Inhaled nitric oxide in neonates and children with pulmonary hypertension

Fourteen critically ill neonatal and paediatric intensive care patients with various primary diagnoses and signs of associated pulmonary hypertension received inhaled nitric oxide (NO), 20–80 ppm, after failure of conventional therapy to improve oxygenation. NO administration was found to be associated with a significant improvement in postductal arterial oxygen tension (pre-NO: 3.75 (SD 1.39) kPa; post-NO: 6.05 (SD 1.70) kPa; p = 0.004). In 10 patients, NO was found to increase arterial oxygen tension with more than 1 kPa. In 2 of these patients, ECMO treatment could be avoided due to the pronounced improvement in gas exchange seen after the initiation of NO administration. The remaining 4 patients failed to respond to NO administration. One patient developed methaemoglobinaemia (13.9%) which required treatment with methylthionine. Since we were unable to produce any beneficial effect of NO in the late phase of the pulmonary disease process, we believe that, in order to be successful, inhaled NO should be instituted when conventional treatment has failed and the administration of an iv vasodilator is usually considered.     

Effects of SCA40 on human bronchi and on guinea pig main bronchi in vitro. Comparison with cromakalim

Summary— The aim of this study was to examine the activity of SCA40, a novel charybdotoxin-sensitive potassium channel opener, against a variety of spasmogens or against electrical field stimulation in guinea pig isolated main bronchi and in human isolated bronchi; the effects of SCA40 were compared with those of cromakalim. Like cromakalim, SCA40 reduced the contractility of guinea pig and human isolated bronchi precontracted with acetylcholine 10^?6 M or neurokinin A 10^?6 M, SCA40 being more efficient and more potent than cromakalim. Moreover, on guinea pig isolated main bronchi, SCA40 can exert a preventive effect on contractions induced by acetylcholine, neurokinin A or capsaicin, that is, it shifts to the right the concentration-effect curves of these substances, whereas cromakalim has no such effect. The effects of cromakalim were antagonized by glibenclamide 10^?5 M, whereas the effects of SCA40 were inhibited by tetraethylammonium (TEA 10^?2 M) and charybdotoxin (3 × 10^?8 M), but this inhibitory effect of TEA was reversed by nifedipine (10^?6 M). Electrical field stimulation of guinea pig isolated main bronchi induced two successive contractile responses. Both contractions were significantly reduced by SCA40 (10^?6 and 10^?5 M) and cromakalim (10^?5 M). Since cromakalim was unable to inhibit the effects of acetylcholine or neurokinin A, it might be suggested that for this latter compound the inhibition seems to take place prejunctionally and to affect the release of neuromediators produced by electrical field stimulation. In contrast, in the case of SCA40, a postjunctional effect seems to be likely, owing to its preventive effects, although a prejunctional effect cannot be excluded. Finally, on guinea pig isolated main bronchi, SCA40 (10^?8-10^?6 M) did not potentiate the relaxant effect of isoprenaline or sodium nitroprusside, suggesting a lack of functional manifestation of inhibition of phosphodiesterase for these concentrations. In conclusion, these results demonstrate that SCA40 is a potent and efficient relaxant of guinea pig and human airway smooth muscle, and is able to inhibit, in the guinea pig isolated main bronchi, the contractions induced by electrical field stimulation. It has an effect on TEA-sensitive K+ channels, but this effect is probably not involved in its relaxant effect which does not also rest on an inhibitory effect of phosphodiesterase.     

Frequency of thyroid disease among Southeast Asian primary care patients

We prospectively assessed 99 Southeast Asians for the presence of thyroid disease who were attending a primary care clinic devoted to the care of refugees. Subjects were undergoing evaluation as new patients and had no previously diagnosed thyroid abnormality. Each patient had a physical examination performed by his or her primary‐care provider, was given a standardized questionnaire that focused on symptoms of thyroid disease and underwent a venipuncture for total thyroxine, triiodothyronine resin uptake and thyrotropin (TSH) concentration. Those who had an abnormal examination, calculated free thyroxine index (FT ₄ I) or TSH level were re‐examined by an endocrinologist and had repeat thyroid studies performed. Although 81% of patients reported ≥1 symptom compatible with thyroid dysfunction, only 17% were found to have laboratory abnormalities. An abnormal FT ₄ I and TSH level was found in 5% and 13% of subjects, respectively, but only one case of clinically significant hyperthyroidism and no cases of hypothyroidism were confirmed. TSH suppression, noted in 12% of subjects, persisted over a median follow‐up of 6 months. Among seven patients with an anatomic abnormality of the thyroid, four had an abnormal FT ₄ I or TSH. We conclude that the clinical prevalence of symptomatic thyroid dysfunction among Southeast Asians is comparable to that reported for non‐Asian populations, but that the frequency of subclinical hyperthyroidism may be higher. Although symptoms suggestive of thyroid disease are common, routine screening for thyroid disease is not indicated in this study.     

Filiform polyposis in Crohn's colitis mimicking toxic megacolon

Summary A patient with filiform polyposis in Crohn's colitis is reported. Unlike previous reports of filiform polyposis, this patient's colitis was of rapid onset and antedated development of pseudopolyps by a short duration. Additionally, unlike previous reports, the disease process was quite aggressive. The extensive degree of fissuring found throughout the bowel wall may have produced the unusually shaped polyps and caused the toxic colonic atony.