Angiogenesis in two animal models of osteoarthritis

OBJECTIVE: We have previously described angiogenesis at the osteochondral junction and in synovium of knees from patients with osteoarthritis (OA), but little is known about how closely animal models of OA resemble human disease with respect to vascular growth. This study aimed to characterise two animal models of knee OA with particular respect to osteochondral and synovial angiogenesis. METHOD: We examined the spontaneous Dunkin-Hartley (DH) guinea pig and medial meniscal transection (MNX) rat models of OA. Vessels at the osteochondral junction and in the synovium were identified by lectin immunohistochemistry and quantified by computer-assisted image analysis. Disease severity was assessed using a scoring system. RESULTS: Blood vessels crossed the osteochondral junction in juvenile rats and guinea pigs, with higher densities in the lateral than medial tibial plateau, the number decreasing with maturation in the absence of other OA changes. In the rat model, increased vascular density was observed both at the osteochondral junction and in the synovium, whilst osteochondral vascularity in control rats decreased with maturation, OA rats showed a persistence of blood vessels at the osteochondral junction. In rat synovium, blood vessel fractional area was increased in the hypertrophied synovium 14 days after surgery, then decreased to control levels by day 28. Significant differences in vascularity were not observed between affected (medial) and spared (lateral) compartments of guinea pig knees. CONCLUSION: The rat meniscal transection model of OA reproducibly displays both osteochondral and synovial angiogenesis comparable to our previous observations in human knee OA. DH guinea pigs, by contrast, display low vascularity throughout their protracted course of OA development. Changes in vascularisation occur early during the development of OA in the rat, and may contribute to the pathogenesis of OA.     

CC ligand 2 levels are increased in LPS-stimulated peripheral monocytes of patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) shows a particular aggressive behaviour. Tumour associated macrophages (TAMs) play an important role in tumour growth and progression and CC ligand 2 (CCL2)/CCR2 axis is markedly involved in their recruitment in the tumour mass from the circulation. The aim of this study was to determine the plasma levels of CCL2 and the expression of CCR2 in the peripheral blood mononuclear cells (PBMCs) of 18 smokers with NSCLC, eight healthy smokers and nine non-smokers. Then, we investigated CCL2 levels in the supernatants of unstimulated and LPS-stimulated PBMC cultures of the same groups of patients. CCL2 levels in plasma and supernatants of PBMC cultures were determined by ELISA. CCR2 expression in PBMC cytospins was assessed by immunocytochemistry. CCL2 plasma levels and CCR2 expression by PBMCs were similar in patients with NSCLC, healthy smokers and non-smokers. In the supernatants of unstimulated PBMC cultures, CCL2 content was not different between the three groups of subjects. Supernatants of LPS-stimulated PBMCs of NSCLC patients showed a higher content of CCL2 as compared to supernatants of non-smokers (p<0.005). CCL2 content increased 28.5-fold vs baseline production in the group of NSCLC patients, 15-fold in healthy smokers and 13-fold in the group of non-smokers. In conclusion, after LPS stimulation, PBMCs of patients with NSCLC release higher levels of CCL2 as compared to those of non-smokers, supporting the hypothesis of a CCL2 involvement in NSCLC biology.     

Theophylline inhibits early and late asthmatic reactions induced by allergens in asthmatic subjects

