Inhibition of histamine release from dispersed human lung and tonsillar mast cells by nicardipine and nifedipine

Progress and Prospect: A Bibliometric Analysis of Research Papers by Korean Allergists Over Recent Five Years (2009-2013)

Since the establishment of the academic society in 1972, Korean allergists have made continuous efforts to elucidate pathogenic mechanisms and therapeutic advances for allergic diseases. The present study aimed to summarize recent progress and explore future prospects of research performance by Korean allergists. We performed a comprehensive bibliometric analysis for research papers published in the Science Citation Index (SCI) or SCI-expanded journals by Korean allergists between 2009 and 2013. Research performance was quantitatively analyzed for the numbers of papers by publication year, research type, and main topic. In addition, the performance was also examined for qualitative indices, such as impact factor and citation number. A total of 1,091 papers were identified. The number of publication increased continuously, with an annual increase rate of 12.3%. Clinical and basic studies were the most frequent types of research, and recently the number of epidemiological studies has increased. By research topic, asthma was the most commonly studied, accounting for 20.9% of the total number of publications. Notably, the amount of rhinitis/rhinosinusitis research has risen steeply in 2013. Qualitative analyses also indicated continuous progress; the median impact factor of published journals increased from 1.918 in 2009 to 2.746 in 2013, yielding an annual increase rate of 7.4%. In conclusion, the present analyses identified a continuous increase in the research performance of Korean allergists over a recent 5 year period (2009-2013), both quantitatively and qualitatively. A more significant contribution is expected in the forthcoming era.

Past, present, and future of allergy in Korea

Korean allergology has made great progress in keeping pace with global scientific advances in spite of a short history. Outstanding academic and scientific researches have been performed in a variety of allergy fields in Korea. Epidemiologic studies revealed increasing prevalence of asthma and allergic diseases and considerable morbidity and mortality in Korea. Novel inhalant allergens such as citrus red mite and two-spotted spider mite as causes of asthma and allergic rhinitis have been discovered and reported in Korea. Bidirectional translational researches have been performed and are underway to elucidate the pathogenesis of asthma and allergy, mechanisms of airway inflammation and remodeling, and new therapeutic modalities for asthma and allergic diseases. Experimental asthma models of different phenotypes according to exposed levels of lipopolysaccharide or double-stranded RNA suggested the crucial role of the innate immunity in the development of allergic airway inflammation and a new insight for asthma pathogenesis, in which both Th1 and Th2 inflammation are involved. In the field of genetic researches, numerous genetic associations with asthma and asthma-related phenotypes, such as atopy, IgE production, and airway hyperresponsiveness, have been demonstrated in Korean population. The Easy Asthma Management (EAM) program, a computer-assisted asthma management program, is anticipated to facilitate the achievement of more successful clinical outcomes by filling the gaps between guidelines and actual practices. The Integration of these multi-disciplinary allergy research resources and translation of scientific achievements to the bedside and society will lead to better allergy and asthma control in Korea.

A brief history of asthma and its mechanisms to modern concepts of disease pathogenesis

The original concept of asthma being primarily a disease of airways smooth muscle drove the development of bronchodilator drugs. However when it was realised that airway inflammation underpinned the disordered airway function, this gave way to the development of controller therapies such as inhaled cromones and corticosteroids. More recently the discovery of complex interconnecting cytokine and chemokine networks has stimulated the development of biologics with varying success. With the recognition that airway wall "remodelling" is present early in asthma inception and is in part driven by aberrant epithelial-mesenchymal communication both genetic and environmental factors beyond allergen exposure such as virus infection and air pollution are being seen as being increasingly important not only in asthma exacerbations but in the origins of asthma and its evolution into different sub-phenotypes. This brings us round full circle to once again considering that the origins of asthma lie in defects in the formed elements of the airway; the epithelium, smooth muscle, and vasculature. Over the last 25 years Professor You Young Kim has engaged in the exciting discovery science of allergy and asthma and has made an enormous contribution in bringing Korea to the forefront of disease management and research, a position that both he and his colleagues can justly be proud of.

