APPA (apocynin and paeonol) modulates pathological aspects of human neutrophil function, without supressing antimicrobial ability, and inhibits TNFα expression and signalling

Neutrophils are key players in the pathophysiological process underlying inflammatory conditions not only by release of tissue-damaging cytotoxic enzymes, reactive oxygen species (ROS) but also by secretion of important immunomodulatory chemokines and cytokines. Here, we report the effects of the novel agent APPA, undergoing formal clinical development for treatment of osteoarthritis, and its constituent components, apocynin (AP) and paeonol (PA) on a number of neutrophil functions, including effects on TNFα- expression and signalling. Neutrophils were treated with APPA (10-1000 µg/mL) prior to the measurement of cell functions, including ROS production, chemotaxis, apoptosis and surface receptor expression. Expression levels of several key genes and proteins were measured after incubation with APPA and the chromatin re-modelling agent, R848. APPA did not significantly affect phagocytosis, bacterial killing or expression of surface receptors, while chemotactic migration was affected only at the highest concentrations. However, APPA down-regulated neutrophil degranulation and ROS levels, and decreased the formation of neutrophil extracellular traps. APPA also decreased cytokine-stimulated gene expression, inhibiting both TNFα- and GM-CSF-induced cell signalling. APPA was as effective as infliximab in down-regulating chemokine and IL-6 expression following incubation with R848. Whilst APPA does not interfere with neutrophil host defence against infections, it does inhibit neutrophil degranulation, and cytokine-driven signalling pathways (e.g. autocrine signalling and NF-κB activation), processes that are associated with inflammation. These observations may explain the mechanisms by which APPA exerts anti-inflammatory effects and suggests a potential therapeutic role in inflammatory diseases in which neutrophils and TNFα signalling are important in pathology, such as rheumatoid arthritis.

Non-bronchoscopic sampling and culture of bronchial epithelial cells in children

BACKGROUND

The bronchial epithelium is likely to play a vital role in airway diseases in children, such as asthma and viral-associated wheeze. In adults, studies with primary bronchial epithelial cells cultured from samples obtained by fibre-optic bronchoscopy have provided key insights into the role of the epithelial cell. However, it is difficult to justify bronchoscopy in children to obtain epithelial cells for research purposes.

OBJECTIVE

To examine the possibility of retrieving and culturing viable epithelial cells using a blind non-bronchoscopic method from children undergoing elective surgery.

METHODS

Subjects were children undergoing elective surgery under general anaesthesia. Following intubation, non-bronchoscopic bronchoalveolar lavage and non-bronchoscopic bronchial brushing were performed. A sheathed bronchial cytology brush was advanced through the endotracheal tube, wedged and then withdrawn 2-3 cm before gentle sampling was used to collect bronchial epithelial cells. Initial samples were used to characterize the number, type and viability of epithelial cells recovered compared to a control group of adults undergoing standard bronchoscopic sampling. Subsequent samples were used to establish primary bronchial epithelial cell cultures in children both with and without wheezing illness.

RESULTS

A total of 63 children underwent bronchial brushing [38 male; median age 7.1 years (1.0-14.2 years]. Initial samples (n=30) showed recovery of viable epithelial cells comparable to that from a single brush obtained via a bronchoscope in an adult control group (n=11). In 27 (82%) of the subsequent 33 samples obtained non-bronchoscopically from children, primary bronchial epithelial cell cultures were successfully established. There were no adverse effects attributable to sampling.

CONCLUSION

We have shown that non-bronchoscopic bronchial brushing is a safe and effective technique for recovering viable bronchial epithelial cells that consistently yield primary cultures. This method will facilitate examination of the role of the epithelium in paediatric disease.

Tremorgenic mycotoxins increase gastric smooth muscle activity of sheep reticulum and rumen in vitro

Reticulum and rumen strips (consisting of both muscle layers and the myenteric plexus) were superfused with Tyrode Ringer and their contractions recorded isometrically. The strips were subjected to exogenous acetylcholine and electrical field stimulation (EFS) resulting in contractions that could be blocked by atropine. Responses to the tremorgenic mycotoxin penitrem A and others thought to be involved in ryegrass staggers, paxilline and lolitrem B (10(-10)-10(-6)M), were compared with those of control vehicle (0.1% DMSO). The tremorgens were without effect on quiescent preparations. Penitrem A and paxilline enhanced spontaneously active preparations and the amplitude of contractions in response to EFS. Responses to paxilline had a shorter latency than to penitrem A. Responses of spontaneously active preparations were resistant to atropine. Penitrem A, but not paxilline, increased responses to exogenous acetylcholine. Lolitrem B (10(-6)M) increased responses to EFS, but many responses were equivocal, possibly due to the lower solubility of lolitrem B in aqueous solutions compared to the other tremorgens. The results show that these mycotoxins have peripheral excitatory effects on the reticulorumen and it is suggested that such activity in vivo may reflexly affect centrally derived cyclical contractions.

