lake gains significantly more or less heat than normal-all of the El Niño years and several others-shows that the depth of the mixed layer and the mixing of heat into the stratified thermocline region control the storage of heat.

Expression of interleukin 2 receptors on activated human B cells.

Using anti-Tac, a monoclonal anti-interleukin 2 (IL-2) receptor antibody, we have explored the possibility that certain activated B cells display receptors for IL-2. Resting normal B cells and unselected B cell lines established from normal individuals were Tac antigen negative. In contrast, the cell surface Tac antigen expression was demonstrable on 6 of 10 B cell lines from patients with Burkitt's lymphoma, 5 of 6 B cell lines derived from patients with HTLV-I-associated adult T cell leukemia (including all four that had integrated HTLV-I into their genome), and on certain normal B cells activated with pokeweed mitogen.

Functional and phenotypic comparison of human T cell leukemia/lymphoma virus positive adult T cell leukemia with human T cell leukemia/lymphoma virus negative Sézary leukemia, and their distinction using anti-Tac. Monoclonal antibody identifying the human receptor for T cell growth factor.

Adult T cell leukemia (ATL) and Sézary leukemia are malignant proliferations of T lymphocytes that share similar cell morphology and clinical features. ATL is associated with HTLV (human T cell leukemia/lymphoma virus), a unique human type C retrovirus, whereas most patients with the Sézary syndrome do not have antibodies to this virus. Leukemic cells of both groups were of the T3, T4-positive, T8-negative phenotype.

Conduct disorder and its synonyms: diagnoses of dubious validity and usefulness.

Psychiatrically hospitalized adolescents from city and voluntary services who had been diagnosed as having conduct disorder were compared with psychiatrically hospitalized adolescents who had never been so diagnosed. There were no significant symptomatic differences. The major factor distinguishing adolescents ever diagnosed as having conduct disorder was violence, regardless of other symptoms.

Effects of ascorbate on a dopaminergic response: apomorphine-induced modification of pentylenetetrazol-induced seizures in mice.

The threshold for pentylenetetrazol (PTZ)-induced clonic seizures is below control levels 15 min after administration of apomorphine (APO) but above them 60 min after APO administration. Pretreatment with ascorbic acid (10 mg/kg) or the presence of ascorbic acid in the APO solution (1 mg/ml) inhibited the early (15 min) decrease in seizure threshold caused by 60 mg/kg APO and reversed the increase in seizure threshold 60 min after a 50 mg/kg APO challenge. Ascorbate co-administration concomitant with APO also counteracted the increase in seizure threshold 60 min after 70/kg APO.