Immediate but not long-term administration of nicardipine inhibits tolbutamide-induced insulin secretion from rat pancreatic beta cells

OBJECTIVES

Calcium channel blockers alter glucose homeostasis, but sufficient data regarding this effect in healthy animals have not been provided. We test the effect of nicardipine on beta cell function in healthy rats.

METHODS

Islets from Sprague-Dawley rats were coincubated with nicardipine, tolbutamide, or their combination for 1 hour. Insulin secretion was measured by radioimmunoassay. The rats were given nicardipine, tolbutamide, or their combination by intravenous injection. Intravenous glucose tolerance tests were performed after the first drug administration and 4 weeks later. Pancreata were excised for assessment of insulin content and immunohistochemical staining in the end.

RESULTS

Nicardipine markedly inhibited not only the insulin secretion by islets per se but also that enhanced by tolbutamide in vitro. Blood glucose was reduced by tolbutamide in vivo but elevated by nicardipine abruptly in parallel with retarded insulin secretion. Long-term administration of nicardipine altered neither fasting blood glucose level nor fasting serum insulin level, whereas pancreatic insulin content was unmodified despite that nicardipine caused shrunken islets with weak immunoreactivity of beta cells by immunohistochemistry.

CONCLUSIONS

In healthy rats, immediate administration of nicardipine inhibits insulin secretion of beta cells both in vitro and in vivo but does not exert a deleterious effect in vivo after long-term treatment.

Therapeutic alternatives for chronic urticaria: an evidence-based review, Part 2

OBJECTIVE

To evaluate the use of alternative therapies for chronic urticaria refractory to first-line treatments in an evidence-based manner.

DATA SOURCES

MEDLINE searches were performed cross-referencing urticaria with the names of multiple therapies. Articles were then reviewed for additional citations. Articles published after 1950 were considered.

STUDY SELECTION

All articles, including case reports, were reviewed for soundness and relevance.

RESULTS

Experience has been reported for a wide variety of alternative therapies in the treatment of chronic idiopathic and physical urticarias. Evidence for most agents is limited to anecdotal reports. The therapies reviewed are also categorized based on criteria of safety, efficacy, convenience, and cost. The less preferred alternative agents in the second part of this review are divided between third-line therapies and others that are unable to be firmly recommended or that seem promising but lack substantial evidence.

CONCLUSIONS

Third-line alternative agents should be considered in patients with chronic urticaria who are severely affected and unresponsive to antihistamines and second-line therapies. Although monitoring for toxicity is important in management with third-line agents, safety remains favorable for most agents compared with corticosteroids.

Synergistic effect of intraperitoneally administered calcium channel blockade and recombinant tissue plasminogen activator to prevent adhesion formation in an animal model

Previous reports have shown the benefits of calcium channel blockers and recombinant tissue plasminogen activator to prevent postoperative adhesion formation in animal models. To assess the potential benefit of synergistic therapy for the prevention of postoperative adhesion formation, these agents were studied in a rabbit uterine horn model. Four groups of New Zealand White rabbits (n = 8 per group) had a bilateral devascularization injury to the uterine horns. Before closure saline solution, verapamil hydrochloride (2.5 mu/kg/hour), recombinant tissue plasminogen activator (4 mg total dose), or a combination of verapamil and recombinant tissue plasminogen activator at the stated doses were instilled by means of an Alzet osmotic pump x 200 hours. Adhesion scores were evaluated after this time period by estimating the total uterine horn surface involved in adhesions at a terminal laparotomy and by clinically grading the response to determine whether minimal adhesions formed. Results of the total uterine horn surface scores were (mean score +/- SE): saline solution, 44% +/- 3.7%; verapamil, 19% +/- 4.8%; recombinant tissue plasminogen activator, 11% +/- 3.6%; combined, 3% +/- 1% (p less than 0.01 to control and p less than 0.05 to single-drug therapy). Results of the number of animals per group with minimal adhesions were as follows: saline solution, 0; verapamil, 1; recombinant tissue plasminogen activator, 3; combined, 8 (P less than 0.01). These results show a synergistic benefit of verapamil and recombinant tissue plasminogen activator to prevent postsurgical adhesion formation when delivered via the intraperitoneal route.

