Evidence of pathway-specific basophil anergy induced by peanut oral immunotherapy in peanut-allergic children.

BACKGROUND: In Westernized countries, over 1% of the population is allergic to peanuts or tree nuts, which carries a risk of severe allergic reactions. Several studies support the efficacy of peanut oral immunotherapy (OIT) for reducing the clinical sensitivity of affected individuals; however, the mechanisms of this effect are still being characterized. One mechanism that may contribute is the suppression of effector cells, such as basophils. Basophil anergy has been characterized in vitro as a pathway-specific hyporesponsiveness; however, this has not been demonstrated to occur in vivo. OBJECTIVE: To evaluate the hypothesis that basophil anergy occurs in vivo due to chronic allergen exposure in the setting of a clinical oral immunotherapy trial. METHODS: Samples of peripheral blood were obtained from subjects during a placebo-controlled clinical trial of peanut OIT. Basophil reactivity to in vitro stimulation with peanut allergen and controls was assessed by the upregulation of activation markers, CD63 and CD203c, measured by flow cytometry. RESULTS: The upregulation of CD63 following stimulation of the IgE receptor, either specifically with peanut allergen or non-specifically with anti-IgE antibody, was strongly suppressed by active OIT. However, OIT did not significantly suppress this response in basophils stimulated by the distinct fMLP receptor pathway. In the subset of subjects with egg sensitization, active peanut OIT also suppressed CD63 upregulation in response to stimulation with egg allergen. Allergen OIT also suppressed the upregulation of CD203c including in response to stimulation with IL-3 alone. CONCLUSION: Peanut OIT induces a hyporesponsive state in basophils that is consistent with pathway-specific anergy previously described in vitro. This suggests the hypothesis that effector cell anergy could contribute to clinical desensitization.

Criteria and challenges of the human placental perfusion ­ Data from a large series of perfusions.

Perfusion of human placental cotyledon has been used extensively to study transplacental transfer of endogenous and exogenous compounds. However, many challenges in the use of the method exist, including availability of placentas and complexity of the method itself. In Kuopio, Finland we have carried out human placental perfusions since 2005 using the same method with data now from over one hundred perfusions. This has allowed us to study whether the way of delivery, placental weight, and/or the length of pregnancy affect the two major criteria of a successful perfusion: volume loss (leak) from fetal to maternal circulation, and transplacental transfer of the reference compound antipyrine. The only statistically significant result was the reduction of the fetomaternal ratio of antipyrine by the placental age over 40 weeks (p=0.0004). The success criteria were not affected by the weight of the placenta or the way of delivery. There was no effect by the antipyrine concentration on antipyrine transfer. In vitro incubation with different concentrations of study compounds and different tubing materials could offer an easy way to study potentially reduced recovery due to binding to perfusion system.

Transplacental transfer of melamine.

OBJECTIVE: To characterize transplacental transfer of melamine and related mechanisms as well as toxicity using human placental perfusion and cultured cells. METHODS: Transfer and toxicity were analyzed in 4-h perfusions with 10 µM or 1 mM melamine, or 10 µM melamine with 10 nM cyanuric acid (CYA). Efflux transporters were studied in accumulation assay and toxicity in BeWo cells by MTT assay. RESULTS: Of added melamine 34-45% was transferred to fetal circulation and CYA made no difference. Histology, hCG production, and PLAP activity indicated functionality of placental tissue with no grave toxicity. Highest concentration of melamine used (2 mM) with CYA and long treatment time decreased viability of BeWo cells. Inhibitors of ABCB1, ABCG2, ABCC2 did not affect the accumulation of melamine in cells. CONCLUSION: Melamine goes through human term placenta with no contribution of efflux transporters. Toxicity of melamine is low in placental tissue and BeWo cells.

Detection of airborne cocaine and heroin by high-throughput liquid-absorption preconcentration and liquid chromatography-electrochemical detection.

A high-throughput liquid-absorption preconcentrator (HTLAP) for rapid and/or ultrasensitive detection and analysis of trace contaminants samples air at a rate of 600-700 l/min and collects analytes from vapors or aerosols at an efficiency of 40-60% into a small volume of liquid absorbent dripping at a rate of 0.1-2 ml/min. These features combine to reduce the lower detection limit (LDL) of available analytical instrumentation by a factor of > 1000 and/or to permit faster sampling and far more rapid on-site air monitoring than were previously practicable. LDLs of ca. 1:10(13) (v/v) of alkaloids have been achieved with LC and electrochemical detection. The HTLAP is directly adaptable to most liquid-phase analyzers. The small rate of liquid collection is also compatible with available interfaces to mass spectrometers. Moreover, the HTLAP permits detection and quantitation of polar or highly reactive compounds that cannot be readily analyzed by conventional preconcentration and GC.

Simple permeation absorber for sampling and preconcentrating hazardous air contaminants.

A permeation absorber was developed and experimentally evaluated for sampling and preconcentrating vapors of a primary aromatic amine into a small volume (ca. 0.1 ml) of a liquid extractant that can be directly injected into a chromatograph or other analytical instrument. Starting with 1-l or 4-l samples containing dry or humidified air (0, 7% or 35% relative humidity) and 0.5-5 parts per million by volume of aniline, the measured collection efficiency (fraction of aniline recovered in the extractant) ranged between 60 and 100% when the samples were recirculated 3-6 times. For a single-pass non-recirculating mode, the collection efficiency is calculated to be 40-50%. The degree of preconcentration is directly proportional to the volume V of the sampled air. The collection method is simple and fast and should also be applicable to the sampling and preconcentration of other hazardous air contaminants.

Leprosy. XII. T-cell subsets in lepromatous leprosy.

The authors quantitated T-rosette-forming cell (TRFC) and T-cell subsets (T mu, T gamma) in the peripheral blood of twenty patients with lepromatous leprosy. The results obtained in their studies are as follows: (1) They reconfirmed the low levels of TRFC in patients with lepromatous type of leprosy; (2) T-cell subsets, both T mu (helper) and T gamma (suppressor) cells, showed lower levels in all patients with lepromatous leprosy than mean values of normal healthy controls; (3) The degree of decreased levels of T mu cells (96%) was more severe than other parameters TRFC (70%) and T gamma cells (47%) in all patients with lepromatous leprosy; and (4) It may be concluded that the alteration of the T-cell subset, T mu-cells, reflects a more fundamental abnormality than TRFC aberration in demonstrating the impairment of cell-mediated immunity in patients with lepromatous leprosy.