To determine whether oral slow-release theophylline inhibits asthmatic reactions and the associated increase of airway responsiveness to methacholine induced by allergens, we examined six asthmatic subjects who developed a dual asthmatic reactions after allergen bronchoprovocation with Dermatophagoides pteronyssinus or with grass pollen. We gave oral slow-release theophylline and placebo to each subject for seven days in two series of experiments in a double-blind, randomized, crossover study. The individual daily dose of theophylline (4.7 to 16.6 mg/kg/day, divided into two doses) was calculated for each subject by measuring individual theophylline clearance and optimal daily dosage. During treatment with placebo, the subjects developed dual asthmatic reactions, ie, FEV1 decreased from 4.1 +/- 0.17 L before bronchoprovocation to 3.2 +/- 0.14 L at 15 minutes and to 3.2 +/- 0.19 L at seven hours after allergen bronchoprovocation. By contrast, during active treatment FEV1 decreased from 4.2 +/- 0.28 L to 3.9 +/- 0.26 L at 15 minutes, and to 3.8 +/- 0.13 L at seven hours (both cases, P less than .03 compared with placebo). Mean serum theophylline concentration was 13.2 +/- 0.6 mg/L. Although 1 week's treatment with slow-release theophylline did not modify significantly either prechallenge airway responsiveness to methacholine or its increase after allergen inhalation challenge, in five out of six subjects theophylline significantly inhibited the increase of airway responsiveness to methacholine induced by allergens compared to placebo and control day (P less than .05). These results suggest that slow-release theophylline may inhibit allergen-induced asthmatic reactions and the associated increase of airway responsiveness, suggesting some antiinflammatory effects for this drug.     

Focally regulated endothelial proliferation and cell death in human synovium.

Angiogenesis and vascular insufficiency each may support the chronic synovial inflammation of rheumatoid arthritis. We have shown by quantitative immunohistochemistry and terminal uridyl deoxynucleotide nick end labeling that endothelial proliferation and cell death indices were each increased in synovia from patients with rheumatoid arthritis compared with osteoarthritic and noninflamed controls, whereas endothelial fractional areas did not differ significantly among disease groups. Markers of proliferation were associated with foci immunoreactive for vascular endothelial growth factor and integrin alpha(v)beta3, whereas cell death was observed in foci in which immunoreactivities for these factors were weak or absent. No association was found with thrombospondin immunoreactivity. The balance between angiogenesis and vascular regression in rheumatoid synovitis may be determined by the focal expression of angiogenic and endothelial survival factors. Increased endothelial cell turnover may contribute to microvascular dysfunction and thereby facilitate persistent synovitis.     

Effect of bumetanide on toluene diisocyanate induced contractions in guinea pig airways.

BACKGROUND: The loop diuretic frusemide has been shown to inhibit the bronchoconstrictor response to exercise, inhaled allergen, distilled water, adenosine, and sodium metabisulphite. Toluene diisocyanate contracts smooth muscle by activating capsaicin sensitive nerves and causes asthma that shares many features with allergen induced asthma. METHODS: The study was designed to assess the effect of two loop diuretics, bumetanide (10 and 100 microM) and frusemide (100 microM), on smooth muscle contraction induced by toluene diisocyanate (0.03-1000 microM) in guinea pig airways with and, in the case of bumetanide, without epithelium. The effect of bumetanide on the response to acetylcholine, neurokinin A, and electrical field stimulation in guinea pig bronchial smooth muscle rings was also examined. RESULTS: Bumetanide (10 and 100 microM) had no effect on toluene diisocyanate induced contraction whether airway epithelium was present or not. Frusemide (100 microM) caused no significant inhibition of toluene diisocyanate induced contraction (mean reduction on the entire curve 25%). Bumetanide inhibited non-adrenergic, non-cholinergic contraction induced by electrical field stimulation of bronchi pretreated with atropine (1 microM) and indomethacin (5 microM) and this inhibition was inversely related to the frequency of stimulation, suggesting that bumetanide may be inhibiting transmitter release at the prejunctional level. Bumetanide and frusemide did not inhibit the responses to exogenous acetylcholine (0.1 microM) or neurokinin A (1 nM). CONCLUSIONS: Bumetanide and frusemide in doses that are known to inhibit non-adrenergic, non-cholinergic contraction due to electrical field stimulation failed to inhibit the response to toluene diisocyanate in guinea pig airways.     

The Tourniquet Gap: A Pilot Study of the Intuitive Placement of Three Tourniquet Types by Laypersons

Background

The “Stop the Bleed” campaign in the United States advocates for nonmedical personnel to be trained in basic hemorrhage control and that “bleeding control kits” be available in high-risk areas. However, it is not clear which tourniquets are most effective in the hands of laypersons.