Nimodipine versus terfenadine in the treatment of physical stimulus-induced urticaria

Basophil and mastocyte degranulation is calcium-dependent. Calcium-antagonists can inhibit synthesis of and release in vitro some mediators in various types of cells. Both immunologically stimulated and non-immunologically stimulated release of material from basophils isolated from normal and allergic subjects can be antagonized by calcium blockers. The present study was aimed at testing the therapeutic effects and side effects of nimodipine therapy, a new dihydropyridine anti-calcium derivative for physical stimulus-induced urticaria, in comparison with a standard H1-antihistamine therapy. The study was done in 32 outpatients who had physical stimulus-induced urticaria: 20 patients received nimodipine three times a day in a daily dose of 180 mg, 12 patients were treated with terfenadine in a dose of 120 mg. In the majority of patients treated with both nimodipine and terfenadine, satisfactory clinical results were obtained after 3 weeks of therapy. There were, however significant (P less than 0.05) differences in responses. Complete clearance after 3 weeks was noted in 50% patients treated with nimodipine, whereas only 16% of patients on terfenadine were completely clear, and some showed only slight improvement. The treatment was easily manageable, and with few side effects.

Therapy of chronic idiopathic urticaria with nifedipine: demonstration of beneficial effect in a double-blinded, placebo-controlled, crossover trial

The efficacy of nifedipine, a calcium channel antagonist, in the treatment of chronic idiopathic urticaria, was evaluated in a double-blinded, placebo-controlled, crossover trial. Ten patients with chronic urticaria refractory to maximally tolerated doses of H1 and H2 antihistamines and in whom extensive evaluation failed to identify a cause for their urticaria were entered into the study. Patients continued with their prestudy antihistamine regimens. A study drug dosage was titrated in each patient and maintained throughout the trial. Patients were treated with placebo or nifedipine for 4 weeks and then crossed over to the other medication for 4 weeks. One patient withdrew because of unrelated medical illness, two patients withdrew after crossover to placebo because of intolerable urticaria, and seven patients completed the study. A beneficial effect of nifedipine was clearly demonstrated. Hive count, hive index, and itch index were all significantly improved at the end of 4 weeks of nifedipine treatment (p = 0.023, 0.003, and 0.003, respectively) but not placebo treatment (p = 0.194, 0.664, and 0.944, respectively). Additionally, end point hive index and itch index scores with nifedipine compared to corresponding placebo scores were significantly improved (p = 0.010 and 0.008, respectively). Nifedipine was well tolerated. Thus, when nifedipine is used as an adjunct to antihistamines, it appears to be a safe, efficacious drug for the treatment of chronic idiopathic urticaria.

Inhibition of exercise-induced asthma by nifedipine: a dose-response study

1. The effect of three single doses of nifedipine on exercise-induced asthma has been examined in 11 asthmatic subjects. 2. On four separate days patients undertook 6 min of exercise on a treadmill 30 min after taking placebo or nifedipine 10, 20 or 30 mg administered double-blind and in random order. 3. Nifedipine had no significant effect on resting FEV1 measurements. 4. Nifedipine, in doses of 10, 20 and 30 mg, inhibited exercise induced bronchoconstriction, reducing the maximum fall in FEV1 from 30.8 +/- 3.5% after placebo to 21.9 +/- 3.4% (NS), 13 +/- 3.4% (P less than 0.01) and 15 +/- 3.9% (P less than 0.01) respectively. 5. This study has shown that the protective effect of nifedipine against exercise-induced asthma is dose related with the maximum inhibitory effect being observed with a single dose of 20 mg.