Three dimensional imaging of the Belousov-Zhabotinsky reaction using magnetic resonance

The combination of 3D magnetic resonance imaging data with polygon based computer graphic display software is ideally suited to the study of the Belousov-Zhabotinsky reaction in extended volumes. In this paper we present the first true three dimensional visualization of experimental data from the Belousov-Zhabotinsky reaction. The time evolution of a twisted scroll wave like isoconcentration surface and its organizing filament are demonstrated for the manganese-catalyzed B-Z mixture. These techniques extend the experimental study of the B-Z reaction as a class of pattern-forming systems to the third dimension. The limitations of the technique are discussed.

Pregnancy, labor and delivery post spinal cord injury

There are approximately 3,000 women of childbearing age who become spinal cord injured each year in the United States. There are few reports in the literature that address pregnancy, labor and delivery in this patient population. We are reporting on 22 women post spinal cord injury who had 33 pregnancies. There were equal numbers of paraplegic and quadriplegic women. Three pregnancies aborted, one spontaneously. The babies were near normal or normal weight with one exception. The mothers waited 5 years on average to become pregnant. Cesarean section was performed on 43% of pregnancies. Abnormal presentations occurred in over 10% of pregnancies. Indications for cesarean section included 5 that were repeats; the remainder were necessary due to bleeding (1), breech presentation (1), transverse presentation (2), lack of progress (2), onset of labor 1 day post spinal fusion, and a mother's request to have tubal ligation. Epidural anesthesia was selected for 9 deliveries; 6 of these patients had controlled autonomic hyperreflexia. Five general and 4 local anesthetics were used, and 12 patients received no anesthesia. Diagnostic ultrasound and amniocentesis were used selectively. Complications included autonomic hyperreflexia (9), frequent urinary tract infections, infected pressure sores (3, 2 resulting in below-knee amputations), seizures during and after delivery, pneumonia, bladder stones (2), episiotomy dehiscence (1), and breakdown of spinal fusion. The newborns were healthy, although one double footing breech vaginal delivery had an APGAR of 1 at 1 min, 7 at 5 min and 9 at 10 min. One premature baby, who weighed only 1600 g, was a precipitate birth at home unattended. Implications for the care of pregnant SCI women are discussed.

Pregnancy following spinal cord injury

Each year about 2,000 women of childbearing age in the United States have a spinal cord injury. Only a few mostly anecdotal reports describe pregnancy after such an injury. In a retrospective study of 16 women with a spinal cord injury, half of whom have a complete injury and about half quadriplegia, 25 pregnancies occurred, with 21 carried to full term. The women delayed pregnancy an average of 6.5 years after their injury, with an average age at first pregnancy of 26.8 years. Cesarean section was necessary in 4 patients because of inadequate progress of labor. In 5 deliveries an episiotomy and local anesthesia were required, 7 required epidural anesthesia, including all cesarean sections, and 10 did not require anesthesia. Several complications have been identified in the antepartum, intrapartum, and postpartum periods including autonomic hyperreflexia, premature labor, pressure sores, urinary tract infections, abnormal presentation, and failure to progress. Ultrasonography and amniocentesis were used selectively. Women with spinal cord injuries can have healthy children, although there are significant risks and these women have special needs.

Pharmacology of (+)- and (-)-baclofen: GABA-dependant rotational behaviour and [3H]GABA receptor binding studies

(+)- and (-)-baclofen were equiactive in inducing contralateral rotational behaviour following their unilateral injection into the zona reticulata of the rat substantia nigra, a proposed GABA-dependent rotational behaviour model, and in displacing the specific binding of [3H]GABA to frozen and thawed membrane preparations of rat brain. These non-stereospecific actions of baclofen at a population of cerebral GABA receptors contrast with stereospecific neuronal depressant effects probably mediated via presynaptic inhibition of the release of excitatory amino acid neurotransmitters. The present results indicate that baclofen may have two distinct mechanisms of action and this may account for the debate on the pharmacology of this compound.