Comparison of the action of calcium antagonists on basophil histamine release

The inhibitory capacity of calcium antagonists on basophil histamine release was examined in allergic patients and in controls. All dihydropyridines tested (nifedipine, nimodipine, nitrendipine, nicardipine, felodipine) dose-dependently inhibited anti-IgE- and A23187-induced release with an order of potency of felodipine greater than nicardipine greater than nifedipine = nimodipine = nitrendipine. Only the inhibition induced by felodipine and nicardipine on anti-IgE-induced release could be counteracted by increasing extracellular calcium. Diltiazem, not belonging to the dihydropyridines, was a weak inhibitor. A combination of felodipine and verapamil in low concentrations exerted a synergistic inhibitory effect on histamine release, whereas this was not the case with other combinations of antagonists. The results suggest differences in the mode of action of the 1.4-dihydropyridines. This might be of significance in the search for calcium antagonists suitable in the treatment of allergic diseases.

Nicardipine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy, in the treatment of angina pectoris, hypertension and related cardiovascular disorders

Nicardipine is an antagonist of calcium influx through the slow channel of the cell membrane and has been shown to be an effective and relatively well-tolerated treatment for stable effort angina and rest angina due to coronary artery spasm, and mild to moderate hypertension. Although its exact mechanism of action in these disease states has not been precisely defined, the potent coronary and peripheral arterial dilator properties of nicardipine, with concomitant improvements in oxygen supply/demand and reductions in systemic vascular resistance, are of major importance. Clinical studies have shown that nicardipine appears to be effective in the treatment of chronic stable exercise-induced angina pectoris and possibly in angina at rest due to coronary artery spasm. In the treatment of stable angina, nicardipine has proved to be equally as effective as nifedipine. However, haemodynamic and clinical studies indicate that nicardipine may have a further advantage of not depressing cardiac conduction or left ventricular function, even in patients with compromised cardiac pumping ability. Nicardipine also appears to be useful as initial monotherapy or in combination with other antihypertensive drugs when used in the treatment of mild to moderate hypertension, and may have some advantages over other vasodilators in this regard in that it may not be as frequently associated with fluid retention or weight gain as other similar drugs. In the treatment of hypertension nicardipine has been shown to be as effective as drugs such as hydrochlorothiazide, cyclopenthiazide, propranolol and verapamil in short term studies although confirmation of its long term usefulness in well-designed clinical trials is still required. Similarly, although the use of nicardipine in other disorders such as congestive heart failure and cerebrovascular disease has provided encouraging preliminary results, more studies are needed to clarify its place in their treatment. Side effects appear to be dose related and more frequent within the first few weeks of therapy. Most of these effects are minor and transient in nature and include headache, flushing and peripheral oedema. Thus, there is no doubt that nicardipine provides a suitable alternative to other drugs available for the treatment of angina and hypertension. However, further well-designed comparative clinical trials are needed to clarify its relative place in the long term management of these disorders.

On the isolation of mast cells from human adenoids and tonsils

Human adenoids and tonsils were disintegrated mechanically and the cells dispersed by passage through a stainless-steel screen in EDTA-containing buffer. Collagenase digestion did not increase the yield of adenoidal cells. The mast cell content of the cell suspensions was in the range of 1-10 mast cells/10(4) cells with an estimated mean of 1-2 mast cells/10(4) cells, a value considerably below previous reports on adenoidal cell suspensions. The mast cell content was determined by staining with toluidine blue at low pH (to prevent interference by phagocytes). The mast cell count as assessed by alcian blue staining and by fluorescence microscopy after FITC-anti-human IgE binding was similar. Various attempts to enrich the cell suspension (i.e. by differential centrifugation, by gradient centrifugation on Ficoll or Ficoll-Hypaque and by velocity sedimentation at unit gravity) all gave negative results.